Carrier 50BA - Manual (Page 4)

Air-Cooled Condenser Connections (50BB Con­
denserless Units) — Install air-cooled condenser in
accordance with Installation Instructions shipped
with condenser. Consult Carrier System Design
Manual for standard refrigerant piping techniques.
Connection locations of liquid and hot gas service
lines are shown in Fig. 1 and 2. Condenserless units
are shipped with a holding charge (Table 1). After
refrigerant connections are made, evacuate, leak
test and charge system as described in Charging the
System.
Condensate Drain — Install a trapped condensate
drain line at unit drain connection (Fig. 1 or 2).
Figure 3 shows proper trap design.
Determine design negative static pressure. This
pressure is not the same as fan total pressure,
which includes pressure losses downstream as well
as upstream of the indoor air fan. Always assume
the worst conditions, such as having return air
filters clogged with dirt. Differential 1 must be
equal or larger than negative static pressure at
design operating conditions. Store enough water to
prevent losing the trap seal (Differential 2). This
must be equal to or larger than one-half the
maximum negative static pressure. When the fan
starts. Differential 3 is equal to the maximum
negative static pressure.
Do not use drain line smaller than size shown in
Fig. 1. Pitch drain downward to open drain or
sump. Fill trap with water to make an air seal.
Observe all local sanitary codes.
Power Supply Wiring — Unit is factory wired for
voltage shown on unit nameplate. Provide an
adequate fused disconnect switch within sight of
unit and out of reach of children. Provision for
locking switch open (off) is advisable to prevent
power from being turned on while unit is being
serviced, especially if disconnect switch is not
visible from unit. Disconnect switch, fuses and
field wiring must comply with National Electrical
Code and local requirements.
Install strain relief and connector in unit side
panel and control box electrical connection open­
ings in accordance with local codes. See Fig. 1.
Route power wires to power terminals as shown on
unit label diagram and Fig. 4.
Affix crankcase heater sticker in instruction
packet to unit disconnect switch (50BB units).
Voltage to unit during operation must be
within voltage range indicated on unit nameplate
and Table 2. Table 2 also contains information
regarding wire and fuse sizes required. Power
phases must be balanced within 2%. Contact local
power company for correction of improper voltage
or phase unbalance. Operation of unit on improper
line voltage or with excessive phase unbalance may
damage unit electrical components.
Air-Cooled Condenser Control Wiring — Connect
outdoor fan relay as shown on unit label diagram
and Fig. 4. Outdoor fan motor must not exceed
1/2 hp at 125 or 250 volts.
Remote Thermostat Installation — Disconnect the
factory-installed thermostat (230-volt) and install
remote thermostat (24-volt) as follows;
1. Obtain these field-supplied components:
Transformer (Carrier Part No. HT01AA140)
Remote Thermostat Relay (Carrier Part No.
HN61KJ007)
Remote Thermostat, 24-volt (type as desired)
Suitable lengths of Class II wire and connectors
as required.
Study Fig. 4.
Disconnect at compressor contactor terminal
C-DU2 the red wire between C-DU2 and the
unit thermostat terminal R. Tape end of loose
wire and tape wire to side of unit.
Install transformer and remote thermostat relay
in unit main control box as shown.
5. Locate 24-volt thermostat in conditioned space
in accordance with instructions packed with
thermostat. Use one thermostat per unit on
multiple unit installations.
6. Connect wires in accordance with all applicable
codes. Accessory electrical connection opening
in unit side panel and control box is shown in
Fig. 1.
2
.
3.
4.
FAN RUNNiNG AND CONDENSATE ORAiNiNG
m
0
Fig. 3 — Condensate Drains