Multi-Pump VFD Controller for Duty Standby Booster Systems

A multi-pump VFD controller coordinates two or more pumps to maintain pressure and share running time. It is used in hotels, apartments, factories and commercial buildings where one pump may not cover all demand.

Recommended Configuration

What Must Be Confirmed?

• Number of pumps and motor current for each pump.
• Whether all pumps need VFD control.
• Target pressure and peak building demand.
• Duty standby or duty assist logic.
• Panel wiring, contactors and protection devices.

Selection Logic

The system logic should be defined before selecting the cabinet. Duty standby focuses on backup reliability, while duty assist adds pumps when demand rises. Pump alternation helps balance running hours and maintenance intervals.

Common Mistakes

• Treating backup logic and assist logic as the same.
• Forgetting pump alternation requirements.
• Using one pressure setting without checking peak demand.
• Selecting contactors and breakers without motor current data.

AUSENIST Solution

AUSENIST YS820 supports multi-pump constant-pressure control for booster applications. We can help define pump sequence, pressure sensor scaling and basic commissioning parameters.

FAQ

Can one VFD control multiple pumps?

Yes, depending on the required control logic and panel design.

What is duty standby?

One pump runs while another remains available as backup.

What is duty assist?

Additional pumps start when one pump cannot meet demand.

Related AUSENIST Pages

• YS820 three-pump constant pressure VFD controller
• Booster pump VFD with PID pressure sensor feedback

Send AUSENIST the pump quantity, motor nameplates and control logic. We can recommend the YS820 configuration.