Carrier 50DK034, Installation Instructions Manual

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16. Remove the end covers from the unit heater housing.
17. Install the rear casing (item 4) on the heater housing as
shown in Fig. 2.
18. Install connector(s) (item 16) and plug button(s)
(item 14) on front casing (item 3). Follow the informa-
tion in Fig. 7 - 13 for proper location and quantity to be
used.
19. Feed the electric heat package power wires through the
appropriate set of connector(s) on the front casing as shown
in Fig. 7 - 13.
20. Locate the two BLACK wires coming off the control
wire plug and feed them through the middle connector
on the front casing. Route these two wires to the back
of the electric heat package and connect them to Limit
Switch #1. On 108 kW packages (Model 50DJ only) the
2 RED wires coming off the electric heat control box
bottom should be fed through the end connector on the
front casing, routed to the back of the heater package
and connected to Limit Switch #2. Fasten the limit switch
wires to the side of the heater package using wire ties
(item 13) and screws (item 10) (see Fig. 3).
21. Insert electric heat package into heater housing as shown
in Fig. 3. Make sure the back end of the heater package
is flush with the back end of the heater housing. Fasten
electric heat package to the unit heater housing using
screws (item 11). Heater housing fastening holes are shown
in Fig. 2.
22. Fasten the front casing to the heater housing and elec-
tric heat package using screws (item 11).
23. Secure the power harness coming out of the electric heat
package at each of the connectors using varnish cloth
(item 12).
24. Route the power wire harness coming out of the electric
heat package to the electric heat control box and feed
them through the appropriate set of connectors as shown
in Fig. 7 - 13.
25. Connect the ring terminals on the harness to the
appropriate contactor as shown in Fig. 7 - 13. Using var-
nish cloth (item 12) secure the harness(es) at the
connectors.
26. Check that all wiring connections are tight.
27. Fasten the front and rear covers (item 19) to the front
and rear casings respectively as shown in Fig. 2 and 3.
28. Dress the power and control wire harness coming out of
the electric heat package using wire ties (item 13).
29. Check that the supply power wiring is sufficient to handle
the load. The unit informative plate has the necessary
data for determining this. The upper section of the in-
formative plate has the MCA (Minimum Circuit Amps)
and MOCP (Maximum Overcurrent Protection) values
for the cooling portion of the unit. The lower section
has the same information for the heating section.
30. Match the accessory package 50DJ901T model num-
ber on the accessory heater packing crate with one of
the accessory model numbers from the lower portion of
the informative plate to determine suitability of power
wiring for handling the unit electrical load. Once the heater
package has been identified, mark the appropriate space
on the lower section of the informative plate.
UNITS 50DJ ONLY
31. Note the MCA and MOCP values for the heater package
and connect properly sized power wiring. Reconnect origi-
nal wires if suitable. Replace main control box access
covers. Replace all panels and door frames removed dur-
ing installation. Close and secure main control box ac-
cess doors as well as any others that are open.
32. Apply power to unit. Set thermostat to call for heat, and
check heating effect at supply air ducts.
UNITS 50DK ONLY
IMPORTANT: See Fig. 5 and 14 and locate DIP (Dual
Inline Package) switch 4 on the microprocessor board
in the main unit control box. Put this switch in the ON
position. Unit will not go into the heating mode if this
switch is not put in the ON position.
33. Note the MCA and MOCP values for the heater package
and connect properly sized power wiring. Reconnect origi-
nal wires if suitable. Replace all panels and door frames
removed during installation.
34. Locate the accessory board in the main control box and
set potentiometer P6 to a temperature setting that is at
least 5°F or more higher than the return air temperature.
This must be done because the unit will not go into the
heating mode unless the return air temperature is at least
5°F or more below the warm-up set point, P6. Apply
power to the unit. After the unit completes its 2-minute
initialization mode, unit should start in the heating mode.
Check supply air ducts for heating effect.
IMPORTANT: It is imperative that a field-supplied
switch be provided to drive the room air terminals
fully open when the unit is in the heating mode.
Connections are provided in the main unit control
box and the wiring connections are shown on the
unit label diagram located on the back side of one
of the main control access doors.
35. Replace main unit control box access cover. Close and
secure main control box access door as well as any oth-
ers that are open.
UNITS 50NK ONLY
36. Note the MCA and MOCP values for the heater package
and connect properly sized power wiring. Reconnect origi-
nal wires if suitable. Replace all panels and door frames
removed during installation.
37. Locate the Local Interface Device (HSIO) in the main
control box (see Fig. 6) and set the MWS (Morning
Warm-up Set point) to a temperature setting that is at
least 5°F or more higher than the return air temperature.
This must be done because the unit will not go into the
heating mode unless the return air temperature is at least
5°F or more below the warm-up set point, MWS. Apply
power to the unit. After the unit completes its 3-minute
initialization mode, unit should start in the heating mode.
Check supply air ducts for heating effect.
IMPORTANT: It is imperative that a field-supplied
switch be provided to drive the room air terminals
fully open when the unit is in the heating mode.
Connections are provided in the main unit control
box and the wiring connections are shown on the
unit label diagram located on the back side of one
of the main control access doors.
38. Replace main unit control box access cover. Close and
secure main control box access door as well as any oth-
ers that are open.
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