Carrier 50EJQ Installation, Start-Up And Service Instructions Manual page 20

accommodate the Motormaster III accessory. The replace-
ment motor part no. is HD52AK652. The circuit no. 2 OFM
is controlled to shut off at 65 F outdoor air temperature (dur-
ing cooling mode only).
Sensor — Install the sensor for thermistor input control in
the location shown in Fig. 32.
Signal Selection Switch — Remove the cover of the Motor-
master III control. Set the switch to accept the thermistor
sensor input signal. Set the frequency to match the unit power
supply (60 Hz).
Motormaster III Control — The recommended mounting
location is in the indoor fan section, mounted on the panel
that separates the indoor and outdoor sections.
Electrical Connections
To avoid possibility of electrical shock and personal in-
jury, turn off all power to unit before making electrical
connections.
When replacing the OFM, reconnect the black, yellow, and
blue wires form the outdoor fan contactor to the black, yel-
low, and blue wires of the Motormaster III control. Run new
wires from the red, orange, and brown wires to the leads of
the new OFM. Connect the green wire from the control to
ground. See Fig. 33.
Install Accessory Low Ambient Kit — An additional Motor-
master relay, HN61KZ024, will be required so that the fan
motor will operate at low ambients during heating. The elec-
trical connections are made to a socket, HY07RB030. After
the electrical connections, the socket is mounted in the con-
trol box and the relay is inserted into the socket.
Connect one sensor lead to the violet control signal lead
on the Motormaster III controller and to a field-supplied
16 AWG wire with a wirenut. Connect the remaining sensor
lead to the gray control sensor lead on the Motormaster III
controller and to another field-supplied 16 AWG wire with
a wirenut. Route both field-supplied wires through a hole in
the control box. Attach the wires to screw terminals 5 and 9
on the socket. There is a normally open set of contacts
between terminals 5 and 9.
Connect a field-supplied 16 AWG wire to screw terminal
13 on the socket and to QC terminal 2 on the HR2 relay.
Connect a field-supplied 16 AWG wire to screw terminal 14
on the socket and to QC terminal 2 on TB2. The HR2 ter-
minal 2 has 24-volt power when there is a call for heat; this
will then energize the Motormaster relay.
OFC1
11 21
12 22
13 23
HR2
13 13
23
MMR
Fig. 33 — Motormaster III Device Wiring, 50EJQ,EWQ024 and 028
GRA
VIO
BLK RED
MOTOR
MASTER
YEL
III BRN
ACY
BLU
ORN
TB2
14
2
1
BOTH SIDES
0.312 DIA
HOLES
17.167
BETWEEN
HOLES
(TYPICAL)
4.62
NOTE: All dimensions are in inches.
MATERIAL: 20 gage galvanized steel or other non-corrosive
material.
Fig. 31 — Motormaster III Baffle Details
Fig. 32 — Motormaster III Sensor Location
MMR
5 9
MMSN
BLK
1
YEL 2
BLU 3
NOTE: Motormaster Relay part no. is HN61KZ024 with HY07RB030 socket.
20
77.7
CROSS-BREAK
78.7
(Sizes 024,028)
LEGEND
HR — Heater Relay
MMR — Motormaster Relay
MMSN — Motormaster Sensor
OFC — Outdoor Fan Contactor
OFM — Outdoor Fan Motor
TB — Terminal Block
OFM1
GRN YEL
18
61
0.5