Dust extractor tripping electrics

[duncanh]

This has been happening occasionally for a while now and it's about time I sorted it as it's annoying!

I can be happily turning wood in my shed but sometimes when I switch on the extractor (Camvac CV386 dual motor) the electrics trip. It's usually the same motor that causes it but sometimes the other one as well. It occurs when I push the switch on the extractor. Sometimes one motor is running ok and the other causes the trip and sometimes it's the first switch that I press. Usually it doesn't trip. I remember that it happened at least once with my previous single motor Camvac 336 (I don't have a great memory so it might have been more than once).
When the happens the 16Amp breaker in the shed and the main box in the shed both trip off. The light breaker in the shed doesn't trip. Also, the main house box usually trips along with the 16Amp breaker for the shed.
The only other things in use in the shed at the time are the lathe (DVR3000), a Microclene MC400 ambient air filter and an IKEA anglepoise lamp. There are usually other things plugged in (bandsaw, dremel, drill, other lights) but they are not in use.

When the electrician put power out to the shed he installed a new box in the house, an underground cable to the shed and the box in the shed. I did the wiring for the lights and the sockets in the shed. This was all about 8 years ago.

Is there anything easy and safe that I can check myself before resorting to the electrician? I don't have any test gear except a basic multi-meter.

 

[Chrispy]

You say its always the extractor that causes the problem so have you tried pluging that in in the house to see what happens, if it blows the house main the I think its safe to say its the extractor, if not then the problem must be in the shed. (nout personal ment)

 

[duncanh]

I should have said - yes, I have tried it in the house and it seems to be fine, although the tripping isn't regular in the shed so it could just be that if I tried often enough in the house then it would happen there. I'll keep trying though

 

[The Bear]

My table saw tripped the electrics every time when I first bought it
I had to have the breaker in the consumer unit changed so it could handle the initial surge of power on start up
Sounds like you might have a similar problem
The fix was cheap and quick for my electrician

Mark

 

[duncanh]

Something else which I forgot - I have a small oil filled rad in there as well and it's usually on whilst I'm in there. 1kw I think.
For now I've gone back to the old extractor to see if that trips. It's motor should be the same as the large one and if that caused trips then the small might as well - should at least help to narrow down the cause

 

[marcros]

what is running at the same time from the same socket faceplate?

 

[duncanh]

Never considered that.
Extractor, radiator, small lamp and lathe are one faceplate. I don't think the lathe draws much power at all when it's not running

 

[riclepp]

Sounds like you are overloading the circut, as above posted you may need to look at the fuse (in the consumer unit). I had the same in my garage...I just got the whole thing rewired, more sockets, lights and a new consumer unit. Oh and 16 amp wire.

 

[Chems]

I used to have a similar problem, had to make sure the saw was on first then the extractor for me so it didn't blow the table saw fuse. I had my sparky friend come and look at it and he said the problem was that the workshop electrics are just on a radial spur, not a ring. So with each spur you take off you half the amp's and there were 2 spurs upto the table saw and extractor. I daisy chained the 2 spurs into one and its been fine ever since. I was planning on joining it back to the consumer unit as its only about 6 feet from the end of the spur but since its been fine I haven't bothered.

Could you look at yours and see what the setup is, maybe an easy fix like that too.

 

[Hudson Carpentry]

16amp Isn't a lot, 3680watts on a 230 supply so I expect your drawing more than the breaker can handle. When you turn things on (even a light bulb) there a surge of power that can be quite high which quickly settles down to its normal rated usage. Breakers are rated to account for this but if its to much for to long it can cause the breaker to trip.

Does it trip when the camvac is full or maybe blocked/gate not open. Anything that causes the motor to work harder will use more watts and on startup that could be even more so just enough to tip over the breakers limit.

Have a look at the breaker, does it say B16? If so putting in a C16 may do the trick. I would if me but in a C32 if your using it as a workshop but only if your main CU can handle it.

What does it trip in the main CU, just the one breaker or an RCD?

 

[duncanh]

These are the labels on the units...

Having just read my DIY manual it does seem as though 16A is a little low. It suggests 30A for a workshop/outbuilding and also 30A for a radial 4mm2 circuit, which this is

 

[duncanh]

What does it trip in the main CU, just the one breaker or an RCD?

Breaker and RCD

 

[mindthatwhatouch]

You should not have 2 RCD's on the same circuit, I am assuming one in the house that feeds the 16A breaker in the main CCU and one in the shed?

Bear in mind that the Circuit breakers are there to protect the cable not the equipment plugged into it, if you increase the 16A breaker in the house the cable feeding the shed must be able to handle it.

As a first effort get an electrician in to remove the RCD in the shed and see if that solves the problem.
Also uprating the Breakers to a C class may help as suggested earlier.

 

[graduate_owner]

I'm glad no-one has suggested replacing breakers with old style fuse boxes, then replacing fuses with nails or wrapping in silver foil. I know of several installations where the owners 'solved the problem of blowing fuses' this way. I also know of one guy who wanted to wire up a cooker, so he pinched some heavy single core cable from his works, split the single core into 3, and wired each of the 3 strands into L N and E. Blew the main fuse of course (and yes, he did repair the fuse with silver foil). Dangerous to say the least.

K

 

[psm]

probably too many things running at once , some machinery takes a large surge on start

 

[Hudson Carpentry]

What does it trip in the main CU, just the one breaker or an RCD?

Breaker and RCD

Does nothing blow in the garage CU?

 

[duncanh]

What does it trip in the main CU, just the one breaker or an RCD?

Breaker and RCD

Does nothing blow in the garage CU?

The 16A MCB and the RCD in the shed were tripping. Given my bad memory I can't guarantee that it was both of them every time or that it was both the breaker and RCD in the main CU, but I think it was.

Yesterday I swapped both the 16A MCB in the shed and in the consumer unit to type C. So far no trips.

So far the electrician who installed the consumer unit, 4mm2 swa to the shed and the shed box 10 years ago hasn't returned my call so I may need to find another. For now though all seems to be working.

 

[custard]

I had the same thing ( also on a dust extractor) the manufacturer recommended a 16 amp type C breaker but it needed a bigger breaker to reliably start up, although if it did manage to start on the 16 amp breaker it would then run fine.