Lincoln Electric Welding System IM575 User Manual

RETURN TO MAIN MENU  
IM575  
MASTER LOAD750  
May, 2006  
For use with equipment code number 10401.  
Safety Depends on You  
Lincoln arc welding and cutting  
equipment is designed and built  
with safety in mind. However, your  
overall safety can be increased by  
proper installation ... and thought-  
ful operation on your part. DO  
NOT INSTALL, OPERATE OR  
REPAIR THIS EQUIPMENT  
WITHOUT READING THIS  
MANUAL AND THE SAFETY  
PRECAUTIONS CONTAINED  
THROUGHOUT. And, most  
importantly, think before you act  
and be careful.  
OPERATORS MANUAL  
Copyright © 2005 Lincoln Global Inc.  
• World's Leader in Welding and Cutting Products •  
• Sales and Service through Subsidiaries and Distributors Worldwide •  
Cleveland, Ohio 44117-1199 U.S.A. TEL: 216.481.8100 FAX: 216.486.1751 WEB SITE: www.lincolnelectric.com  
 
ii  
ii  
WELDING EQUIPMENT SAFETY  
ARC RAYS can burn.  
ELECTRIC SHOCK can  
4.a. Use a shield with the proper filter and cover  
plates to protect your eyes from sparks and  
the rays of the arc when welding or observing  
open arc welding. Headshield and filter lens  
should conform to ANSI Z87. I standards.  
kill.  
3.a. The electrode and work (or ground) circuits  
are electrically “hot” when the welder is on.  
Do not touch these “hot” parts with your bare  
skin or wet clothing. Wear dry, hole-free  
gloves to insulate hands.  
4.b. Use suitable clothing made from durable flame-resistant  
material to protect your skin and that of your helpers from  
the arc rays.  
3.b. Insulate yourself from work and ground using dry insulation.  
Make certain the insulation is large enough to cover your full  
area of physical contact with work and ground.  
4.c. Protect other nearby personnel with suitable, non-flammable  
screening and/or warn them not to watch the arc nor expose  
themselves to the arc rays or to hot spatter or metal.  
In addition to the normal safety precautions, if welding  
must be performed under electrically hazardous  
conditions (in damp locations or while wearing wet  
clothing; on metal structures such as floors, gratings or  
scaffolds; when in cramped positions such as sitting,  
kneeling or lying, if there is a high risk of unavoidable or  
accidental contact with the workpiece or ground) use  
the following equipment:  
FUMES AND GASES  
can be dangerous.  
5.a. Welding may produce fumes and gases  
hazardous to health. Avoid breathing these  
• Semiautomatic DC Constant Voltage (Wire) Welder.  
• DC Manual (Stick) Welder.  
fumes and gases.When welding, keep  
your head out of the fume. Use enough  
• AC Welder with Reduced Voltage Control.  
ventilation and/or exhaust at the arc to keep  
fumes and gases away from the breathing zone. When  
welding with electrodes which require special  
ventilation such as stainless or hard facing (see  
instructions on container or MSDS) or on lead or  
cadmium plated steel and other metals or coatings  
which produce highly toxic fumes, keep exposure as  
low as possible and below Threshold Limit Values (TLV)  
using local exhaust or mechanical ventilation. In  
confined spaces or in some circumstances, outdoors, a  
respirator may be required. Additional precautions are  
also required when welding on galvanized steel.  
3.c. In semiautomatic or automatic wire welding, the electrode,  
electrode reel, welding head, nozzle or semiautomatic  
welding gun are also electrically “hot”.  
3.d. Always be sure the work cable makes a good electrical  
connection with the metal being welded. The connection  
should be as close as possible to the area being welded.  
3.e. Ground the work or metal to be welded to a good electrical  
(earth) ground.  
5.b. Do not weld in locations near chlorinated hydrocarbon vapors  
coming from degreasing, cleaning or spraying operations.  
The heat and rays of the arc can react with solvent vapors to  
form phosgene, a highly toxic gas, and other irritating  
products.  
3.f. Maintain the electrode holder, work clamp, welding cable and  
welding machine in good, safe operating condition. Replace  
damaged insulation.  
3.g. Never dip the electrode in water for cooling.  
5.c. Shielding gases used for arc welding can displace air and  
cause injury or death. Always use enough ventilation,  
especially in confined areas, to insure breathing air is safe.  
3.h. Never simultaneously touch electrically “hot” parts of  
electrode holders connected to two welders because voltage  
between the two can be the total of the open circuit voltage  
of both welders.  
5.d. Read and understand the manufacturer’s instructions for this  
equipment and the consumables to be used, including the  
material safety data sheet (MSDS) and follow your  
employer’s safety practices. MSDS forms are available from  
your welding distributor or from the manufacturer.  
3.i. When working above floor level, use a safety belt to protect  
yourself from a fall should you get a shock.  
3.j. Also see Items 6.c. and 8.  
5.e. Also see item 1.b.  
Mar ‘95  
 
