Kriwan Motor Protection Module Troubleshooting; Kriwan Motor Protection Wiring - Carrier AquaSnap 30MPA Series Controls, Start-Up, Operation, Service, And Troubleshooting

Kriwan Motor Protection Module Troubleshooting — Co-
peland models with a "TW" in the electrical code (i.e.,
ZP182KCE-TWD), have a motor overload system that con-
sists of an external Kriwan *
have been replaced by the CoreSense
for motor protection. This section is included for reference, and
contains instructions for replacing the Kriwan module with the
CoreSense module in the field.
Follow the steps listed below to troubleshoot the Kriwan
module in the field. See wiring diagram on terminal box cover,
or Fig. 35.
WARNING
Do not supply power to unit with compressor cover
removed. Failure to follow this warning can cause a fire,
resulting in personal injury or death.
WARNING
Exercise extreme caution when reading compressor cur-
rents when high-voltage power is on. Correct any of the
problems described below before installing and running a
replacement compressor. Wear safety glasses and gloves
when handling refrigerants. Failure to follow this warning
can cause fire, resulting in personal injury or death.
CAUTION
Do not manually operate contactors. Serious damage to the
machine may result.
1
LEGEND
1 — Kriwan Motor Protection Module Power
2 — Kriwan Control Circuit Connections
3 — Motor Thermal Sensor
Fig. 35 — Kriwan Motor Protection Wiring
1. De-energize control circuit and module power. Remove
the control circuit wires from the module (terminals M1
and M2). Connect a jumper across these control circuit
wires. This will bypass the control contact of the module.
CAUTION
The motor protection system within the compressor is now
bypassed. Use this configuration to temporarily test mod-
ule only.
2. Re-energize the control circuit and module power. If the
compressor will not operate with the jumper installed,
then the problem is external to the solid-state protection
system. If the compressor operates with the module by-
passed but will not operate when the module is
electronic control module. These
communication module
†
2 3
reconnected, then the control circuit relay in the module
is open. Remove the temporary jumper installed in Step
1.
3. The thermistor protection chain now needs to be tested to
determine if the module's control circuit relay is open due
to excessive internal temperatures or a faulty component.
Check the thermistor protection chain located in the
compressor as follows:
a. De-energize control circuit and module power.
b. Remove the sensor leads from the module (S1 and
S2).
c. Measure the resistance of the thermistor protection
chain through these sensor leads with an ohm
meter.
Use an ohmmeter with a maximum of 9 volts to check the
sensor chain. The sensor chain is sensitive and easily dam-
aged; 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 requiring 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
connector plug from the compressor and measure the re-
sistance 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 resis-
tance 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 original module.
CoreSense Replacement of Kriwan
Module — The Kriwan module has been replaced by the Core-
Sense communication module for motor protection. Minor
wiring changes are required as described below.
Electrical shock can cause personal injury and death. Shut
off all power to this equipment during installation and ser-
vice. There may be more than one disconnect switch. Tag
all disconnect locations to alert others not to restore power
until work is completed.
Do not supply power to unit with compressor cover
removed. Failure to follow this warning can cause a fire,
resulting in personal injury or death.
* Kriwan is a registered trademark of Kriwan Industrie-Elektronik.
GmbH
† CoreSense is a registered trademark of Emerson Climate
Technologies.
55
CAUTION
Motor Protection
WARNING
WARNING