Electrical Connections - Lennox Merit Series13HPD Units Installation Instructions Manual

Electrical Connections

NOTE − 24VAC, Class II circuit connections are made in
the low voltage junction box
NOTE − Units are approved for use only with copper
conductors.
NOTE − A complete unit wiring diagram is located inside
the unit control box cover.
NOTE − To facilitate conduit, a hole is in the bottom of the
control box. Connect conduit to the control box using a
proper conduit fitting.
Refer to the indoor unit installation instruction for additional
wiring application diagrams and refer to unit nameplate for
minimum circuit ampacity and maximum overcurrent
protection size. Figures 21 and 22 illustrate typical outdoor
unit wiring diagrams for the 13HPD series heat pumps.
S
In the U.S.A., wiring must conform with current local
codes and the current National Electric Code (NEC).
S
In Canada, wiring must conform with current local codes
and the current Canadian Electrical Code (CEC).
WARNING
Electric Shock Hazard. Can cause
injury or death.
Line voltage
components on units with single-pole
contactors, even when unit is not in
operation!
Unit may
supplies.
electric
opening access panel.
Unit must be grounded in accordance
with national and local codes.
WIRING CONNECTIONS
1. Install line voltage power supply to unit from a properly
sized disconnect switch. Any excess high voltage field
wiring should be trimmed or secured away from the
low voltage field wiring.
2. Ground unit at unit disconnect switch or to an earth
ground.
NOTE − For proper voltages, select thermostat wire gauge
per the following table:
Table 5. Wire Run Lengths
Wire run length AWG #
Less than 100 feet (30 m) 18
More than 100 feet (30 m) 16
3. Connect conduit to the unit using provided conduit
bushing.
505361M 09/07
is present at
have multiple power
Disconnect all remote
power supplies before
Insulation type
Color−coded with a minimum
temperature rating of 35
4. Install room thermostat (ordered separately) on an
inside wall approximately in the center of the
conditioned area and five feet (1.5 m) from the floor.
It should not be installed on an outside wall or where
it can be affected by sunlight, drafts or vibrations.
5. Install low voltage wiring from outdoor to indoor unit
and from thermostat to indoor unit as illustrated in
figures 21 and 22.
6. Do not bundle any excess 24VAC control wire inside
control box. Run control wire through installed wire tie
and tighten wire tie to provided low voltage strain relief
and to maintain separation of field installed low and
high voltage circuits.
Thermostat
24V POWER
R
COMMON
C
1ST STAGE
W1
AUXILIARY HEAT
INDOOR BLOWER
G
REVERSING VALVE
O
all
COMPRESSOR
Y1
(SOME CONNECTIONS MAY NOT APPLY. REFER TO SPECIFIC
THERMOSTAT AND INDOOR UNIT.)
Figure 19. Outdoor Unit and Blower Unit Thermostat
Thermostat
24V POWER
R
COMMON
C
EMERGENCY
E
HEAT
1ST STAGE
W1
AUXILIARY HEAT
INDOOR BLOWER
G
REVERSING VALVE
O
COMPRESSOR
Y1
(SOME CONNECTIONS MAY NOT APPLY. REFER TO
º
C.
SPECIFIC THERMOSTAT AND INDOOR UNIT.)
Figure 20. Outdoor Unit and Blower Unit Thermostat
Designation (with Emergency Heat)
Page 12
Indoor Unit Outdoor Unit
24V POWER
R
COMMON
C
C
1ST STAGE
W1
W1
AUXILIARY HEAT
W2
W3
G
Y1
Designation
Indoor Unit Outdoor Unit
24V POWER
R
R
COMMON
C
C
1ST STAGE
W1 W1
AUXILIARY HEAT
W2
W3
G
O
Y1
R
O
EMERGENCY
HEAT RELAY
OUTDOOR
THERMOSTAT