# Interest group forums > Electrical Contracting Industry Forum >  Earth leakage trips when it's raining - pool pump unit the cause.

## Boeriemore

Occasionally the house E/L switch trips and the pool pump unit is always
the cause and it happens only when it is raining.
The fibre glass cover prevents water from reaching the motor or it's elect. box.
The cable from the box to the pump lies on the ground which is likely to become damp
during prolonged rain.
I don't know if this could be the problem or simply moisture in the air or something else entirely,
but to wake up in the morning to find the freezer partially thawed is not pleasant.
Any suggestions would be appreciated.

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## AndyD

The best way to address this is to actually find the fault and repair/replace whatever is causing it. You'll probably need an experienced electrician with suitable test equipment such as a mega tester and and earth leakage clamp meter. With it being a swimming pool which is a higher risk of shock than most things I'd strongly recommend you go this route.

If you just want to address the inconvenience factor you could either put the pool circuit on it's own RCBO in the main DB or you could take the pool circuit off the earth leakage in the main DB and install another earth leakage in the pool control box where the circuit breakers for the light and pump are located. This second earth leakage will contain the tripping to just the pool itself. Both of these options aren't actually addressing the fault causing the tripping they're only addressing the inconvenience of thawed boerewors in the freezer so I wouldn't recommend them. 

Note; An RCBO is like a circuit breaker and earth leakage breaker combined in a single compact device. It's usually a bit longer that a standard circuit breaker so sometimes you can't fit them in an existing DB because there isn't room.


RCBO

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## Boeriemore

Thanks for your advise Andy. What I find strange is that there are two E/L breakers, one in the house that serves everything,
the other serves the circuit serving the pool, garage and outbuilding. The pool circuit also has an overload switch.
Sometimes both E/L breakers trip but in the latest occurrence the house E/L only tripped as well as the pool overload switch.
I hope I've made sense as I'm only a layman in this field.

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## bergie

most likely the earth leakages are wired incorrectly. the house e/l will be fine but the pool e/l must be disconnected from the house e/l. i find that a lot

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## AndyD

Yeah, you've probably got your pool board with its earth leakage supplied via the main earth leakage breaker in the DB. If they're both 30mA then there's no 'discrimination' as it's known in the trade which means it's basically a lottery which one trips when there's a fault because they're equally sensitive. 

The chances of you finding the fault without specialised test equipment is pretty slim especially if it's an intermittant fault. It's unlikely to be the cable you suspected unless the cable is physically damaged so you really need to get an experienced electrician I'm afraid. If you indicate your location maybe one of the forum members is close enough to assist you, there's quite a few guys here with the skills and test equipment to localise the fault quickly.

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## Boeriemore

Thanks Guys, I guess I'll have to start looking for an electrician as the electrician I used in the past has passed away.

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## bergie

you mentioned the pool overload switch tripped as well. most likely pool pump motor is faulty.

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## Boeriemore

It's a fairly new pump and my son's PC, TV and room lights are on the same circuit.

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## Jacques#1

This is my busiest time of the year :Wink:   Everyone has a tripping earth leakage due to rain soaking electrical equipment or penetrating deep into the earth and creating earth faults on a slightly nicked cable etc.  Check if the two earth leakages are "joined", one feeding the other, change this immediately.  They interfere with each other and may cause tripping for no reason in certain circumstances.

Disconnect the supply line feeding the pool box on both sides and megger it between L - N, L-E, N - E.  A lot of times I find an installation that has a minor nick on the cable, and it only becomes problematic months or years later, especially with heavy rains.

Check if there is a light or a plug on the pool DB.  99 percent of all my faults are usually a garden light.  DO NOT TRY to seal a light, you are wasting your time.  Take a drilling machine and drill a small hole at the bottom of the light for the water to drain, take some silicone and cover the terminals to allow the light to pass the "standard test finger test", if you can reach the live ends of the terminal with a piece of wire.  Spray bug spray in the light, around it and close it, to prevent ants from nesting inside.  Clients phone me and by the time I get there, the water seeped out and I cant find the problem, which becomes a painfull and long excercise which could have been solved if I was standing in the rain wating for the next trip  :Wink: . 

Finally, a simple thing to check is all the terminals in the DB.  Check to see if anything is black, or if any terminals are loose.  I get about 6 DB's per year that burnt out due to a loose connection, this is almost always on the neutral supply or feeding side.  A neutral supply has a resonance that actually "vibrates" and creates loose connections (as explained to me by an apparent professor, so dont take my word on the exact science of how this occurs, but it does, i've seen it too many times to disregard this).  Tighten each connection, and if there is a black terminal, the carbon or the actual CB may be causing the installation to trip.

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Dave A (30-Nov-13)

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## Sparks

Like Andy said, get someone with the knowledge and proper equipment to find the problem and solve it before someone gets hurt. That might just be the last time it tripped, you have no way of knowing that it still works.

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## Boeriemore

I have an outdoor light standing on a pedestal. Before calling in an Electrician I will disconnect the light from the pump elect. box. Thanks to all for the input.

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