Miller Electric Shopmaster 300 AC/DC, Owner'S Manual

Page: 21 / 32

OM-322 Page 17
4-3. Troubleshooting
Trouble Remedy
No weld output; unit completely
inoperative. Place line disconnect switch in On position (see Section 2-10).
Check and replace line fuse(s), if necessary (see Section 2-10).
Check for proper input power connections (see Section 2-10).
Check for proper jumper link position (see Section 2-10).
No weld output; fan on. If using remote control, place Output (Contactor) switch in Remote 14 position, and make sure remote
control is connected to Remote 14 receptacle. If remote is not being used, place Output (Contactor)
switch in On position.
Check, repair, or replace remote control.
Unit overheated. Allow unit to cool with fan On (see Section 2-3).
Have Factory Authorized Service Agent check control board PC1.
Unit provides only maximum or
minimum weld output. Have Factory Authorized Service Agent check control board PC1 and hall device HD1.
Weld output always above or always
below set value. Have Factory Authorized Service Agent check control board PC1 and hall device HD1.
Erratic or improper weld output. Use proper size and type of weld cable (see Section 2-6).
Clean and tighten all weld connections.
Check position of Output Selector switch (see Section Figure 3-1).
Have Factory Authorized Service Agent check control board PC1 and hall device HD1.
Fan not working. Check for anything blocking fan.
Have Factory Authorized Service Agent check fan motor.
No control of weld output. If using remote control, place Amperage/Voltage control switch in Remote 14 position, and make sure
remote control is connected to Remote 14 receptacle. If remote is not being used, place switch in
Panel position.
Have Factory Authorized Service Agent check control board PC1.
No 115 volts ac output from duplex
receptacle or Remote 14 receptacle. Reset circuit breaker CB1 (see Section 4-2).
No 24 volts ac output at Remote 14 re-
ceptacle Reset circuit breaker CB2 (see Section 4-2).
Wandering arc – poor control of
direction of arc. Reduce gas flow rate.
Select proper size tungsten.
Properly prepare tungsten.
Tungsten electrode oxidizing and not
remaining bright after conclusion of
weld. Shield weld zone from drafts.
Increase postflow time.
Check and tighten all gas fittings.
Properly prepare tungsten.
Check for water in torch, and repair torch if necessary. See torch Owner’s Manual.