Low Pressure Detection; High Pressure Detection; Test Mode; Brownout Protection With Adjustment - Bard W42AC-A Installation Instructions Manual

Low Pressure Detection

Low pressure switch monitoring allows for a lockout
condition in a situation where the switch is open. If
the low pressure switch remains open for more than
2 minutes. the CCM will de-energize the compressor
for the delay-on-break time. If the switch closes again,
it will then restart the compressor. If the switch trips
again during the same Y call, the compressor will be
de-energized and the alarm terminal will be energized
indicating an alarm. The blue LED will light and
stay on until power is cycled to the control or a loss
of voltage is present at Y terminal for more than ½
second.

High Pressure Detection

High pressure switch monitoring allows for a lockout
condition in a situation where the switch is open. If
the high pressure switch opens, the CCM will de-
energize the compressor. If the switch closes again,
it will then restart the compressor after the delay-
on-break setting has expired on the device. If the
switch trips again during the same thermostat call,
the compressor will be de-energized and the alarm
terminal will be energized indicating an alarm. The
red LED will light and stay on until power is cycled
to the control or a loss of voltage is present at Y
terminal for more than ½ second.

Test Mode

By rapidly rotating the potentiometer (POT) clockwise
(see Figure 22), all timing functions will be removed
for testing.
The conditions needed for the unit to enter test mode
are as follows: POT must start at a time less than or
equal to the 40 second mark. The POT must then be
rapidly rotated to a position greater than or equal to
the 280 second mark in less than ¼ second. Normal
operation will resume after power is reset or after the
unit has been in test mode for at least 5 minutes.

Brownout Protection with Adjustment

Brownout protection may be necessary if the utility
power or generator power has inadequate power to
prevent the voltage from dropping when the compressor
starts. This is rare but can happen if the generator
is undersized at the site or if the site is in a remote
location far from the main power grid. Under normal
circumstances, allowing the brownout to be ignored for
a time period should not be needed. The 8201-164 is
shipped with all the DIP switches in the 'off' or 'do not
ignore' position (see Figure 22).
If ignoring the brownout is needed because of the
above conditions, three preset timers can be set by DIP
switches in order to delay signaling a power brownout
for a specific length of time after compressor contactor
is energized. This allows the compressor a time period
to start even if the voltage has dropped and allows the
voltage to recover. This delay only happens when the
Manual 2100-692
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CC terminal energizes. The delay can be set to 500
milliseconds (A DIP switch), 1000 milliseconds (B DIP
switch) or 1500 milliseconds (C DIP switch); time is
not cumulative—only the longest setting will apply. If
the voltage recovers during the brownout time period,
the compressor will start.
If a brownout condition is detected by the 8201-164,
the troubleshooting light will flash blue. The light will
continue to flash until the cooling call is satisfied or
power is removed from the Y terminal. This condition
does not prevent operation, it only indicates that a
brownout condition was present at some point during
the cooling call. If a brownout condition is detected,
CC will be de-energized and will retry after the delay-
on-make timer is satisfied; this process will continue
until call is satisfied.
If user chooses the 'do not ignore' position when the
site has inadequate utility or generator power, this
could lead to the compressor never starting. The
control will see the brownout immediately and not start.
A common scenario and one that has been seen in the
field is when a unit or units switches from utility power
to generator power. With slower transfer switches, the
time delay between the utility power and generator
power didn't cause a problem. The units lost power,
shut off and came back on line normally. With the
introduction of almost instantaneous transfer switches,
the millisecond long power glitch can be enough that
the compressor will start to run backwards. In this
scenario, the CCM will catch this and restart the units
normally.

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 30 and 31. 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.
WARNING! Do NOT use a Schrader valve core removal
tool with these valves. Use of such a tool could result
in eye injuries or refrigerant burns!
To change a Coremax valve without first removing the
refrigerant, a special tool is required which can be
obtained at www.fastestinc.com/en/SCCA07H. See the
replacement parts manual for replacement core part
numbers.