Soft Starters; Configuring The System; Setting-Up The Cascade Parameters - Danfoss VLT Series Operating Instructions Manual

1 Extended and Advanced Cascade Controller
Option
For this configuration relay selections in Group 27-7* "Connections" are as follows:
27-70 RELAY 1→ [8] Pump 1 to Drive 1
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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 → [74] Pump 3 to Mains
Illustration 1.13: 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
27-72 RELAY 10 → [74] Pump 3 to Mains
27-73 RELAY 11 → [75] Pump 4 to Mains
27-74 RELAY 12 → [76] Pump 5 to Mains

1.4.7 Soft Starters

Soft Starters can be used in place of contactors for any configuration using fixed speed pumps. If Soft Starters are selected, they must be used for ALL
fixed speed pumps. Mixing Soft Starters and contactors will result in an inability to control the output pressure during staging and de-staging transitions.
When using soft-starters a delay will be added from staging signal occurs until staging takes place. The delay is necessary due to the ramp time of the
fixed speed pump because of the soft-starter.

1.5 Configuring the System

The Extended- and Advanced Cascade Controller can be quickly configured using many of the default parameters. However, it is first necessary to describe
the configuration of frequency converters and pumps in the system and to describe the desired level of control of the systems output.

1.5.1 Setting-up the cascade parameters

Parameter groups 27-1* "Configuration" and 27-7* "Connections" are used to define the hardware configuration of the installation. Start the configuration
of the cascade controller by selecting values for the parameters in the 27-1* "Configuration" group.
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MI.38.C3.02 - VLT is a registered Danfoss trademark
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VLT Operating Instructions