Rj Series Controls - Premier Microprocessor - Johnson Controls RJ H Series Installation Operation & Maintenance

RJ SERIES INSTALLATION MANUAL

RJ Series Controls - Premier Microprocessor

Standard Premier Microprocessor
The Premier control system is a microprocessor-based printed
circuit board conveniently located in the unit control box for
accessibility. The microprocessor control is specifically designed
for the RJ Series heat pumps and integrate single speed and
dual capacity compressors, variable speed ECM fan motors and
advanced features needed in geothermal applications. All ECM
airflow selections are conveniently configured on the control via
DIP switches. The microprocessor provides control of the entire
unit as well as outputs for status modes, faults, and diagnostics.
Removable low voltage thermostat terminal strips provide
convenient field connections. LEDs are located on the front of the
cabinet for quick inspection without removing any access panels.
Startup
The unit will not operate until all the inputs and safety controls are
checked for normal conditions. At first power-up, a four minute
delay is employed before the compressor is energized.
Component Sequencing Delays
Components are sequenced and delayed for optimum space
conditioning performance.
Accessory Relay
An accessory relay on the control board allows for field connection
of solenoid valves, electronic air cleaners, etc. The accessory relay
has a normally open output and a normally closed output.
Short Cycle Protection
The control employs a minimum "off" time of four minutes to provide
for short cycle protection of the compressor.
Condensate Overflow Protection
The control board incorporates an impedance sensing liquid sensor
at the top of the drain pan. Upon a continuous 30-second sensing
of the condensate, compressor operation is suspended (see Fault
Retry), and the condensate overflow lockout LED begins flashing.
Shutdown Mode
A 24VAC common signal to the "shutdown" input on the control
board puts the unit into shutdown mode. Compressor, hot water
pump and fan operation are suspended.
Safety Controls
The control receives separate signals for a high pressure switch
for safety, a low pressure switch to prevent loss of charge damage,
and a low suction temperature thermistor for freeze sensing. Upon
a continuous 30-second measurement of the fault (immediate
for high pressure), compressor operation is suspended, the
appropriate lockout LED begins flashing. (Refer to the "Fault Retry"
section below).
Testing
The control allows service personnel to shorten most timing delays
for faster diagnostics.
Fault Retry
All faults (except for low RPM faults with the ECM2 fan motor) are
retried twice before finally locking the unit out. An output signal is
made available for a fault LED at the thermostat. The "fault retry"
feature is designed to prevent nuisance service calls.
Diagnostics
The control board allows all inputs and outputs to be displayed on
the LEDs for fast and simple control board diagnosis.
Resistance Heat Control (208-230 Units)
The electric heat control module contains the appropriate high-
voltage control relays. Control signals energize the relays in the
proper sequence, and the LED display board indicates which
stages are energized.
Heating Operation
Heat, 1st Stage (Y1)
The fan motor is started on low speed immediately (PSC ON), the
loop pump is energized 5 seconds after the "Y1" input is received,
and the compressor is energized on low capacity 10 seconds after
the "Y1" input. The fan is switched to medium speed 15 seconds
after "Y1" input (ECM only).
Heat, 2nd Stage (Y1,Y2) Single-Speed Units
Fan changes to high speed 15 seconds after the "Y2" input (ECM
only).
Heat, 2nd Stage (Y1,Y2) Dual Capacity Units
The second stage compressor will be activated 5 seconds after
receiving a "Y2" input as long as the minimum first stage compressor
run time of 1 minute has expired. The ECM blower changes from
medium to high speed 15 seconds after the "Y2" input.
The control will delay the second stage compressor until 5 seconds
after it receives a "Y2" from the board.
Heat, 3rd Stage (Y1,Y2,W) Single-Speed Units
The first stage of resistance heat is energized 10 seconds after "W"
input, and with continuous 3rd stage demand, the additional stages
of resistance heat engage sequentially every 5 minutes.
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