Danfoss VLT HVAC Drive FC 102 Design Manual page 168

Application Examples
•
K1 blocks for K2 via the mechanical interlock
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 de-energise and now
Relay 2 is energised as the first relay.
6 6
166
Design Guide
Danfoss A/S © Rev. 05/2014 All rights reserved. MG16C202