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CoreSense is compatible with VFD applications by turning on the DIP-Switch 12 in the front module. The features
available for VFD are limited: motor overheat protection, insufficient oil pressure protection and high discharge
temperature protection. Other features are available in Control Techniques frequency inverters.
Figure 2
3.1 Insufficient oil pressure protection
The CoreSense Diagnostics module replaces the mechanical oil pressure switch. Furthermore, it provides the
added value of communication for
insufficient
oil pressure warning and lockouts via LED flash codes and/or a
supervisory pack controller. Total insufficient oil pressure time for the compressor is stored and accumulated in the
module memory.
CoreSense Diagnostics will issue a warning when the oil pressure differential falls below 0.48-0.62 bar for
4 seconds.
Once the oil pressure
differential
falls below 0.48-0.62 bar for 2 minutes (120 sec), the module will shut the
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 CO
2
compressors) as these have no positive oil
pump fitte
d and are “splash” lubricated.
3.2
Motor overheat protection
Using Positive Temperature Coefficient (PTC) sensors on 4M* and 6M* Stream compressor models, the
CoreSense Diagnostics module provides motor overheating protection. The CoreSense Diagnostics module
replaces the Kriwan module INT69TM.
Alarm conditions:
Trip cond
ition: PTC Resistance > 4.5 kΩ;
Reset c
ondition: PTC Resistance < 2.5 kΩ; 5 min time delay.
3.3
High discharge temperature protection
Discharge temperature protection is provided using a NTC sensor in the compressor cylinder head.
The sensor is pre-installed at the factory and connected to the module. CoreSense will protect the compressor from
high discharge temperature conditions. If the temperature sensor detects a discharge temperature higher than
