6
To verify proper must trip amps header configuration, press
and use the up arrow key on the HSIO to locate the
must trip amp values. Press the reset button on the control pan-
el to update these values. See Appendix A. If the values do not
match those in Appendix A, verify that the configuration head-
ers have been properly punched out.
The CPM communicates on the COMM3 communication
bus to the PSIO-1 module. Proper operation of the CPM board
can be verified by observing the 2 LEDs (light-emitting diodes)
located on the board. The red LED blinks at a rate of once ev-
ery 1 to 2 seconds. This indicates that the module is powered
and operating correctly. The green LED blinks when the mod-
ule is satisfactorily communicating with the PSIO-1 module.
The CPM communicates the status of its inputs and outputs,
and reports 15 different alarm conditions to the PSIO-1. The
alarms are listed in Table 5.
The PSIO-1 will generate an alert when it receives an alarm
input from the CPM. The alert will be generated in a y.xx for-
mat, where “y” refers to the compressor and “xx” to the alarm
value in Table 5 (decimal point removed). For example, the
HSIO might display Alarm 1.75 for a contactor failure occur-
ring on compressor A1. Similarly, the display would read 5.85
for a motor overtemperature condition on compressor B1.
Alerts for compressors A2 and B2 (if present) would be gener-
ated as “2.xx” and “6.xx,” respectively. Alarm codes 3 and 4
would not be used. Ending zeros are not displayed.
The high-pressure switch is wired in series with the relay
coils of the 8 relays on the CPM. If this switch opens during
operation, all relays on the CPM are deenergized and the com-
pressor is stopped. The failure is reported to the PSIO-1 and the
processor module locks off the compressor from restarting un-
til the alarm is manually reset.
The CPM module has many features that are specifically
designed to protect the compressor, including reverse rota-
tion protection. Do not attempt to bypass or alter any of the
factory wiring. Any compressor operation in the reverse
direction will result in a compressor failure that will require
compressor replacement.
1
1
1
1
0
0
SW1
SW2
SW3
SW4
0
0
1 2
3 4 5
1
2
3
1
2
3
4
5 4 3 2 1
3
2
1
3
2
1
1
2
3
4
3
2
1
8
1
8
1
GREEN LED
COMP 1
MTA
HEADER
RED LED
COMP 2
MTA
HEADER
J1
J7
J6
J9
J8
J4
J5
J2
J3
J10
J11
RESET
BUTTON
DIP
SWITCH
1
2
3
4
1
2
3
1
2
3
1
2
3
LEGEND
NOTES:
1. The red LED blinks continuously when the module
is operating properly.
2. The green LED blinks continuously when communi-
cating properly with PSIO-1.
3. On all plugs, pin 1 is identified by a “
●
.’’
LED
— Light-Emitting Diode
MTA
— Must Trip Amps
Fig. 1 — Compressor Protection Module (HN67LM101)