Electrician / fuse question

[Starshine]

I've got a call into a friend who is an electrician, but I thought I'd get opinions from our DIS electricians too.

Our well pump quit working, turns out a fuse is blown. Our house was built in 1967 so these are the old plug type fuses. The blown one is a T series 12amp. When I went to the hardware store, they didn't have those, the closest they had was a TL series 15amp. They told me that the TL series is a medium duty fuse whereas the T series is heavy duty, so the 15amp one is fine because the medium duty will blow faster if necessary so it all evens out.

I did some Googling and was able to verify that the heavy duty/medium duty reponse is true, but I couldn't find anything specific about the extra 3 amps. I looked on the box and it does say 30amp, but not sure if that means it's safe to use 2 15amp fuses or not.

I have the TL-15's in there now because we needed water, but if it could be dangerous I don't want to leave them in long term. I was able to find the T-12's online but they're $40 for four fuses so I hate to spend that if the 15amp ones are ok.

Thanks!!

 

[IndyRnRfan]

Pardon my ignorance because I haven't looked at a fuse panel like yours in about 20 years but you say you pulled(unscrewed) a 12 amp fuse out of a 30 amp spot? I assume there were two fuses there?

Anyway, you will be fine for now but the difference between the T and TL is the T can handle surge of current more than the TL. You are correct in saying the T is a Heavy Duty and the TL is medium duty. The reason you would want to use a T is in situations like yours where you have a heavy surge of current right away like a water pump. There is a time delay on it blowing. The TL will most likely blow more often even though it is rated at 3 amps more because it is a medium duty. Either way, you aren't going to burn your house down but I would replace it with a T fuse. Yes, those fuses can be expensive but if you are blowing the cheaper fuse every so often, you'll eventually spend more money on the cheaper fuses. And, who knows, maybe the 15 TL won't blow but I'd just spend the extra money and replace it with what came in it. Just my opinion.

 

[Starshine]

Pardon my ignorance because I haven't looked at a fuse panel like yours in about 20 years but you say you pulled(unscrewed) a 12 amp fuse out of a 30 amp spot? I assume there were two fuses there?

Exactly, there were 2 12 amp fuses in there. Sorry for the confusion! And thank you so much for the advice too. I did find a place on Amazon selling the T fuses for $10 each which is cheaper than having to get 4 at once.

 

[IndyRnRfan]

Exactly, there were 2 12 amp fuses in there. Sorry for the confusion! And thank you so much for the advice too. I did find a place on Amazon selling the T fuses for $10 each which is cheaper than having to get 4 at once.

No biggie. Now, I am not a certified electrician but I did wire my basement when I finished it and it hasn't burned down, LOL. However, get the advice from a certified electrician just to be on the safe side. But, I'm 99.9% sure in your case you'd just blow the fuse a little more often using the TL rather than the T since the pump uses a lot of amps immediately and that is a medium duty fuse.

My rule of thumb is I'll give anyone advice and help with anything but electricity and gas needs to be carefully done. Bad things happen real quick when this isn't done correctly.

Good job on the fuse prices. I about crapped my pants when you said $40 per fuse. I use to work at a mom and pop hardware store and we sold those for $3-$5. I was going to suggest Amazon or something off the internet.

 

[rajak73]

The box says 30amp because that is the biggest fuse you could get in that box. The fuse holders will accept any amp fuse up to 30 amp. A t fuse is for motor starting. t=time delay. Only place I would know other than where you looked to find a 12 amp fuse would be a electrical supply house and then they might have to order, it is not a standard fuse size. Fuses are usually for short circuit and ground fault and not for motor overload. Your well pump probably has a control box somewhere and there is a overload unit in the control box or the motor itself could have a overload built in. I wouldn't worry much about putting a 15 amp fuse in instead of the 12 amp, it's kinda complicated to determine the fuse size but you can fuse up to 175% above motor load. Hope it helps.

 

[Starshine]

Thanks to both of you! My friend pretty much said the same thing.

 

[tvguy]

I'd check around with electrical supply places or another hardware store. Unless you live in a very small town, those are pretty commonly used. My parents house had a domestic well, and an air conditioner that used them. Mom kept a spare box on hand in the pumphouse. Only time they seem to blow was if there was a power surge.

 

[Starshine]

Definitely a small town (20 minutes to the nearest Walmart). I called everywhere locally and had no luck, nor at Lowes or Home Depot. Looks like Amazon it is!

 

[rajak73]

I'd check around with electrical supply places or another hardware store. Unless you live in a very small town, those are pretty commonly used. My parents house had a domestic well, and an air conditioner that used them. Mom kept a spare box on hand in the pumphouse. Only time they seem to blow was if there was a power surge.

The T fuse is common, but the 12 amp is not common. A "standard" size fuse rating is 15, 20, 25, 30 amp. I still wouldn't worry about the 15 amp fuse in the circuit as I stated before, fuses are usually for short circuit and ground fault protection.