Carrier AquaSnap 30RAP011-060 Controls, Start-Up, Operation, Service, And Troubleshooting page 87

c. Measure the resistance of the thermistor protection chain
through these sensor leads with an ohm meter.
CAUTION
Use an ohmmeter with a maximum of 9 volts to check the sen-
sor chain. The sensor chain is sensitive and easily damaged; no
attempt should be made to check continuity through it with
anything other than an ohmmeter. The application of any
external voltage to the sensor chain may cause damage requir-
ing the replacement of the compressor.
d. The diagnosis of this resistance reading is as follows:
• 200 to 2250 ohms: Normal operating range
• 2750 ohms or greater: Compressor overheated. Allow
time to cool.
• Zero resistance: Shorted sensor circuit. Replace the
compressor.
• Infinite resistance: Open sensor circuit. Replace the
compressor.
4. If the resistance reading is abnormal, remove the sensor con-
nector plug from the compressor and measure the resistance
at the sensor fusite pins. This will determine if the abnormal
reading was due to a faulty connector.
5. On initial start-up, and after any module trip, the resistance of
the sensor chain must be below the module reset point before
the module circuit will close. Reset values are 2250 to 3000
ohms.
6. If the sensor chain has a resistance that is below 2250 ohms,
and the compressor will run with the control circuit bypassed,
but will not run when connected properly, the solid-state
module is defective and should be replaced. The replacement
module must have the same supply voltage rating as the orig-
inal module.
CoreSense Replacement of Kriwan Motor Protection Module
The Kriwan module has been replaced by the CoreSense commu-
nication module for motor protection. Minor wiring changes are
required as described below.
WARNING
Electrical shock can cause personal injury and death. Shut off
all power to this equipment during installation and service.
There may be more than one disconnect switch. Tag all dis-
connect locations to alert others not to restore power until
work is completed.
WARNING
Do not supply power to unit with compressor cover removed.
Failure to follow this warning can cause a fire, resulting in per-
sonal injury or death.
Removing the Kriwan motor protection module:
1. Disconnect and lock out the high voltage and control voltage
supply to the unit.
2. Using a straight blade screwdriver, carefully depress the tabs
holding the terminal cover to the terminal box to remove the
terminal cover. Before proceeding, use a volt meter to verify
that the power has been disconnected from the unit.
3. Using wire markers, label the M1, M2, T1, and T2 wires that
are connected to the Kriwan module. Using needle nose pli-
ers, remove the M1, M2, T1, T2, S1 and S2 wires from the
Kriwan motor protector module.
4. Gently bend the holding tabs holding the Kriwan module in
the terminal box and remove the Kriwan module from the ter-
minal box. See Fig. 63.
5. Take note of the S1-S2 plug orientation on the compressor
thermistor fusite. Remove the S1-S2 wire harness and plug
from the compressor.
HOLDING
TAB
Fig. 63 — Kriwan Motor Protection Module Removal
Installing the CoreSense communications module:
1. A new S1-S2 thermistor wiring harness is shipped with the
CoreSense kit and must be used. The wiring harness connec-
tor block should be fully inserted on the three pins in the ori-
entation shown in Fig. 64 for proper operation.
Fig. 64 — Compressor Motor Sensor Harness
Installation
2. Review the DIP switch settings on the CoreSense module.
DIP switch no. 1 should be ON (up position) and all other
DIP switches should be OFF (down position). See Fig. 65.
1 2 3 4
O
ON
F
F
OFF OFF OFF
ROCKER DOWN
Fig. 65 — CoreSense Communication DIP
Switch Settings for Kriwan Retrofit
87
HOLDING
TAB
a38-7310
INSTALL IN THIS
ORIENTATION
A38-7311
5 6 7 8 9
OFF
OFF OFF OFF OFF
A38-7812
10
OFF