iii  
iii  
WELDING EQUIPMENT SAFETY  
WELDING SPARKS can  
CYLINDER may explode  
if damaged.  
cause fire or explosion.  
6.a. Remove fire hazards from the welding area.  
If this is not possible, cover them to prevent  
7.a. Use only compressed gas cylinders  
containing the correct shielding gas for the  
the welding sparks from starting a fire.  
Remember that welding sparks and hot  
materials from welding can easily go through small cracks  
and openings to adjacent areas. Avoid welding near  
hydraulic lines. Have a fire extinguisher readily available.  
process used and properly operating  
regulators designed for the gas and  
pressure used. All hoses, fittings, etc. should be suitable for  
the application and maintained in good condition.  
7.b. Always keep cylinders in an upright position securely  
chained to an undercarriage or fixed support.  
6.b. Where compressed gases are to be used at the job site,  
special precautions should be used to prevent hazardous  
situations. Refer to “Safety in Welding and Cutting” (ANSI  
Standard Z49.1) and the operating information for the  
equipment being used.  
7.c. Cylinders should be located:  
Away from areas where they may be struck or subjected to  
physical damage.  
6.c. When not welding, make certain no part of the electrode  
circuit is touching the work or ground. Accidental contact  
can cause overheating and create a fire hazard.  
•A safe distance from arc welding or cutting operations and  
any other source of heat, sparks, or flame.  
7.d. Never allow the electrode, electrode holder or any other  
electrically “hot” parts to touch a cylinder.  
6.d. Do not heat, cut or weld tanks, drums or containers until the  
proper steps have been taken to insure that such procedures  
will not cause flammable or toxic vapors from substances  
inside. They can cause an explosion even though they have  
been “cleaned”. For information, purchase “Recommended  
Safe Practices for the Preparation for Welding and Cutting of  
Containers and Piping That Have Held Hazardous  
Substances”, AWS F4.1 from the American Welding Society  
(see address above).  
7.e. Keep your head and face away from the cylinder valve outlet  
when opening the cylinder valve.  
7.f. Valve protection caps should always be in place and hand  
tight except when the cylinder is in use or connected for  
use.  
7.g. Read and follow the instructions on compressed gas  
cylinders, associated equipment, and CGA publication P-l,  
“Precautions for Safe Handling of Compressed Gases in  
Cylinders,” available from the Compressed Gas Association  
1235 Jefferson Davis Highway, Arlington, VA 22202.  
6.e. Vent hollow castings or containers before heating, cutting or  
welding. They may explode.  
6.f. Sparks and spatter are thrown from the welding arc. Wear oil  
free protective garments such as leather gloves, heavy shirt,  
cuffless trousers, high shoes and a cap over your hair. Wear  
ear plugs when welding out of position or in confined places.  
Always wear safety glasses with side shields when in a  
welding area.  
FOR ELECTRICALLY  
powered equipment.  
6.g. Connect the work cable to the work as close to the welding  
area as practical. Work cables connected to the building  
framework or other locations away from the welding area  
increase the possibility of the welding current passing  
through lifting chains, crane cables or other alternate cir-  
cuits. This can create fire hazards or overheat lifting chains  
or cables until they fail.  
8.a. Turn off input power using the disconnect  
switch at the fuse box before working on  
the equipment.  
8.b. Install equipment in accordance with the U.S. National  
Electrical Code, all local codes and the manufacturer’s  
recommendations.  
6.h. Also see item 1.c.  
8.c. Ground the equipment in accordance with the U.S. National  
Electrical Code and the manufacturer’s recommendations.  
Mar ‘95  
 
iv  
iv  
WELDING EQUIPMENT SAFETY  
5. Toujours porter des lunettes de sécurité dans la zone de  
soudage. Utiliser des lunettes avec écrans lateraux dans les  
zones où l’on pique le laitier.  
PRÉCAUTIONS DE SÛRETÉ  
Pour votre propre protection lire et observer toutes les instruc-  
tions et les précautions de sûreté specifiques qui parraissent  
dans ce manuel aussi bien que les précautions de sûreté  
générales suivantes:  
6. Eloigner les matériaux inflammables ou les recouvrir afin de  
prévenir tout risque d’incendie dû aux étincelles.  
7. Quand on ne soude pas, poser la pince à une endroit isolé de  
la masse. Un court-circuit accidental peut provoquer un  
échauffement et un risque d’incendie.  
Sûreté Pour Soudage A L’Arc  
1. Protegez-vous contre la secousse électrique:  
a. Les circuits à l’électrode et à la piéce sont sous tension  
quand la machine à souder est en marche. Eviter toujours  
tout contact entre les parties sous tension et la peau nue  
ou les vétements mouillés. Porter des gants secs et sans  
trous pour isoler les mains.  
b. Faire trés attention de bien s’isoler de la masse quand on  
soude dans des endroits humides, ou sur un plancher  
metallique ou des grilles metalliques, principalement dans  
les positions assis ou couché pour lesquelles une  
grande partie du corps peut être en contact avec la  
masse.  
8. S’assurer que la masse est connectée le plus prés possible  
de la zone de travail qu’il est pratique de le faire. Si on place  
la masse sur la charpente de la construction ou d’autres  
endroits éloignés de la zone de travail, on augmente le risque  
de voir passer le courant de soudage par les chaines de lev-  
age, câbles de grue, ou autres circuits. Cela peut provoquer  
des risques d’incendie ou d’echauffement des chaines et des  
câbles jusqu’à ce qu’ils se rompent.  
9. Assurer une ventilation suffisante dans la zone de soudage.  
Ceci est particuliérement important pour le soudage de tôles  
galvanisées plombées, ou cadmiées ou tout autre métal qui  
produit des fumeés toxiques.  
c. Maintenir le porte-électrode, la pince de masse, le câble  
de soudage et la machine à souder en bon et sûr état  
defonctionnement.  
d.Ne jamais plonger le porte-électrode dans l’eau pour le  
refroidir.  
10. Ne pas souder en présence de vapeurs de chlore provenant  
d’opérations de dégraissage, nettoyage ou pistolage. La  
chaleur ou les rayons de l’arc peuvent réagir avec les  
vapeurs du solvant pour produire du phosgéne (gas forte-  
ment toxique) ou autres produits irritants.  
e. Ne jamais toucher simultanément les parties sous tension  
des porte-électrodes connectés à deux machines à soud-  
er parce que la tension entre les deux pinces peut être le  
total de la tension à vide des deux machines.  
f. Si on utilise la machine à souder comme une source de  
courant pour soudage semi-automatique, ces precautions  
pour le porte-électrode s’applicuent aussi au pistolet de  
soudage.  
11. Pour obtenir de plus amples renseignements sur la sûreté,  
voir le code “Code for safety in welding and cutting” CSA  
Standard W 117.2-1974.  
2. Dans le cas de travail au dessus du niveau du sol, se pro-  
téger contre les chutes dans le cas ou on recoit un choc. Ne  
jamais enrouler le câble-électrode autour de n’importe quelle  
partie du corps.  
PRÉCAUTIONS DE SÛRETÉ POUR  
LES MACHINES À SOUDER À  
TRANSFORMATEUR ET À  
REDRESSEUR  
3. Un coup d’arc peut être plus sévère qu’un coup de soliel,  
donc:  
a. Utiliser un bon masque avec un verre filtrant approprié  
ainsi qu’un verre blanc afin de se protéger les yeux du  
rayonnement de l’arc et des projections quand on soude  
ou quand on regarde l’arc.  
b. Porter des vêtements convenables afin de protéger la  
peau de soudeur et des aides contre le rayonnement de  
l‘arc.  
1. Relier à la terre le chassis du poste conformement au code  
de l’électricité et aux recommendations du fabricant. Le dis-  
positif de montage ou la piece à souder doit être branché à  
une bonne mise à la terre.  
c. Protéger l’autre personnel travaillant à proximité au  
soudage à l’aide d’écrans appropriés et non-inflamma-  
bles.  
2. Autant que possible, I’installation et l’entretien du poste  
seront effectués par un électricien qualifié.  
3. Avant de faires des travaux à l’interieur de poste, la  
debrancher à l’interrupteur à la boite de fusibles.  
4. Des gouttes de laitier en fusion sont émises de l’arc de  
soudage. Se protéger avec des vêtements de protection  
libres de l’huile, tels que les gants en cuir, chemise épaisse,  
pantalons sans revers, et chaussures montantes.  
4. Garder tous les couvercles et dispositifs de sûreté à leur  
place.  
Mar. ‘93  
 
