6
Thermostat Second Stage Cooling Wiring
This Comfort Alert module requires a two stage thermostat to operate properly. The
Y2 thermostat wire coming into the outdoor unit should be connected to the Y2 input
on Comfort Alert.
While the compressor is running, Comfort Alert will provide power to the second stage
cooling solenoid inside the compressor after Y2 has been energized for 5 seconds.
Whenever the compressor is not running, Comfort Alert will not power the solenoid,
regardless of the state of Y2. If Alert codes 1 or 9 appear while the compressor is
running, Comfort Alert will turn off the solenoid to prevent solenoid damage from
overheating conditions.
L Terminal Wiring
The L connection is used to communicate Alert codes to compatible White-Rodgers
thermostats. The L terminal of the thermostat should be connected directly to the Comfort
Alert L terminal.
On select White-Rodgers thermostats, an icon on the thermostat display will fl ash at
the same rate as the Comfort Alert yellow Alert LED. An advanced option on these
thermostats is to lock out the compressor when certain Alert codes are detected indicating
impending compressor damage. Refer to White-Rodgers thermostat manuals for more
information.
DC SOL Connection
The two pin DC SOL connector provides a connection to the Copeland UltraTech
second stage compressor solenoid. This solenoid is internal to the compressor. This
24VDC solenoid will not operate properly if 24VAC is applied to the compressor solenoid
terminals.
To reduce the VA load of the solenoid on the system, Comfort Alert uses a phase control
method to reduce the DC voltage to the solenoid to the minimum level required to keep
the solenoid pulled in. As the 24VAC supply voltage varies, Comfort Alert intelligently
changes the solenoid DC voltage supply to minimize power consumption. A voltmeter
attached to the DC SOL output will measure 4-18VDC, when solenoid should be
energized, depending on the level of the 24VAC supply.
