Troubleshooting - MAC TOOLS MW250 Owner's Manual

5-5.
Troubleshooting
a
WARNING
READ SAFETY BLOCKS
at start
of
Section 5 before proceeding.
Replace contact tip.
SECTION
6-
ELECTRICAL DIAGRAMS
ONIVE
H~.J9IN0
WORK
CLA~
SB-i 74 099
Welding Trouble
No weld
output;
wire does
not
feed.
Remedy
Secure power cord
plug
in
receptacle.
Reset circuit breaker CB1. Replace fuse Fl and/or F2.
Replace building
line fuse
or
reset circuit breaker if open
Section
No weld
output;
wire does
not
feed; fan
~
-~
motor
continues
to
run
and pilot light is
off.
Secure gun
trigger plug in receptacle
or
repair leads,
or
replace
trigger switch.
I
No weld
output;
wire feeds.
-~
3.5
-~
5-2
-a
3-5
-~
3-4
Thermostat
open
(overheating).
Allow fan
to
run;
the thermostat
will close when the unit has cooled.
I
Low weld
output.
-~ Connect work
clamp to get good
metal
to
metal
contact.
Wire Drive/Gun Trouble
--.~__5-2
Electrode wire feeding
stops
during
~
-~
welding. I
-
Connect
unit to proper input voltage
or
check for low line volta
-
3-5
I
1
-~
Figure 4-3
I-..-
5-4
-~
5.4 Straighten gun cable and/or replace damaged
parts.
Adjust hub tension.
Adjust drive roll pressure.
Replace contact tip
if blocked.
Clean
or
replace
wire inlet
guide
or
liner if
dirty
or
plugged.
Replace drive roll
or pressure
bearing
if
worn or
slipping
Secure gun
trigger plug
in
receptacle
or
repair leads,
or
replace
trigger switch.
Check and
replace
Fl and/or F2.
Check and clear any restrictions
at
drive assembly
and liner
Have
nearest Factory
Authorized Service Station check drive
motor.
----~
--~
--~
---
--~
---
3-6
3-7
5-4
5-3,
5-4
5.3
3-4
5-2
5-3, 5-4
--~
--~
---
PLG2O
914
091
CBI
Rd
52
I
PL~TI
nr~
_ t ~ i
f~1 ~ ~I
~
i
~
2
A
A~~-A-A
~G2
.0 C. 0 0 0 ~0 0 CU
RC3-13>
RC3-Il).>--~--<3
14r1
PCI
CONTROL BOARD
RC3-
I
>>~-<
4
RC3/PLG~
RCO_3>>_____I!?_<
~
RC4/PLG4
RC5/PLG5
RC3-2)d.-~--<
7
10
RC3-
I9>)–~~(
I
12
Figure 6-1.
Circuit
Diagram For Welding Power Source
OM-154
501 Page 16