VLT
®
6000 HVAC
109
MG.60.B1.02 - VLT is a registered Danfoss trade mark
★
= factory setting. ( ) = display text [ ] = value for use in communication via serial communication port
Programming
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Sleep mode
Sleep mode makes it possible to stop the motor
when it is running at low speed and thus has almost
no load. If consumption in the system goes back up,
the VLT frequency 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 for how long the output
frequency can be lower than the frequency set in
parameter 404
Sleep frequency
. When the timer runs
out, the VLT frequency converter will ramp down the
motor to stop via parameter 207
Ramp-down time
. If
the output frequency rises above the frequency set in
parameter 404
Sleep frequency
, the timer is reset.
While the VLT frequency converter has stopped the
motor in sleep mode, a theoretical output frequency
is calculated on the basis of the reference signal.
When the theoretical output frequency rises above
the frequency in parameter 405
Wake up frequency
,
the VLT frequency converter will restart the motor and
the output frequency will ramp up to the reference.
In systems with constant pressure regulation, it is
advantageous to provide extra pressure to the
system before the VLT frequency converter stops the
motor. This extends the time during which the VLT
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 VLT
frequency converter stops the motor, parameter 406
Boost setpoint
is set to 125%.
Parameter 406
Boost setpoint
is only active in
Closed
loop
.
