Sequence Of Operation; Compressor Control Module; Pressure Service Ports - Bard I30A1DA Installation Instructions Manual

SEQUENCE OF OPERATION

COOLING PART LOAD – Circuit R-Y1 makes at
thermostat pulling in compressor contactor, starting
the compressor and outdoor motor. The G (indoor
motor) circuit is automatically completed on any call
for cooling operation or can be energized by manual fan
switch on subbase for constant air circulation.
COOLING FULL LOAD – Circuit R-Y1 & Y2 makes at
the thermostat energizing the 2nd stage solenoid in the
compressor. The default position of the compressor
staging solenoid is non-energized. The compressor will
run at low capacity until this solenoid is energized.
HEATING STAGE 1 – Circuit R-G & W1 makes at
the thermostat energizing the corresponding heater
contactors. The indoor blower is also energized.
HEATING STAGE 2 – Circuit R & W2 makes at the
thermostat energizing the corresponding heater
contactors. The indoor blower remains energized.

COMPRESSOR CONTROL MODULE

The compressor control module is standard on all
models covered by this manual. The compressor
control module is an anti-short cycle/lockout timer with
high and low pressure switch monitoring and alarm
relay output.
Adjustable Delay-on-Make and Delay-on-Break Timer
On initial power up or anytime power is interrupted to
the unit, the delay-on-make period begins, which will
be 2 minutes plus 10% of the delay-on-break setting.
When the delay-on-make is complete and the high
pressure switch and low pressure switch are closed, the
compressor contactor is energized. Upon shutdown,
the delay-on-break timer starts and prevents restart
until the delay-on-break and delay-on-make periods
have expired.
During routine operation of the unit with no power
interruptions, the compressor will operate on demand
with no delay.
High Pressure Switch and Lockout Sequence
If the high pressure switch opens, the compressor
contactor will de-energize immediately. The lockout
timer will go into a soft lockout and stay in soft lockout
until the high pressure switch closes and the delay-
on-break time has expired. If the high pressure switch
opens again in this same operating cycle, the unit will
go into manual lockout condition and the alarm relay
circuit will energize. Recycling the wall thermostat
resets the manual lockout.
Low Pressure Switch, Bypass and Lockout Sequence
If the low pressure switch opens for more than 120
seconds, the compressor contactor will de-energize
and go into a soft lockout. Regardless the state of the
low pressure switch, the contactor will reenergize after
the delay-on-make time delay has expired. If the low
pressure switch remains open, or opens again for longer
than 120 seconds, the unit will go into manual lockout
condition and the alarm relay circuit will energize.
Recycling the wall thermostat resets the manual lockout.
Alarm Relay Output
Alarm terminal is output connection for applications
where alarm relay is employed. This terminal is
powered whenever the compressor is locked out due to
HPC or LPC sequences as described.
NOTE: Both high and low pressure switch controls are
inherently automatic reset devices. The high
pressure switch and low pressure switch cut
out and cut in settings are fixed by specific air
conditioner unit model. The lockout features,
both soft and manual, are a function of the
compressor control module.
Adjustments
Adjustable Delay-on-Make and Delay-on-Break Timer
The potentiometer is used to select delay-on-break time
from 30 seconds to 5 minutes. Delay-on-make (DOM)
timing on power up and after power interruptions is equal
to 2 minutes plus 10% of delay-on-break (DOB) setting:
0.5 minute (30 seconds) DOB = 123 second DOM
1.0 minute (60 seconds) DOB = 126 second DOM
2.0 minute (120 seconds) DOB = 132 second DOM
3.0 minute (180 seconds) DOB = 138 second DOM
4.0 minute (240 seconds) DOB = 144 second DOM
5.0 minute (300 seconds) DOB = 150 second DOM
During routine operation of the unit with no power
interruptions, the compressor will operate on demand
with no delay.
Typical Settings for Dual Unit Installation:
Unit 1: DOB set at 2 minutes and DOM is 132 seconds
Unit 2: DOB set at 4 minutes and DOM is 144 seconds

PRESSURE SERVICE PORTS

High and low pressure service ports are installed on
all units so that the system operating pressures can be
observed. Pressure tables covering all models can be
found on pages 52 and 53. It is imperative to match
the correct pressure table to the unit by model number.
This unit employs high-flow Coremax valves instead of
the typical Shrader type valves.
Manual 2100-597G
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