Electrical Supply, Protection (D‑Curve) & Commissioning — Braemar RPS / RPM / RPL / RPXL


Important Disclaimer — Read Before Use

This article is a general electrical guide. Final responsibility for electrical compliance, breaker selection, cable sizing, isolation and workmanship rests with the installing electrician. All work must comply with AS/NZS wiring rules and local regulations and be cross‑checked against the latest official Seeley International Installation & Operation Manual for the specific model. Specifications may change without notice.


1) What the installation manuals detail

  • Dedicated circuit & adjacent isolator for every cooler. Verify the incoming supply matches the rating label before connecting.

  • Use D‑curve circuit breakers on RPS/RPM/RPL because the 2‑speed squirrel‑cage induction motor has a starting (inrush) current significantly higher than FLA.


  • Route power cables via the corner‑pillar knockouts and ensure the mains cable is not in contact with water inside the reservoir. (Electrical routing & safety instruction.)


  • Controls: Supplied switch‑plate gives FAN ON/OFF, COOL ON/OFF, SPEED LO/HI; each cooler needs a dedicated switch‑plate (no group control). Control circuit is 240 V, 4‑wire run by the installer back to the unit.

2) Why D‑curve?

“These belt‑drive models use 2‑speed induction motors. Start‑up (locked‑rotor) current is much higher than running current, so the manuals specify D‑curve breakers to tolerate inrush and prevent nuisance tripping.

(Background: Industry trip ranges — B curve ≈ 3–5× Inrush current, C curve ≈ 5–10× Inrush current, D curve ≈ 10–20× Inrush current — but the enforceable requirement is simply “use D‑curve” per the manuals.)


3) Electrical quick‑reference (2026 RPS / RPM / RPL)

Use this to brief Electricians and to set the right breaker curve at quoting stage.                                                  IMPORTANT!!! Always confirm the rating label on the unit supplied.


Electrical Supply, Protection & Cable‑Routing Quick Table

FamilyModelsNameplate supply & currentControl wiringProtection & isolationCable routing / safety
RPSRPS3200230 V / 1‑phase / 8.1 A240 V, 4‑wire from switch‑plateD‑curve breaker; dedicated circuit; adjacent isolatorRoute via corner‑pillar knockouts; keep mains clear of reservoir water
RPS4000415 V / 3‑phase / 5.9 ASame as aboveSame as aboveSame as above
RPMRPM5000415 V / 3‑phase / 6.6 A240 V, 4‑wireD‑curve; dedicated circuit; adjacent isolatorRoute via Corner‑pillar knockouts; keep cable clear of water
RPM6000415 V / 3‑phase / 6.6 ASame as aboveSame as aboveSame as above
RPM8000415 V / 3‑phase / 11.1 ASame as aboveSame as aboveSame as above
RPLRPL10000415 V / 3‑phase / 14.2 A240 V, 4‑wireD‑curve; dedicated circuit; adjacent isolatorRoute via Corner‑pillar knockouts; keep cable clear of water
RPL12000415 V / 3‑phase / 22.1 ASame as aboveSame as aboveSame as above
RPL14000415 V / 3‑phase / 29.4 ASame as aboveSame as aboveSame as above
RPXLRPXL16000415 V / 3‑phase / 32 ASame as aboveD‑curve; dedicated circuit; adjacent isolator 
Route via Corner‑pillar knockouts; keep cable clear of water
RPXL18000415 V / 3‑phase / 34 ASame as aboveSame as above Same as above
Switch‑plate operation: FAN ON/OFF, COOL ON/OFF, SPEED LO/HI; no group control — one switch‑plate per cooler.

4) Commissioning — electrical (field checklist)

  • Lock‑out / tag‑out and complete mechanical checks before energising. (Fan, pulleys, taper‑locks, belt condition/tension per model table in the manual.)


  • Set mains isolator to ON, then from the switch‑plate: FAN ON, select LOW then HIGH, confirm correct rotation, and check no abnormal noise/vibration on both speeds.


  • Do not start against closed dampers/blocked ducts; ensure downstream dampers/registers are open before fan run.


  • Record on your commissioning sheet: supply voltages (for 3‑phase, L1‑L2, L1‑L3, L2‑L3) and any observations. Use the installation checklist pages in the manual.

5) Quick points for electricians (to include on quotes)

  • “Each unit on its own circuit with an adjacent isolator.
  • “Allow for D‑curve breakers — these are two‑speed induction motors with high inrush.
  • 240 V, 4‑wire control from switch‑plate; one switch‑plate per cooler (no group control).