v
v
LOAD BANK SAFETY  
The load bank is an industrial test unit designed to be  
used indoors or outdoors (sheltered from moisture).  
However, because the nature of the load bank’s func-  
tion is the dissipation of electrical energy, electrical  
energy is transformed into heat by the resistor ele-  
ments. The heat is removed from the load bank by  
airflow through the resistor elements. If there are any  
restrictions or stoppage of airflow, the load bank may  
overheat. For safe operation the following recommen-  
dations should be observed:  
7. Allow cool room air to pass into the unit to cool  
the elements. Do not allow the unit to be placed  
where hot exhaust air can recirculate back  
through the unit causing a constant rise in cooling  
air temperature.  
8. After running a load test, residual heat may be  
removed from the load bank by allowing the blow-  
er to operate for a few minutes after load is  
removed. This procedure is not required for load  
bank integrity, but it may guard operating person-  
nel from possible burn injuries.  
1. Read the manual before operating the Load Bank.  
9. The operator should avoid coming in contact with  
the resistor elements or surrounding covers during  
and for some time after operation. These por-  
tions of the load bank become hot .  
2. Run an approved ground wire from the Load Bank  
ground lug located on the connection panel to the  
frame of the power source. Run an approved  
ground wire from the power source frame to a  
good earth ground. Size ground wire in accor-  
dance with National Electrical Code and any local  
codes.  
10. Do not allow objects to enter or block the air  
intake or exhaust of the load bank. A blockage  
would cause overheating. If an object enters the  
screens, it may cause damage to the resistor ele-  
ments, possibly shorting them and causing shock  
and fire hazards.  
3. Do not bypass the airflow safety switch or temper-  
ature sensing switch to prevent nuisance tripping.  
The switches will drop out the load if insufficient  
cooling air is reaching the elements.  
11. Emergency Shutdown Procedure  
4. Replace any burned out lamps on the control  
panel. Each lamp is an indication that a system  
is active or has failed and is important to the oper-  
ation of the unit and safety of the operator.  
A. In an emergency, shut down the MASTER  
LOAD switch, then the power source. The  
MASTER LOAD switch will allow disconnec-  
tion of all load steps and still allow for the fan  
motor to run, cooling any heated elements.  
B. The POWER ON/OFF switch will disconnect  
both load steps and fan motor. The power  
source EMERGENCY OFF switch should be  
located near the load system.  
WARNING  
ELECTRIC SHOCK can kill.  
Personal injury from electrical shock  
may result if all sources of power are  
not disconnected before servicing.  
Only qualified personnel should  
Install, Operate and Service this equip-  
ment.  
12. An approved electrical fire extinguisher should be  
on hand at all times.  
13. It is the responsibility of the customer to take dili-  
gent care in installing the Load Bank. The  
National Electrical Code (NEC), sound local elec-  
trical and safety codes, and the Occupational  
Safety and Health Act (OSHA) should be followed  
when installing the equipment to reduce hazards  
to persons and property.  
------------------------------------------------------------------------  
5. Maintenance should be performed with no power  
on the unit. The majority of troubleshooting can  
be performed with an ohmmeter. There are mul-  
tiple sources of input power to the Load Bank.  
Insure each is disconnected.  
14. Flammable objects (cardboard, paper, etc.) must  
not be stored near the load bank  
6. Venting the heated air from the exhaust toward  
overhead cables, sprinkler systems, or into a  
room with insufficient volume or "Make-Up" air, is  
a potential hazard. The Load Bank should be  
used in a cool, well-ventilated area.  
15. As part of your safety program, an initial inspec-  
tion after receiving the unit(s) and periodic preven-  
tive maintenance and safety inspections should  
be conducted to insure the reliability and safety.  
 
