Example Of Application - Constant Pressure Regulation In Water Supply System - Danfoss VLT 6000 series Operating Instructions Manual

Example of application - Constant pressure
regulation in water supply system
The demand for water from waterworks varies
considerably during the course of a day. In the night,
practically no water is used, while in the morning
and in the evening the consumption is high. In order
to maintain a suitable pressure in the water supply
lines in relation to the current demand, the water
supply pumps are equipped with speed control.
The use of frequency converters enables the energy
consumed by the pumps to be kept at a minimum,
while optimizing the water supply to consumers.
Set the following parameters:
Par. 100
Par. 205
Par. 302
Par. 314
Par. 315
Par. 316
Par. 403
Par. 404
Par. 405
Par. 406
Par. 413
Par. 414
Par. 415
Par. 418
Par. 420
Par. 423
Par. 424
Par. 427
12
Configuration
Maximum reference
Terminal 18 Digital inputs
Terminal 60, analog input current
Terminal 60, min. scaling
Terminal 60, max. scaling
Sleep mode timer
Sleep frequency
Wake-up frequency
Boost setpoint
Minimum feedback
Maximum feedback
Process units
Setpoint 1
PID normal/inverse control
PID proportional gain
PID integration time
PID low pass filter
®
VLT 6000 HVAC Series
A VLT 6000 HVAC with its integral PID controller
ensures simple and quick installation. For example,
an IP54 unit can be mounted close to the pump on
the wall and the existing line cables can be used as
mains supply to the frequency converter. A Pressure
transmitter (e.g. Danfoss MBS 33 0-10) bar can
be fitted a couples of metres from the joint outlet
point from the waterworks to obtain closed loop
regulation. Danfoss MBS 33 is a two-wire transmitter
(4-20 mA) that can be powered directly from a VLT
6000 HVAC. The required setpoint (e.g. 5 bar) can
be set locally in parameter 418 Setpoint 1.
Closed loop [1]
10 bar
Start [1]
Feedback signal [2]
4 mA
20 mA
10 sec.
15 Hz
20 Hz
125%
0
10 bar
Bar [16]
5 bar
Normal
0.5-1.0
3-10
0.5-1.5
MG.61.A5.02 - VLT is a registered Danfoss trademark