Fixed Variable Speed Pump Wiring Diagram; Lead Pump Alternation Wiring Diagram - Danfoss VLT AQUA Drive FC 202 Design Manual

Application Examples

6.1.9 Fixed Variable Speed Pump Wiring Diagram

L1/L2/L3
6 6
Illustration 6.10 Fixed Variable Speed Pump Wiring Diagram
6.1.10 Lead Pump Alternation Wiring
Diagram
L1/L2/L3
k3
k2
K1
Illustration 6.11 Lead Pump Alternation Wiring Diagram
Every pump must be connected to 2 contactors (K1/K2 and
K3/K4) with a mechanical interlock. Thermal relays or other
motor protection devices must be applied according to
local regulation and/or individual demands.
•
RELAY 1 (R1) and RELAY 2 (R2) are the built-in
relays in the frequency converter.
•
When all relays are de-energized, the first built-in
relay that is energized cuts in the contactor
corresponding to the pump controlled by the
relay. For example, RELAY 1 cuts in contactor K1,
which becomes the lead pump.
146
Design Guide
L1/L2/L3
L1/L2/L3
FC
k3 K1
K1
k1
K4
K3
K2 K4
K3
Danfoss A/S © Rev. 06/2014 All rights reserved.
•
K1 blocks for K2 via the mechanical interlock
L1/L2/L3
preventing mains to be connected to the output
of the frequency converter (via K1).
•
Auxiliary break contact on K1 prevents K3 to cut
in.
•
RELAY 2 controls contactor K4 for on/off control
of the fixed speed pump.
•
At alternation, both relays deenergise and now
RELAY 2 are energised as the first relay.
L1/L2/L3
MG20Z202