Danfoss VLT 6000 HVAC Series

Sleep mode
Sleep mode makes it possible to stop the motor when
it is running at low speed, similar to a no load situation.
If consumption in the system goes back up, the fre-
quency converter will start the motor and supply the
power required.
NB!
Energy can be saved with this function,
since the motor is only in operation when
the system needs it.
Sleep mode is not active if Local reference or Jog has
been selected
The function is active in both Open loop and Closed
loop.
In parameter 403 Sleep mode timer, the Sleep mode is
activated. In parameter 403 Sleep mode timer, a timer
is set that determines how long the output frequency
can be lower than the frequency set in parameter 404
Sleep frequency. When the timer runs out, the fre-
quency converter will ramp down the motor to stop via
parameter 207 Ramp-down time. If the output frequen-
cy rises above the frequency set in parameter 404
Sleep frequency, the timer is reset.
While the frequency converter has stopped the motor
in sleep mode, a theoretical output frequency is cal-
culated on the basis of the reference signal. When the
theoretical output frequency rises above the frequency
in parameter 405 Wake up frequency, the frequency
converter will restart the motor and the output frequen-
cy will ramp up to the reference.
In systems with constant pressure regulation, it is ad-
vantageous to provide extra pressure to the system
before the frequency converter stops the motor. This
extends the time during which the frequency converter
has stopped the motor and helps to avoid frequent
starting and stopping of the motor, e.g. in the case of
system leaks.
If 25% more pressure is required before the frequency
converter stops the motor, parameter 406 Boost set-
point is set to 125%.
Parameter 406 Boost setpoint is only active in Closed
loop.
NB!
In highly dynamic pumping processes, it
is recommended to switch off the Flying
Start function (parameter 402).
VLT
®
6000 HVAC Series
= factory setting, () = display text, [] = value for use in communication via serial communication port
MG.61.B5.02 - VLT
®
is a registered Danfoss trademark 141
Programming