vi  
vi  
for selecting a QUALITY product by Lincoln Electric. We want you  
to take pride in operating this Lincoln Electric Company product  
••• as much pride as we have in bringing this product to you!  
Thank You  
Please Examine Carton and Equipment For Damage Immediately  
When this equipment is shipped, title passes to the purchaser upon receipt by the carrier. Consequently, Claims  
for material damaged in shipment must be made by the purchaser against the transportation company at the  
time the shipment is received.  
Please record your equipment identification information below for future reference. This information can be  
found on your machine nameplate.  
Product _________________________________________________________________________________  
Model Number ___________________________________________________________________________  
Code Number or Date Code_________________________________________________________________  
Serial Number____________________________________________________________________________  
Date Purchased___________________________________________________________________________  
Where Purchased_________________________________________________________________________  
Whenever you request replacement parts or information on this equipment, always supply the information you  
have recorded above. The code number is especially important when identifying the correct replacement parts.  
On-Line Product Registration  
- Register your machine with Lincoln Electric either via fax or over the Internet.  
• For faxing: Complete the form on the back of the warranty statement included in the literature packet  
accompanying this machine and fax the form per the instructions printed on it.  
• For On-Line Registration: Go to our WEB SITE at www.lincolnelectric.com. Choose “Quick Links” and then  
“Product Registration”. Please complete the form and submit your registration.  
Read this Operators Manual completely before attempting to use this equipment. Save this manual and keep it  
handy for quick reference. Pay particular attention to the safety instructions we have provided for your protection.  
The level of seriousness to be applied to each is explained below:  
WARNING  
This statement appears where the information must be followed exactly to avoid serious personal injury or  
loss of life.  
CAUTION  
This statement appears where the information must be followed to avoid minor personal injury or damage to  
this equipment.  
MASTER LOAD 750  
 
vii  
TABLE OF CONTENTS  
DESCRIPTION  
TECHNICAL SPECIFICATIONS.........................................................................................1  
SAFETY PRECAUTIONS...................................................................................................2  
GENERAL DESCRIPTION .................................................................................................2  
CONTROL UNIT.................................................................................................................2  
ENCLOSURE......................................................................................................................2  
INSTALLATION  
BEFORE INSTALLATION...................................................................................................3  
LOCATION..........................................................................................................................3  
AIRFLOW CONSIDERATIONS ..........................................................................................3  
POWER REQUIREMENTS ................................................................................................3  
OPERATION  
PURPOSE AND USE OF CONTROLS ..............................................................................4  
LOAD BANK OPERATION .................................................................................................4  
OPERATING INSTRUCTIONS...........................................................................................4  
MAINTENANCE  
ROUTINE AND PERIOD MAINTENANCE .........................................................................5  
TROUBLESHOOTING  
HOW TO USE TROUBLESHOOTING GUIDE ...................................................................6  
TROUBLESHOOTING GUIDE ...........................................................................................7  
DIAGRAMS  
WIRING DIAGRAM...........................................................................................................10  
DIMENSION PRINT..........................................................................................................11  
PARTS ...............................................................................................................appendix  
MASTER LOAD 750  
 
1
DESCRIPTION  
1
TECHNICAL SPECIFICATIONS – MASTER LOAD 750  
INPUT – POWER  
120 VOLT, 15 A, 60 Hz , SINGLE PHASE  
LOAD CAPABILITY  
750 Amps @50V AC or DC (in incrementing fixed steps of 25, 25, 50, 50, 100, 250, 250)  
PROTECTION FUSES  
Control Circuit  
15 amp  
Voltmeters  
3 amp  
COOLING BLOWER  
82 dBA at 3 ft  
MAXIMUM COOLING AIR TEMPERATURE  
120°F (50° C)  
PHYSICAL DIMENSIONS  
Height  
34.75 in  
883 mm  
Width  
24 in  
Depth  
28.5 in  
724 mm  
610 mm  
MASTER LOAD 750  
 
2
2
DESCRIPTION  
of all switched ON load steps.  
SAFETY PRECAUTIONS  
Before installation, read and observe all safe-  
ty precautions throughout this manual.  
4. LOAD STEPS switches - Connect and discon-  
nect load steps. Values are shown above  
each switch.  
WARNING  
5. Analog Meters - Monitors DC volts, DC amps,  
AC volts, and AC amps applied to the load  
bank.  
ELECTRIC SHOCK can kill.  
• Turn the input supply power  
OFF at the disconnect switch or  
fuse box before working on this  
equipment.  
ENCLOSURE  
CAUTION  
• Do not touch electrically hot  
parts.  
The outside dimensions of the Master Load 750 Load  
Bank are listed on Technical Specifications page at  
the beginning of this section of the manual. The Load  
Bank is mounted on casters. One set of casters has  
lockable wheels.  
HOT EXHAUST can burn skin.  
• Allow resistance elements to cool  
before working near them.  
Do not allow the Load Bank to be placed where hot  
exhaust air can recirculate back through the unit caus-  
ing a constant rise in cooling air temperature.  
------------------------------------------------------------------------  
ROTATING FAN can cause injury.  
• Do not touch moving fan  
components.  
The Master Load 750 Load Bank contains a blower  
(approximately 82dBA at 3 ft.) which provides the nec-  
essary cooling air for the load elements. An exhaust  
temperature sensor is provided to monitor the exhaust  
temperature. This switch is electrically interlocked  
with the load application circuit. If an unsafe tempera-  
ture is detected in the exhaust of the Load Bank, the  
BLOWER FAIL light comes on and the load is discon-  
nected from the resistive elements.  
------------------------------------------------------------------------  
GENERAL DESCRIPTION  
The Master Load 750 Load Bank is designed for elec-  
trically loading and testing power sources. The unit is  
designed for production line and job site use.  
Air to cool the load elements enters the screened  
intakes located on one end of the Load Bank. The air  
passes over the resistive elements and is then dis-  
charged through the screened opening at the other  
end of the Load Bank.  
The total loading capability of the Master Load 750 is  
in fixed steps of 25, 25, 50, 50, 100, 250, 250 Amps  
@ 50V AC or DC, totaling 750 Amps. Using the tog-  
gle switches on the control panel, any combination of  
the available load steps may be selected to achieve a  
desired load.  
The Load Bank also contains fuses for short circuit  
protection. The control circuit is protected with a 15  
amp fuse while the voltmeters are protected with 3  
amp fuses.  
CONTROL UNIT  
The loads described above are controlled from an  
integral control panel.  
WARNING  
Do not operate the Load Bank with any screen or  
cover removed. This may expose the operator to  
high voltage and rotating fan blades.  
1. CONTROL POWER ON/OFF switch - Applies  
power to the load bank and starts the blower.  
The CONTROL POWER indicator lights when  
power is applied.  
---------------------------------------------------------------------  
CAUTION  
2. BLOWER FAIL indicator - Indicates an air fail-  
ure condition or insufficient cooling airflow.  
Do not exceed the voltage rating of load resistive cir-  
cuit configuration.  
------------------------------------------------------------------------  
3. MASTER LOAD ON/OFF switch - Allows  
instantaneous connection and disconnection  
MASTER LOAD 750  
 
