PL Fault – Braemar SCHV / SDHV Inverter Systems

⚠️ Safety Notice – Reverse Cycle Air Conditioners

This equipment must only be installed, commissioned, serviced and repaired by suitably qualified and licensed personnel.


Before commencing work, complete a task-specific risk assessment and ensure electrical isolation procedures, safe access, adequate service clearances and appropriate PPE have been considered. All work must comply with applicable regulations, standards and manufacturer requirements.


Particular care must be taken when working around electrical systems, refrigerant circuits, moving parts, roof spaces, ceiling spaces, confined spaces and working-at-heights hazards where applicable.


Do not proceed if safe access, required clearances, confined space risks or appropriate safety controls cannot be achieved and maintained. 


Safety takes priority over diagnosis, repairs, installation schedules and customer expectations. If the task cannot be completed safely, it must not proceed until the risks have been adequately controlled.

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