Pentair IntelliFlo XF Over Voltage Alarm

The over voltage alarm on the Pentair IntelliFlo XF indicates that voltage on the drive's internal DC bus has exceeded safe operating limits. The drive will restart automatically 20 seconds after the over voltage condition clears.

How the Over Voltage Alarm Works

The over voltage alarm indicates excessive supply voltage or an external water source is causing the pump and motor to rotate, thereby generating an excessive voltage on the drive's internal DC bus. The drive will restart 20 seconds after the over voltage condition clears.

Two Causes of Over Voltage

Cause 1: Excessive Supply Voltage

The supply voltage coming into the drive is too high. The IntelliFlo XF is rated for 230 VAC input. If the incoming supply voltage exceeds safe limits — for example due to utility fluctuations, incorrect wiring, or a shared circuit with voltage-generating equipment — the drive will fault on over voltage.

From the manual's troubleshooting chart:

• Check voltage at motor terminals and at the panel while the pump is running
• Check line voltage: if less than 90% or more than 110% of rated voltage, consult a licensed electrician
• Check for loose connections
• Tighten any loose wiring connections

Cause 2: Back-EMF from an External Water Source

An external water source — such as a waterfall, elevated body of water, or another pump in the system — can cause the pump impeller to rotate even when the pump is powered off or not commanded to run. This rotation causes the motor to act as a generator, producing a back electromotive force (back-EMF) that feeds voltage back into the drive's DC bus and triggers the over voltage alarm.

If the over voltage alarm appears when the pump is at rest or starting up, check whether water flow from another source is spinning the impeller.

Power Out / OFF Condition

A related condition — separate from the over voltage alarm — is the Power Out/OFF fault. This occurs when the incoming supply voltage drops below 170 VAC. The drive faults to protect itself from over current. The drive contains capacitors that keep it powered long enough to save the current run parameters. If power is restored during this process (approximately 20 seconds), the drive will not restart until the save process is completed.