Start Up; Description Of Standard Equipment - Bard QW Series Installation Instructions Manual

START UP

DESCRIPTION OF STANDARD
EQUIPMENT
Low Pressure Switch
NOTE: This unit is supplied with two low pressure
switches installed, a 55 PSIG and a 75 PSIG.
The 75 PSIG is wired into the system. This switch is
suitable for ground water (pump and dump), and water
loop (boiler/tower applications).
To avoid nuisance lockouts for ground loop application
with antifreeze, the 75 PSIG switch should be
disconnected and connect the 55 PSIG switch.
The leads for both switches are located in the lower
electrical connection panel. The switch bodies are
marked with pressure settings. The 75 PSIG switch
has blue leads. The 55 PSIG switch has yellow leads.
Water Flow Switch
These models are equipped with a water flow switch.
It is a magnetic (sealed) switch that closes electrical
contacts above 3 gallons per minute. This enables the
compressor to shut down in the event of low water flow
conditions, thus preventing long-term mechanical issues.
High Pressure Switch
This unit is equipped with a high pressure switch that
will stop the compressor in the event of abnormal high
pressure occurrences.
The high and low pressure switches are included
in a lockout circuit that is resettable from the room
thermostat.
Geothermal Compressor Control Module
The geothermal compressor control module is standard
on all models covered by this manual. It is an anti-
short cycle/lockout timer with high pressure, low
pressure and flow switch monitoring and alarm output.
Adjustable Delay On Make and Delay On Break Timer
On initial power up or any time 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, if employed)
is 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.
Manual 2100-577C
Page 26 of 50
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 the 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/Flow Switch, Bypass and Lockout
Sequence
On an initial call for the compressor (minus the short
cycle timer), the geothermal compressor control
module (GCCM) allows the compressor to start (output
on "CC" terminal) and will run for 30 seconds if the
low pressure switch (LPS) or flow switch (FS) remain
open. If both the LPS and FS fail to close within 30
seconds, the GCCM will open the "CC" output as a soft
lockout. The system will again restart and run in the
same sequence following the anti-short cycle timer
sequence. If the LPS and FS both show "closed" within
30 seconds, the compressor will continue to run. If it
fails again a second time during a single call for "Y", it
will shut down the compressor again and go into a hard
lockout, energizing the "ALR" output. Recycling the
wall thermostat resets the lockout.
Alarm Relay Output
Alarm terminal is output connection for applications
where alarm relay is employed. This terminal is
powered whenever compressor is locked out due to
high pressure switch or low pressure switch 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 or heat pump unit model. The
lockout feature, both soft and manual, are a
function of the geothermal compressor control
module.