3
3
INSTALLATION  
The over temperature switch, a protective device in  
the load bank, will guard against some of these prob-  
lems. If protective circuitry prevents application of the  
load, determine the source of the problem. DO NOT  
DISABLE THE OVER TEMPERATURE SWITCH.  
This causes a safety hazard and voids our warranty.  
The following installation instructions are critical to the  
safe operation of the Load Bank. Refer to the Load  
Bank Safety section of this manual.  
BEFORE INSTALLATION  
Inspect the Load Bank for obvious damage such as  
broken wires, broken or dented panels, cracked  
ceramic insulators, or any other component breakage  
that may have occurred in shipment.  
LOCATION  
------------------------------------------------------------------------  
The Master Load 750 is a portable, indoor, outdoor  
Load Bank, and should be installed in a dry, cool,  
well-ventilated area. Cool air must be continually  
available and the hot exhaust air must be dissipated,  
not recirculated through the unit. Install the Load  
Bank so that the inlet and exhaust panels have unre-  
stricted airflow clearance.  
POWER REQUIREMENTS  
The Load Bank requires a 120 volt, single phase, 60  
Hz, 15 amp source of power for operation of the con-  
trol panel and cooling fan. A power cord for control  
power is provided with the Load Bank. Connect the  
power cord to a grounded 120 volt source.  
Load power is connected to the Load Bank through  
receptacles on the side of the Load Bank labeled L1  
and L2.  
CAUTION  
Installation must prevent hot exhaust air from recircu-  
lating into the air intake. Inlet air temperatures  
exceeding 120° F (50° C) may cause damage to the  
Load Bank. After installation, test the unit at full load  
and verify that the inlet air temperature does not  
exceed 120° F (50° C).  
WARNING  
Do not energize the Load Bank with  
the top cover removed. Make sure  
the top cover panel is securely fas-  
tened to the frame.  
------------------------------------------------------------------------  
AIRFLOW CONSIDERATIONS  
Even with an ample supply of cooling air, the load bank  
may overheat if it is not properly installed. There are  
two types of airflow problems that should be avoided:  
------------------------------------------------------------------------  
Cables to the Load Bank should be of adequate size  
to handle the maximum rated current according to the  
1. Recirculating Airflow - If the hot, exhausted air  
is permitted to recirculate through the load bank,  
the air will reach such a high temperature and low  
density that it will no longer cool the resistance  
elements. A load bank should not be installed so  
close to any surface as to reflect the exhausted air  
back to the air intake. When two or more load  
banks are being used, care must be taken in posi-  
tioning the units so that the exhausted air of one  
unit does not feed the air intake of another.  
National Electrical Code and any local codes.  
A
ground stud is provided and must be connected to the  
frame of the power source, which in turn must be con-  
nected to a good earth ground.  
WARNING  
Never exceed the rated voltage as this will cause the  
Load Bank to overheat.  
2. Restriction of Cooling Air - Any obstruction  
located within 8 feet (2.4 m) of the inlet and  
exhaust screens will restrict the load bank's air-  
flow. Airflow is also restricted when two or more  
load banks have air inlets positioned too close to  
each other. This competition for cooling air caus-  
es a low pressure area, restricting adequate air-  
flow.  
------------------------------------------------------------------------  
Lower voltages and different frequencies may be  
applied to the load circuit of the Load Bank.  
Frequency change causes no derating of the load;  
however, the applied KW with a lower voltage is com-  
puted by using the following formula:  
2
(Voltage Applied)  
KW  
= KW  
X
Applied  
Rated  
WARNING  
2
(Voltage Rated)  
It is important to install the Load Bank properly.  
Installation errors may result in a catastrophic failure.  
MASTER LOAD 750  
 
4
4
OPERATION  
PURPOSE AND USE OF CONTROLS OPERATING INSTRUCTIONS  
1. POWER ON/OFF switch - Turns on cooling fan  
and powers remainder of control circuit. Red light  
shows POWER ON.  
1. Connect Load Bank to 120 volts, single phase, 60  
Hz power source.  
2. Connect a wire from the Load Bank frame ground  
stud to power source frame.  
2. BLOWER FAIL indicator - The purpose of the  
BLOWER FAIL lamp is to warn the operator and  
remove the load to the load bank in case of an air  
failure or improper cooling of the load elements.  
3. Connect power source frame to a good earth  
ground.  
3. MASTER LOAD ON/OFF switch - The MASTER  
LOAD switch connects power to all load steps,  
thus allowing all load steps which are actuated to  
load at the same time. It is also a master load  
disconnect.  
4. Connect appropriate power source leads to Load  
Bank.  
5. With POWER and MASTER LOAD switches in the  
OFF position, start the generator.  
4. LOAD STEPS switches - The load in amps is  
marked above each actuating switch. A load step  
may be turned ON or OFF before or during a test  
but will load the unit only when the MASTER  
LOAD switch is ON. NOTE: For DC loads, if the  
polarity is not correct the load step switches will  
not activate the load.  
6. Place the POWER switch in the ON position.  
The red POWER lamp will light.  
7. Position the LOAD STEPS switches for the  
desired load.  
8. Turn on the MASTER LOAD switch to apply  
desired load. Load steps may be added or delet-  
ed at any time.  
5. ANALOG METERS - Monitors load characteristics  
DC and AC, Volts, and Amps.  
9. Use analog meters to monitor applied load.  
LOAD BANK OPERATION  
10. After running tests, remove the load by turning off  
the MASTER LOAD switch. Residual heat may  
be removed from the Load Bank by allowing the  
blower to run a few minutes after load is removed.  
Although not required for maintaining Load Bank  
integrity, this procedure may guard operating per-  
sonnel from possible burn injuries.  
All tests start with control panel switches in the OFF  
position.  
CAUTION  
Before energizing any load, verify that load voltage  
does not exceed rated voltage of load bank.  
------------------------------------------------------------------------  
WARNING  
DO NOT touch the exhaust screen  
during operation. The screen will  
become hot from the exhausted heat  
and may cause a serious burn.  
Refer to the Load Bank Safety sec-  
tion of this manual.  
The unit is energized by turning the POWER switch  
ON. This also energizes the cooling fan motor.  
CAUTION  
Do not attempt operation if fan is not running. Fan  
inlet and exhaust must be unrestricted. The opera-  
tion of the fan is vital to the safe operation of this Load  
Bank. If BLOWER FAIL indicator light comes on and  
stays on for more than a few seconds without the load  
dropping out, shut off the POWER switch at once.  
Remove all power to the unit and check for proper  
operation of fan safety circuit. Failure to correct cool-  
ing air loss condition will result in destruction of the  
Load Bank. Refer to the Load Bank Safety section  
of this manual.  
DO NOT allow objects to enter or block screens.  
------------------------------------------------------------------------  
11. Place the POWER switch to the OFF position.  
12. Shut down all power sources to the Load Bank.  
13. Disconnect the power source cables to the Load  
Bank.  
------------------------------------------------------------------------  
MASTER LOAD 750  
 
