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OPERATING SEQUENCE
Base Unit Controls
INDOOR (SUPPLY) FAN
If the thermostat fan operation is selected as Continuous the in-
door (supply) fan motor runs continuously. If the thermostat
fan operation is selected as Automatic, the indoor (supply) fan
motor runs when there is a call for cooling, heating, or ventila-
tion. When thermostat call is satisfied, the indoor (supply) fan
motor stops. If there is a fan fault or shutdown condition in the
fan coil, the indoor (supply) fan will not run if there is a call for
ventilation, cooling, or heating, and the 569J unit will act as if
it is not receiving a thermostat demand.
COOLING, UNIT WITHOUT ECONOMIZER
569J***A/B (Single Circuit)
On a thermostat call for Cooling the indoor (supply) fan motor
runs (subject to there being no fan fault or shutdown condition,
see above section). Thermostat output Y1 is energized; termi-
nal Y1 at 569J***A/B unit receives 24-v. 24-v received at
CADM1 terminal Y. If anti-recycle time delay period has not
expired, CADM1 relay will remain open, de-energizing Sole-
noid Valve Relay (SVR) and preventing compressor start.
When safety pressure switches are closed and CADM1 time
delay expires, CADM1 relay closes, SVR and compressor con-
tactor C1 are energized; liquid line solenoid valve LLSV
opens, all outdoor fan motors start and Compressor 1 starts.
On a thermostat calling for Stage 2 Cooling, thermostat output
Y2 is energized; terminal Y2 at 569J***A/B unit receives
24-v. 24-v is received at CADM2 terminal Y. If anti-recycle
time delay period has not expired, CADM2 relay will remain
open, preventing Compressor 2 start. When safety pressure
switches are closed and CADM2 time delay expires, CADM2
relay closes, compressor contactor C2 is energized; Compres-
sor 2 starts.
As space cooling load is satisfied, thermostat outputs Y2 and
Y1 are sequentially de-energized, removing 24-v at
569J***A/B terminals Y2 and Y1. Compressor 2 stops on Y2
opening. CADM2 begins its three-minute anti-recycle time de-
lay. On Y1 opening, Compressor 1 stops, all outdoor fan mo-
tors stop and SVR relay is de-energized. Liquid line solenoid
valve is de-energized and valve closes. CADM1 begins its
three-minute anti-recycle time.
569J***T/U (Two Circuits/3-Stage Cooling)
On a thermostat call for Cooling the indoor (supply) fan motor
runs. Thermostat output Y1 is energized; terminal Y1 at
569J***T/U unit receives 24-v and the Compressor Lockout
Relay (CLR) is energized (if there is a fan fault or shutdown
condition in the fan coil unit, the CLR will not energize, pre-
venting a Y1, Y2, or Y3 call from turning on the compressors).
24-v is received at CADM1 terminal Y1. If anti-recycle time
delay period has not expired, CADM1 relay will remain open,
de-energizing Solenoid Valve Relay 1 (SVR1) and preventing
compressor start. When safety pressure switches are closed and
CADM1 time delay expires, CADM1 relay closes, SVR1 and
compressor contactor C1 are energized; liquid line solenoid
valve LLSV1 opens and Circuit 1 compressor starts. On
569J*16-25 units, all outdoor fan motors start, subject to ambi-
ent temperature (see Fan Cycling section). On 569J*28 units,
Outdoor Fans 1 and 2 start, subject to ambient temperature.
On a thermostat calling for Stage 2 Cooling, thermostat output
Y2 is energized; terminal Y2 at 569J***T/U unit receives 24-v.
24-v received at CADM2 terminal Y. If anti-recycle time delay
period has not expired, CADM2 relay will remain open, de-
energizing Solenoid Valve Relay 2 (SVR2) and preventing
compressor start. When safety pressure switches are closed and
CADM2 time delay expires, CADM2 relay closes, SVR2 and
compressor contactor C2 are energized; liquid line solenoid
valve LLSV2 opens and Circuit 2 compressor starts. On
569J*16-25 units, Outdoor Fans 3 and 4 start, subject to ambi-
ent temperature.
On a thermostat calling for Stage 3 Cooling, thermostat output
Y3 is energized; terminal X at 569J***T/U unit receives 24-v.
24-v is received at CADM1 terminal Y2. CADM1 DC SOL
terminal outputs 24-vdc to the compressor loader plug (LDR)
and the Compressor 1 operates at full load capacity.
As space cooling load is satisfied, thermostat outputs Y3, Y2
and Y1 are de-energized, removing 24-v at 569J***T/U termi-
nals X (Y3), Y2 and Y1. Compressor 2 loader plug is de-
energized on Y3 opening. Circuit 2 compressor stops on Y2
opening; SVR2 is de-energized and LLSV2 closes. On
569J*28 units, Outdoor Fans 3 and 4 stop. CADM2 begins its
three-minute anti-recycle time delay. On Y1 opening, Circuit 1
compressor stops, all outdoor fan motors stop and SVR1 relay
is de-energized. Liquid line solenoid valve LLSV1 is de-
energized and valve closes. On 569J*16-25 units, all outdoor
fans stop; on 569J*28 units, Outdoor Fans 1 and 2 stop. Com-
pressor Lockout Relay is also de-energized. CADM1 begins its
three-minute anti-recycle time delay.
FAN CYCLING
569J***T/U units are equipped with a temperature switch that
will shut down Outdoor Fans 2 and 4 in cooling mode when the
outdoor temperature falls below 55°F (13°C) to ensure contin-
uous operation in both stages. The outdoor fan will turn back
on when the temperature rises above 60°F (16°C). See Fig. 30
and 34 for outdoor fan labeling.
All Units
If either the Low Pressure Switch or High Pressure Switch
opens while thermostat output Y1 or Y2 remain energized, the
compressor contactor is de-energized, the compressor stops
and liquid line solenoid is de-energized (valve closes). CADM
initiates a TRIP event (cooling demand sensed at CADM ter-
minal Y but no current is measured at T1, T2, T3 motor sen-
sors); CADM relay opens and RED LED is illuminated. TRIP
condition maintains lockout of compressor operation until
CADM is manually reset. Reset CADM by cycling unit main
power.
Complete system shutdown may be caused by loss of main
power, open compressor internal overload, open low-pressure
or high-pressure switch, or a fault detected by the CADM
logic. Compressor operation without cooling may indicate the
compressor's ASTP feature is active; disconnect unit power
and allow compressor to cool. See Service section for further
details.
COOLING, UNIT WITH ECONOMIZER
Refer to fan coil unit installation instructions and economizer
accessory installation instructions for operating sequences
when system is equipped with accessory economizer.
HEATING
Refer to fan coil unit installation instructions and accessory heat-
ing device installation instructions for operating sequences in
heating mode.
27
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