Section 7 - Maintenance And Troubleshooting; Routine Maintenance; Changing Drive Roll Or Wire Inlet Guide; Overheating - Miller Multimatic 255 Owner's Manual

SECTION 7 – MAINTENANCE AND TROUBLESHOOTING
SECTION 17
7-1.

Routine Maintenance

17-1. Routine Maintenance
Disconnect power before maintaining.
�
Maintain more often during severe conditions.
� = Check
Every 3
Months
1/2 in.
Every
(13 mm)
3
Months
� Damaged Or Unreadable
Labels
Every 6
Months
� Inside Unit
7-2.

Changing Drive Roll Or Wire Inlet Guide

2
1
3
7-3.

Overheating

Thermistors RT1, RT2, and the thermistors contained within the inverter module PM1 protect the unit from damage due to overheating. If the out-
put diode heat sink, output inductor L2, and/or inverter module PM1 gets too hot, they command the weld controller to disable the output. The
fan keeps running to cool the unit. Wait several minutes before trying to weld.
OM-278174 Page 56
�
Complete Parts List is available at www.MillerWelds.com
MAINTENANCE & TROUBLESHOOTIN
◇ = Change
� Repair Or Replace Cracked Weld Cables
� Clean Drive Rolls
7/16 in.
A complete Parts List is available at www.MillerWelds.com
� = Clean
1 Securing Screw
2 Inlet Wire Guide
Loosen screw. Slide tip as close to drive rolls
as possible without touching. Tighten screw.
3 Drive Roll
The drive roll consists of two different sized
4
grooves. The stamped markings on the end
surface of the drive roll refers to the groove
on the opposite side of the drive roll. The
groove closest to the motor shaft is the prop-
er groove to thread.
4 Drive Roll Securing Nut
Turn nut one click to secure drive roll..
Replace Cracked
Torch Body
� = Replace
Repair Or Replace
Cracked Cables And
Cords
Clean
And
Tighten Weld
Connections
OM-249336 Page 1
OM-231242 P