Unit installation

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The BSK field installed kits include the sheet metal enclo-
sure with cover, wire harness, boilerless system board, aux-
iliary relay, and water temperature sensor. When used, one
BSK is required for each unit. To use the BSK kit you attach
the sheet metal enclosure to the unit, route the 4-wire har-
ness through knockouts and connect to the Mark IV/AC
board, mount and connect and insulate the water tempera-
ture sensor on the water supply line, and then connect the
duct heater control contacts to the duct heater control
circuit.
If night setback (U-terminal) is used, the duct heater will
respond to the occupied W1 thermostat signal. The load
shed input (L-terminal) cannot be used for other control
functions when being used with the BSK.
The BSK is a DC voltage device, when the BSK is used the
thermostat must be wired for VDC operation, one example
is provided below (bottom of page). This example is for a 2-
circuit WSHP, R1 is a field supplied 24vdc relay. R1 is not
required on 1-circuit units.
The BSK option for use with the Mark IV/AC con-
trol board provides the capability to control a
remote duct heater. The duct heater must be pro-
vided with a low voltage control circuit that only
requires a set of dry contacts for operation.
The contacts shown on the Boilerless System
board (terminals 1, 2, and 3) are used to control
the remote duct heater, the N.O. contacts will
close on a call for duct heater heat.
POT1 provides a means to manually adjust the
water temperature setpoint (adjustment range is
43
O
F to 60
O
F). The Normal/Override switch pro-
vides a means to manually force electric heat to
always be used in place of heat pump heat when
in the override position (default position is normal
- heat pump heat).
When the water temperature drops below the
value of POT1, then the duct heater will be used
instead of heat pump heat on a call for heat from
the low voltage thermostat (not included).
Boilerless System Kit (BSK) – P/N 061251501 for sizes 070 - 120
RD
1
2
3
Auxiliary Relay
Orange
Yellow
White
12345
RD
BR
WH
OR
OR
WH
WH
YE
GR GR
BK
WH
RD
OR
Normal
Override
Pot 1
Boilerless
System
Board
43 Ohm
4-pin
Plug
Water
Temperature
Sensor
Wire Ends to be Field
Connected to the
Mark IV/AC Board
Signal to remote
duct heater
control circuit
9.66
(245 mm)
(007 – 042)
14.50
(368 mm)
(048 – 060)
6.5 (165 mm) (007 – 042)
4.12 (105 mm) (048 – 060)
1.75
(44.5 mm)
OW2GW1Y1 F E L U A P V R C
Thermostat Terminals
WSHP Mark IV/AC Board Low
Voltage Terminal Strip
Strip
RCW1Y1 W2 Y2 G
OW2GW1Y1 F E L U A P V R C
WSHP Mark IV/AC Board Low
Voltage Terminal Strip
Strip
OR
BR
RD
WH
R1
+
43 Ohm
R1