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D7.8.4/0112-0415/E 

 

15/17

 

Troubleshooting 

Flash 
code 

Alarm conditions 

Possible failure reasons 

Troubleshooting measures 

Insufficient 

oil 

pressure 

Alert:  Appears  when  the  differential 
oil  pressure  is  less  than  0.48 

–  0.62 

bar for 4 seconds. 

Lockout: 

Appears 

when 

the 

differential  oil  pressure  is  less  than 
0.48 

–  0.62  bar  for  2  minutes 

continuous 

or 

intermittent 

but 

determined to be unsafe. 

 

Loose  wiring  connections 
between  CoreSense  module 
and oil sensor. 

 

Faulty oil sensor (missing O-
ring 

or 

clogged 

sensor 

screen). 

 

Faulty oil pump. 

 

Clogged  strainer  screen  or 
worn bearings. 

 

Check  the  oil  level  present  in  the  sight  glass.  If  the  oil  is  not  present,  resolve 
reservoir oil supply problem or oil level control setting issues. 

 

Check that the harness is fully engaged to the sensor. 

 

Measure oil pump differential pressure. If less than  0.48 to 0.62 bar, inspect for 
clogged oil screen, faulty oil pump, liquid floodback or worn bearings. 

 

If  good  oil  pressure  exists,  measure  resistance  across  the  oil  sensor  while  the 
compressor  runs.  If  the  sensor  resistance  is  "open"  inspect  for  clogged  sensor 
screen or missing O-ring. 

 

If sensor resistance is "closed", temporarily jumper across the harness connector 
pins (do not damage the pins!) while the compressor runs. If the oil warning does 
not go away, check harness connector engagement at the module circuit board. 

Motor overheat 

Trip:  Appears  when  the  motor  is 
overheated. 

 

Motor  rotor  is  mechanically 
seized. 

 

Open circuit in harness. 

 

Connector  pin  not  engaging 
at  connector  on  control 
module. 

 

Faulty CoreSense module. 

 

In case of trip alarm, allow the motor to cool down for a minimum of 2 minutes (it 
may take longer) and the compressor will start automatically. 

 

If  resistance  is  low,  inspect  for  loose  terminal  strip  connections,  harness 
connection failure at circuit  board,  open harness  circuit or  high  motor temp  due 
to return gas temperature, motor voltage or load condition. 

Discharge  temp 
protection 

Alert:  Appears  when  the  discharge 
temperature  sensor  is  defective  or 
disconnected. 

Trip/Lockout:  Appears  when  the 
discharge temperature is > 154°C for 
2 seconds. 

 

Open 

discharge 

probe 

(faulty). 

 

The  probe  connection  has 
not  been  made  to  the 
harness connector. 

 

The connector is not plugged 
into  the  CoreSense  circuit 
board. 

 

The  discharge  temperature 
has  exceeded  the  maximum 
limit 154°C. 

 

Blocked condenser. 

 

Possible loss of refrigerant. 

 

If  there  is  an  alert,  check  proper  probe  connection  to  the  harness  and  proper 
harness connection into the circuit board. 

 

If there is an alert, unplug the discharge temp probe and check if the resistance 
of the probe is as specified vs its approximate ambient temperature. 

 

If  the  probe  resistance  is  correct  inspect  the  harness  connector  receptacle  for 
damage and apply NyoGel 760G connector lubricant. 

 

Trip  or  Lockout:  resolve  system  issues  (high  superheat,  high  head  pressure), 
inspect for mechanical damage that can lead to high temps (valve plate gasket, 
suction or discharge valve failure). 

 

Summary of Contents for CORESENSE

Page 1: ...3 7 Voltage imbalance protection 4 3 8 Jog feature 5 3 9 Crankcase heater CCH control 5 3 10 Flash memory information 5 3 11 Modbus communication 6 3 12 Reset 7 3 13 Alarm history and running conditions 7 3 14 Compressor status codes 7 3 15 LEDs on the module to display the failure alarms 7 3 16 Oil functionality self test option 9 4 Electrical connections 9 4 1 System wiring diagram 9 4 2 Termina...

Page 2: ...mpressor with CoreSense Diagnostics 2 Specifications Power supply for control module in front of the compressor is 120V AC or 240V AC The sensor module needs 24V AC power supply Operating temperature 32 C to 66 C Steady load current for relay 3A Voltage requirements 120V AC or 240V AC Power rating for the sensor module 3VA Inrush current for relay 19A Storage temperature 40 C to 85 C Voltage senso...

Page 3: ...he compressor off and a low oil pressure lockout will be reported Before using the reset button troubleshooting needs to be done to understand the failure The compressor will switch back on once the reset has been manually activated or when power has been cycled to the CoreSense module This feature is not applicable to compressor models 4MTL Stream CO2 compressors as these have no positive oil pum...

