HEEELLPP!! Bandsaw tripping breaker

[MikeJhn]

For a definitive answer from professional electricians, post here: DIY Electrical Forum

 

[sometimewoodworker]

So turn it on and the flag is red, after it trips the flag is black. Same as pressing the test button.

I do remember the electrician doing earth checks when he installed the circuit which were all fine, it was only turned on yesterday for the first time.

Absolutely. That is a virtual guarantee that there is a wiring fault in your band saw giving an earth fault.

to be sure test trip the RCBO on it. Check the flag colour.
reset the switch then flip it off, check the colour

assuming that with a test trip the flag is black and turning in on then off leaves the flag red. That is a guarantee that there is a wiring fault in the band saw, it’s cable, or plug.

Again a check is to plug something else into the outlet and if you can plug the saw into another outlet.

if as I think it’s in the saw you should be able to check most of the wiring yourself, it could be something simple or it could be enough to send it back.

this is something to do before you bother changing RCBOs or swapping in a MCB

when you hear hoof beats, think horses, not zebras

 

[Woody2Shoes]

Sorry, though you are an electrician you seem to have missed the training that shows exactly if it’s an overload trip or earth leak trip

the flag in the window under the letters RCBO will change colour if it’s an earth leak fault, but will not if it’s an overload.

the speed of the trip suggests that an earth fault is more likely but the flag colour when tripped while not an absolute will give a better idea which it is.

This is something that anyone can safely check. The flag gets reset when you turn on the RCBO so you need to look after it trips.

Not all RCBOs have this tristate indication feature.

I bought a brand new bandsaw from Axi a few months ago and, although it worked fine on a B curve RCBO, I sensed an unpleasant tingling when touching the cast iron table. There was a certain amount of leakage to earth (but not enough to trip the RCBO in this case) - now fixed (leaky capacitor).

 

[MikeJhn]

Absolutely, an RCBO's primary function is to detect and trip on overload and differential current, its sensitivity to earth leakage is supplementary to its main function.

 

[MikeJhn]

I know this will not be popular, but at 3hp x 750W / 230 = 9.8A, put a 13amp plug on it and plug into your 20A Radial circuit, if it works fine, its the 16amp circuit thats at fault, if it trips the 20A Radial its the machine.

 

[TheTiddles]

Not all RCBOs have this tristate indication feature.

I bought a brand new bandsaw from Axi a few months ago and, although it worked fine on a B curve RCBO, I sensed an unpleasant tingling when touching the cast iron table. There was a certain amount of leakage to earth (but not enough to trip the RCBO in this case) - now fixed (leaky capacitor).

I get this too on my machines, but it’s static from the extractor hoses!

Can we have a voting link put in as to what we think the problem with Craig’s setup is?

a

 

[craigs]

I know this will not be popular, but at 3hp x 750W / 230 = 9.8A, put a 13amp plug on it and plug into your 20A Radial circuit, if it works fine, its the 16amp circuit thats at fault, if it trips the 20A Radial its the machine.

I like this idea, but with a brand new machine i don't want to go outside of Laguna's documentation just in case there's a warranty call needed.

Sparks is coming Friday to replace the type b with a type c rcbo.

 

[craigs]

Not all RCBOs have this tristate indication feature.

I bought a brand new bandsaw from Axi a few months ago and, although it worked fine on a B curve RCBO, I sensed an unpleasant tingling when touching the cast iron table. There was a certain amount of leakage to earth (but not enough to trip the RCBO in this case) - now fixed (leaky capacitor).

I don't think this rcbo has tristate indication, no matter what I do to both they go red or black.

 

[MikeJhn]

I doubt the 16A plug is moulded onto the cable of the machine and may be able to be changed without cutting it off.

 

[gmgmgm]

I like this idea, but with a brand new machine i don't want to go outside of Laguna's documentation just in case there's a warranty call needed.

Sparks is coming Friday to replace the type b with a type c rcbo.

It's easy to get 16A blue plugs to 13A "white" sockets and the other way around- Amazon has them, and probably Screwfix too. Very handy for fault-finding (carefully of course). If you have any camping friends they probably have one (campers/caravans use 16A extension leads).

Worth trying it out. Have a couple of spare 13A fuses to hand.

 

[guineafowl21]

I like this idea, but with a brand new machine i don't want to go outside of Laguna's documentation just in case there's a warranty call needed.

Sparks is coming Friday to replace the type b with a type c rcbo.

