3-phase isolator switches are the simple, rugged manual switches that electricians use to safely isolate 3-phase equipment for maintenance, emergency shut-off and code compliance — think HVAC compressors, industrial motors, commercial ovens, hot-water plant, and EV chargers or on-site generators. In New Zealand you’ll commonly need weatherproof (outdoor) isolators with the right current rating, pole count and an AS/NZS standard rating for the application.

Why 3-phase Isolator Switches Matter for Commercial Sites

Safety & maintenance — provide a clear, physical break of the three live conductors before work. Useful at motor control panels, rooftop HVAC units, compressor rooms, plant rooms and temp/portable plant.

Local compliance — some installations (eg fixed hot-water heaters, certain PV components and some motor circuits) require a “true isolating switch” (switch-disconnector) to meet AS/NZS/IEC switchgear standards. Always check the relevant clause in AS/NZS 3000 and product standards AS/NZS IEC 60947-3.

Environment & reliability — commercial outdoor sites need IP-rated enclosures (IP65 or IP65 is common) to resist dust, water and UV so the isolator keeps working in harsh conditions

Common Weatherproof Isolator Switches in New Zealand

Below is a compact table of 3-phase isolator types listed on Sparky Shop (product pages used as sources). For each product I show the core features you’ll care about.

Practical Checklist — What to Look for When Buying a 3-Phase Isolator Switch (Commercial)

• Correct current rating (A) — choose an isolator with a continuous current rating at or above the load, with some headroom. Common commercial ratings include 20A, 32A, 35A, and 63A, with higher options for distribution.
• Number of poles — most 3-phase equipment requires a 3-pole isolator. Some applications (such as EV chargers or certain water-heating circuits) may require a 4-pole isolator to also switch the neutral.
• IP / environmental rating — for outdoor or exposed installations, select at least IP66 for dust and water resistance. Indoor plant rooms may allow lower ratings.
• Standards & certification — confirm the isolator complies with AS/NZS IEC 60947-3 or equivalent standards for code compliance, especially for hot-water systems, PV isolators, and major circuits.
• Padlockable — look for models with padlock or lock-out provisions for safe maintenance and compliance with lock-out/tag-out procedures.
• Terminal capacity & conductor size — ensure terminals are large enough to accommodate the cable sizes required (e.g., 6 mm², 10 mm²). Larger motors and higher loads need larger terminal capacity and correct torque specifications.
• Mounting type — choose between surface-mount, flush-mount, or DIN/industrial enclosures based on site layout and conduit runs.
• M-rating and making/breaking capacity — check the isolator’s duty rating (e.g., AC-23) or M-rating to ensure it can safely break motor and inductive loads on-load.
• Temperature / UV durability & warranty — for rooftop or outdoor use, select UV-stable and weather-resistant enclosures. Check warranty details for long-term durability.