relay. For example, relay 1 cuts in contactor K1,
which becomes the lead pump.
•
K1 blocks for K2 via the mechanical interlock,
preventing mains from being connected to the
output of the drive (via K1).
•
Auxiliary break contact on K1 prevents K3 from
cutting in.
•
Relay 2 controls contactor K4 for on/o control of
the xed speed pump.
•
At alternation, both relays de-energize and now
relay 2 is energized as the 1
st
relay.
Application Examples Design Guide
MG16C302 Danfoss A/S © 11/2017 All rights reserved. 215
12 12