SPAL Fans, what size fuse???

Rockrz · Post by **Rockrz** » Thu Oct 30, 2008 5:30 am

What size fuse are you guys using on your electric fans?

I'm using a 30 amp and it blows about every 4 to 6 months for some reason.

Should I go with a 35 amp, or maybe switch to some sort of breaker switch?

Post by **HenryJ** » Thu Oct 30, 2008 6:38 am

What fans are you using?

Rockrz · Post by **Rockrz** » Thu Oct 30, 2008 6:44 am

SPAL dual electric fans

If I remember right, the reason I was using a 30 amp fuse was because that is what they recommended.

I thought about going to a heavy duty fuse holder that will accept the 30 amp fuse as far as physical size is concerned...but is designed to handle much larger fuses and amps.

When it blows, it melts the fuse holder on one side so it may be that the fuse holder is too small for the amperage.

Post by **HenryJ** » Thu Oct 30, 2008 6:52 am

Consult the wiring size tables. Make sure you are using the correct size wire.
Consider splitting the supply for them if you are drawing more amperage than is reasonable for one wire.

Make sure your system is capable of maintaining the voltage with out a large drop. That can create heating in a motor.

Usually a bigger fuse is not the answer. The problem lies elsewhere.

There have been some SPAL fan failures. That might be a possibility too.

Rockrz · Post by **Rockrz** » Thu Oct 30, 2008 6:57 am

Maybe I need to go with larger wires, but I am using the same size wires that SPAL uses coming out of the motors so one would think this would be OK.

Seems like the wires would be damaged by excessive heat if they were too small, right? Wouldn't they get all stiff and discolored?

So far the wire themselves don't apear to be harmed at all, and the fans continue to work just fine.

It's only popped the fuse twice in about a year.

Post by **HenryJ** » Thu Oct 30, 2008 7:07 am

If you add length, you must increase the size. The heat will always build at the weakest link. While the wire may not be getting hot to the touch or so it is visible, the resistance will increase.

Poor connections can be a problem too. Make sure they are all clean and a little dielectric grease is na good idea.

Rockrz · Post by **Rockrz** » Thu Oct 30, 2008 7:17 am

OK, I guess it wouldn't hurt to go with a larger wire size.

What about lithium grease?
I've always heard that's how many connectors are lubed at the factory.

Also, is it possible to use a 30amp breaker switch instead of an inline fuse?
Or would that not be a good idea...

Post by **HenryJ** » Thu Oct 30, 2008 8:04 am

Do not use lithium grease. Dielectric silicone is designed for this.

A manually resettable breaker might be just fine. I would not use an auto resetting breaker , if there is a problem it will get really hot.

raven2510 · Post by **raven2510** » Thu Oct 30, 2008 11:36 am

idk....but to me dual spal efans are gonna be using more than 30 amps...especially on start up

Post by **HenryJ** » Thu Oct 30, 2008 12:43 pm

I agree. The quick jump on start usually won't blow the fuse. Fuses blow slowly, relatively speaking. It takes more time than starts usually offer in this situation.

If they recommend 30 amps , that is probably as much as I would run, just to be within their recommendations. That covers you if there is a fan meltdown.

Rockrz · Post by **Rockrz** » Sun Nov 02, 2008 11:03 pm

So, what guage wire are you guys using with the Taurus eFan?