-17-
P I N S D O N O T W E L D
P O O R W E L D Q U A L I T Y
SYMPTOM
CORRECT
FUNCTION
INDICATOR
POSSIBLE
PROBLEM
ACTION
All Indicators are
functioning except:
Weld Signal, Weld
#1 and Weld #2
do not function.
Weld Signal Indica-
tor goes on and off
with every cycle.
(A) Short Cycle
Relay.
(A) The Short Cycle Relay controls the voltage that turns on the solid- state
Weld Relays that turn on the Weld Transformer. To test the Short Cycle
Relay circuit check the voltage (24VAC approx.) at terminals #5 and #7 in
the Trolley. Terminals #5 and #7 should go from 0 to 24VAC and back to
0 on every cycle. If this voltage reading is incorrect Proceed to step B.
(B) Pressure
Switch.
(B) To test the Pressure Switch place a jumper between terminals #5 and #8
in the Trolley. If the machine welds with jumper in place replace Pressure
Switch. If the machine does not weld replace the Short Cycle Relay.
All Indicators are
functioning except:
Weld #1 and Weld
#2 do not func-
tion.
Weld Relay #1 or
Weld Relay #2 In-
dicator should cor-
respond with Weld
Signal Indicator.
Goes on and off
with every cycle.
Head Test
Switch.
The Head Test Switch is single-pole, double-throw and center off switch.
This switch selects which of the 2 solid state Weld Relays will control
the Weld Transformer. To test this switch check for continuity at the
switch in the Control Console.
All Indicators are
functioning.
Welding Indicator
on the frame is
n o t f u n c t i o n -
ing. This Indica-
tor shows when
there is voltage
(230VAC approx.)
present at the pri-
mary of the Weld
Transformer.
All lights flash in
sequence.
Weld Relay.
The Weld Relay controls the voltage to the primary of the Weld Trans-
former. To check the Weld Relays, test for voltage (24VAC approx.)
at terminals A1 and A2 on the selected relay in the Triangle Enclosure.
Terminals A1 and A2 should go from 0 to 24VAC and back to 0 on every
cycle. If this voltage reading does not correspond, check the Head Test
Switch is in Weld 1 or Weld 2 position and that the weld relay you are
checking is the active one. If the voltage reading was correct, test the
voltage (208-230 VAC approx.) at the terminals L1 and T1. Terminals L1
and T1 should go from (208-230 VAC approx.) to 0 and back to (208-
230 VAC approx.) with every cycle. If this voltage is incorrect replace
the Weld Relay.
All Indicators are
functioning in-
cluding the Weld
Indicator on the
frame.
All lights flash in
sequence.
Weld
Transformer.
To test the primary of the Weld Transformer check the voltage at the
terminals L1 and T1 on either of the Weld Relays. They should go from
(208-230 VAC approx.) to 0 and back to (208-230 VAC approx.) every
time the machine cycles. Now test the secondary output voltage. Place
the meter leads on the copper bars coming out of the Weld Transformer
and test the voltage every time the machine is cycled. The Mach 2 Weld
Transformer should read approximately 10VAC. (or 5VAC if on the center
tap) If the secondary voltage reading is incorrect replace the transformer.
(Turn the weld time to the highest setting when performing this test.)
SYMPTOM
CORRECT
FUNCTION
INDICATOR
POSSIBLE
PROBLEM
ACTION
Dwell Delay Indica-
tor is not func-
tioning.
Dwell Delay Indicator
comes on when
the Weld Timer
Indicator goes off
and then goes off
when the Dwell
Solenoid Indicator
goes off.
(A) Short Cycle
Relay or First
Pulse Relay.
(A) The Dwell Timer keeps the dwell circuit on 150ms longer than the Weld
Timer circuit. To check the Dwell Timer, test for voltage (24VAC approx.)
at terminals #1 and #2 on Dwell Timer located in the trolley. The voltage
on terminals #1 and #2 should go from 24VAC to 0 and back to 24VAC
with every machine cycle. If this voltage reading is correct proceed to
step (B). If this voltage reading is incorrect replace the Short Cycle
Relay. If the voltage reading at terminals #1 and #2 is still incorrect
replace the First Pulse Relay.
(B) Dwell Delay
Timer.
(B) If procedures in (A) test correctly, check the voltage (24VAC approx.) at
the terminals #1 and #4 on the Dwell Delay Timer. The voltage at termi-
nals #1 and #4 should go from 0 to 24VAC and back to 0 on every machine
cycle. If this voltage reading is incorrect replace the Dwell Timer.
All Indicators are
functioning.
All lights flash in se-
quence.
(A) Weld Cable. Any connection from the secondary of the Weld Transformer to the weld
tips can contribute to a poor quality weld. All the connections should
be clean, bright and tight. The Weld Cable can break down from
use. Always inspect the Weld Cable, Weld Transformer secondary con-
nections and weld tips for they are the most common causes for a
poor weld quality.
(B) Upper and
Lower Weld-
ing Tips.
Clean and Retighten
(C) Upper Tip
Retainer.
Clean and Retighten
(D) Female Cam-
lock.
Clean and Retighten
(E) Flush Mount
Camlock.
Clean and Retighten
(F) Power Supply
Bar.
Clean and Retighten
