A.
Wire 24-v Control Systems
1. Connections to unit
Use No. 18 AWG color-coded, insulated (35° C minimum) wire to make low-voltage connections between thermostat, fan coil unit, and
outdoor unit. If thermostat is located more than 100 ft from unit (as measured along the low-voltage wire), use No. 16 AWG color-coded,
insulated (35° C minimum) wire. All wiring must be separated from line voltage power leads. Refer to outdoor unit wiring instructions for
additional wiring procedure recommendations.
2. Transformer
Transformer is factory wired for 230-v operation. For 208-v applications, disconnect black wire on transformer 230-v terminal and
reconnect it to 208-v terminal. (See Fig. 5.) The secondary circuit of transformer is protected by a 5-amp fuse mounted on PCB.
CAUTION: On FA, FB, FC, FH, FX, or PF1MNB018-070 if W2, W3, and E are individually connected on any 3 stage
heater (18, 20 24, 30 kw), as with outdoor thermostats or any other situation, an emergency heat relay must be used. This
relay is in kit Part No. KHAOT0201SEC and is normally used with kit Part No. KHAOT0301FST for 2 outdoor thermostat
systems.
Fig. 3—Installation of Circuit Breaker Model Heater
A90153
SINGLE
CIRCUIT
GROUND
FAN
COIL
BLOWER
SHELF
MOUNTING
BRACKET
COVER
PLATE
WIRE ROUTING
LOAD SIDE
LINE SIDE
CONNECTION
DUAL CIRCUIT
GROUND LUG
WIRE TIE
(REMOVE ON
LARGER UNITS)
WIRES TO
HEATER
→
Fig. 4—Installation of Window Bezel for Circuit Breaker Model Heater
A03069
—5—
