Electrical problem - fuse board and wiring issues

[IdealStandard]

Hi All

 

I've been having a problem recently with fuses blowing and the fuse board getting warm when using my water pump. I have installed new batteries recently and the problem only seems to have started since then. I have a Jabsco Par Max 4 and it works perfectly.

 

When I use the water system for any period of time (say a five minute shower or more) the fuse board gets warm. Recently I have had the 10amp fuse blow and even more annoyingly, the fuse holders have been popping out (this type http://www.iboatsimages.com/mall/image/view/4/6/fuseholder_1.jpg) and snapping so that they don't clip back in again.

 

Am I right in thinking that this is likely to be due to the cable to the water pump being too thin?

 

In the short term I need some replacement fuse holders and in the long term I need to figure out exactly what is going on and remedy it. All suggestions welcomed.

 

Many thanks
Tim

[Keeping Up]

It's unlikely to be that the wiring to the pump is too thin.

 

The literature for the Par Max 4 says it needs a 15 amp fuse. Maybe that's the problem?

[IdealStandard]

Interesting.

 

The only problem with that diagnosis is that the fuse had only gone once, whereas the problem of the fuse holder snapping has happened twice now. I originally though it might be due to the plastic simply corroding, but I purchase a new fuse holder and it happened again and I think it must be down to the heat that they are going.

 

Is the heat cause by excess resistance?

[Paul C]

Heat is caused by excessive resistance, which suggests a fault with the fuseboard or at least that fuse etc. There's loads of different kinds around over the years/decades, do you have any pics of yours?

[IdealStandard]

I'l take some pics tonight and post tomorrow. Thanks.

[Pete & Helen]

If it was working fine before you changed your batteries then its worth just double checking your battery wiring, Have you used 6v batts by any chance? make sure you have the correct series or parallel configuration and your not putting too much voltage through the pump. (quick check with a multimeter if you havent one on your distribution board)

[springy]

Also check the wiring/connections all the way back to the battery - you may have "disturbed" something when changing the

battery and created a high resistance -> voltage drop -> increased current to compensate.

 

springy

 

eta beaten to it !

Edited May 6, 2014 by springy

[Ex- Member]

Isn't 5 minutes rather a long time to run a shower pump. I let water accumulate in the shower tray, gives me feet a good soak too LOL When the tray fills I flick the pump on, under a minute it's empty, repeat as necessary.

 

We do have a double shower tray though so it can hold a fair bit of water.

[John V]

IMHO a large percentage of the electrical gear sold for use on boats...switches, fuses etc are junk

If you can't go for a domestic type fuseboard and fit mcb's that are suitable for dc use. (many standard mains types are suitable for dc as well)

then IMO the next best type are the blade type car fuse, these have an advantage that there are mcbs that are direct plug in replacements for this type of fuse. Robust fuseholders are available for them, some with splash proof covers

[jonathanA]

from a quick look at the type of 'panel mounting' fuse holder you posted a picture of, most of those are rated at only 6.3 or 10A, if the other poster is right and your pump needs nearer to 15 A then its probably overloading your fuseholder which is then getting hot.

 

If you have changed your batteries and the new bank is now operating at a higher voltage this could mean there is an increased current flowing or in the process of changing the batteries you have cleaned up or re-made a connection that was perhaps a bit dirty/corroded and was dropping a bit of voltage (possibly coupled with the other batteries being on the way out too...)

 

Personally I prefer resettable circuit breakers over fuses so if you can replace them with some sort of circuit breaker. It might be worth trying to localise the heat source is it the fuse holder it self, the wiring or the connections to the fuse holder ?

 

short term a Car blade type fuse holder might help - there are cheap enough and if you use one and it solves the problem you know what the issue is and can look for a better fuse board/distribution panel, if not its won't have cost a lot of money...

[Bod]

Hi All

 

I've been having a problem recently with fuses blowing and the fuse board getting warm when using my water pump. I have installed new batteries recently and the problem only seems to have started since then. I have a Jabsco Par Max 4 and it works perfectly.

 

When I use the water system for any period of time (say a five minute shower or more) the fuse board gets warm. Recently I have had the 10amp fuse blow and even more annoyingly, the fuse holders have been popping out (this type http://www.iboatsimages.com/mall/image/view/4/6/fuseholder_1.jpg) and snapping so that they don't clip back in again.

 

Am I right in thinking that this is likely to be due to the cable to the water pump being too thin?

 

In the short term I need some replacement fuse holders and in the long term I need to figure out exactly what is going on and remedy it. All suggestions welcomed.

 

Many thanks

Tim

 

Hi Tim

Have you added anything to the fuse board?

Extra circuits, shower waste pump, lights, extractor fan, connected to run with water pump?

What happens when the kitchen sink taps are used for a long time?

Are all the new battery connections good?

 

Bod

[IdealStandard]

Hi All

 

Thanks for all of your excellent advice and help.

 

I looked into a few of your suggestions and then tried wiring in a seperate fuse for the water system which has solved the problem. No overheating or blown fuses which is great. It also has the appropriate fuse now too.

 

It's all a bit of a mess and I will look at getting a new fuse board/circuit breakers soon but this only cost £2 so it was a winner for th eitme being.

 

Thanks again and happy boating

Tim

Oh and I think JonathanA was spot on in his diagnosis after some head scratching.