Manual 2100-502A
Page
6 of 15
High Pressure Switch and Lockout Sequence
• If the high pressure switch opens, the compressor
contactor will de-energize immediately. The
lockout time in the CCM will go into a soft
lockout and stay locked out until the high
pressure switch closes and the delay on break has
expired.
• If the high pressure switch opens again during
the same operating cycle the CCM will go into a
manual lockout condition.
• Recycling the wall thermostat resets the manual
lockout.
Low Pressure Switch, Bypass and Lockout
Sequence (Optional)
• If the low pressure switch opens for more than
120 seconds the compressor contactor will de-
energize and the CCM will go into soft lockout.
• Regardless of the state of the low pressure switch
the compressor contactor will reenergize after
the delay on break time has expired.
• If the low pressure switch remains open, or opens
again for longer than 120 seconds, the CCM will
go into a manual lockout and the alarm relay
circuit will energize.
• Recycling the wall thermostat resets the manual
lockout.
NOTE:
Both high and low pressure switch controls
are inherently automatic reset devices. The
high pressure switch opens at 425 and closes
at 325 psig, and the low pressure switch opens
at 14 and closes at 30 psig. The lockout
features, both soft and manual, are a function
of the Compressor Control Module.
Alarm Relay Output
• Alarm terminal on Compressor Control Module
is 24V AC output connection for applications
where signal is desired. This terminal is
powered whenever compressor is in manual
lockout due to high pressure or low pressure
sequences as described.
SECTION 4 • TURNING OFF FURNACE IN
AN EMERGENCY
PHASE MONITOR
All units with three phase scroll compressors are
equipped with a three phase line monitor to prevent
compressor damage due to phase reversal.
The phase monitor in this unit is equipped with two
LEDs. If the “&” signal is present at the phase monitor
and phases are correct, the green LED will light.
If phases are reversed, the red fault LED will be lit and
compressor operation is inhibited.
3.3 MANUAL FAN (CONTINUOUS AIRFLOW)
OPERATION
If wall thermostat is set to MANUAL (ON) position to
operate comfort air blower continuously to provide air
circulation throughout the building, the blower will
operate at a level that is lower than cooling or heating
airflows. This permits the air to circulate as desired but
helps keep the operating noise level down as well a
conserving energy.
During a call for cooling, the blower automatically
shifts up to cooling speed, and remains there until 60
seconds after thermostat is satisfied then drops back to
heating speed.
WARNING
Have a qualified installer, service agency
or gas supplier teach you location and
operation of gas and electrical shut-off
devices. Ask them any questions you have
about this section. If you don’t turn off your
furnace in an emergency damage, injury or
death could result.
