Table 4 – Output Torque Foldback
Action taken by the Drive
Output Torque >= Foldback Limit of operating speed
range
Will reduce the speed at the rate of 60 rpm/s
Recovering Torque <= Output Torque < Foldback Limit
of operating speed range
Will remain in the current speed
Output Current < Recovering Current
Speed will be recovered to commanded speed
If the compressor load is not recovered and continue to
exceed the foldback limit in one of the conditions below:
• After compressor running speed has reached to
Envelope min foldback speed and then stay at
Envelope min foldback speed for >= 30sec.
OR
• If the original running speed was already <
Envelope min foldback speed for >= 30sec
Compressor will be tripped
Table 5 – IGBT Temperature Foldback
Action taken by the Drive
IGBTTemperature >= Foldback Temperature
Will reduce the speed at the rate of 180 rpm/s
Recovering Temperature <= IGBT Temperature <
Foldback Temperature
Will remain in the current speed
IGBT Temperature < Recovering Temperature
Speed will be recovered to commanded speed
If the compressor load is not recovered and continue to
exceed the foldback limit in one of the conditions below:
• After compressor running speed has reached to
Envelope min foldback speed and then stay at
Envelope min foldback speed for >= 30sec.
OR
• If the original running speed was already <
Envelope min foldback speed for >= 30sec
Compressor will be tripped
Table 6 – Inverter Temperature Foldback
Action taken by the Drive
Inverter Temperature >= Foldback Temperature
Will reduce the speed at the rate of 180 rpm/s
Recovering Temperature <= Inverter Temperature <
Foldback Temperature
Will remain in the current speed
Inverter Temperature < Recovering Temperature
Speed will be recovered to commanded speed
If the compressor load is not recovered and continue to
exceed the foldback limit in one of the conditions below:
• After compressor running speed has reached to
Envelope min foldback speed and then stay at
Envelope min foldback speed for >= 30sec.
OR
• If the original running speed was already <
Envelope min foldback speed for >= 30sec
Compressor will be tripped