Solid State Temperature Controller Test (Sg4D/Sg6D); Test Steps - Vulcan-Hart SG4D ML-114875 Service Manual

SOLID STATE TEMPERATURE
CONTROLLER TEST
(SG4D/SG6D)
WARNING: DISCONNECT (UNPLUG) ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.

Test Steps

1. Remove the right side panel as outlined
under Cover and Panels in Removal and
Replacement of Parts.
2. Place a thermocouple in the geometric center
of the oven cavity. Oven temperature must
be below 450°F.
3. Set the temperature controller to the maximum
setting.
4. Set the power control to 100%.
5. Check machine data plate for correct voltage
to oven. Refer to diagram below for proper
terminal locations and voltages before
checking the temperature controller. Use the
correct terminals for the corresponding
voltage.
6. Turn the ON-OFF-OVEN COOL switch to
ON.
5 4
WHT
R
PROBE
RELAY
6
7
C
7. Check for proper voltage across terminals 8
& 9 (120 VAC) or terminals 8 & 10 (208-240
VAC) for power to the control.
A. If correct, proceed to step 8.
B. If incorrect, the problem is not in
the temperature controller (see
Troubleshooting).
3 2 1
8
9 10
NO N 120 240
VAC VAC
PL-56057
8. Check relay voltages on the board:
A. For 120 VAC controls - check across
terminals 7 & 9 for input to the internal
relay and 6 & 9 for output from the
internal relay.
B. For 208-240 VAC controls - check across
terminals 7 & 10 for input to the internal
relay and 6 & 10 for output from the
internal relay.
1) If input voltage to the internal relay is
correct, proceed to step 9. If input
voltage to the internal relay is not
present, problem is not with the
temperature
Troubleshooting).
2) If output voltage from the internal
relay is correct proceed to step 9. If
output voltage from the internal relay
is not correct, check temperature
probe as outlined under Temperature
Probe Test (SG4D/SG6D).
9. Set the temperature controller to the minimum
setting. Oven temperature must be above
300°F.
10. Check for zero (0) volts AC across terminals
6 & 9 (120 VAC) or 6 & 10 (208-240 VAC) for
no output from the internal relay.
A. If correct, temperature controller is
functioning properly.
B. If incorrect, check temperature probe as
outlined under Temperature Probe Test
(SG4D/SG6D).
1) If temperature probe is OK, replace
the temperature controller and check
calibration as outlined under Solid
State Temperature Controller
Calibration (SG4D/SG6D).
– 21 –
controller (See