This one will bugger you lot up

[ackbarthestar]

The supply comes in from small cable on the LHS, measurements for RCD/VOELB taken from the socket.



What do you think the men in boots were up to?

Abuse freely available ......

 

[MDJ]

+4 whats all this about then, take the voltage tester out and throw it in the river or use it as an isolator, either way who cares haha, I can't think of a situation where it should be used in this day and age tbh.

 

[ackbarthestar]

Errrrrm, Frankly NO, ...Fine for the RCD, but not for the VOELCB!! The clue lies in the name ''VOLTAGE operated earth leakage circuit breaker''!!! Getting the picture now?? lol!! Both units have test buttons, but they will only confirm tripping, not measurable values, the same goes for your two way switch!!

Lol, I have just had a look at your old school report. It states: 'He is a difficult child who needs to apply himself more in class' :cry_smile::jester: However, I'll keep mine under wraps

Now, these VOELBs operate by detecting the change in voltage on the cpcs and when that rises under earth fault conditions, approximately 35V, it compares the result with the earth potential (steak) and then engages the trip mechanism .
But have a look at the attached label and you'll notice that it also requires a minimum current to energize the solenoid

View attachment 17734

The idea was to use a separate way in a DB to supply an imaginary installation via a VOELB, the armour is connected to the MET, a second earthing conductor is used to supply a reference earth to the other installation.
A RCD test measurement was taken with the test switch set to RCD and the value was 100mA. The RCD tripped at its rated value leaving the VOELB intact.
When the test switch puts the fault on the armour it trips the VOELB at 33mA leaving the 100mA RCD intact.

This doesn't fully explain why when a fault appears on the MET from the remote RCD the voltage doesn't rise causing both to trip out. We have theories about that but that's something else.......

 

[Silly Sausage]

Not this one ! we followed the instructions on the packet. However, we will try it the other way round since the crucial part are the earthing conductor terminations.

+5!

You built this pile of crap then?

I'd go and find one of these...

 

[ackbarthestar]

Lol, Archy, that was very good ha ha ha

 

[Stroppy]

How would a chemists help?

 

[SPARTYKUS]

Nah Stroppy he meant the pallet to mount the electrical gear on.

 

[Deleted member 9648]

Lol, I have just had a look at your old school report. It states: 'He is a difficult child who needs to apply himself more in class' :cry_smile::jester: However, I'll keep mine under wraps

Now, these VOELBs operate by detecting the change in voltage on the cpcs and when that rises under earth fault conditions, approximately 35V, it compares the result with the earth potential (steak) and then engages the trip mechanism .
But have a look at the attached label and you'll notice that it also requires a minimum current to energize the solenoid

View attachment 17734

The idea was to use a separate way in a DB to supply an imaginary installation via a VOELB, the armour is connected to the MET, a second earthing conductor is used to supply a reference earth to the other installation.
A RCD test measurement was taken with the test switch set to RCD and the value was 100mA. The RCD tripped at its rated value leaving the VOELB intact.
When the test switch puts the fault on the armour it trips the VOELB at 33mA leaving the 100mA RCD intact.

This doesn't fully explain why when a fault appears on the MET from the remote RCD the voltage doesn't rise causing both to trip out. We have theories about that but that's something else.......

:dizzy2:...Anyone for a beer?

 

[Engineer54]

I think it's you that needs to apply yourself more!! Your theory on the operation of the VOELCB is i'm afraid Flawed!! lol!!

They do not sense current in any way, shape or form, and as i remember the test voltage was 50V not 35V, and was also the operating voltage of these devices... You may be able to purchase an old VOELCB test kit on E-bay, but it will still need calibrating after 30 odd years sitting in someone garage cupboard shelf for 30 years...lol!!

On a side note, i hope you don't think these devices give, or ever gave protection to persons coming in contact with a live conductor, because the don't!!

