Mixed Pump Configuration With Alternation - Danfoss VLT Series Operating Instructions Manual

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VLT Operating Instructions

1.4.6 Mixed Pump Configuration with Alternation

In this configuration is possible to alternate the Drive between two pumps along with controlling additional fixed speed pumps. The cascade controller
will attempt to balance the running hours between all of the pumps as specified by the Runtime Balancing parameter.
Illustration 1.11: Example 1
The two pumps can be ether variable speed or fixed speed with equal running hours.
For this configuration relay selections in Group 27-7* "Connections" are as follows:
27-70 RELAY 1 → [8] Pump 1 to Drive 1
27-71 RELAY 2 → [16] Pump 2 to Drive 1
27-72 RELAY 10 → [72] Pump 1 to Mains
27-73 RELAY 11 → [73] Pump 2 to Mains
27-74 RELAY 12→ [0] Standard Relay
Illustration 1.12: Example 2
The first two pumps can be either variable speed or fixed speed with equal running hours between all three pumps as long as the system demand is
typically greater than 1 pump.
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MI.38.C3.02 - VLT is a registered Danfoss trademark
1 Extended and Advanced Cascade Controller
Option
1
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