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Figure 3.8: 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.
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 Line Voltage
27-73 RELAY 11
→
[73] Pump 2 to Line Voltage
27-74 RELAY 12
→
[74] Pump 3 to Line Voltage
Figure 3.9: Example 3
The first two pumps alternate each with 50% of the running hours. The fixed-speed pumps turned on and off as needed with equal running time between
them.
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
3 Supported Configuration
Extended and Advanced Cascade Controller
Option
3-8
MI.38.C2.22 - VLT
®
is a registered Danfoss trademark
3