Pentair IntelliFlo VSF Over Voltage Alarm
The over voltage alarm on the Pentair IntelliFlo VSF indicates excessive voltage on the drive's internal DC bus. This is an alarm condition — the red alarm light illuminates and all control panel buttons are disabled until the alarm is cleared.
How the Alarm Works
The over voltage alarm indicates excessive supply voltage or that 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 automatically 20 seconds after the over voltage condition clears.
Power Out / OFF Condition
A related condition occurs when the incoming supply voltage drops below what is required. In this case, 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 — approximately 20 seconds. If power is restored during this 20-second window, the drive will not restart until the save process completes.
Important
If power is restored during the approximately 20-second capacitor discharge period after a power outage, the drive will not restart until the parameter-save process completes. Allow the drive to complete this process before expecting the pump to restart.
Causes and Corrective Actions
Excessive Supply Voltage
Check voltage at the motor terminals and at the panel while the pump is running. If voltage is too high, consult the power company. Check line voltage — if greater than 110% of rated voltage, consult a licensed electrician.
External Water Source Rotating the Motor
An external water source (such as a return line with significant back-pressure or a waterfall feeding into the plumbing) can cause the pump and motor to rotate when the pump is not commanded to run. This rotation generates back-EMF (voltage) that appears on the drive's internal DC bus as an over voltage condition. Install a check valve in the discharge line to prevent back-flow from rotating the pump when it is stopped. Use a check valve when plumbing in parallel with another pump to prevent reverse rotation of the impeller and motor.
Loose Connections
Check for loose connections at the motor terminals and in the field wiring compartment. Tighten any loose wiring connections.