Compressor Protection; Module Led Description; Module Operation/Code Description; Resetting Alert Codes - Emerson Coresense Diagnostics Bulletin

Compressor Protection

The CoreSense Diagnostics module utilizes proprietary
algorithms to protect the compressor and system from
repeated trips of system pressure controls and the
compressor internal overload. The protection terminal
of the module should be wired in series with the system
low pressure and high pressure cutouts, as well as
the compressor contactor. When the module detects a
series of trips as described below, it will activate a
lockout feature that opens the normally closed protection
contacts in the module, thereby cutting power to the
contactor and shutting off the compressor.

Module LED Description

RUN/ALERT LED (Yellow)
A solid yellow LED indicates the module is powered
and the compressor/system is running normally.
Abnormal system conditions are indicated through
a unique yellow flash code. The Yellow RUN/ALERT
LED will flash consecutively, pause and then repeat
when adverse conditions are detected within the
compressor or system. The number of consecutive
flashes, defined as the flash code, correlate to a
particular abnormal condition. See Tables 1 and 2.
TRIP/LOCK LED (Red)
A solid red LED indicates the compressor is in a
TRIP state where the module detects the presence
of a demand signal from the thermostat, however
no current to the compressor is detected by the
module. A compressor trip typically indicates the
compressor's internal overload is open or may
indicate missing supply power to the compressor.
The Red TRIP/LOCK LED will flash consecutively,
pause and then repeat when the compressor lockout
feature is active. The number of consecutive flashes,
defined as the flash code, correlate to a particular
lock condition. See Table 2. (Note: The Yellow
Run/Alert LED will be turned off)

Module Operation/Code Description

The following is a description of the protection coding
of the CoreSense Diagnostics module:
Code 1 - Long Run Time
The module will flash yellow one time when the
compressor operates for longer than 18 continuous
hours. This is an alert code only, and the module will
not lockout the compressor for this condition.
Code 2 - Compressor (Pressure) Trips
The module will flash yellow two times when the
compressor operates from 12 seconds to 15 minutes
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followed by a trip condition lasting longer than seven
minutes. When four consecutive Code 2 events are
recorded, the module will lockout the compressor
and flash red two times.
Code 3 - Pressure Switch Cycling
The module will flash yellow three times when
the compressor operates from 12 seconds to 15
minutes followed by a trip condition lasting between
35 seconds to 7 minutes. When four consecutive
Code 3 events are recorded, the module will lockout
the compressor and flash red three times. A lockout
will also occur in the case that 10 events have been
recorded without resetting the alert.
Code 4 - Locked Rotor Trips
The module will flash yellow four times when the
compressor trips within 12 seconds of operation, and
does not reset and start within 35 seconds. When 10
consecutive Code 4 events are recorded the module
will lockout the compressor and flash red four times.
Code 5 - Compressor (Moderate Run) Trip
The module will flash yellow five times when the
compressor has operated between 15 minutes
and 18 hours, followed by a compressor trip lasting
longer than 7 minutes. When four consecutive Code
5 events are recorded, the module will lockout the
compressor and flash red five times. A lockout will
also occur if ten Code 5 events are recorded without
resetting the alert (see Resetting Alert Codes
below).
Code 9 - Over-Current Protection
When the current at the PROT terminal is greater
than 2A for 40ms, the module will flash a Code 9.
The red LED will flash 9 times with the yellow LED
remaining off. This alert indicates that the module is
mis-wired or the contactor coil is shorted to ground.
NOTICE
Code 9 is not specified on the module label.
Low Supply Voltage
If the 24 VAC supply voltage to the module drops
below the required amount to power the processors,
the processor will be continuously reset. Both LEDs
may flicker, and the alerts on the module will be
reset.

Resetting Alert Codes

When the CoreSense Diagnostics module has detected
a series of adverse conditions that have caused it to
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AE8-1379 R2