PL Fault – Braemar SCHV / SDHV Inverter Systems

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Applies To (Common Models)

  • Single‑phase outdoor units
    • SCHV07D1S / SCHV10D1S / SCHV12D1S / SCHV14D1S / SCHV16D1S
    • Used with SDHV, SBHV, KBHV, SACV, KACV indoor units
  • Three‑phase ducted units
    • SCHV20D3S / SCHV24D3S with SDHV20D1S / SDHV24D1S
Model and electrical details: Residential Service Guide – SDHV Series overview (pp. 14–16)

Fault Code

PL

Fault Description

The PL fault is a power‑supply protection fault generated by the outdoor inverter.
⚠️ The meaning depends on whether the unit is single‑phase or three‑phase.

Supply Type

PL Fault Meaning

Single phase

Low supply voltage / DC bus under‑voltage protection

Three phase

Phase loss, phase imbalance, or incorrect phase supply

General inverter protection behaviour: Error Codes – Ducted Split Systems (pp. 61–62)

Single‑Phase Units – PL Fault (e.g. SCHV10D1S)

Meaning

The inverter has detected incoming voltage below allowable limits, typically when the compressor attempts to start or ramp up.
Electrical limits for single‑phase SDHV/SCHV systems: SDHV Technical Specifications (p. 15)

Common Causes

  • Low mains voltage (network brown‑out)
  • Voltage drop under load
  • Long cable run to outdoor unit
  • Undersized supply cable
  • Loose or heat‑damaged isolator, breaker, or terminals
  • Failing circuit breaker or isolator

Troubleshooting – Single Phase

  1. Measure voltage at the outdoor unit: 
    • Static (unit idle)
    • During compressor start / under load
  2. Inspect: 
    • Outdoor isolator
    • Circuit breaker
    • Power terminals at outdoor unit
  3. Confirm: 
    • Cable size matches specification
    • No signs of overheating or loose connections
  4. Rectify supply issue and power reset the system
✅ If voltage remains within 220–240 V under load and PL fault persists, suspect outdoor inverter / power PCB.
Voltage requirements: SDHV Technical Specifications (p. 15)

Three‑Phase Units – PL Fault (SDHV20 / SDHV24)

Meaning

The inverter has detected loss of one or more phases, phase imbalance, or incorrect 3‑phase supply.
Three‑phase electrical data: SDHV 3‑Phase Technical Specifications (p. 16)

Common Causes

  • One phase missing
  • Blown fuse or single pole tripped
  • Loose phase connection
  • Incorrect phase rotation
  • Supply voltage outside 380–415 V range
  • Faulty isolator or contactor

Troubleshooting – Three Phase

  1. Measure phase‑to‑phase voltages: 
    • L1–L2
    • L2–L3
    • L1–L3
  2. Confirm voltages are balanced and within specification
  3. Check: 
    • All fuses and breaker poles
    • Terminal tightness
    • Phase sequence
  4. Restore correct supply and reset system
✅ If correct supply is confirmed and PL fault remains, suspect outdoor inverter / power PCB.
Electrical limits: SDHV 3‑Phase Technical Specifications (p. 16)

Important Notes

  • PL is an electrical supply fault, not a refrigeration fault
  • Do not check refrigerant charge or sensors until supply integrity is confirmed
  • Common after: 
    • Power outages
    • Electrical upgrades or rewiring
    • Hot weather peak demand conditions

Quick Field Summary

Single‑phase PL = Low voltage under load
Three‑phase PL = Phase loss or imbalance

Related Documents

  • Braemar Residential Service Guide ES E247‑A 
    • SDHV Series Overview – pp. 14–16
    • Error Codes – Ducted Split Systems – pp. 61–62