Main RCD trip Question " Beer Shed"

Greetings,

Question please,

I have a device in my shed that I want to use ( Ill tell you what it is in a sec)

When I plug it in and then turn it on It trips the main RCD switch.

Now as a basic Fault find I used other Items ( High load drill and a light bulb) in the same plug socket from the same Plug and they are fine.

I pluged my device to an extention lead from the house (for ease of testing) from other plug sockets in the house and the same happens main RCD trips.

If I disconnect the Neutral inside my devices plug, my device works ok but without the saftey of the Neutral.

what could be the reason for this?

Is it because the device that I am using has its own Eletrical cut out built in to one side of its operation, can any one shed some light please.


MY Device is a PID (proportional–integral–derivative controller) with its own built in 13A output for an external heater element used to power my micro brewerys mash tun, it also has its own adjustable temprature cut out built in that trips the output to the heater element when a set value is reached (over heat safey option) but the unit remains active ie: PID temprature control unit display.

NB: my PID does not have the heater element attached at the moment just to rule that out of the mix

any advice of fault finding very very welcome.

One test I am about to do is Isolate the sheds power and test using the extention lead from the house but need to post this just in case the main RCD trips Ill let you know if this helps.

Thanks in advance

Smiffy

It trips the RCD because somewhere inside the device is a neutral-earth fault. It doesn't happen if you disconnect the neutral because the neutral needs to be part of the circuit for the fault to register with the RCD.

I'm not familiar with the device you describe, but if it's possible to disassemble it you might find the problem. Is the plug wired properly? If the earth and neutral pins have been reversed, for instance ... ?

PJ

If it still works without the neutral connected then something is quite wrong, is this a mix up of terminology, did you mean to say earth (Please don't do that even as a test )

GARYSMIFF said:

Greetings,

Question please,

I have a device in my shed that I want to use ( Ill tell you what it is in a sec)

When I plug it in and then turn it on It trips the main RCD switch.

Now as a basic Fault find I used other Items ( High load drill and a light bulb) in the same plug socket from the same Plug and they are fine.

I pluged my device to an extention lead from the house (for ease of testing) from other plug sockets in the house and the same happens main RCD trips.

Click to expand...

all good so far

If I disconnect the Neutral inside my devices plug, my device works ok but without the saftey of the Neutral.

Click to expand...

oh-oh, not so good. Can i ask what prompted you to do this test. I wouldn't really choose to describe a neutral connection as a safety feature

what could be the reason for this?

Click to expand...

Your device is ferked?

Is it because the device that I am using has its own Eletrical cut out built in to one side of its operation, can any one shed some light please.

Click to expand...

I don't think thats the answer

MY Device is a PID (proportional–integral–derivative controller) with its own built in 13A output for an external heater element used to power my micro brewerys mash tun, it also has its own adjustable temprature cut out built in that trips the output to the heater element when a set value is reached (over heat safey option) but the unit remains active ie: PID temprature control unit display.

NB: my PID does not have the heater element attached at the moment just to rule that out of the mix

any advice of fault finding very very welcome.

One test I am about to do is Isolate the sheds power and test using the extention lead from the house but need to post this just in case the main RCD trips Ill let you know if this helps.

Thanks in advance

Smiffy

Click to expand...

No offence Smiffy, but you may want to get a sparky in to take a closer look at (and possibly test) your device.

Firstly check you have wired the supply to the PID controller correctly and ensure it is rated for use on 230VAC.

For others:
A PID controller basically takes an input from a sensor such as a thermocouple, a resistance thermometer or a straight 1-5v or 4-20mA signal.
The controller looks at the signal, compares it to the set point (error) and applies it to the output (1-5v, 4-20mA, on/off, ramped outputs etc).
The proportional part being in direct proportion to the input with or without a gain. The integral part will cause the output to increase over time (area under the graph). The derivative part looks at the rate of change of the input and adds to the output.
The outputs from all 3 terms are summed and applied to the output.

Not the sort of thing a normal spark will come across, more of a instrument technicians thing.

People, I am very very very very impressed with you for the speed of your responce.

I said I would report back and I here I am.

So as I left it I was about to isolate the shed and try using my extention lead from the house to see if it still trips thus telling me that the problem is in the shed well guess what.

I put the earth wire back in ( just remembered that I said neutral in my 1st post sorry it was Earth so sorry) Isolated the shed and plugged into extention lead and unit works fine, put the shed power back online and the unit works ( Thats strange) why is this, had a cup of tea and then it hit me, after the shed breaker I have power feeding to another shed that has a double socket with a built in breaker.

Is this what has happened to cause this: at some point the double socket with built in breaker in the 2nd shed tripped out and me removing the power via the 1st shed breaker reset it?

any how I am now going to replicate this and see if I get the same condition.


Once again thank you all for your advice and speed of your replies.


PS so so so so sorry about saying Neutral when it was Earth , I think It was because wife asking me about blue paint and I must have just said in my head Blue is Neu but it was defo my fault.

www.btinternet.com/~garypetersmiff/pid.JPG
www.btinternet.com/~garypetersmiff/worktop1.JPG

a few links of the Kit in question.

If you intrested the PID is from a kiln and the inside wiring loom is a work of art should take a pic one day,all hand made by an ICI boffin.

The other pic is my Brew set up in the middle is the Heat stick inside 22mm Copper that recycles the brew "wort" driven by the pump that gives me the ability to control the temprature to make many styles of beer,lager, ale,Stout wheat....blah blah the list is huge.



Thanks People have a great weekend

neutral / earth, ah, it does make a bit more sense now

Has your device been stored in the shed for a while? Could it have a bit of condensation inside causing some kind of earth fault? If the problem persists, is it possible to take it in the house (or somewhere warm) for a day or two and then see if the problem is still there?

nice shed heres wishing you many trouble-free hours of fun lying on the floor of your shed, gripping your stomach, singing regional folk songs to the roof-angels