Mixed Pump Configuration - Danfoss MCO 101 Manual

Extended and Advanced Cascade Controller
Option

3.1.5 Mixed Pump Configuration

The Mixed Pump configuration supports a mix of variable speed pumps connected to drives as well as additional fixed-speed pumps. In this configuration,
all of the variable speed pumps and drives must be the same size. The fixed-speed pumps may be of different sizes. The variable speed pumps are staged
on and staged off first based on drive speed. The fixed-speed pumps are then staged on last and staged off last based on the feedback pressure.
Figure 3.5: Example
For this configuration, relay selections in Group 27-7* "Connections" are as follows:
27-70 RELAY 1 → [1] Drive 2 Enable
27-71 RELAY 2 → [74] Pump 3 to Line Voltage
27-72 RELAY 10→ [75] Pump 4 to Line Voltage
27-73 RELAY 11→ [0] Standard Relay
27-74 RELAY 12→ [0] Standard Relay
This configuration provides some of the benefits of the Master-Follower configuration with some of the initial cost savings of the Fixed Speed configuration.
It is a good choice when the extra capacity of the fixed pumps is rarely needed.
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MI.38.C2.22 - VLT is a registered Danfoss trademark
3 Supported Configuration
3
3-5