Emerson Comfort Alert 543-0038-02 - Troubleshooting Miswiring and Model Selection; Correct Model Selection Importance; Miswiring Troubleshooting Guide

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NOTE: The correct Comfort Alert model must be used for the application (refer to
the Product Specifi cation section on page 2). If the wrong model is installed, the
ALERT Flash Codes for system faults will function incorrectly: the Comfort Alert
module may indicate system faults that are not present or fail to indicate system
faults that are present.
NOTE: Miswiring the Comfort Alert module will cause false LED codes. Table 1
describes LED operation when the module is miswired and what troubleshooting
action is required to correct the problem.
Miswired Module Indication Recommended Troubleshooting Action
Green LED is not on, Determine if both R and C module terminals are
module does not power up connected. Verify voltage is present at module’s R and
C terminals. Review 24VAC Power Wiring (page 4) for
R and C wiring.
Green LED intermittent, Determine if R and Y terminals are wired in reverse.
module powers up only Verify module’s R and C terminals have a constant
when compressor runs source. Review 24VAC Power Wiring (page 4) for R
and C wiring.
TRIP LED is on but system Verify Y terminal is wired properly per OEM wiring
and compressor check OK diagram. Verify voltage at contactor coil falls below 0.5VAC
when off. Verify 24VAC is present across Y and C when
thermostat demand signal is present. If not, R and C are
reverse wired.
TRIP LED and ALERT LED Verify R and C terminals are supplied with 19-28VAC.
fl ashing together
ALERT Flash Code 3 Verify Y terminal is connected to 24VAC at contactor coil.
(Compressor Short Cycling) Verify voltage at contactor coil falls below 0.5VAC when
displayed incorrectly off.
ALERT Flash Code 5 or 6 Check that compressor T1 and T3 wires are through
(Open Circuit, Missing module’s current sensing holes. Verify Y terminal is
Phase) displayed connected to 24VAC at contactor coil. Verify voltage at
Incorrectly contactor coil falls below 0.5VAC when off.
ALERT Flash Code 8 Determine if module’s Y terminal is connected. Verify Y
(Welded Contactor) terminal is connected to 24VAC at contactor coil. Verify
displayed incorrectly 24VAC is present across Y and C when thermostat
demand signal is present. If not, R and C are reverse
wired. Verify voltage at contactor coil falls below 0.5VAC
when off. ReviewThermostat Demand Wiring (page 4)
for Y and C wiring.
Table 1