5
5
MAINTENANCE  
4. Inspect for loose hardware or loose connections.  
Tighten where required.  
SAFETY PRECAUTIONS  
Before servicing, read and observe all safety  
precautions throughout this manual.  
5. Inspect all connections for oxidation or corrosion.  
Clean the connection or replace the hardware  
where required.  
WARNING  
6. Inspect all magnetic contactors to make sure that  
the contacts are not severely pitted or corroded.  
The contacts must move freely and be properly  
seated.  
ELECTRIC SHOCK can kill.  
• Only qualified personnel should  
perform this maintenance.  
7. Clean all dirt and debris out of the load bank.  
This can be accomplished by blowing the inside of  
the unit with clean, dry compressed air (not to  
exceed 40 PSI). Eye protection should be worn  
when cleaning the Load Bank with compressed  
air.  
• Turn the input supply power  
OFF at the disconnect switch or  
fuse box before working on this  
equipment.  
• Do not touch electrically hot  
parts.  
8. Inspect all the wiring for any sign of insulation fail-  
ure.  
• Allow resistance elements to  
cool before working near them.  
9. Replace all access panels and screens. Tighten  
all the fastening hardware securely.  
• Do not touch moving fan  
components.  
------------------------------------------------------------------------  
10. Check the indicator lamps on the control panel.  
ROUTINE AND PERIOD  
MAINTENANCE  
ANNUALLY  
DAILY  
The blower motor should be lubricated according to  
the motor manufacturers' requirements and specifica-  
tions on the motor nameplate.  
1. Remove any restrictions to airflow through the  
Load Bank.  
2. Check the screens to make sure that no objects  
have blocked or entered the openings.  
3. Verify that the airflow is in the proper direction.  
4. Assure that there is no recirculation of the exhaust  
air through the Load Bank.  
THREE MONTHS OR 500 HOURS  
1. Remove access panels and screens.  
2. Inspect the load resistors for mechanical break-  
down which is demonstrated by excessive sag-  
ging of the elements. Replace with new resistor  
elements as required.  
3. Inspect for broken ceramic insulators. Replace  
with a new ceramic insulator if any cracks are  
found.  
MASTER LOAD 750  
 
6
6
TROUBLESHOOTING & REPAIR  
HOW TO USE TROUBLESHOOTING GUIDE  
WARNING  
This Troubleshooting Guide is designed to be used by qualified service personnel.  
Unauthorized repairs performed on this equipment may result in danger to the technician  
and machine operator and will invalidate your factory warranty. For your safety, please  
observe all safety notes and precautions detailed in the Safety Sections of this manual to  
avoid electrical shock or danger while troubleshooting this equipment.  
This Troubleshooting Guide is provided to  
help you locate and repair possible  
problems.  
Step 3.  
If you have exhausted all of the  
recommended checks in step 2, contact the  
Lincoln  
Electric  
Customer  
Service  
Step 1. LOCATE PROBLEM (SYMPTOM)  
Look under the column labeled “PROBLEM  
(SYMPTOMS)”. This column describes  
possible symptoms that your unit may  
exhibit. Find the listing that best describes  
the symptom that your machine is exhibiting.  
Department.  
Step 2. Check Possible Causes  
The second column labeled “POSSIBLE  
CAUSES/REMEDIES”  
lists  
typical  
possibilities that may contribute to the  
machine symptom. Perform these checks  
and remedies in the order listed.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the  
Lincoln Electric Service Department for technical troubleshooting assistance before you proceed. Call 216-383-2531 or  
1-800-833-9353.  
MASTER LOAD 750  
 
7
7
TROUBLESHOOTING & REPAIR  
Observe all Safety Guidelines detailed throughout this manual  
PROBLEMS  
(SYMPTOMS)  
POSSIBLE CAUSES/REMEDIES  
1. Load bank main power fails to  
come on.  
a. Main switch or circuit breaker is not closed.  
b. Unit is not connected according to the Schematic/Interconnection dia-  
gram.  
c. Terminals may be damaged.  
1.  
d. Fuses may be blown. (Check and replace as required.)  
e. Fuse may be blown in load bank control circuit. (Check and replace as  
1.  
required.)  
f. Dirty or loose connection at main power switch.  
2. Blower motor does not operate.  
a. Main switch or circuit breaker may not be closed.  
b. Power may not be connected to load bank blower circuit.  
c. External power supply may be inadequate.  
1.  
d. Control Circuit fuse may be blown. (Check and replace as required.)  
e. Main power switch may be faulty.  
f. Check for loose or broken connections.  
1.  
When checking fuses for continuity, be sure to remove all fuses from clips (in fuse block or disconnect switch).  
Test each fuse individually, out of circuit.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric  
Service Department for technical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.  
MASTER LOAD 750  
 
