The SUPCO SUPR is a universal potential relay (EPR technology) designed for single-phase, capacitor-start compressor motors. It helps licensed HVAC/R techs, apprentices, and contractors get fast, consistent starts with a compact, non-positional unit — fair dinkum, it’s built for quick installs and fewer headaches.
Key Features & Trade Benefits
- EPR technology, 110–270 VAC single-phase — precise, reliable pick-up across common service voltages, so you can standardise van stock.
- Start time function: 1.0–1.5 s — protects the start winding if the motor doesn’t kick, reducing call-backs.
- Up to 5 hp (≈3.7 kW) — covers most light commercial and residential compressors you see week-to-week.
- Normally-closed 30 A contacts — trade-tough contact rating for dependable switching.
- Non-positional mounting — fits tight spaces and awkward panels without dramas.
- Screw or push-on terminals + adapters included — faster retrofits and cleaner changeovers.
- Wire-to-wire replacement for most potential relays — simplify parts selection across mixed fleets.
Why This Product Matters
On a steamy Brisbane arvo, a split condenser kept tripping on start. Swapped in the SUPR, set it up wire-to-wire, and the compressor came back to life in seconds — no worries. The universal voltage window (110–270 VAC), time-out protection (1.0–1.5 s), and non-positional mounting mean less mucking around and more first-time fixes. For techs juggling mixed brands and models, a true universal potential relay is a bloody good way to standardise stock and reduce repeat visits. For broader gear browsing, see our HVAC supply catalogue.
Pro Tip
Before swap-out, photograph the existing relay wiring and label the leads. After fitting the SUPR, verify start/line connections and allow the safety time-out to complete before re-testing. This simple habit avoids crossed leads and makes on-site troubleshooting a breeze. For electrical safety on site, follow recognised Australian WHS guidance.
Compatibility & System Info
- Application: single-phase, capacitor-type motors on HVAC/R compressors
- Operating voltage: 110–270 VAC, single-phase
- Motor rating: up to 5 hp (≈3.7 kW)
- Function: time function relay, 1.0–1.5 s safety time-out
- Replacement type: wire-to-wire replacement for most potential motor starting relays
Local SEO Reference
Whether you’re commissioning in humid Brisbane or battling summer rooftop heat in Perth, fast restarts and solid start-winding protection help keep systems online — she’ll be right when the relay’s sorted.
What’s Included
- SUPCO SUPR universal potential relay
- Universal mounting bracket (snap-off sections for easy fit)
- Terminal adapters (screw-to-push-on)
- Manufacturer instructions
Specifications
| Operating Voltage | 110–270 VAC, single-phase |
| Motor Power Rating | Up to 5 hp (≈3.7 kW) |
| Contact Rating | Normally closed, 30 A |
| Start / Safety Time-Out | 1.0–1.5 s |
| Mounting | Non-positional; universal bracket with snap-off sections |
| Terminals | Screw or push-on; adapters provided |
| Dimensions | ≈44.5 (W) × 57.2 (L) × 38.1 (H) mm (1.75″ × 2.25″ × 1.50″) |
Warranty & Returns
Backed by HVAC Shop’s standard warranty and returns policy for parts installed by qualified personnel. For safe installation and testing, work to Australian WHS guidance before energising.
FAQs
Will the SUPR replace the potential relay in my older single-phase condensing unit?
In most cases, yes — it’s designed as a wire-to-wire replacement across 110–270 VAC, up to 5 hp. Always match wiring to the manufacturer diagram and verify current/voltage conditions.
Does it need a specific mounting orientation?
No — SUPR is non-positional, which is handy in tight panels or rooftop packages.
What if the compressor doesn’t start within the time window?
The relay opens after ~1.0–1.5 s to protect the start winding; diagnose underlying supply or mechanical issues before re-attempting.
Hard-start kit or potential relay?
Hard-start kits add extra starting torque. A universal potential relay like SUPR controls the start winding cleanly on capacitor-type motors. If you’re troubleshooting chronic low-voltage starts, a hard-start kit may be the better call — see the related products below.
Related Products
- SUPCO URSC20 Universal Power Start Relay — a helpful alternative when you’re tackling low-voltage or hard-start situations.
- SUPCO ICG220 Solid-State Relay (220 V) — for solid-state switching where a potential relay isn’t appropriate.
- SUPCO Timer Delays (TD series) — reduce short-cycling with adjustable delay-on/break timers.
- SUPCO SPP Super Boost Hard-Start Kits — extra starting torque when compressors are sluggish.