SmartPlate Installation, Operation & Maintenance Manual
CHAPTER 7
– TROUBLESHOOTING
OMM-0069_0H
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of
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TROUBLESHOOTING PROCEDURES Instructions
3. Perform the corresponding checks and procedures listed in the CORRECTIVE ACTION
column for the first PROBABLE CAUSE.
4. Continue checking each additional PROBABLE CAUSE for the existing fault until the fault
has been corrected.
5. Refer to the applicable procedures in Chapter 8
–
Corrective Maintenance
if component
removal and/or replacement is required.
TABLE 7-1. Troubleshooting
– Control Valve MXG-461 and Piping Assembly
No.
Fault Indication
Probable Cause
Corrective Action
T1
System not operating.
Control Valve is closed
and outlet water temp. is
far below setpoint.
1. No power supplied to
Control Valve
2. Control signal not being
supplied from Temp.
Controller.
1. Remove Valve Electronics Module cover
(Figure 4-1) and verify that 24 VAC power
is present at pin 1 of terminal strip.
Restore power if necessary. Proceed to
Table 7-2 and check Over-Temp Switch
and 24 VAC Transformer circuit breaker to
ensure they have not tripped.
2. Verify presence of a 0 to 10 VDC control
signal at pin 5 of terminal strip. If control
signal is not present, troubleshoot
ECS/SP per Table 7-2.
T2
System over-heats by
more than 10°F above the
desired setpoint.
Outlet temp is below
Over-Temp limit setting
1. Control Valve is in the
MANUAL mode.
2. Control Valve not fully
closed.
3. Temp. Controller not
set properly or
defective.
4. Control Valve not
calibrated correctly
5. Heat exchanger scaled
on DHW side.
1. Ensure Control Valve is set to the AUTO
mode.
2. Check the 0
– 10 VDC control signal
being supplied to Actuator. If signal is
greater than 0 VDC when heater outlet
temperature is 10°F (or more) above the
desired setpoint, proceed to next item in
list.
3. Refer to Chapter 4
–
Adjustments
and
check current setting of Temp. Controller.
Readjust if necessary. If adjustment does
not clear fault, proceed to Table 7-2 and
continue.
4. Refer to Chapter 4, section 4.2 and auto-
calibrate the valve by pressing the button
(Figure 4-2). If Valve stem does not fully
stroke up and down, contact AERCO for
assistance.
5. Clean and de-scale heat exchanger.
