Carrier 38AUZ User Manual

Page 12

Fig. 11 — Weatherproof Cover Installation

All Units —
Voltage to compressor terminals during operation must be

within voltage range indicated on unit nameplate. See Table 5.

On 3-phase units, voltages between phases must be balanced

within 2% and the current within 10%. Use the formula shown

in the legend for Table 5, Note 5 (see page 13) to determine the

percent of voltage imbalance. Operation on improper line

voltage or excessive phase imbalance constitutes abuse and

may cause damage to electrical components. Such operation

would invalidate any applicable Carrier warranty.
Field Control Wiring — Unit control voltage is 24 v. See

Fig. 8 and the unit’s label diagram for field-supplied wiring

details. Route control wires through the opening in unit’s end

panel to the connections terminal board in the unit’s control

box.
The 38AUZ unit requires an external temperature control

device. This device can be a thermostat (field-supplied) or a

PremierLink controller (available as factory-installed option or

as field-installed accessory, for use on a Carrier Comfort

Network or as a stand alone control).
Thermostat —
Install a Carrier-approved accessory thermostat according to

installation instructions included with the accessory. For

complete economizer function, select a two—stage cooling

thermostat. Locate the thermostat accessory on a solid wall in

the conditioned space to sense average temperature in

accordance with the thermostat installation instructions.
If the thermostat contains a logic circuit requiring 24-v power,

use a thermostat cable or equivalent single leads of different

colors with minimum of four leads. If the thermostat does not

require a 24-v source (no “C” connection required), use a

thermostat cable or equivalent with minimum of three leads.

Check the thermostat installation instructions for additional

features which might require additional conductors in the

cable.
For wire runs up to 50 ft. (15 m), use no. 18 AWG (American

Wire Gage) insulated wire (35°C minimum). For 50 to 75 ft.

(15 to 23 m), use no. 16 AWG insulated wire (35°C minimum).

For over 75 ft. (23 m), use no. 14 AWG insulated wire (35°C

minimum). All wire sizes larger than no. 18 AWG cannot be

directly connected to the thermostat and will require a junction

box and splice at the thermostat.
PremierLink (accessory installation) – Refer to Form 33CS-

58SI for details on connecting the PremierLink controller and

its various sensors.

Fig. 12 — Typical Remote Thermostat Connections

CONTROL CIRCUIT WIRING — Control voltage is 24 v.

See Fig. 8 and the unit’s label diagram for field-supplied

wiring details. Route control wires through the opening in

unit’s end panel to the connection in the unit’s control box.
CONTROL TRANSFORMER WIRING (38AUZ07-14

Units)

—

On multivoltage units, check the transformer

primary wiring connections. See Fig. 13 or refer to the unit’s

label diagram.
If the unit will be operating at 208-3-60 power, remove the

black wire (BLK) from the transformer primary connection

labelled “230” and move it to the connection labelled “208”.

See Fig. 13.

Fig. 13 — Control Transformer Wiring

RECEPTACLE
NOT INCLUDED

COVER – WHILE-IN-USE
WEATHERPROOF

BASE PLATE FOR
GFCI RECEPTACLE

O/B/Y2

(Notes 1, 2)

(Note 3)

Note 1: Typical multi-function marking. Follow manufacturer’s configuration

instructions to select Y2.

Note 2: Y2 to economizer required on single-stage cooling units when

integrated economizer function is desired

Note 3: Connect only if thermostat requires 24-vac power source.

Field Wiring

Central

Terminal

Board

T–STAT