Carrier 48TJ016-028 - Manual (Page 11)

step 8 — Install Gas Piping — Unit is equipped for
use with natui'iil gas. Installation must conform with local
building codes or. in the absence of lociil codes, with the
National Fuel Gas Code. ANSI Z22.3.1.
Install field-supplied manual gas shutoff valve with a Vs-in.
NPT pressure tap for test gage connection at unit. Field gas pip­
ing must include sediment trap and union. See Fig. 1.1.
A WARNING
Do not pressure test gas supply while connected to unit.
Always disconnect union before servicing. Exceeding
maximum manifold pressure may cause explosion and
injuiy.
IMPORTANT: Natural gas pressure at unit gas connec­
tion must not be less than 5.5 in. wg or greater than
1.3.5 in. wg.
Size gas-supply piping for 0.5-in. wg maximum pressure
drop. Do not use supply pipe smiillei' than unit gas connection.
MANUAL SHUTOFF
step 9 — Make Electrical Connections
FIELD POWER SUPPLY — Unit is factoiy wired for volt­
age shown on nameplate.
When instiilling units, provide a disconnect per NEC (Na­
tional Electrical Code) of adequate size (Table 5).
All field wiring must comply with NEC and local
requirements.
Route power ground lines through control box end panel or
unit basepan (see Fig. 4 and 5) to connections as shown on unit
wiring diagram and Fig. 14.
A CAUTION
Tlie correct power phasing is critical in the operation of the
scroll compressor. An incorrect phasing will cause the
compressor to rotate in the wrong direction. This may lead
to premature compressor failure.
A WARNING
Tlie unit must be electrically grounded in accordance with
local codes and NEC ANSl/NFPA 70 (National Fire Pro­
tection Association) to protect against fire and electric
shock.
Field wiring must confirm to temperature limitations for
type “T’ wire. All field wiring must comply with NEC and lo­
cal requirements.
Transformer no. 1 is wired for 230-v unit. If 208/230-v unit
is to be nan with 208-v power supply, the transformer must be
rewired as follows:
1. Remove cap from red (208 v) wire,
2. Remove cap from orange (230 v) spliced wire.
3. Replace orange wire with red wire.
4. Recap both wires.
A CAUTION
Be certain unused wires are capped. Failure to do so may
damage the transformers.
Operating voltage to compressor must be within voltage
range indicated on unit nameplate. On 3-phase units, voltages
between phases must be balanced within 2%.
Unit failure as a result of operation on improper line voltage
or excessive phase imbalance constitutes abuse and may cause
damage to electrical components.
FIELD CONTROL WIRING — Install a Carrier-approved
accessoiy thermostat assembly according to installation in-
stmctions included with accessoiy. Locate thermostat assembly
on a solid interior wall in the conditioned space to sense aver­
age temperature.
Route thermostat cable or equivalent single leads of
colored wire from subbase terminals through conduit in unit to
low-voltage connections as shown on unit label wiring diagram
and in Fig. 15.
NOTE: For wire nans up to 50 ft, use no. 18 AWG (American
Wire Gage) insulated wire (35 C minimum). For 50 to 75 ft,
use no. 16 AWG insulated wire (.35 C minimum). For over
75 ft, use no. 14 AWG insulated wire (35 C minimum). All
wire larger than no. 18 AWG cannot be directly connected at
tlae thermostat and will require a junction box and splice at the
tliermostat.
Set heat anticipator settings as follows:
VOLTAGE W1 W2
208/230,575 0.98 0.44
460 0,80 0.44
Settings may be changed slightly to provide a greater degree
of comfort for a particulai' installation.
LEGEND
EQUIP — Equipment
GND — Ground
NEC — National Electrical Code
TB — Terminal Block
NOTE: The maximum wire size for TB1 is 2/0.
Fig. 14 — Field Power Wiring Connections
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