From what’s been written already, this sounds like an earth fault (rcbo flag indicator). A type C breaker won’t fix this, so I hope your spark isn’t just a parts changer. The machine needs a PAT test either side of the starter switch. The better testers offer earth leakage testing during running, as some faults only show up when everything’s powered up.

Warranty claim also worth looking into.

 

[TheTiddles]

I know this will not be popular, but at 3hp x 750W / 230 = 9.8A, put a 13amp plug on it and plug into your 20A Radial circuit, if it works fine, its the 16amp circuit thats at fault, if it trips the 20A Radial its the machine.

I had the same thought!

 

[porker]

My bet is on an earth fault on the machine itself and probably a capacitor gone leaky as some have stated before.

It needs an IR test on the machine between line, neutral and earth which may be a bit trickier if it has an NVR switch as you need to test on the machine side. If you don't have an IR tester, I would test straight continuity between earth and line and earth and neutral with a DVM in the first instance. Good call to test on the radial circuit with a 13A plug top. It will at least confirm it is not the supply. I wouldn't be changing out the RCBO type at this stage. I know this can be an issue but with no load I would expect the machine to start occasionally at least. An adaptor from the 16A socket to 13A would be the easiest and no warranty issue with that.

 

[craigs]

So I went to screwfix and got a 16A socket then used some blue flex > 13A plug and plugged it into the 20A radial, fired up ok, didn't trip the breaker, just took out the 13a fuse (to be expected)....nice to hear it run if a short while though

 

[MikeJhn]

WARNING make sure you turn off your supply if you are going to start testing as per the last post.

 

[sometimewoodworker]

I don't think this rcbo has tristate indication, no matter what I do to both they go red or black.

That was why I was asking you to test to see if the flag did not change colour when you flipped the breaker on and off as well as when you did an earth leak test trip.

it is usually the case that an over current trip should be able to be easily distinguishable from an earth leak trip. All my RCBOs and the ones JW and BigClive on YouTube have taken apart have that function.
As you say yours doesn’t indicate I suspect that either I didn’t communicate the test well enough, that RCBO is faulty, or it doesn’t indicate. So as you’re determined to get the sparky in ask him to check the RCBO before pulling it out.

My guess is that there is a fault in the machine as I suggested before and that the swapping to a C curve is not going to solve the problem.

EDIT I see you’ve probably found that it’s the Circuit or RCBO that doesn’t change the need to check the function of your current RCBO with your sparky.

 

[craigs]

That was why I was asking you to test to see if the flag did not change colour when you flipped the breaker on and off as well as when you did an earth leak test trip.

it is usually the case that an over current trip should be able to be easily distinguishable from an earth leak trip. All my RCBOs and the ones JW and BigClive on YouTube have taken apart have that function.
As you say yours doesn’t indicate I suspect that either I didn’t communicate the test well enough, that RCBO is faulty, or it doesn’t indicate. So as you’re determined to get the sparky in ask him to check the RCBO before pulling it out.

My guess is that there is a fault in the machine as I suggested before and that the swapping to a C curve is not going to solve the problem.

EDIT I see you’ve probably found that it’s the Circuit or RCBO that doesn’t change the need to check the function with your sparky.

He's coming Friday, hopefully it will be resolved then.

 

[MikeJhn]

Make sure your electrician tests the RCBO I∆n @ 1 and 5 times, did he give you a EICR when he completed the works, because all of that information should be on page eight.

I also think that putting in a new CU and circuits come under part P Regulations and should have been informed to your local council.

 

[Spectric]

Hi all

You still get RCBO's with the the earth sensing wire, these provide for loss of supply neutral protection which in domestic installations is important where you rely on the Neutral for your means of earthing, IE TNCS or PME. They are the ones I would always fit and the four Sneider type B's I purchased three days ago all have the white wire and no indication window! In an industrial/office enviroment fitting RCBO's without the earth sensing wire is ok because the means of earthing is TNS.

You also get type C RCBO's and for your Steeple board

https://www.denmans.co.uk/den/root-...-|-6kA-|-30mA/p/2500549699?showBackLink=false

or if Wylex fit then screwfix gives you the choice of with and without earth sense in type C
Eaton RCBOs | Eaton Memera RCBOs | Screwfix.com

As I said before, unless you have a multifunction tester then get the electrician to inspect because you are not going to resolve without his knowledge.

 

[craigs]

Im leaving it to the electrician, should have an update friday/saturday