Carrier 38AUM Series Installation, Operation & Maintenance Manual page 17

The 38AUMD is a dual-circuit, two-stage cooling unit. Select a two—stage cooling thermostat, with or without
supplemental heating as needed.
Select a thermostat cable or equivalent single leads of different colors with minimum of five leads for 38AUMZ or
six leads for 38AUMD unit. 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.
Control Circuit Wiring — Control voltage is 24 v. See Fig: - Power Wiring Connections 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 — On multi voltage units, check the transformer primary wiring connections. See Fig: -
Control Transformer Wiring 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".
Fig: - Typical Remote Thermostat Connections — 38AUMD
Fig: - Control Transformer Wiring
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