The Supco RO Series Relay–Overload Combo (RO22/RO42/RO62/RO82) is a fair dinkum plug-and-play start solution for single-phase refrigeration compressors. Built for licensed HVAC/R techs and apprentices, it snaps on quick, protects the start winding, and gets you off the roof faster—no worries.
Key Features & Benefits
- Pre-wired relay + overload: Minimal terminations = faster swaps and fewer wiring errors on hot, dusty sites.
- Works with or without a start capacitor: One part covers multiple compressor setups—cuts van stock and guesswork.
- Locked-rotor protection: Built-in overload prevents start-winding burnout when motors hang at LRA.
- Snap-on bracket: Quick, secure mounting—even when you’re on a ladder in 40 °C, it’s a bloody good time-saver.
- UL Recognized: Recognised safety compliance for easy sign-off on residential and light commercial jobs.
- 230 VAC models with clear HP ranges: Pick the right RO model for clean starts and fewer call-backs.
Why This Product Matters
Hot Brisbane rooftop, unit short-cycling, client breathing down your neck—you know the drill. We’ve dropped an RO42 on a café coldroom before lunch, pressed the thermostat, and she fired first go. That’s the point: reliable starts, protected windings, and less downtime. If you’re matching across systems or replacing failed start gear, browse the relay overload range to confirm your HP/amps in one hit.
Pro Tip
Isolate power and let the compressor cool before fitting. Heat-soaked overloads can nuisance-trip—waiting a few minutes helps the RO seat properly and saves a “why won’t it start?” headache. For safe isolation practices, see Safe Work Australia.
Compatibility & System Info
- Supply: 230 VAC, single-phase
- Refrigerants: R32, R410A, R134a (typical AU service work)
- Start capacitor: optional (RO series operates with or without)
Local Trade Context
From Darwin humidity to Tassie winters, these Supco RO units cop the lot and keep on. Less mucking about, more reliable starts—too easy.
What’s Included
- 1 × Supco Relay–Overload Combo (select RO22 / RO42 / RO62 / RO82)
- Snap-on mounting bracket (integrated)
- Factory pre-wired terminals
Specifications
| Model | HP Range | Voltage | Mount |
|---|---|---|---|
| RO22 | ½ HP | 230 VAC | Snap-on bracket |
| RO42 | ¼–⅓ HP | 230 VAC | Snap-on bracket |
| RO62 | 1⁄6–1⁄5 HP | 230 VAC | Snap-on bracket |
| RO82 | 1⁄12–1⁄8 HP | 230 VAC | Snap-on bracket |
Warranty & Returns
Backed by manufacturer warranty. 30-day returns if unused in original packaging—she’ll be right if you need to swap.
FAQs
- Which RO model do I choose? Match the compressor nameplate HP/run amps. If unsure, check our relay–overload options.
- Do I need a start capacitor? Not necessarily—RO units are designed to run with or without a start cap.
- What about diagnostics? Use a quality manifold/vacuum setup. Start at Refrigerant & Digital Manifold Gauges.
Related Products
- Run Capacitors (450 V P2) – Handy when the cap’s out of spec and you want fresh starts to stick.
- Fieldpiece Digital Manifolds – Faster charge/diagnostic checks with logged data.
- Supco SPP Hard-Start Kits – Extra kick for tough compressors or marginal supply.