Instruction manual

3. Disconnect power leads, pigtail leads (black and yellow), fan leads (yellow, red, blue, and black), primary and secondary transformer leads,
and all low-voltage control wires. Remove existing printed-circuit board (PCB). Remove existing heater package or cooling control plate
from fan coil. (See Fig. 1.)
4. Insert heater assembly into front of fan coil until element rods engage holes in heat shield.
5. Attach heater control plate to fan coil using 2 screws. (See Fig. 1.)
PROCEDURE 2—ATTACH FUSE BOX
For 15- and 20-kw fused heater:
1. After installing heater assembly, attach fuse assembly to side of fan coil unit by inserting fuse box tab between insulation and left side of
unit and fan deck, if necessary.
2. Mount front of assembly to side flange with 2 screws provided. On fan coil units size 042 and larger, remove wire tie that shortens wire
length between heater and fuses.
3. Close cover by engaging dimples in fuse box. (See Fig. 1.)
PROCEDURE 3—PRINTED-CIRCUIT BOARD (PCB) AND BRACKET INSTALLATION
CAUTION: Avoid direct contact with the PCB. The PCB is a static sensitive device. Handle by the sheet metal bracket
only. Static discharge can damage the PCB.
Fig. 1—Installation of Heater Package and Printed-Circuit Board
A94126
COVER PLATE
OR
KNOCKOUT
FUSE BOX
DIMPLE
FUSE BOX TAB
SINGLE-CIRCUIT
GROUND LUG
INSERT FUSE
BOX TAB HERE
DUAL-CIRCUIT
GROUND LUG
FUSE COVER
WIRE TIE
(REMOVE ON
LARGE FAN COILS)
HEATER/CUTOUT
COVER
SLOTS
Table 2—Minimum Motor Low-Speed Tap Selection
FAN COIL HEATER KW
FA4, FB4, FC4 FX4 10 15 20
018 — Med* — —
024 — Low Med† —
030 030 Low Low Med†
033 — Low Med† Low†
036 036 Low Low Low†
038 — — Low† Low†
042 042 — Low Low†
048 048 — Low Low†
060 060 — — Low†
070 — — — Low†
* High speed with 208v.
† Requires a minimum 1-in. clearance to combustible materials for the first 36 in. of ductwork. On 2-speed fan models, low speed may be used in place of medium (Med)
speed.
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