Instructions / Assembly
3
DHM2 DHM HM2 HM LSYSTEM
POWER
RC
R
C
LED On/Off
to terminal
connections on
HVAC equipment
Connect
W/E
W2
Y
Y2
G
O/B
L
DHM
DHM2
HM2
HM
R
C
To Return Air Sensor (RAS) Required
W/E
W2
Y
Y2
G
O/B
L
HM
HM2
DHM
SYS
DRY
SYS
DHM2
RC
RH
R
C
DRY
R and C
from HVAC
Terminal Strip
or System
Transformer
Wire Tie
Wire Tie
MOUNT RETURN AIR SENSOR AND EQUIPMENT CONTROL
IMPORTANT
The RAS monitors temperature of the return air and is needed at
all times for system operation.
Drill 1/4” hole in return air duct at least 18” upstream from
Insert RAS into duct and fasten with two sheet metal screws.
If the system is hydronic, locate return air sensor in conditioned
space.
Return Air Duct
Supply
Duct
Equipment Control
Module
Return
Air Sensor
(Required)
Return Air
Mount Equipment Control Module on wall near HVAC equipment,
or on the air handler. Do not install Equipment Control Module
inside of the HVAC equipment. Use screws to securely fasten
control in place. Do not drill into critical furnace components. Wall
anchors and screws are provided for dry wall mounting (3/16”).
See next page for wiring.
1. Remove the cover from the Equipment Control Module.
2. Plug Return Air Sensor (RAS) lead into return air sensor
connection on the Equipment Control Module .
Route the sensor lead into the wiring channel and out the top
of the control.
3. Use thermostat wire to make the connections from Equipment
Control Module to the HVAC equipment or terminal strip. Strip
the sheath of the wire bundle back approximately 10”.
4. Insert wire bundle into the bottom of Equipment Control
Module. Two slots are provided if more than one bundle of wire
are required.
5. Route two wires from the bundle to the left side of the
Equipment Control Module for terminals R and C.
6. Route the rest of the wires in the bundle to the right side of the
Equipment Control Module and fasten loosely with wire ties.
7. Trim wires to length for each connection required, strip ends
and insert into control quick connect block.
Refer to wiring diagram for terminal functions and wire routing.
Note: Ten (10) feet of wire is supplied with the RAS.