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Comfort Alert Diagnostic Module
The Comfort Alert Diagnostic Module (CADM) monitors and
analyzes data from the Copeland Scroll three-phase com-
pressor and the thermostat demand. The CADM also pro-
vides a 3-minute anti-recycle time delay to compressor
cycling.
The CADM detects causes for electrical and system related
failures. Flashing LEDs communicate the Alert codes to
guide service technicians in accurately and quickly trouble-
shooting the system and determining root cause for the
failure.
Inputs to the CADM include 24-vac power, demand signal Y,
compressor contactor coil (common side) and compressor
power leads (from the compressor contactor).
INPUT
TERMINAL
Control Power
Control Common
Demand
Contactor Coil
Compressor T1
Compressor T2
Compressor T3
Control of the compressor contactor coil is through a contact
between terminals P and C.
Communications of status and alert conditions is through
three LEDs located on the top edge of the module housing
(see Fig. 26): POWER (green), ALERT (yellow), and TRIP
(red).
The POWER LED indicates the presence of control power
to the CADM.
28
VOLTAGE
R
24-V
C
24-V
Y
24-V
P
24-V
T1
Line
T2
Line
T3
Line
Specifications subject to change without notice.
Power
(GRN)
POWER
Alert
(YEL)
ALERT
TRIP
Trip
(RED)
Fig. 26 — CADM Housing/LED Locations
The ALERT LED indicates an abnormal condition exists in
the system through a flash code. The ALERT LED will blink
a number of times consecutively, pause and the repeat the
process. The number of blinks, defined in Table 14, cor-
relates to a particular abnormal condition; troubleshooting
tips are provided for each Alert code. Reset of the ALERT
may be automatic or manual. If the fault condition causing
the Alert is self-corrected, the Alert code will be removed
and the CADM will automatically reset and allow the system
to restart normally. Manual reset for lockouts requires that
main power to the CHS unit be recycled after the cause for
the Alert condition has been detected and corrected.
The TRIP LED indicates either a time-delay period is cur-
rently active (RED LED is blinking) or the module has
locked out the compressor (RED LED is on steady). A lock-
out condition will occur for some faults as identified in
Table 14. Reset of the TRIP LED requires that unit main
power be recycled after the loss of power to the compressor
condition has been detected and corrected.
Simultaneous Blinking of YELLOW and RED LEDs indi-
cates control power input to the CADM is low. Check control
circuit transformer and wiring.
Troubleshooting the CADM Wiring – Flashing LEDs also in-
dicate wiring problems to the CADM. See Table 15 for dis-
cussion of additional LED flash codes and troubleshooting
instructions.
Comfort Alert
™
Commercial Diagnostics
Green LED - 24VAC Power
Yellow LED - Flash Code
2
System Pressure Trip
3
Short Cycling
4
Locked Rotor
5
Open Circuit
T1
6
Missing Phase
7
Reverse Phase
8
Welded Contactor
9
Low Voltage
Red LED - Protector Open
or no compressor power
Active Protection
T2
PROT breaks 24VAC common
leg of compressor contactor coil
Reset codes and PROT lockout
by removing 24VAC to module
For Two-Stage Applications:
T3
DC SOL operating range: 4-18VAC
Compressor second stage is
energized when YA & Y2 are 24VAC
and Alert and Trip LEDs are off
EMERSON ™
Climate Technologies
CHS-180-240-01SI Rev. A
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