ION SYST0101CW Installation Instructions Manual page 10

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DX+ — Green = Data A

DX- — Yellow = Data B

C — White = 24VAC (Com)

R — Red = 24VAC (Hot)

It is not mandatory that the above color code be used, but each communications connector in the

system MUST be wired consistently.

NOTE: Some outdoor units, typically those with multiple compressor stages, provide their own

low-voltage power source and do not require the "C" (24VAC common) and "R" (24VAC

power) connections. See the outdoor unit installation instructions for more information.

ELECTRICAL OPERATION HAZARD

Failure to follow this warning could result in personal injury or death.

Before installing, modifying, or servicing system, the main electrical disconnect switch must

be in the OFF position. There may be more than one disconnect switch. Lock out and tag

switch with a suitable warning label.

4.4.1. Shielded Wire and Communication Bus Configuration

If the thermostat wiring will be located near or in parallel with high voltage wiring, radio, TV or

Ethernet wiring, then four conductor, twisted-pair, shielded cable can be used to reduce or

eliminate potential interference. The shield wire should be connected to the C terminal, or

ground, AT THE INDOOR UNIT, ONLY. The shield wire should NOT be connected to any

terminal at the Ion System Control. Connecting the shield to ground at both ends can cause

current loops in the shield, reducing shield effectiveness.

Connect one pair of the two-pair (minimum) cable to the DX+ and DX- communication

terminals, and another pair to the C and R terminals at both ends of the cable. The shield wire

should ONLY be connected at the indoor equipment ground or C terminal. Note that some

outdoor units only require the DX+ and DX- connections. See the outdoor unit installation

instructions for more information.

WARNING

DX+ DX-

A03193I