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154°C, the CoreSense will shut off the compressor until the temperature cools down to an acceptable level (about
130°C).
Either trip or lockout alarm can be selected by user using the PC interface software. Default is trip alarm. Trip and
reset settings are configurable using PC interface software. The configurable range of trip settings is 108°C to
154°C and the reset value is 83°C to 130°C.
Trip/lockout v
alue ≥ 154°C for 2 sec.
Trip alarm: automatic reset after 2 minutes; discharge temp < 130°C.
Lockout alarm: manual reset is necessary.
3.4
Locked rotor protection
CoreSense detects the locked rotor condition of the compressor. It has trip and lockout alarms. Initial alarm will be
“Trip” alarm with autoreset and 10 consecutive trip alarms will result in “Lockout” alarm which requires manual
reset.
3.5
Missing phase protection
If any one of the 3 power phases is missing immediately after the compressor contactor is energized, a single-
phasing condition exists.
The maximum response time shall be 1.2 seconds from the time of contactor energization.
Alarm conditions:
Appears in case of missing phase conditions.
Trip time: 5 minutes with automatic reset.
Lockout condition: Appears after the 10 consecutive trip alarms. Manual reset (using 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 voltage.
Alarm conditions:
Motor compressor voltage < low voltage setting at compressor running state. The default low
voltage setting is 75% of the nominal line voltage stored in the module for 2 seconds.
Trip time: 5 minutes.
The module determines the operating frequency of the compressor. The compressor low voltage setting shall be
lowered by the same percentage as the operating frequency if less than the nominal frequency. For example if a
60 Hz nominal frequency compressor is running at 57 Hz (5% less), then the low voltage setting shall be reduced
by 5%.
3.7
Voltage imbalance protection
The purpose of this feature is to protect the compressor against a voltage imbalance condition that leads to motor
overheating.
A configurable setting (default = 5%) for voltage imbalance is used to determine the operating limit of the
compressor. The voltage imbalance setting is configurable in the range of 2 to 8 % using the PC interface software.
Alarm conditions:
Trip: When the voltage imbalance > 5% (configurable).
Reset: Automatic reset after 5 min; voltage imbalance < 5%.
