Metal oil tank

[norwood]

Morning guys & Happy Christmas

Id like to start the morning with a little debate over the bonding of metal oil tanks in regards to a PME install and the potential of broken neutrals etc. This one always confuses me because I lot of people have different opinions. I cant test to see if its completely extraneous because I cant shut down the whole school which I would like to do. I have heard of electricians putting a spike in the ground at the tank, is this a normal procedure, could I have your views on this please?

Thanks again for your help

 

[Richard Burns]

If you were to put a "spike" in the ground then you would have caused the oil tank to be definitely extraneous and it would now require bonding back to the MET.
Hmm, well I suppose it saves having to test to see if it is extraneous, but if it wasn't to begin with you have now made the installation more dangerous.

The only way to do this is to test it. If the oil pipe goes underground then it is almost definitely extraneous.

I have just thought that you could put a decent rod in the ground near the supply incomer and test continuity from the tank to the earth rod to see if there it is above or below 22Kohms, this may indicate if it were extraneous, but a lot of work to go to for a measurement.

 

[norwood]

Hi Richard

Its is a pain to be honest, its a little school out in the sticks which we don't normally do a lot of and all the oil boilers/installs I have ever come across have plastic tanks. This is a huge metal one on a concrete slab. The oil line does go underground I just wanted to double check myself. It is a lot of work. It is bonded at the MET as far as I can see but I need to double check.

 

[Pete999]

Morning guys & Happy Christmas

Id like to start the morning with a little debate over the bonding of metal oil tanks in regards to a PME install and the potential of broken neutrals etc. This one always confuses me because I lot of people have different opinions. I cant test to see if its completely extraneous because I cant shut down the whole school which I would like to do. I have heard of electricians putting a spike in the ground at the tank, is this a normal procedure, could I have your views on this please?

Thanks again for your help

[h=3]Main Bonding[/h] Main bonding is the electrical interconnection of incoming (metallic) services (e.g. water, gas, and oil pipes) plus any extraneous conductive parts of a building (like the metal framework used in some buildings, or the central heating pipework), to the main electrical earth. This ensures that under fault conditions things like pipework running through a building are not able to take on a dramatically different electrical potential to that of the installation's earth connection. Note this also covers the fault situation where it is the installations electrical earth that is itself introducing the dangerous voltag

 

[norwood]

Thanks Pete. Basically text book stuff which you know already. You just need that second opinion to not doubt yourself because you here other things that electricians make up, specially when reading old reports like I do on a daily basis.

Thanks again

 

[Pete999]

Thanks Pete. Basically text book stuff which you know already. You just need that second opinion to not doubt yourself because you here other things that electricians make up, specially when reading old reports like I do on a daily basis.

Thanks again

You are welcome, where in the southwest do you hail from??

 

[norwood]

Sunny Exeter! I have just stumbled upon a half a meter of rubber pipe from where it leaves the tank and connects on to the oil line which go down under somewhere. Its installed in a nice alloy box with a lid. There is a 10mm G/Y at the other end before the tiger loop which they have just taken to the boiler panel, not great.

 

[gnselectricals]

Most of the ones I come across the pipe is plastic of some kind to prevent corrosion I imagine but havnt found one that needed bonding yet. Testing is the way to go as stated if poss

 

[HandySparks]

Morning guys & Happy Christmas

Id like to start the morning with a little debate over the bonding of metal oil tanks in regards to a PME install and the potential of broken neutrals etc. This one always confuses me because I lot of people have different opinions. I cant test to see if its completely extraneous because I cant shut down the whole school which I would like to do. I have heard of electricians putting a spike in the ground at the tank, is this a normal procedure, could I have your views on this please?

Thanks again for your help

I can't see why you would want to bond a metal oil tank (assuming that it's located outside). Surely it's any metallic oil pipe that needs bonding (if extraneous) near the point of entry to the building?

 

[Leesparkykent]

The idea of having an earth rod at the metal oil tank is to prevent the build up of static with the transfer of liquids. The oil pipe if extraneous needs bonding at the point of entry to the building.