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structure so that all of the units do not start at the
same time which could happen after a power loss or
building shutdown. The delay-on-make time period is
2 minutes plus 10% of the delay-on-break time period.
To ensure that all of the units do not start at the same
time, adjust the delay-on-break timer on each unit to a
slightly different delay time.
Short Cycle Protection/Delay-on-Break
An anti-short cycle timer is included to prevent short
cycling the compressor. This is adjustable from 30
seconds to 5 minutes via the adjustment knob (see Figure
39). Once a compressor call is lost, the time period must
expire before a new call will be initiated.
10% of this time is also considered on the delay-on-
make timer (see above).
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, it will then restart
the compressor after the delay-on-break setting has
expired on the device. If the switch trips again during
High Pressure Switch
18-30 VAC Input
Y Input from Thermostat
and High Pressure Switch
Troubleshooting Light
Manual 2100-694B
Page
26 of 62
the same Y call, the compressor will be de-energized.
The ALR terminal will be energized, signaling the unit
control board that a high pressure event has occurred
(see Refrigerant High Pressure Alarm on page 27).
Test Mode
By rapidly rotating the potentiometer (POT) clockwise
(see Figure 39), 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
FIGURE 39
8201-169 Compressor Control Module
Jumper
Brownout Ignore Time DIP Switches*
* Turn on only one switch for that specific ignore time setting
Compressor Contactor Output
Alarm Output
Common
Delay-on-Break Time
Adjustment Potentiometer
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