Hibernation Mode - Siemens SED2 series Operating Instructions Manual

Siemens Building Technologies
HVAC Products
6.4.7

Hibernation mode

If the VSD reaches the hibernation setpoint in PID operating mode, the hibernation
timer P2391 starts. After the timer has expired, the VSD drives the output frequency of
the ramp to 0 Hz. See illustration below.
f
Output [Hz ]
P2392 Restart freq.
P2390 Hibernation freq.
Min. freq.
PID error [% ]
0%
max.
hibernation
(-) error [%]
T1 – Hibernation frequency reached.
– Start of hibernation timer.
T2 Minimum output frequency reached.
T3
– Output frequency decreased in accordance with the set ramp.
– PID control of the output frequency is interrupted.
T4 Output frequency = zero (motor standstill).
T3 to The PID fault signal [%] is monitored.
T5 Note:
– The polarity of the PID fault signal.
– The polarity of the PID fault signal must match the sequence of the
controlled functions (cooling/heating or vice-versa).
– The temperature setpoint can be below 0 °C.
– The PID fault signal can be positive or negative.
T5
– The VSD output frequency is again increased.
– The PID control of the output frequency is again enabled.
SED2 variable speed drives
Programming
Drive frequency
P2391 Hibernation
Hibernation timer
T1 T2 T3 T4
PID frequency
Restart
mode
T5
CM1U5192en
Time [s]
Time [s]
5192D06en
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