Installation Manual

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Humidifier Connection

A 24VAC bypass or fan powered humidifier may be installed.

NOTE: Do Not Use a traditional humidistat to control humidi-

fier operation. If a humidifier is installed, let the Observer

Control operate humidifier.

Bypass Humidifiers

A bypass humidifier is normally wired directly to the furnace

or fan coil HUM and 24VAC COM terminals. The Observer

Control will automatically energize the HUM output during a

call for humidification. See the humidifier installation instruc-

tions for the proper wiring procedure for each particular hu-

midifier.

Fan Powered Humidifiers

Most fan powered humidifiers produce internal 24VAC in or-

der to energize upon a switch or contact closure. For this

application, a 24VAC N.O. Isolation Relay (DPST) MUST be

used to prevent mixing the internal humidifier power with the

indoor equipment transformer. Applying 24VAC isolation re-

lay coil to f urnace or fan coil HUM and COM terminals will

allow the Observer

Control to automatically energize the

HUM output during a call for humidification. The N.O. relay

contacts will be used to energize the humidifier. See fan

powered humidifier installation instructions for m ore details.