20A vs 32A IP65 Rotary Isolator: Select the Rating From the Design

20A vs 32A IP65 rotary isolator is a circuit-design and equipment-rating decision, not a choice based on enclosure size. These two Knightsbridge four-pole AC isolators share the same weather-resistant format, red-and-yellow handle, 230–415V published voltage range and M20–M25 cable-entry provision. The difference is the current rating: select 20A or 32A only after the connected equipment, conductors, protective device, switching duty and manufacturer requirements have been checked.

Quick Shop: 20A vs 32A IP65 rotary isolator

Knightsbridge 20A Rotary Isolator 4P AC IP65

Model IN0025 is the 20A member of the range. It provides four-pole switching in an IP65 enclosure for suitably designed equipment-isolation duties.

View the Knightsbridge 20A isolator

Knightsbridge 32A Rotary Isolator 4P AC IP65

Model IN0026 carries the 32A rating in the same four-pole IP65 format. Use it only where the completed design calls for that rating and switching duty.

View the Knightsbridge 32A isolator

20A vs 32A IP65 rotary isolator: compare the published details

Choose the rating from the design, not the appliance label alone

The Knightsbridge IN0025 20A rotary isolator is not automatically the right answer because normal running current appears below 20A. The designer still needs to check the equipment manufacturer's isolation instructions, the nature of the load, starting current where relevant, utilization category, conductor capacity, upstream protective device and prospective fault conditions. A rotary isolator provides switching and isolation; it is not a substitute for overcurrent or fault protection.

The same rule applies to the Knightsbridge IN0026 32A rotary isolator. Moving up to 32A does not correct undersized conductors, unsuitable terminations or a protective-device mismatch. It also does not prove the isolator is suitable for every motor, air-conditioning unit, pump or commercial appliance. Read the connected equipment documentation and design the circuit as a complete system.

Where a schedule already specifies the isolator rating and pole arrangement, match that schedule exactly. Where it does not, stop and resolve the design before ordering. The cost and time saved by choosing from the title alone are quickly lost if the isolator has to be replaced during commissioning.

Four poles: confirm what must be isolated

Both products are published as four-pole AC isolators. That format is commonly used where multiple live conductors need simultaneous switching, including three-phase equipment arrangements. Do not assume every installation needs four poles, or that every conductor should be switched in the same way. Earthing conductors are not switched, and neutral treatment depends on the system design and applicable requirements.

Before fitting either model, confirm the supply arrangement, equipment terminals and required disconnection. Trace conductors, identify them correctly and verify dead using an approved procedure before work begins. Labels and handle positions support safe operation, but they do not replace proving the circuit state.

20A vs 32A IP65 rotary isolator: enclosure and cable-entry checks

Knightsbridge lists both models at 125mm high, 100mm wide and 120mm projection, with ABS and polycarbonate construction. The matching external dimensions mean the rating choice does not change the planned footprint, but installers should still allow room for the handle, lid opening, cable bend radius and secure termination.

The manufacturer lists M20–M25 knockouts. Select entries and glands to suit the actual cable type, diameter and environment. A published IP65 enclosure rating depends on the complete installation: badly cut entries, unsuitable glands, missing seals, damage or an incorrectly closed lid can undermine the intended ingress protection. Position the enclosure so water is not directed at entries and so routine isolation remains accessible.

The red-and-yellow handle gives a clear operating point. Knightsbridge also states that the switch interlocks with the lid to prevent opening while it is in the ON position. Treat that as an enclosure feature, not as permission to skip safe-isolation controls. Lock-off, warning notices and verification requirements remain job-specific.

Installation checks before energisation

Confirm product identity

Match the order, carton and device. The 20A IN0025 isolator is tied to barcode 5055832903802; the 32A IN0026 isolator is tied to barcode 5055832903833. Do not rely only on similar-looking enclosures.

Check terminations and conductor preparation

Follow the current manufacturer instructions for stripping, terminal capacity and tightening. Keep copper fully contained, avoid damaged strands and arrange conductors without forcing the terminals. After termination, complete the required inspection and testing before energisation.

Leave a clear handover

Label what the isolator controls and make the operating point accessible. Record the selected product and circuit reference in the job documentation. If later maintenance depends on upstream isolation as well, make that boundary clear rather than allowing the local rotary handle to be mistaken for complete control of every source.

Check the exact model before collection

Knightsbridge's current manufacturer pages identify the IN0025 20A four-pole IP65 rotary isolator and the IN0026 32A four-pole IP65 rotary isolator. Both pages publish the same 230–415V range, IP65 rating, enclosure dimensions and cable-entry provision. The rating remains the key difference, and it must follow the design.

For related items, browse APM's rotary isolators and wider switches collection. Check the live product page for the exact item details before ordering or travelling.