Manual 2100-749
Page
27 of 68
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.
High Pressure Safety Switch
All units have a high pressure switch as a safety device.
This device will open when pressure in the system
reaches 650 PSIG. The switch is directly connected
to the dedicated compressor control module (see
High
Pressure Detection
).
Refrigerant High Pressure Alarm
When the wall-mount unit receives a signal from the
compressor control module (CCM) indicating a high
pressure event, the wall-mount unit will generate an
alarm. Upon receiving the alarm, the wall-mount unit
will remove the “Y” call from the CCM, resetting the
status of the CCM. The alarm will stay present on the
wall-mount unit until manually cleared with TEC-EYE
hand-held diagnostic tool.
In addition to the CCM, the discharge pressure
transducer is used to prevent a high pressure event.
When the discharge pressure is above the discharge
pressure alarm setpoint (set 30 pounds below high
pressure switch, which is 650), the system will disable
stage 2 of mechanical cooling.
Phase Monitor
Used only on three 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.
If a fault condition occurs, reverse two of the supply
leads to the unit.
Do not reverse any of the unit factory
wires as damage may occur.
FIGURE 39
8201-169 Compressor Control Module
High Pressure Switch
Compressor Contactor Output
Alarm Output
Common
Delay-on-Break Time
Adjustment Potentiometer
Brownout Ignore Time DIP Switches*
18-30 VAC Input
Y Input from Thermostat
and High Pressure Switch
Troubleshooting Light
* Turn on only one switch for that specific ignore time setting.
10 seconds is the maximum brownout ignore time. If all
switches are "off", the control is in "do not ignore".
Jumper
