Bell and Gossett E15

What does Bell and Gossett E15 mean?

E15 indicates that one of the three power supply phases is missing on a three-phase e-90E Smart Pump installation. The drive detects the loss and shuts down immediately to prevent single-phase operation, which causes severe motor overheating and bearing damage in delta-connected motors. E15 only applies to three-phase pump models.

Symptoms

• Pump stops and displays E15 on the control panel.
• STATUS LED illuminates red steady.
• Fault occurs only on three-phase pump models.
• Fault signal relay activates on terminal pins 24 and 25.

Common causes

• Upstream fuse or circuit breaker has blown on one phase.
• Loose or disconnected power supply terminal inside the pump terminal box.
• Open-circuit failure in the supply wiring between the electrical panel and the pump.
• Faulty disconnect switch with one pole not making contact.
• Utility power disturbance causing temporary single-phasing.

Diagnostic steps

1. 01

   Isolate and lock out the supply

   Switch off and lock out the upstream disconnect before opening the pump terminal box. Verify zero voltage with a meter on all three phases before touching any wiring. Wait 5 minutes after disconnecting for DC-bus capacitors to discharge.

2. 02

   Check upstream fuses and circuit breakers

   Inspect the electrical panel supplying the pump. Test each fuse for continuity or check each breaker pole for trip condition. Replace blown fuses with the correct rating specified on the pump data plate.

3. 03

   Verify voltage at the pump terminals

   Restore power to the disconnect (with the pump isolated) and measure voltage between each pair of phases at the pump's L1, L2, L3 terminals. All three phase-to-phase voltages must be present and within ±10% of nameplate voltage.

4. 04

   Inspect terminal block connections

   Check the L1, L2, and L3 power terminals inside the pump terminal box for tightness. Retighten any loose connections to the specified torque of 0.8 Nm (7.1 lbf·in) for power terminals.

5. 05

   Restart after confirming all three phases present

   Once all three phases are confirmed present and balanced, restart the pump. Monitor the display for immediate recurrence of E15.

When to call a professional

Call a licensed electrician if E15 persists after confirming fuses and connections are intact. Tracking a phase loss fault through an electrical distribution system — including checking disconnect switch contacts, panel bus connections, and utility service — requires a licensed electrician with appropriate test equipment and arc-flash PPE.