Miller Electric MARK VIII-2, Owner'S Manual

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OM-218 Page 24
6-4. Troubleshooting
Y Turn Off polyweld system, and disconnect input power
before inspecting, maintaining, or servicing.
Trouble Remedy
No weld output from any module; fan
motors off; pilot light off.
Place line disconnect device in On position (see Section 4-10).
Check line fuse(s), and replace if needed. Reset circuit breakers (see Section 4-10).
Check for proper input connections (see Section 4-10).
Check position of input voltage jumper links (see Section 4-10).
Be sure power switch is On (see Section 5-3).
Check fuse F3 and/or F4, and replace if needed (see Section 6-2).
Have Factory Authorized Service Station/Service Distributor check Start/Stop push buttons PB1/PB2
and replace if necessary.
No weld output from any module; fan
motors on; pilot light off.
Thermostat TP1 open (overheating). Allows fans to run; thermostat closes when unit has cooled (see
Section 6-2).
No weld output from any module; fan
motors on; pilot light on.
Have Factory Authorized Service Station/Service Distributor check contactor W and replace if needed.
Limited output and low open circuit volt-
age from All modules.
Check incoming power for correct voltage. Replace line fuse if open or reset circuit breaker (see Section
4-10).
Check position of input voltage jumper links (see Section 4-10).
No weld output from one module only. Check fuse links, and replace if needed (see Section 6-2).
Low weld output from one module only.
No amperage control.
Place Remote Amperage control switch in Off position or connect remote amperage control to Remote
Amperage Control receptacle (see Section 5-2).
Check module fuse link, and replace if needed (see Section 6-2).
Reset module supplementary protector (see Section 6-2).
Module thermostat open (overheating). Allow module to cool down; thermostat closes when module has
cooled (see Section 6-2).
Erratic weld output. Tighten all weld cable connections (see Section 4-6).
Check for proper size and type of cable (see Section 4-10).
Check for proper input and output connections (see Sections 4-10 and 4-6).
Use dry, properly stored electrodes.
No weld output at 115 volts ac duplex
receptacle.
Reset overload supplementary protector CB1 (see Section 6-2).
Check fuse F3 and/or F4, and replace if needed (see Section 6-2).
Fan motor(s) does not run when On
push button is pressed.
Check fuse F3 and/or F4, and replace if needed (see Section 6-2).
Have Factory Authorized Service Station/Service Distributor check control relay CR1 and fan motor FM1
or FM2.
For GTAW, wandering arc − poor control
of direction of arc.
Select proper size tungsten (see Section 8-1).
Properly prepare tungsten (see Sections 8-2 or 8-3).
Tungsten electrode oxidizing and not re-
maining bright after conclusion of weld.
Shield weld zone of drafts.
Properly prepare tungsten (see Sections 8-2 or 8-3).
Replace torch parts if water has leaked into torch.