Sequence of Operation
•
R_ _C
units are straight cool, single stage air
conditioners available with electric or hydronic heat.
•
R_ _H
units are limited range, single stage heat pump.
Mechanical compression heating (heat pump mode) is
locked out at outdoor temperatures of approximately
35º F (1.7º C) and below. Below these ambient
temperatures, auxiliary electric or hydronic heat will be
used.
General
Microprocessor controlled unit. Thermostat and control
connections are made to the control board.
Two configuration jumpers are located on the board. See
Figure 9.
• Straight
Cool
units R_ _C, locate jumper on outside two
pins.
• Heat
Pump units R_ _H, locate jumper on inside two
pins.
•
Heat Pump Configuration Jumper is a 3 pin jumper.
Second configuration jumper “TEST” allows for control’s
internal timers to be by-passed for test purposes. Placing
jumper on two pins enables test mode.
Status LED (Light Emitting Diode), LED1 is located
on center of board. Series of blinks communicates
board status. Between blink sequence is separation of
approximately 2 seconds. See Table 1.
Initial Power-Up or Power Restoration
•
When power is applied to the unit, either for the first
time or after a power failure, board initializes itself.
• During initialization, LED1 is lit for approximately 5
seconds.
• Following initialization, a random start timer is
initiated. Timer adds randomly selected 5-120
seconds to start-up sequence, reducing possibility of
multiple units starting at same time.
• Once random start timer has expired, 180 second
Anti-Short Cycle Timer is initiated and Processor
Board Trouble Code LED is set to blink a 2 flash code.
Timer prevents compressor from rapid cycling.
• After Anti-Short Cycle Timer expires, Processor Board
Trouble Code LED is set to blink 1 blink Trouble Code,
indicating normal operation.
R_ _C / R_ _H; Cooling Operation
Unit Mount Controls
• With System Switch [SS] set to “Cool”, and Fan Cycle
Switch [FCS] set to “On” (Continuous Fan Operation),
indoor fan motor starts.
• If Fan Cycle Switch [FCS] is set to “Off” (Cycling Fan
Operation), indoor fan motor starts with call for cooling
from internal thermostat [T’stat].
SEQUENCE OF OPERATION
LED
Indicator
Light
TEST
Configuration
Jumper
Heat
Pump
Configuration
Jumper
Figure 26
- Control Board
Trouble Code
(Blinks)
Status
1
Normal Operation
2
Anti-Short Cycle Timer Active
3
Outdoor Coil Freeze Protection
4
Indoor Coil Freeze Protection
5
Simultaneous “Y” and “W” Call
Table 1 - Status Codes
25
Made in USA
P/N 240010545, Rev. B [10/24/2014
]