8
8
TROUBLESHOOTING & REPAIR  
Observe all Safety Guidelines detailed throughout this manual  
PROBLEMS  
(SYMPTOMS)  
POSSIBLE CAUSES/REMEDIES  
3. BLOWER OVER TEMPERATURE a. Airflow restrictions present at load bank intake or exhaust.  
indicator lights are on, but the  
blower is operating.  
b. Maximum rating of the load bank may have been exceeded.  
4. Fan blade is broken or not turning. a. Fan blade motion may be obstructed.  
b. Fan blade may be loose at hub or is not keyed properly.  
5. Load step(s) cannot be energized. a. Check to see if over temperature indicator is lit. (See problem 3.)  
b. A blower failure may exist. (See problem 2.)  
c. Master load switch may be faulty.  
d. Control power may be inadequate.  
e.  
Fuse may be blown in load bank control circuit. (Check and replace as  
1.  
required).  
f. Load step switch may be faulty.  
g. Load step contactor may be inoperative.  
h. Load step resistor may be open.  
i. Output polarity connection is incorrect. Verify correct polarity connection  
to the load bank.  
1.  
When checking fuses for continuity, be sure to remove all fuses from clips (in fuse block or disconnect switch).  
Test each fuse individually, out of circuit.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric  
Service Department for technical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.  
MASTER LOAD 750  
 
9
9
TROUBLESHOOTING & REPAIR  
Observe all Safety Guidelines detailed throughout this manual  
PROBLEMS  
(SYMPTOMS)  
POSSIBLE CAUSES/REMEDIES  
6. Contactor “chattering” exists.  
a. Contacts and/or core may be dirty.  
b. Check for loose or faulty connections to the contactor coil.  
c. Control circuit line voltage may be too low.  
7. Load bank or load step does not a. Applied load voltage may be either derated or inadequate.  
give rated load.  
b. Contactor may not be closing properly.  
c. Load step resistor element may be open.  
1.  
When checking fuses for continuity, be sure to remove all fuses from clips (in fuse block or disconnect switch).  
Test each fuse individually, out of circuit.  
CAUTION  
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric  
Service Department for technical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.  
MASTER LOAD 750  
 
10  
10  
DIAGRAMS  
MASTER LOAD 750  
 
11  
11  
DIAGRAMS  
MASTER LOAD 750  
 
PARTS  
MASTER LOAD 750  
 
# Indicates a change this printing.  
* Recommended Spare Part  
ITEM DESCRIPTION  
Use only the parts marked xin the column under the  
heading number called for in the model index page.  
PART NO.  
QTY. 1 2 3 4 5 6 7 8 9  
1
2
3
4
5
6
7
8
9
Base, Load Bank  
Side Panel, (Left)  
Side Panel, (Right)  
Venturi, Fan  
Rail (For Relay K8 Mtg.)  
Pan, Relay  
Panel, Screened  
Cover. Load Bank  
Cover. Res Element  
M18720  
1
1
1
1
1
1
2
1
2
1
1
6
3
12  
21  
28  
1
1
1
2
1
1
1
1
1
1
4
1
1
2
2
1
1
1
2
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
M18720-1  
M18720-2  
M18720-3  
M18720-62  
M18720-5  
M18720-6  
M18720-7  
M18720-8  
M18720-9  
M18720-10  
M18720-11  
M18720-12  
M18720-13  
M18720-14  
M18720-15  
M18720-16  
M18720-61  
M18720-58  
M18720-59  
M18720-60  
M18720-21  
M18720-22  
M18720-23  
M18720-24  
M18720-25  
M18720-26  
M18720-27  
M18720-28  
S16656-4  
10 Terminal Board {RB}  
11 Terminal Board {RA}  
12 Resistance Element  
13 Resistance Element  
14 Resistence Element  
15 Rod, Element Support  
16 Bus Link  
17 Plate Identification  
18 Relay (K8)  
19 Label Warning  
20 Label Warning  
21 Label Warning  
22 Plate, Designation (L1,L2,+,-)  
23 Plate, Designation (GND)  
24 Line Cord {P1}  
25 Control Panel  
26 Schematic/Wiring Diagram  
27 Relay {K1-K4}  
28 Relay {K5}  
29 Support, Motor  
30 Terminal Connector {W1, W2}  
31 Relay {K6, K7}  
32 Fuseholder {XF1 - XF3}  
33 Fuse, 15A {F1}  
34 Motor, 1/4 HP, 120V {B1}  
35 Fuse, 3A {F2.F3}  
36 - -  
M18720-29  
M18720-30  
M18720-31  
M9983-4  
M18720-32  
37 Caster, Swivel  
38 Impeller, Fan  
39 Tube, Steatite  
40 Molding  
41 Transformer, Current {CT1}  
42 Bus Bar  
M18720-34  
M18720-35  
M18720-36  
M18720-37  
M18720-38  
M18720-39  
2
1
X
X
210 X  
AR X  
1
1
X
X
43 - -  
44 Caster, Rigid  
45 Pin, Spring Clip  
46 Grommet  
47 Cover  
48 Nut, Jam  
M18720-41  
M18720-42  
M18720-43  
M18720-63  
M18720-64  
2
42  
1
1
1
X
X
X
X
X
3-18-97  
 
# Indicates a change this printing.  
* Recommended Spare Part  
ITEM DESCRIPTION  
Use only the parts marked xin the column under the  
heading number called for in the model index page.  
PART NO.  
QTY. 1 2 3 4 5 6 7 8 9  
49 Bushing, Seal  
50 Spring  
51 Switch, Temp {S11}  
52 - -  
M18720-44  
M18720-45  
M18720-46  
1
42  
1
X
X
X
53 Nut Assembled Washer  
54 Threadlocker  
55 Stud  
M18720-47  
M18720-48  
M18720-49  
84  
AR X  
4
X
X
56 - -  
57 - -  
58 Semiconductor, Rectifier {CR1}  
59 - -  
60 Shunt, 800A. 50MV {R10}  
61 Wire, Electrical 2 AWG  
62 - -  
M18720-52  
1
1
X
X
M18720-53  
M18720-54  
75ft. X  
63 Nut #1/2 - 13  
64 Washer, Flat, 1/2  
65 - -  
M18720-56  
M18720-57  
4
1
X
X
3-18-97  
 
