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Rotary isolator sizing

Baldyhugh

Hi

is it acceptable to use a rotary isolator which is a larger rating than required eg. Using a 32a isolator for a 16a or 20a circuit? Dependant on manufacturer, the higher rated ones are physically larger and offer more space inside for wiring. With my wholesaler there is only a couple of pounds difference in price, so it seems sensible to use the larger one but was curious if there was a regulation reason why I shouldn’t.

 

thanks

 

Peter

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    Normally we might  call using the next size up conservative design. Generally, apart from cost, it is a good thing, bigger contact areas  run cooler, last longer.

    Note that larger terminals may need the wire doubling over or something to get a decent grip.

     The only situation where it might be a source of confusion is if there is a combined switch and fuse, and it may encourage the unskilled to fit an oversized fuse. clear labeling helps then.

    no reg as far as I know that ever prohibits you, further  I'd  suggest it is actually  a good idea if the project budget can stand it.

    Mike.

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  • 0

    Normally we might  call using the next size up conservative design. Generally, apart from cost, it is a good thing, bigger contact areas  run cooler, last longer.

    Note that larger terminals may need the wire doubling over or something to get a decent grip.

     The only situation where it might be a source of confusion is if there is a combined switch and fuse, and it may encourage the unskilled to fit an oversized fuse. clear labeling helps then.

    no reg as far as I know that ever prohibits you, further  I'd  suggest it is actually  a good idea if the project budget can stand it.

    Mike.

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