Limit Control; Cooling Section Operation; Cooling Mode; Continuous Fan Mode - Rheem H2AC Installation Instructions Manual

LIMIT CONTROL

The supply air high temperature limit cut-off is set at the factory and cannot be adjust-
ed. It is calibrated to prevent the air temperature leaving the furnace from exceeding
the maximum outlet air temperature.
WARNING
DO NOT JUMPER THIS DEVICE! DOING SO CAN CAUSE A FIRE OR EXPLO-
SION RESULTING IN PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
IMPORTANT: Replace this control only with the identical replacement part.
VII. COOLING SECTION OPERATION

COOLING MODE

NOTE: For this two-stage cooling and potable water heating unit, the water heating
section is located on the rear (second stage) refrigerant system. Because of the pres-
ence of the eSYNC control, the unit will always start the rear compressor first (lag
mode is permanently engaged), and then a Y2 call will energize the front compressor.
A. Call for first stage cooling
1. Zone thermostat contacts close and a call for cooling is initiated.
2. Inputs 'Y1' and 'G' to the control are energized.
3. Control senses 'Y1' and 'G'. After 1 sec. delay, control energizes indoor blower
and first stage compressor.
4. Control enters normal operating loop where all inputs are continuously checked.
5. Zone thermostat is satisfied.
6. Control de-energizes indoor blower relay after 80 second indoor blower delay off.
7. Control in the standby mode with solid red LED.
B. Call for second stage cooling. After first stage cooling established: starting
from A4.
1. If a call for second stage cooling is initiated after a call for first stage cooling is
established, the control energizes Y2 and energizes the second stage compres-
sor.
2. Control enters normal operating loop where all inputs are continuously checked.
C. Second stage satisfied: first stage still called for: starting from B2.
1. Y2 is de-energized and second stage compressor is de-energized.
D. First stage and second stage called simultaneously.
1. Zone thermostat contacts close, a call for first and second stage cooling is initiat-
ed.
2. Inputs Y1, Y2 and G to the control are energized.
3. Control senses Y1, Y2 and G, after 1 second delay, control energizes indoor
blower, first and second stage compressor are energized.
E. First stage and second stage removed simultaneously.
1. Upon a loss of Y1 and Y2 each compressor is de-energized. Control de-energizes
indoor blower relay after 80 second indoor blower delay off.
2. Control in the stand by mode with solid red LED.

CONTINUOUS FAN MODE

A 'G' input only indicates a zone thermostat call for continuous indoor blower operation.
VIII. SYSTEM OPERATING INFORMATION

ADVISE THE CUSTOMER

1. Change the air filters regularly. The heating system operates better, more efficiently
and more economically.
2. Arrange the furniture and drapes so that the supply air registers and the return air
grilles are unobstructed.
37