![](/images/new-backgrounds/1303337/30333715x1.webp)
25HPA6
Time Delays
The unit time delays include:
SFive minute time delay to start cooling or heating operation when there is a call from the thermostat or user interface. To bypass this feature, momentarily short and release Forced
Defrost pins.
SFive minute compressor
STwo minute time delay to return to standby operation from last valid communication (with Infinity only).
SOne minute time delay of outdoor fan at termination of cooling mode when outdoor ambient is greater than or equal to 100_F
(37.78_C).
SFifteen second delay at termination of defrost before the auxiliary heat (W1) is
STwenty second delay at termination of defrost before the outdoor fan is energized (unless fan delay defeated).
SThirty second compressor delay when quiet shift enabled.
SThere is no delay between staging from low to high and from high to low capacity. The compressor will change from low to high and from high to low capacity “on the fly” to meet the demand.
Compressor Operation:
The basic scroll design has been modified with the addition of an internal unloading mechanism that opens a
A single speed, high efficiency motor continues to run while the scroll modulates between the two capacity steps. Modulation is achieved by venting a portion of the gas in the first suction pocket back to the low side of the compressor, thereby reducing the effective displacement of the compressor.
Full capacity is achieved by blocking these vents, thus increasing the displacement to 100%. A DC solenoid in the compressor controlled by a rectified 24 volt AC signal in the external solenoid plug moves the slider ring that covers and uncovers these vents.
The vent covers are arranged in such a manner that the compressor operates at approximately 67% capacity when the solenoid is not energized and 100% capacity when the solenoid is energized. The loading and unloading of the two step scroll is done ”on the fly” without shutting off the motor between steps.
NOTE: 67% compressor capacity translates to approximately 75% cooling or heating capacity at the indoor coil.
The compressor will always start unloaded and stay unloaded for five seconds even when the thermostat is calling for high stage capacity.
MODEL |
PLUG |
UTILITY RELAY * |
UTILITY SIGNAL
OPEN RELAY
MODEL |
PLUG |
LLS |
* SUPPLIED BY UTILITY PROVIDER | Liquid Line Solenoid |
A06525 | A06526 |
Fig. 6 - 2-Stage Control Board
8