64
Sleep Mode
Sleep mode makes it possible to stop the drive when the system
demand drops below a preset level. When the demand increases to a
higher preset level, the drive will restart. A significant amount of energy
can be saved using sleep mode. Unlike a set-back time clock, the drive
is always available to run when the demand reaches the preset wake
up level. Sleep mode is not active if
Local Reference
is selected in
parameter 203,
Reference Handling
, or if the
Jog
function activates via
digital inputs. Sleep mode operates in both
Open Loop
and
Closed
Loop
.
Activate sleep mode in parameter 403,
Sleep Mode Timer
. In this
parameter, set how long the output frequency must be lower than the
sleep frequency set in parameter 404,
Sleep Frequency,
before sleep
mode activates. After the set time, the drive will ramp down the motor to
a stop, as controlled by parameter 207,
Ramp Down Time
. If the output
frequency needed to meet the system demand rises above the sleep
frequency during the timed period, the drive will simply ramp up to the
demanded frequency.
When the sleep mode timer expires and the drive is stopped in sleep
mode, a theoretical output frequency is calculated based upon the
reference signal. When the theoretical output frequency rises above the
frequency set in parameter 405,
Wake-up Frequency
, the drive will
restart the motor and ramp up to the commanded reference.
For closed loop operation, it may be useful to over satisfy the system
before putting the drive into sleep mode. The boost setpoint parameter
provides for this. After the sleep mode timer expires, the drive will reset
the set point based on the value in parameter 406,
Boost Setpoint
.
Once this new setpoint is satisfied, the drive enters sleep mode. A
setting of 100% in parameter 406,
Boost Setpoint,
indicates no setpoint
boost. Boost setpoint is only active in
Closed Loop
, selected in
parameter 100,
Configuration.
Sleep Mode Frequency Response
