Operation - Honeywell REDLINK ERM5220R Product Data

OPERATION

ERM USED FOR OUTDOOR UNIT: CALL FOR COOLING
1. Thermostat is set to cool or auto mode. Cool set-point is below room temperature.
2. Thermostat will show "cool on" in the display. (the display may show "waiting for equipment" if the minimum com-
pressor off delay has not expired prior to the call for cool. Typically this is up to 5 minutes).
• If thermostat is set for either conventional system or heatpump with heat changeover, the LED will be lit green over
the Y at the ERM. The switch will close from J to Y at the ERM. If an EIM is wired to the air-handler/furnace, the EIM
will close a switch from Rc to Y and Rc to G. If no EIM is used, the thermostat will close from Rc to Y and Rc to G at
the subbase.
• If thermostat is set for heatpump with cool changeover, the LEDs will be lit green over the Y and O/B at the ERM.
The switch will close from J to Y and J to O/B at the ERM. If an EIM is wired to the air-handler/furnace, the EIM will
close a switch from Rc to Y, Rc to G, and Rh to O/B. If no EIM is used, the thermostat will close from Rc to Y, Rc to G,
and R to O/B at the subbase.
• If the thermostat is configured for 2 stage compressor, then in addition to the operation listed above, with a call for
stage 2 cooling the LED over Y2 will be lit green on ERM. If an EIM is wired to the air-handler or furnace, the EIM
will close an additional switch from Rc to Y2. If no EIM is used, the thermostat will close an additional switch from
Rc to Y2 at the subbase. The Y2 at EIM or subbase is not connected to some furnace and air-handler models.
ERM USED FOR OUTDOOR UNIT: CALL FOR HEATING (HEATPUMP ONLY)
1. Thermostat is set to heat or auto mode. Heat set-point is above room temperature.
2. Thermostat will show "Heat on" in the display. (the display may show "waiting for equipment" if the minimum com-
pressor off delay has not expired prior to the call for heat. Typically this is up to 5 minutes).
• If thermostat is set for heatpump with cool changeover valve, the LED will be lit green over the Y at the ERM. The
switch will close from J to Y at the ERM. If an EIM is wired to the air-handler/furnace, the EIM will close a switch
from Rc to Y and Rc to G. If no EIM is used, the thermostat will close from Rc to Y and Rc to G at the subbase.
• If thermostat is set for heatpump with heat changeover valve, the LEDs will be lit green over the Y and O/B at the
ERM. The switch will close from J to Y and J to O/B at the ERM. If an EIM is wired to the air-handler/furnace, the
EIM will close a switch from Rc to Y, Rc to G, and Rh to O/B. If no EIM is used, the thermostat will close from Rc to Y,
Rc to G, and R to O/B at the subbase.
• If the thermostat is configured for 2 stage compressor, then in addition to the operation listed above, with a call for
stage 2 heating the LED over Y2 will be lit green on ERM. If an EIM is wired to the air-handler/furnace, the EIM will
close an additional switch from Rc Y2. If no EIM is used, the thermostat will close an additional switch from Rc to
Y2 at the subbase.
ERM USED FOR BOILER: CALL FOR HEATING
1. Thermostat is set to heat or auto mode. Heat set-point is above room temperature.
2. Thermostat will show "Heat on" in the display.
• The LED will be lit green over the second T at the ERM. (The LED over the first T does not light when ERM is used
for a boiler). The dry contact switch will close from T to T at the ERM*. If an EIM is also used, the EIM will close a
switch from Rh to W. If no EIM is used, the thermostat will close from R to W at the subbase. If the thermostat is set
to energize the fan in heat (hydro-coil) the thermostat or EIM will also close from Rc to G.
* you may not be able to measure continuity across this closed switch. See Fig. 18 for troubleshooting heat.
HEATPUMP GOES INTO DEFROST
NOTE: This feature is intended for heatpumps with electric auxiliary heat only. If the thermostat is set for dual fuel, the D
terminal on ERM should not be used, and would have no function other than to light the D LED when the defrost
board is engaged.
1. The heatpump controls when defrost is engaged, not the zone panel.
2. The thermostat subbase or EIM closes from Rc to Y and Rc to G at air-handler with a call for heat. This operation does
not change when the defrost terminal is energized by the ERM.
3. If the heat pump defrost board sends the signal for defrost on the D wire, ERM5220 shows the D LED solid green.
4. Assuming the thermostat is calling for heat, ERM is still closing from the J to the Y. The LED for Y should remain lit.
5. ERM does not change operation of changeover valve when heatpump is in defrost.
6. ERM communicates to thermostat or EIM when the defrost terminal (D) is energized. Thermostat subbase or EIM (if
used) closes additional switch from R (Rh) to AUX to run the electric heat strips. There is not any indication on the
thermostat that it is energizing the AUX contact when the ERM is driving this operation. The thermostat might show
"auxiliary heat on" in the display, but that is due to a demand for auxiliary heat from the thermostat, independent of
what the ERM is doing.
COMPRESSOR FAULT MONITOR ENERGIZES L ON ERM
1. The heatpump compressor fault monitor energizes the L terminal on the ERM. The LED above L is lit green on
ERM5220R.
2. ERM communicates fault to thermostat. Thermostat display shows 1 active alert and says to "press here for more
info". When the customer presses "here", the thermostat says "heat pump needs service".
This does not change the outputs of the thermostat or ERM..
ERM5220R EQUIPMENT REMOTE MODULE
19 33-00205—01