 

[PEG]

Interesting post,ackbar...it put me in mind of an incident that occurred when i was about 16...a mate of mine let his family pet,one yorkshire terrier out by accident and it run straight under a passing shell oil petrol tanker.He picked up the "remains",ran to his dads' garage,put it on the bench and started prodding it with the croc clips of an old battery charger.The sad,limp mess started to twitch and jerk about and he was sure he was helping...This taught me a valuable lesson,JUST because you CAN do something,DOSENT always mean you should......the skips calling...

 

[ackbarthestar]

I think it's you that needs to apply yourself more!! Your theory on the operation of the VOELCB is i'm afraid Flawed!! lol!!

They do not sense current in any way, shape or form, and as i remember the test voltage was 50V not 35V, and was also the operating voltage of these devices... You may be able to purchase an old VOELCB test kit on E-bay, but it will still need calibrating after 30 odd years sitting in someone garage cupboard shelf for 30 years...lol!!

On a side note, i hope you don't think these devices give, or ever gave protection to persons coming in contact with a live conductor, because the don't!!

Lol, Now, remember we are not a UKAS calibration centre.......

I don't think that I suggested a VOELB senses current, but i did suggest that the tripping solenoid needed a certain amount of current to trip it which can be measured.

50V is the target value but that doesn't mean that individual devices will not trip out at lower voltages as we well know with stated values of mA rated RCDs...

Having said that. it was an experiment to show under certain circumstances there are curious advantages.

Now back to your last comment. A particular class I light fitting that failed as i turned it on tripped out the old VOELB still in situ. After stripping down the light fitting I found that the insulation inside had failed. So IMO, some VOELBs that are still connected correctly will offer shock protection although they are now past their sell by date.

I rest my case and pick up my hat........Lol

 

[itselectric]

A lot of problems we had during the VOLEB days was nuisance tripping from neighbours houses whose fault current followed the path through earth electrode and tripped the VOLEB mainly due to poor electrode siting and poor sub-structure.

 

[ackbarthestar]

A lot of problems we had during the VOLEB days was nuisance tripping from neighbours houses whose fault current followed the path through earth electrode and tripped the VOLEB mainly due to poor electrode siting and poor sub-structure.

Yep, this was a real problem. One fault could take out a row of these devices.

 

[Engineer54]

Lol, Now, remember we are not a UKAS calibration centre.......

I don't think that I suggested a VOELB senses current, but i did suggest that the tripping solenoid needed a certain amount of current to trip it which can be measured.

50V is the target value but that doesn't mean that individual devices will not trip out at lower voltages as we well know with stated values of mA rated RCDs...

Having said that. it was an experiment to show under certain circumstances there are curious advantages.

Now back to your last comment. A particular class I light fitting that failed as i turned it on tripped out the old VOELB still in situ. After stripping down the light fitting I found that the insulation inside had failed. So IMO, some VOELBs that are still connected correctly will offer shock protection although they are now past their sell by date.

I rest my case and pick up my hat........Lol

No idea what calibration services came under back then, but i can assure you, there were requirements for calibration, The company i did all my training with in the early day's were red hot on having all the factories test equipement calibrated, be they electrical or otherwise!!

Wrong again i'm afraid, the VOELB never has, was, or indeed ever is able to give shock protection end of!!

So your using the current specified on the tripping coil, ...Oh Dear!! lol!!

I can understand passing your time away on an experiment, but it seems you have somehow come to all the wrong conclusions as far as the VOELB is concerned!!


EDIT... Oppps, sorry ...misread your opening statement on calibration!!

 

[itselectric]

I agree with engineer 54 regarding shock protection I have been called to a location where a plumber had cut the main water pipe to put a tee in it and received electric shock. the VOELB hadn't tripped due to a good earth path through the water pipe and once he cut it he had a pd acros the two pipes

 

[Engineer54]

I agree with engineer 54 regarding shock protection I have been called to a location where a plumber had cut the main water pipe to put a tee in it and received electric shock. the VOELB hadn't tripped due to a good earth path through the water pipe and once he cut it he had a pd acros the two pipes

Must have been a fault elsewhere on the system. Anyway, the reason why they Don't provide shock protection, is the fact that the voltage won't change when a person comes into contact with a line conductor and earth, so the unit won't see any difference between the E and F terminals (think that's what they were called) on the VOELCB.