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C09022
Fig. 14 -- Weatherproof Cover Installation
All Units —
Voltage to compressor terminals during operation must be
within voltage range indicated on unit nameplate. See
Table 7. 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 7, Note 4 (see
page 15) 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 —
38AUZ unit control voltage is 24 v. See Fig. 20 for typical
field control connections and the unit’s label diagram for
field-supplied wiring details. Route control wires to the
38AU unit through the opening in unit’s end panel to the
connections terminal board in the unit’s control box.
Remainder of the system controls connection will vary
according to the specific construction details of the indoor
section (air handler or packaged fan coil). Fig. 15 depicts
typical connections to a Carrier 40RU fan coil unit. Plan
for field connections carefully and install control wiring
correctly per the project plan. Additional components and
supplemental transformer accessory may be required.
The 38AUZ unit requires an external temperature control
device. This device can be a thermostat (field-supplied) or
a PremierLink controller (available as a 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.
Locate the thermostat accessory on a solid wall in the
conditioned space to sense average temperature in
accordance with the thermostat installation instructions.
The 38AUZD/E08 unit is a single--circuit, two--stage
cooling unit. Select a two--stage cooling thermostat, with
or without supplemental heating, as needed.
(Note 1)
(Note 2)
(Note 2)
Note 1: Connect only if thermostat requires 24-vac power source.
Note 2: Connect W1 and W2 if supplemental heaters are installed
Field Wiring
C14292
Fig. 15 -- Typical Remote Thermostat Connections
Select a thermostat cable or equivalent single leads of
different colors with minimum of five leads for
38AUZD/E08 units. 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-68SI (or later) for details on connecting the
PremierLink controller and its various sensors.
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. 16.
C10079
Fig. 16 -- Control Transformer Wiring
38A
U