Componentry Specifications; Compressor Control Module; Low Ambient Control; Phase Monitor - Bard D25A2PA Installation And Service Instructions Manual

COMPONENTRY SPECIFICATIONS

WARNING
!
Electrical shock hazard.
Disconnect both VAC and VDC power supplies
before servicing.
Failure to do so could result in electric shock
or death.
LOW PRESSURE SWITCH
Cut-out pressure: 40psi (+/- 4 psi)
Cut-in pressure: 55psi (+/- 4psi)
HIGH PRESSURE SWITCH
Cut-out pressure: 650psi (+/- 10 psi)
Cut-in pressure: 520psi (+/- 15psi)

LOW AMBIENT CONTROL

Modulating head-pressure control that allows full
speed at pressures above 315psi. Below 315psi, the
control will slow fan speed—following internal head
pressures—until a minimum RPM is reached (approx
300 RPM). Below this point, the control will shut the
fan completely off until internal pressures rise. The
control is preset from the factory, but should adjustment
become necessary, there is an adjustment screw located
on the bottom of the control behind a weatherproof cap.
One full turn clockwise equals approximately +48 psi.
REMOTE INDOOR TEMPERATURE
SENSOR
White, decorative plastic casing, Bard logo, field-
installed in shelter: 10k ohm resistance, see Table 2.3.
DISCHARGE TEMP SENSOR
4.75" stainless probe factory mounted in supply
opening of wall-mount unit: 10k ohm resistance, see
Table 2.3.
RETURN TEMPERATURE SENSOR
Exposed thermistor-element style with copper-coated
steel clip, attached in return opening of wall-mount
unit: 10k ohm resistance, see Table 2.3.
EVAPORATOR TEMP SENSOR
(FREEZESTAT)
Exposed thermistor-element style with copper-coated
steel clip, attached to evaporator coil of wall-mount unit:
10k ohm resistance, see Table 2.3.
Manual 2100-643C
Page 30 of 59
OUTDOOR TEMPERATURE/HUMIDITY
SENSOR
Gray, weather-proof octagonal case with dip tube,
located in condenser section of wall-mount unit.
• Temperature sensor: 10k ohm resistance, see Table
2.3.
• Humidity sensor: 4-20mA.

COMPRESSOR CONTROL MODULE

Compressor protection device that has an adjustable
30-second to 5-minute timer (red-dial). This module
features a delay-on-make for initial start-up (or anytime
power is interrupted) for a minimum 2 minutes plus
10% of the red-dial setting. There is no delay during
routine operation of the unit. The compressor control
module (CCM) also monitors the high pressure switch,
and will allow one automatic retry (after soft lockout
delay) before disabling the compressor in a hard
lockout (requires manual reset). If hard lockout does
occur, the ALR terminal on the CCM will become active
with 24V, which will power the high pressure relay
within the wall-mount unit, breaking a digital input to
the control board—signaling a high-pressure situation
to the system.

PHASE MONITOR

Used only on 3-phase equipment, the phase
monitor is a compressor protection device that will
prohibit operation of the compressor if the device
senses a possible reverse-rotation situation due to
incorrect phasing. On a call for compressor (and only
compressor), the device will check incoming phase,
check for severe voltage imbalance and check for
proper frequency. Under nominal conditions, a green
LED light will show on the face of the monitor. If there
is improper phasing, voltage imbalance or frequency
deviation, the device will show a red LED light and
prohibit compressor operation.
TRANSFORMER
75VA with external 4A circuit breaker, 230VAC/208VAC
convertible. Directly feeds power loss relay in wall-
mount unit during normal operation. Should loss of
utility power occur, transformer failure or transformer
external circuit breaker open, the loss of VAC power
will cause the contacts within the power loss relay to
open, interrupting a digital input to the control board—
signaling a loss-of-power situation to the system.