SmartPlate EV Installation, Operation and Maintenance Manual
CHAPTER 7
– TROUBLESHOOTING
OMM-0147_C
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TABLE 7-2. Troubleshooting
– Electronic Control System (ECS II)
No.
Fault Indication
Probable Cause
Corrective Action
T2
Temperature Controller is
ON, but Temperature
Indicators are blank
1. Circuit breaker tripped
2. Defective 24 VAC
transformer in Control
Box
1. Reset the circuit breaker on the 24 VAC
step-down transformer.
2. Check that 120-230VAC is present across
the L and N terminals on the Power Box
(see Appendix B). Verify that 24 VAC is
present across the V+ and V- terminals on
the Power Box. If 24 VAC is not present,
replace the 24 VAC transformer in the
Control Box.
T3
Water Heater outlet temp.
consistently above
Setpoint by 10°F or more.
However, temperature is
below Over-Temp. limit
setting.
1. Temperature
Controller is not
properly set.
2. Faulty Temp. Sensor
(thermocouple) is
connected to Temp.
Controller.
1. Refer to Chapter 4
–
Adjustment
and
check current setting of Temperature
Controller. Readjust if necessary.
2. Verify Outlet Temp Sensor is securely
connected to cable plug. Replace the Dual
Sensor if necessary
T4
Over-Temp Alarm occurs
repeatedly.
NOTE
Audible alarms will be
generated if Outlet Temp
Sensor is open. Erroneous
temperature readings will
be displayed if Sensor is
shorted.
1. Over-Temp switch not
properly set.
2. Open or shorted
Outlet Temp. Sensor
(thermocouple)
connected to Over-
Temp switch.
3. Over-Temp switch is
defective.
1. Refer to Chapter 4 and check the current
setting of the ECS Over-Temp switch.
Readjust if necessary.
2. Check thermocouple connections between
Sensor connector plug and Over-Temp
switch terminals 1 and 2 and leads 2100
(+) and 2101 (-). If connections are secure,
replace Dual Temp Sensor.
3. Replace Over-Temp switch.
T5
Over-Temp. Alarm
condition cannot be
cleared.
Over-Temp switch
displays erroneous
temperature readings
1. Shorted Outlet Temp.
Sensor.
2. Defective Over-Temp
switch.
3. 3-Way Control Valve
not closing fully during
no-load conditions.
4.
A “No-Flow” condition
caused a gradual
buildup of heat to the
water in vessel.
1. Replace Outlet Temp Sensor.
2. Replace Over-Temp switch.
3. Calibrate 3-Way Control Valve per section
4.2.1.
4. Open hot water valve at sink or tub outlet
to see if fault clears.
