McQuay WMC Fault Code E15
McQuay WMC Fault Code E15 is a warning alarm indicating: Power supply fault. The most common causes include Voltage outside acceptable range. Estimated repair time: 1-2 hours. This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
Power supply fault
Brand: McQuay | Model: WMC (Water-Cooled Screw Chiller) | Code: E15 | Severity: Warning
Observable Symptoms
- Controller displays alarm code and description
- Chiller may be locked out or running in degraded mode
- Alarm indicator light is illuminated on control panel
What to Check First
Before diving into detailed diagnostics, start with this quick first check:
Probable Causes
- Voltage outside acceptable range
- Phase voltage imbalance exceeding limits
- Transformer failure or tap wrong
- Power factor correction issue
Recommended Inspection Steps
- Measure power supply voltage on all phases
- Check phase-to-phase voltage balance
- Verify transformer tap settings
- Inspect power factor correction capacitors
- Contact utility if voltage is consistently abnormal
Required Tools & Equipment
- Digital multimeter
- Phase rotation tester
- Safety PPE (gloves, safety glasses, face shield)
Estimated Repair Time
1-2 hours
When to Call a Professional
- If the fault persists after completing all recommended inspection steps
- If you observe unusual noises, vibrations, or oil leaks from the compressor
- If refrigerant charge levels are outside OEM specifications and EPA-certified recovery is needed
- If electrical measurements show voltage imbalance greater than 2% between phases
- If the fault recurs immediately after reset, indicating an unresolved safety condition
- Contact an authorized McQuay service representative for warranty-covered repairs
Related Fault Codes
Other McQuay WMC codes that may be related:
OEM Service Manual Reference
OEM Reference: McQuay WMC Water-Cooled Screw Chiller Service Manual. Available through Daikin Applied (formerly McQuay) technical support.
Frequently Asked Questions
What does McQuay WMC fault code E15 mean?
Fault code E15 on a McQuay WMC chiller indicates: Power supply fault. This is a warning alarm that requires diagnostic attention.
What causes McQuay WMC alarm code E15?
Common causes include: Voltage outside acceptable range; Phase voltage imbalance exceeding limits; Transformer failure or tap wrong
How do I fix McQuay WMC error code E15?
Follow the recommended inspection steps below. Start with the quick check, then proceed through each step. If the fault persists after all steps, contact an authorized McQuay service representative.