lightweight EFLI tester?

[333rocky333]

I would have thought as most boilers are connected to spurs, aside from disconnecting the incoming earthwire to test, any readings at the boiler terminals are likely to show a good earth anyway via the copper pipework, regardless of the state of the actual incoming cable earth

 

[EFLImpudence]

 

[ericmark]

The last boiler I worked on 35 sec gas oil had plastic pipes. I commented on the plastic right up to the boiler and the guy rightly said the boilers plastic so what's the problem.

The Eberspacher was indeed made of plastic. At least top bit. It was so small compared with house type boilers and nearly same output. Steel hull boats take some heating.

I think we all tend to jump to conclusions all boilers are similar but not so.

As made one would assume for Europe where some countries do not have sockets which are polarised so the line and neutral can easy be swapped I would guess if any single pole switching is involved would need some safety system to stop it being used until the user unplugged and turned the plug around and plugged back in.

Where reed switches are used near impossible to use all pole switching so either isolation transformer or some other safety device.

I have given reasons for considering 10v to be a reasonable figure but this is what I personally consider reasonable not a figure taken from any manual.

It would be interesting to know what the manufacturers consider acceptable. I had problems with a PAT tester in a school with a overhead projector. Some transformer action between the overhead projector and the TV stopped me testing the TV until the D connector was disconnected. Clearly some safety device.

In my own house there is enough transformer action to stop my LED lamps from going completely out. There are all sorts of odd things we come across which really have no danger yet trigger a safety device.

But the boiler is unlikely to measure loop impedance far more likely it measures voltage so measuring the same thing as the boiler is far more likely to highlight it as the problem than measuring loop impedance even if they are linked.

 

[ecowarrior]

There is a BS that requires the first 600mm to be copper to 'cope' with high slugs of hi temp water, however the gas always has to be copper.

As to including the copper in the earth circuit I think we are going from Fault current path to short circuit path? IIRC this is where the 'shorted' current is higher than the fault current? (as the extra copper of the pipes lowers the Zs? )
As u can tell I dont get overly entangled on your side of the fence!
Nice to get some constructive help though. Thanks.
The boiler always has to be earthed via the cpc conductors & never by the pipework. If they are (well should be) all bonded correctly (the pipework) and the pipes are at earth potential - what is the issue with this? (this is just a theoretical question)

 

[martinxxxxxx]

If they are (well should be) all bonded correctly (the pipework) and the pipes are at earth potential - what is the issue with this? (this is just a theoretical question)

I just wondered if you were following the wiring regs when bonding the boliers, I have seen a lot of cross bonding and I wondered if you gas guys are told to do it regardless of the electrical installation.

 

[EFLImpudence]

I just wondered if you were following the wiring regs when bonding the boliers, I have seen a lot of cross bonding and I wondered if you gas guys are told to do it regardless of the electrical installation.

I don't know what the gas guys are told but it is not required nor necessary.

The boiler is earthed by the cpc and so the pipes are connected together and to the boiler by their connections.
Even if the pipes were not connected by the boiler connections this supplementary bonding may only be required IF the boiler were in a special location AND IF the resistance between the pipes and the boiler were higher than the required level for the situation.

It is sometimes demanded by 'plumbers' otherwise they will not sign off/commission the boiler - so easier to fit than explain to someone who doesn't want to listen nor understand.