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geez
Wiring Question

I have a 240 volt cable coming from 20 amp breakers in the main box going to an outlet for the dryer. Some years ago, another 240 cable was taken from the dryer outlet, through a fused (20 amps) on-off switch box and on to another 240 volt outlet (for a power saw) and two 120 volt outlets.

My question is, why should there be fuses in the the switch box since the circuit is protected by the breakers in the main box? Is there any reason why I couldn't replace the switch box with one without fuses?

Geez

Re: Wiring Question
geez wrote:

I have a 240 volt cable coming from 20 amp breakers in the main box going to an outlet for the dryer. Some years ago, another 240 cable was taken from the dryer outlet, through a fused (20 amps) on-off switch box and on to another 240 volt outlet (for a power saw) and two 120 volt outlets.

My question is, why should there be fuses in the the switch box since the circuit is protected by the breakers in the main box? Is there any reason why I couldn't replace the switch box with one without fuses?

Geez

It sounds like someone tried to put an awful lot of loads on a
20A circuit, gambling not more than one load would come on at a time.

Only one set of fuses (or breakers) are require to protect the entire branch circuit. Often, someone will add another breaker, either larger or smaller, to simply serve as a disconnect or to insert more protection into the circuit, which might be required at an air conditioning load.

Having said all that:

1) A typical water heater must be fed with 10-2 (w/ ground) wire by a 30A breaker. On it's own circuit.

2) A dryer must now be fed by 10-3 wire (w/ground) on it's own 30A circuit.

3) Two 20A 120V receptacles may be fed by 12-3 wire (w/ ground) from a 20A 2 pole 240V breaker. This is known as a multi-wire branch circuit (MWBC). This circuit offers some advantages but to a layman can bring on many problems.

You have a little wiring to clean up.

geez
Re: Wiring Question

You're right; I will be cleaning it up. Thanks for the detailed response.

marygrace
Re: Wiring Question

you need cleaning and tuning it up.

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