6.4 High discharge temperature protection
Discharge temperature protection is provided using a PT1000 sensor in the compressor
cylinder head.
The sensor is pre-installed at the factory and connected to the Next Gen CoreSense
module. The module will protect the compressor from high discharge temperature
conditions. If the temperature sensor detects a discharge temperature higher than 154
°C, the module will shut off the compressor until the temperature cools down to an
acceptable level (20 K below setpoint).
The configurable range of trip settings is 108 °C to 154 °C and the reset value is 83 °C to
134 °C.
•
Trip value ≥ 154 °C for 0.5 sec
•
Trip alarm: automatic reset after 2 minutes; discharge temp < 130 °C
PT1000 sensor technical data:
•
Measuring range: -40°C to 155°C, 170°C for
30 minutes max
•
Tightening torque: 15 Nm
•
Protection class: IP65
6.3 Motor overheat protection
By using Positive Temperature Coefficient (PTC) thermistors on 4M* and 6M* Stream
compressor models, Next Gen CoreSense provides motor overheating protection.
Two chains of three thermistors each connected in series are embedded in the motor
windings.
-
Static overheat protection
The Next Gen CoreSense module will trip the compressor if the motor windings are
getting too hot.
•
Standard condition:
Total resistance of the thermistor chains @ 25 °C ≤ 1.8 k
Ω
•
Alarm condition:
Trip condition: PTC resistance > 4.5 k
Ω
;
Reset condition: PTC resistance < 2.75 k
Ω
; 5 min time delay.
•
Trip due to sensor failure:
Short circuit: PTC resistance < 20
Ω
; Open circuit: PTC resistance > 20k
Ω
. 5
-
Dynamic overheat protection
If the motor winding temperature increases in a short period (>240
Ω
/400ms), the
module will trip the compressor. The compressor will restart after 5 minutes.
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