Manual 2100-366
Page 4
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 on the heating speed rather than the cooling as
is typical with most systems. 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.
