Danfoss VLT Programming Guide

25-27 Stage Function
Option: Function:
If the Stage Function is set to Disabled [0], par. 25-28 Stage Function Time will not be activated.
[0] Disabled
[1] * Enabled
25-28 Stage Function Time
Range: Function:
15 s* [0 - 300 s] The Stage Function Time is programmed to avoid frequent staging of the fixed speed pumps. The
Stage Function Time starts if it is
Enabled [1] by par. 25-27 Stage Function , and when the variable
speed pump is running at
Motor Speed High Limit , par. 4-13 Motor Speed High Limit [RPM] or
par. 4-14
Motor Speed High Limit [Hz] , with at least one fixed speed pump in the stop position.
When the programmed value of the timer expires, a fixed speed pump is staged.
25-29 Destage Function
Option: Function:
The Destage Function ensures that the lowest numbers of pumps are running to save energy and
to avoid dead head water circulation in the variable speed pump. If the Destage Function is set to
Disabled [0], the par. 25-30 Destage Function Time will not be activated.
[0] Disabled
[1] * Enabled
25-30 Destage Function Time
Range: Function:
15 s* [0 - 300 s] The Destage Function Timer is programmable to avoid frequent staging/destaging of the fixed speed
pumps. The Destage Function Time starts when the adjustable speed pump is running at
par. 4-11
Motor Speed Low Limit [RPM] or par. 4-12 Motor Speed Low Limit [Hz] , with one or more
fixed speed pumps in operation and system requirements satisfied. In this situation, the adjustable
speed pump contributes a little to the system. When the programmed value of the timer expires, a
stage is removed, avoiding dead head water circulation in the adjustable speed pump.
3.23.4 25-4* Staging Settings
Parameters determining conditions for staging/destaging the pumps.
VLT
®
HVAC Drive Programming Guide 3 Parameter Description
MG.11.C9.02 - VLT
®
is a registered Danfoss trademark 245
3

Danfoss VLT Specifications

General

Frequency	50/60 Hz
Enclosure	IP20, IP21, IP55, IP66
Series	VLT
Control Technique	Flux Vector Control
Output Voltage	0-Vinput
Control Method	Fieldbus
Communication Interface	PROFIBUS, CANopen
Protection Features	Overload, Overvoltage, Undervoltage, Short Circuit, Ground Fault
Cooling Method	Liquid Cooled
Storage Temperature	-25°C to +70°C
Relative Humidity	5-95% non-condensing
Altitude	Up to 1000m (3280ft) without derating, up to 4000m (13120ft) with derating
Operating Temperature	-10°C to +50°C (14°F to 122°F)