Field Installed Electric Heater Kits - Bosch DX Series Installation And Maintenance Manual

12 Unitary Air Handler DX and Hydronic Series
Follow the steps below to connect the power
supply wires.
Single Circuit line Wiring Connections
1. Remove the blower and control box access
panel (door).
2. Remove the control box cover.
3. Install the cable connectors on the 7/8" dia
holes on the left side and top right side of the
control box.
4. Strip ½" of the insulation on the end of each wire.
5. Insert the wires through the holes in the casing
and through the cable connectors.
6. Insert the black wire into the L1 screw terminal
on the first circuit breaker from the top and
tighten the set screw to clamp down on the wire.
7. Insert the white or red wire into the L2 screw
terminal on the first circuit breaker down from
the top and tighten the set screw to clamp
down on the wire.
8. If you are using a single circuit for a 15kW or
20kW model you will need to install a black
jumper wire from the L1 terminal on circuit
breaker #1 to the L1 terminal on circuit breaker
#2 and a white or red jumper wire from the L2
terminal on circuit breaker #1 to the L2 terminal
on circuit breaker #2.
9. Insert the green wire into the ground lug and
tighten the set screw.
Dual Circuit line Wiring Connections:
15kW or 20kW Models
10. You will need to insert the black wire from the
second power supply into the L1 screw terminal
on the second circuit breaker down from the
top and tighten the set screw to clamp down on
the wire.
11. You will need to insert the white or red wire
from the second power supply into the L2
screw terminal on the second circuit breaker
down from the top and tighten the set screw to
clamp down on the wire.
12. You will need to insert both green wires into the
ground lug and tighten the set screw.
6720220327
13. Tighten the screws on the cable connectors
The 15kW and 20kW models may be connected to a
single or dual branch circuit.
Caution
Field wiring must use copper conductors only.
Tighten all wire connectors. Take care not to
damage heater ceramic insulators on electric heat
models. For correct field wire size see unit
nameplate and field wiring table inside electrical
compartment door or on blower housing. Use 75°C
wire in unit wiring compartment.
Field wiring must comply with local and national
electric codes. Power to the unit must be within the
operating voltage range indicated on the unit
nameplate or on the performance data sheet.
Caution
Caution
Properly sized fuses or HACR circuit breakers must be
installed for branch circuit protection. See unit
nameplate for maximum fuse or breaker size. The unit
is provided with a concentric knock-out, route power
supply wiring through this opening. Always connect
the ground lead to the grounding lug provided.
fIElD INStAllED ElECtRIC HEAtER
KItS
This instruction covers the physical installation of
the following electric heat kits on the DX and HY
series models. Refer to Table in back of this manual
for electrical specifications.
Subject to change without prior notice
Electric Heater Kits
until the power supply wires are securely
fastened to the connector.
Refer to the NEC National Electrical Code (NFPA
70) or the Canadian Electrical Code, Part I (CSA
C22.1) and local codes for wiring material
requirements.
See unit for complete wiring diagram located
inside electrical compartment door or on blower
housing.
Operation of unit on improper line voltage or with
excessive phase imbalance will be hazardous to
the unit, constitutes abuse and may void the
warranty.
Revised 11-11