Gun Polarity Connections; Installing Welding Gun - MAC TOOLS MW250 Owner's Manual

3-3. Gun Polarity Connections

WARNING
ELECTRIC SHOCK can kill.
•
Do not touch live electrical parts.
•
Turn Off welding power source, and disconnect input power before inspecting or installing.
Shown As Shipped − Set For Electrode
Positive (DCEP) For Solid Steel Or
Aluminum Wires (GMAW Process).
Wire Drive Assembly Lead
To Positive (+) Output Terminal
Work Clamp Lead To
Negative (−) Output Terminal
GUN POLARITY
CHANGEOVER CONNECTIONS
Reverse Lead Connections − For Electrode
Negative (DCEN) For Flux Cored Wires
(FCAW Process). Drive Assembly
Becomes Negative

3-4. Installing Welding Gun

OM-154 501 Page 5
6
1
2
S-144 449-D
Figure 3-3. Gun Polarity Connections
1
Figure 3-4. Gun Connections
5
3 4
4
3
2
swarn1.1 2/93
1 Polarity Changeover Label
2 Wire Drive Assembly
3 Positive (+) Output Terminal
4 Negative (−) Output Terminal
Always read and follow wire man-
ufacturer's recommended polarity.
5 Circuit Breaker CB1 (see
Section 5-2).
6 Pilot Light (see Section 5-2)
Close door.
Tools Needed:
3/4, 11/16 in
Ref. ST-801 103-B
1 Wire Drive Assembly
2 Gun Securing Knob
3 Gun End
Loosen securing knob. Insert gun
end through opening until it bottoms
against drive assembly. Tighten
knob.
4 Gun Trigger Plug
Insert into receptacle, and tighten
threaded collar.
Close pressure assembly. Close
door.
Ref. ST-801 101-B