Delta VFD-EL-W Series, User Manual

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Chapter 4 Parameters

VFD-EL-W
4-93
1: Fixed time circulation (alternative operation)
2: Fixed quantity control (multi-pump operating at constant pressure)

When using the multi-pump control mode, you must set Pr.10.35 for each pump to the same value.
10.36 Multi-pump ID
Settings 0–4
0: Multi-pump control mode is disabled
1: Master
2–4: Slave Default: 0

When using the multi-pump control mode, the settings of each pump for Pr.10.36 cannot be the same.
10.37

Multi-pump’s Fixed Time Circulation Period
Settings 1–65535 minutes Default: 60

This parameter is only valid for master pump settings.

Fixed time circulation mode (alternative operation): Assume that when pump #1’s operating time is longer
than the setting for Pr.10.37, pump #1 stops, and then pump #2 activates, and so on.

Fixed quantity control (multi-pump operating at constant pressure): Assume that when the master pump’s
operating time is longer than the setting for Pr.10.37, the master pump and the slave pump switch
alternatively.
10.38

Frequency to Start Switching Pumps
Settings 0.00 Hz–F
MAX
Default: 60.00
10.39

Time Detected When Pump Reaches the Starting Frequency
Settings 0.0–3600.0 sec. Default: 1.0
10.40

Frequency to Stop Switching Pumps
Settings 0.00 Hz–F
MAX
Default: 48.00
10.41

Time Detected When Pump Reaches the Stopping Frequency
Settings 0.0–3600.0 sec. Default: 1.0

This parameter is only valid for master pump settings.

This parameter is only valid for fixed quantity control (multi-pump operating at constant pressure) mode.

When the master pump’s operating frequency ≥ Pr.10.38, and the time exceeds Pr.10.39, slave pump #1
activates. If the quantity of water is still insufficient, slave pump #2 and #3 activates under the same
conditions.

If the master pump’s operating frequency ≤ Pr.10.40, and the time exceeds Pr.01.41, slave pump #1 stops.
If the master pump can fulfill the conditions, slave pump #2 and #3 stop in sequence, and leave the master
pump in operation only.

Whether the master pump stops depends on the stopping detection function.
10.42

Pump’s Frequency at Time-out (Disconnection)
Settings 0.00 Hz–F
MAX
Default: 0.00

This parameter is only valid for slave pump settings.

For details on the conditions of communication disconnection and treatment, refer to Pr.09.02
Transmission Fault Action and Pr.09.03 Time-out Detection.

If disconnection (time-out) occurs in the fixed quantity control (multi-pump operating at constant pressure)
mode, the frequency for the slave pump is Pr.10.42. When you press the STOP key, the disconnected
slave pump is in single-pump mode. (The RUN command and operating frequency is set by the parameter
settings for the slave pump.)

The master pump can re-detect the disconnection of the salve pump.