Danfoss VLT 2800 Series Operating Instructions Manual page 55

• Dry run protection. Shuts down at no or low
flow and protects the motor and pump from
overheating.
• Improved energy savings with Enhanced
sleep mode.
• Minimized risk of bacterial growth in drinking
water because of insufficient motor cooling.
• Easy commissioning.
Only centrifugal pumps with radial impeller show a
clear one to one relationship between flow and power.
Consequently proper functionality of the Enhanced
Sleep Mode and Dry Run Detection is only given for
this type of pump.
462 Enhanced Sleep Mode Timer
(ESL timer)
Value:
Value 0 – 9999 sec.
Function:
The timer prevents cycling between Sleep mode and
normal operation. If for instance the power consump-
tion falls below the no/low flow power curve the fre-
quency converter will change mode when the timer
expires.
Description of choice:
In case of cycling, set the timer to an appropriate value
that limits the number of cycles.
The value 0 disables Enhanced sleep mode.
Note: In parameter 463 Boost set point it is possible to
set up the frequency converter to provide a pressure
boost before the pump is stopped.
= factory setting, () = display text, [] = value for use in communication via serial communication port
54
VLT
463
Value:
1 - 200 %
Function:
This function can only be used if Closed loop has been
selected in parameter 100.
In systems with constant pressure regulation, it is ad-
vantageous to increase the pressure in the system
before the frequency converter stops the motor. This
extends the time during which the frequency converter
stops the motor and helps to avoid frequent starting
and stopping of the motor, e.g. in the case of leaks in
the water supply system.
There is a fixed boost time-out on 30 sec. in case the
boost setpoint cannot be reached.
Description of choice:
0 = OFF
Set the required Boost setpoint as a percentage of the
resulting reference under normal operation. 100% cor-
responds to the reference without boost (supplement).
MG.27.A2.02 - VLT
®
2800 Series
Boost setpoint
(BOOST SETPOINT)
100 % of setpoint
®
is a registered Danfoss trademark