NOTES  
 
NOTES  
 
NOTES  
 
Do not touch electrically live parts or  
electrode with skin or wet clothing.  
Insulate yourself from work and  
ground.  
Keep flammable materials away.  
Wear eye, ear and body protection.  
WARNING  
Spanish  
No toque las partes o los electrodos Mantenga el material combustible  
Protéjase los ojos, los oídos y el  
bajo carga con la piel o ropa moja-  
da.  
Aislese del trabajo y de la tierra.  
fuera del área de trabajo.  
cuerpo.  
AVISO DE  
PRECAUCION  
French  
Ne laissez ni la peau ni des vête-  
ments mouillés entrer en contact  
avec des pièces sous tension.  
Gardez à l’écart de tout matériel  
inflammable.  
Protégez vos yeux, vos oreilles et  
votre corps.  
ATTENTION  
Isolez-vous du travail et de la terre.  
German  
Berühren Sie keine stromführenden  
Teile oder Elektroden mit Ihrem  
Körper oder feuchter Kleidung!  
Isolieren Sie sich von den  
Entfernen Sie brennbarres Material! Tragen Sie Augen-, Ohren- und Kör-  
perschutz!  
WARNUNG  
Elektroden und dem Erdboden!  
Portuguese  
Não toque partes elétricas e elec-  
trodos com a pele ou roupa molha-  
da.  
Mantenha inflamáveis bem guarda- Use proteção para a vista, ouvido e  
dos.  
corpo.  
ATENÇÃO  
Isole-se da peça e terra.  
Japanese  
Chinese  
Korean  
Arabic  
READ AND UNDERSTAND THE MANUFACTURER’S INSTRUCTION FOR THIS EQUIPMENT AND THE CONSUMABLES TO BE  
USED AND FOLLOW YOUR EMPLOYER’S SAFETY PRACTICES.  
SE RECOMIENDA LEER Y ENTENDER LAS INSTRUCCIONES DEL FABRICANTE PARA EL USO DE ESTE EQUIPO Y LOS  
CONSUMIBLES QUE VA A UTILIZAR, SIGA LAS MEDIDAS DE SEGURIDAD DE SU SUPERVISOR.  
LISEZ ET COMPRENEZ LES INSTRUCTIONS DU FABRICANT EN CE QUI REGARDE CET EQUIPMENT ET LES PRODUITS A  
ETRE EMPLOYES ET SUIVEZ LES PROCEDURES DE SECURITE DE VOTRE EMPLOYEUR.  
LESEN SIE UND BEFOLGEN SIE DIE BETRIEBSANLEITUNG DER ANLAGE UND DEN ELEKTRODENEINSATZ DES HER-  
STELLERS. DIE UNFALLVERHÜTUNGSVORSCHRIFTEN DES ARBEITGEBERS SIND EBENFALLS ZU BEACHTEN.  
 
Keep your head out of fumes.  
Use ventilation or exhaust to  
remove fumes from breathing zone.  
Turn power off before servicing.  
Do not operate with panel open or  
guards off.  
WARNING  
Spanish  
Los humos fuera de la zona de res-  
piración.  
Mantenga la cabeza fuera de los  
humos. Utilice ventilación o  
aspiración para gases.  
Desconectar el cable de ali-  
mentación de poder de la máquina  
antes de iniciar cualquier servicio.  
No operar con panel abierto o  
guardas quitadas.  
AVISO DE  
PRECAUCION  
French  
Débranchez le courant avant l’entre- N’opérez pas avec les panneaux  
tien.  
Gardez la tête à l’écart des fumées.  
Utilisez un ventilateur ou un aspira-  
teur pour ôter les fumées des zones  
de travail.  
ouverts ou avec les dispositifs de  
protection enlevés.  
ATTENTION  
German  
Strom vor Wartungsarbeiten  
abschalten! (Netzstrom völlig öff-  
nen; Maschine anhalten!)  
Anlage nie ohne Schutzgehäuse  
oder Innenschutzverkleidung in  
Betrieb setzen!  
Vermeiden Sie das Einatmen von  
Schweibrauch!  
Sorgen Sie für gute Be- und  
Entlüftung des Arbeitsplatzes!  
WARNUNG  
Portuguese  
Não opere com as tampas removidas.  
Desligue a corrente antes de fazer  
serviço.  
Mantenha-se afastado das partes  
moventes.  
Não opere com os paineis abertos  
ou guardas removidas.  
Mantenha seu rosto da fumaça.  
Use ventilação e exhaustão para  
remover fumo da zona respiratória.  
ATENÇÃO  
Não toque as partes elétricas nuas.  
Japanese  
Chinese  
Korean  
Arabic  
LEIA E COMPREENDA AS INSTRUÇÕES DO FABRICANTE PARA ESTE EQUIPAMENTO E AS PARTES DE USO, E SIGA AS  
PRÁTICAS DE SEGURANÇA DO EMPREGADOR.  
 
World's Leader in Welding and Cutting Products •  
Sales and Service through Subsidiaries and Distributors Worldwide •  
Cleveland, Ohio 44117-1199 U.S.A. TEL: 216.481.8100 FAX: 216.486.1751 WEB SITE: www.lincolnelectric.com  
 

KWC Indoor Furnishings 10501004 User Manual
LG Electronics Clothes Dryer DLEX4270V User Manual
Logitech Computer Keyboard K250 User Manual
LOREX Technology Security Camera lh1 10 User Manual
Lucent Technologies Marine Radio 555 670 116 User Manual
Makita Paint Sprayer BVF104 User Manual
Manitowoc Ice Ice Maker IB00820 User Manual
Maytag Clothes Dryer MDG76PC User Manual
Maytag Washer Dryer MVW18CSAGW0 User Manual
Melissa Mixer 746 086 User Manual