Page 4: ...ing reset button below the module or by cycling the power to the module In the case of a part winding motor this feature is detectable for primary winding only Missing phase voltage imbalance and low voltage are not detectable for the secondary winding A missing phase can be detected during start up but not while the motor is running 3 6 Low voltage protection Appears when there is a low supply vo...

Page 5: ...e following asset information will be saved in the flash memory EEPROM Compressor model number Compressor serial number Compressor model number modified Compressor serial number modified Compressor nominal voltage and frequency Sensor module firmware revision For dual voltage motors the lower value is saved in EEPROM memory It is advised to change the nominal voltage setting values to the correct ...

Page 6: ...cent version The communication cable is wired from the pack controller to the first compressor Additional compressors are wired in a daisy chained configuration The last compressor in the daisy chain should be terminated by jumper JP3 in the front module Please refer to Figures 4 and 5 Figure 4 RS485 daisy chain connection Figure 5 Two rack daisy chain connection CoreSense modules can be connected...

Page 7: ...o reset Flashing red An indication that the compressor is in lockout state Steady red An indication that the control module has failed 3 15 LEDs on the module to display the failure alarms Two multi color LEDs on the CoreSense front module display the failure alarms The LED on the top is green red and the LED on the bottom is orange For warning alert green trip orange and lockout red the flash cou...

Page 8: ... N A If flashing green current sensor is disconnected from the sensor module Compressor run state is not known by the control module 5 Communication error N A N A N A N A Communication between control module and system controller has been lost Communication between control module and sensor module has been lost 6 N A Locked rotor Locked rotor 5 min 10 consecutive events If flashing orange compress...

Page 9: ...ockout can be observed Test mode Step 1 Power On reset module Step 2 Within 5 seconds switch DIP switch 11 from Off to On Step 3 Low oil pressure warning for 2 minutes followed by low oil pressure lockout red LED blinking once Step 4 Press reset button 4 Electrical connections 4 1 System wiring diagram Fuses and wire cable sizing must be done in accordance with all applicable electrical code stand...

Page 10: ...kcase heater Power supply control module 115V or 230V 24V AC Communication to CoreSense module 24V AC output To terminal plate Crankcase heater Current sensor Modbus communication port Control module communication to sensor module LED Module power 220V or 110V Contactor DIP switch Line Alarm Discharge temperature sensor PTC Oil sensor ...

Page 11: ...f the leads are white and one is black For proper calculation of power factor and motor power it is necessary for the black voltage sensing lead and the power lead through the current sensing module to be connected to the same motor terminal The sensor module needs 3VA Volt Ampere and a 24V AC power supply Therefore a Class II transformer must be used Class II transformers have a maximum rating of...

Page 12: ...g If the leads L2 and L8 in picture below are not routed in the same direction the running current may indicate close to zero Legend A4 Sensor module K1 Contactor M1 A5 Terminal box compressor K4 Contactor M1 for second part winding CCH Crankcase heater M21 Fan motor condenser F6 Fuse for control circuit R2 Crankcase heater F7 Fuse for control circuit Y21 Solenoid valve capacity control 1 F8 Fuse ...

Page 13: ...in the daisy chain must be terminated by moving the JP3 jumper from 2 3 to 1 2 For all other compressors the jumper should remain in the default 2 3 position JP4 factory setting is 1 2 2 Stop Bits Depending on the Modbus parameters it can be switched to position 2 3 1 Stop Bits Do not remove JP1 This is reserved for future use Figure 16 CoreSense circuit board ...

Page 14: ...cation assign a unique node address to each CoreSense Diagnostics module using switches 1 through 6 a Set the communications baud rate for the module using switch 7 Off 19200 baud On 9600 baud The baud rate for each module should be set to match the pack controller b Set switch 8 to Off for no parity to On for even parity c Set switch 9 to Off for stand alone mode to On for network mode Network mo...

Page 15: ...ars when the motor is overheated Motor rotor is mechanically seized Open circuit in harness Connector pin not engaging at connector on control module Faulty CoreSense module In case of trip alarm allow the motor to cool down for a minimum of 2 minutes it may take longer and the compressor will start automatically If resistance is low inspect for loose terminal strip connections harness connection ...

Page 16: ...ork If not set the network dip switch to stand alone and press reset Is there a communication network If not check that the communication harness is engaged at both the CoreSense module and the sensor module If the LED on the top edge of the sensor module is dark check 24 VAC power to the sensor module or replace the sensor module If communication network amber light is continuously on reverse the...

Page 17: ...nections are tight at the compressor Check that there are not any faults with other peripheral electrical loads for example fan motors 9 Voltage imbalance Trip Appears when the voltage imbalance value exceeds the set value default 5 Loose wiring connections at the compressor terminal plate inside T Box Worn out contactors Faults with other peripheral electrical loads Single phasing conditions Chec...

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