Fuse locations

[QSIMDO]

The wiring diagram for a DC speed control I bought shows fuses wired in between the main switch and the unit itself.

Would that not be redundant since there are breakers in the panel?
(230v)

[Carld]

What they are probably showing or talking about is a fused disconnect. Are you hard wiring the speed control in or are you plugging it in to an outlet?

[japcas]

QSIMDO, I'm not an electrician or a guru on electricity so I may not explain this technically correct so I'll try to keep it simple.

Often there will be an inline fuse to protect the equipment because the circuit you plug it into may be capable of handling a bigger load than the device your plugging in. So without an inline fuse your device could be overloaded and burn up without ever tripping the breaker. So the fuse is selected for the load that the device will see which should protect it in case of an overload on the device end.

[mayfieldtm]

Often times, fuses are to protect the wiring, thus preventing fires.
I would use fuses at the controller for this reason.
Tom M.

[QSIMDO]

What they are probably showing or talking about is a fused disconnect. Are you hard wiring the speed control in or are you plugging it in to an outlet?

To an outlet.

[QSIMDO]

QSIMDO, I'm not an electrician or a guru on electricity so I may not explain this technically correct so I'll try to keep it simple.

Often there will be an inline fuse to protect the equipment because the circuit you plug it into may be capable of handling a bigger load than the device your plugging in. So without an inline fuse your device could be overloaded and burn up without ever tripping the breaker. So the fuse is selected for the load that the device will see which should protect it in case of an overload on the device end.

Well, that brings up another question as I can't remember seeing a spec for those fuses.
I'll have to go back & check.

[QSIMDO]

Often times, fuses are to protect the wiring, thus preventing fires.
I would use fuses at the controller for this reason.
Tom M.

Makes perfect sense.

[QSIMDO]

Looks like 8 amps.
Sounds right?

[Carld]

If your plugging it into a wall receptacle I wouldn't use a fuse but if it makes you feel good then do it. Everybody likes to feel good .

[japcas]

If your plugging it into a wall receptacle I wouldn't use a fuse but if it makes you feel good then do it. Everybody likes to feel good .

Carld, like I stated above I'm not an electrician but I don't understand why you wouldn't use a fuse. If he plugs this device in which he seems to think needs an 8 amp fuse into a 120 volt outlet that is protected by a 15 or 20 amp fuse then his device could burn up way before the breaker ever trips if it becomes overloaded or shorts. With a fuse built into the line it would blow hopefully before any major damage was done to the device. I may be overlooking something obvious but I don't understand why you would not put a fuse in the line.