bonding help

[JACKC]

I was in a mates engineering firm doing some PAT testing on the QT and came across the following. Stainless steel handwash trough with 15ltr hot water heater directly underneath supplied from SFCU mounted to the side away from trough. All pipework is copper but no sign of supplementary bonding. Am I correct is assuming this needs bonding to the cpc of the water heater or just crossbonding the cold water to the hot water pipework. TIA.

 

[ericmark]

Bonding does not need to be visible and at the point where the supplies enter the building is normally enough. Unless you stick a meter on the pipes it is hard to tell what is there.

As to PAT testing on QT how can you provide traceable records on the QT?

Either they are all above board or no point in doing unless one is trying to prove some is not doing their job!

I have when I think something should have failed re-tested on QT so when suspicions are raised I already know results. But to PAT test not only test results need to be traceable but also all calibration on the machine.

 

[JACKC]

Ericmark, when I said on the QT, I meant as a favour to a friend with no invoice from my firm. Certificates will be issued and traceable to me with my name and address on, using Megger Powersuite Professional. Meter has a valid calibration certificate aswell. Last calibrated in Nov 08 when I bought it.

My concern with the hand wash trough was the pipework is copper the cold supply quite possibly connected to the MET via this, and as such is now an extraneaus conductive part. SFCU for the water heater is within 2 feet of the trough. Similtaneous contact could happen. As the hot and cold pipework under the trough is not cross bonded, does this need doing to enable the protective device to operate at less than the 50v mark. Should this be supplementary bonded by crossbonding the hot to the cold or by hot to cold to cpc of the SFCU?

 

[ColJack]

the P in PAT is Portable, so why are you testing parts of the fixed installation?

and no you don't need to bond it, it's not a bathrooom, it's a toilet with washing facilities..

(I'm assuming that there is no bath or shower stall fitted? )

 

[JACKC]

Page 1 of the Code of Practise for the In Service Inspection and Testing of Electrical Equipment 3rd edition is why I am testing this particular piece of electrical equipment. Please read it.

 

[ColJack]

I'll have to get a copy of that, you're the third or fourth person to mention it in the past few days..

I only got my I&T qual's 2 years ago and the extent of my use of them is to test the units we make prior to dispatch.. the factory doesn't have a maintenence shedule and stuff gets fixed as and when needed.. they won't even let us PAT test the 110 tools and leads...

 

[JACKC]

Bonding is required where there is a possibility of simultaneous contact between extraneous conductive parts and exposed conductive parts. It is required in a bathroom as it is a special location.

BAS are you on line and can answer this before I go to bed please. Many thanks

 

[ColJack]

then please tell me why it's no longer required to bond the taps and sink in a kitchen, a situation where any number of appliances can be in one hane while running a tap or leaning on the drainer..

 

[JACKC]

Those regs are before my time, I can only assume that a kitchen is not classed as a special location. However having said that, my mains water incomer is directly under the sink and the taps are connected to the sink. So they are at earth potential. For instances where the water incomer is not so handy then I would guess the electrician make a professional assessment of the situation and bond accordingly.
It is this assessment knowledge that I require in this situation of the hand trough, as it looks like it should be bonded.
At work all of our metal benches are bonded as they have mains sockets near them and they IR tested out to less than the 20Kohm requirement.

 

[Spark123]

Bonding is required where there is a possibility of simultaneous contact between extraneous conductive parts and exposed conductive parts. It is required in a bathroom as it is a special location.

The extraneous conductive part should be main protectively equipotentially bonded so should not become greater than 50v above that of the MET.
The circuit supplying the electrical heater should be designed to disconnect quickly in the event of a fault thus limiting the danger.

Supp bonding is only often required in some of the special locations, however it may also be specified in other places where there is a risk of a dangerous potentials being apparent.

 

[JACKC]

Thanks for that Sparks, that is what I needed to know and can understand now what ericmark meant on his first reply. Thanks for the help people. Goodnight.