Hardware Troubleshooting
9 - 8
Modified: 9/17/08
MedWeld 4000 Operator’s Guide
M-032116 Programs #T03300, #T02300 and #T02400
Is the inverter receiving firing
signals?
If
YES
, check the firing card and SCR
wiring. Replace as necessary. Also check
to see if firing into an open primary or
secondary of the weld transformer.
If
NO
, check the weld processor card.
Replace as necessary.
I/O not respond-
ing as expected.
Problem with the I/O.
Check the device supplying the input or
receiving the output.
Incorrect or loose wiring to the input or
output module.
Isolation con-
tactor not being
pulled in
The weld schedule does not contain
the function to activate the isolation
contactor (Function #52).
Check the weld schedule to confirm that it
contains Function #52.
The isolation contactor is driven by a
single solid-state relay (based on the
status of the CONTROL STOP and
WELD/NO WELD inputs). Voltage
must be present at these inputs to
allow the weld processor to open or
close the isolation contactor.
Use the
I/O Status
display on the DEP-
100S to verify that the inputs are HIGH
(= 1).
The solid-state relay is faulty.
Replace solid-state relay.
If the control is externally-powered,
one of the internal control transformer
fuses may be blown.
Check fuses. Replace as necessary.
The control was unable to pull in the
isolation contactor due to incorrect or
loose wiring to the output module.
Check the wiring diagram that came with
your control for proper I/O designations.
Make sure all connections are secure.
Isolation contactor is not being held in
between weld sequence.
Check the I/O point enabling the
ISOLATION CONTACTOR SAVER Input.
Check the setting of the Isolation
Contactor Delay setup parameter.
Faulty I/O module.
Replace I/O module.
No current
reading (10 A. or
less)
Did the control weld?
If
NO
, see
Control sequences without
firing
on page 9-7.
If
YES
, check for part fit-up, foreign
material between electrodes and work
piece, electrode pressure and tooling.
Bad connection between current coil
and firing card.
Check for proper and secure wiring
connections between firing card and
current coil.
Faulty firing card.
Replace firing card.
Problem
Possible Cause
Possible Solution