Section 10 − Maintenance; Routine Maintenance; Additional Maintenance (If Necessary); Overheating - Miller Millermatic 350P Technical Manual

10-1. Routine Maintenance

n = Check
* To be done by Factory Authorized Service Agent
3 Months
l Damaged Or Unreadable Labels
6 Months
OR
~ Inside Unit
.
When using a 16 lb spool of wire per day, blow out gun liner after each spool of wire.

10-2. Additional Maintenance (If Necessary)

Check for seal (label) between front panel and sheet metal wrapper of machine. If seal is not present, add
Part No. 234 083 (see field instructions F233 608 for details).
Check for rubber washers on PC2 encoder shafts, if washers are not present, add Part No. 234 197 to encoder shafts.
Contact Miller Service for information on adding weatherstripping adhesive, silicon caulk, polarity indicator seals, and
contactor side shield seals to locations on machine.

10-3. Overheating

Thermistors RT1 and RT2 protect the unit from damage due to overheating. If output diode heatsink or IGBT heatsink
gets too hot, RT1 and/or RT2 opens and output stops. The fan keeps running to cool the unit. Wait several minutes
before trying to weld.

10-4. Ground Clamp And Gun Connections

Clean and tighten ground clamp and gun connections. Be sure that ground clamp is connected to a clean, paint-free
surface on the workpiece.
TM-1327 Page 70
SECTION 10 − MAINTENANCE
Z = Change ~ = Clean
l Repair Or Replace
Cracked Weld Cable
~ Drive Rolls
l = Replace
~ Clean And Tighten Weld
Terminals
~ Clean Gun Liner
!
Disconnect power
before maintaining.
.
Maintain more often
during severe
conditions.
Reference
n Check Gun Cable
Millermatic 350