Cable & Pipe Proximity - OSG Ref - Can U help?

[chrissiebaker]

Dear All

Can anyone help?

Am working for the Bob "the know it all" builder on a re-furb and huge extension. I want to move some existing cables because they are touching and in some instances wrapped round hot water pipes.

I know it's not specific in Regs re distances Sec 522, however have been told by Napit - 2 inches which is mentioned somewhere in OSG. - Has anybody come across this if so which page ideally amend 1 (but still have 2008 OSG)?

Many thks
Female Spark

 

[ezzzekiel]

25mm seperation from gas pipes springs to mind

 

[MarkieSparkie]

The 528.3 group of regulations apply ... but these only state suitable spacing or use of mechanical or thermal shielding.
However, I think the separation distances quoted in OSG 2.3 for electrical cables/gas pipes would be appropriate suitable spacing ... 25mm spacing for pipes <=35mm diameter and 50mm for pipes >35mm diameter.

 

[Guest123]

As you've said, 522 doesn't stipulate an actual distance only 'sufficiently far so as not to be harmfully affected'.

528 has guidance also

IMO if they are wrapped around hot water pipes then they are not 'sufficiently far' so we can either move them the 50mm as Napit suggested, or shield them from the heat source.

 

[ezzzekiel]

also proximity of non electrical services and other influences on the eic to consider

 

[acvc]

OSG 7.4.3 'Separation of Gas Installation Pipework' (P76): "Gas installation pipes must be spaced a) at least 150mm from electricity meters, controls , electrical switches or socket outlets, distribution boards or consumer units; and b) at least 25mm from electrity supply and distribution cables". Plumbers should know this from their BS6891 ......

 

[brman]

I am probably completely wrong here but isn't the OSG 2.3 comment part of the gas regs. i.e. to ensure protection of the gas system from the electrical system, not the other way round?
In that case I am not sure the separations mentioned are so relevant?

Doesn't that then leave us with the 522/528 where we are worried about a detrimental affect on the cct by heat, moisture, maintenance of the other service etc. In this case the most relevant being heat so you can't guarantee the temp will not go over the max rating of the cable (assuming it is 70degC rated). Or very close, creating a low Ca at least?

If I am right and temp is the problem then perhaps worry more about insulation than separation - perhaps a bit of pipe lagging will do a sufficient job?

I could be talking rubbish so don't take this as informed opinion but I'd like to know what others think about my reasoning!

Toby

 

[Silly Sausage]

Ask Bob if he'd like his **** permanently wrapped around a hot water pipe.

 

[chrissiebaker]

Thanks to everyone for their very useful suggestions! Yeap I'm going to pursuade 'Bob' with Regs 522 & 528 i.e. min 150mm. I would prefer to just rip out and start again - but I live in hope at least with some regs to quote he might listen to me!

Many thks
Female Spark

 

[acvc]

Even if it is part of the Low Pressure Gas Standards ..... we'd still be contravening it if we ignored it just because it isn't an Wiring Reg. Also: why would gas pipes get hot. It's more 'maintenance of the other service' than 'thermal effects' that would be of concern I would have thought.

 

[Spudnik]

Ask Bob if he'd like his **** permanently wrapped around a hot water pipe.

And your point is what exactly?

 

[brman]

Even if it is part of the Low Pressure Gas Standards ..... we'd still be contravening it if we ignored it just because it isn't an Wiring Reg. Also: why would gas pipes get hot. It's more 'maintenance of the other service' than 'thermal effects' that would be of concern I would have thought.

I thought we were talking about cables wrapped around a hot water pipes. I am not sure where the gas standards came in except as a comparison for separation distances.

 

[chris murphy]

Dear All

Can anyone help?

Am working for the Bob "the know it all" builder on a re-furb and huge extension. I want to move some existing cables because they are touching and in some instances wrapped round hot water pipes.

I know it's not specific in Regs re distances Sec 522, however have been told by Napit - 2 inches which is mentioned somewhere in OSG. - Has anybody come across this if so which page ideally amend 1 (but still have 2008 OSG)?

Many thks
Female Spark

"Hello chrissiebaker",


From a Heating Engineers point of view - Copper Heating Flow Pipes get Hotter than the 70 Degrees C [?] that I have read on here is the Maximum Heat that Domestic Electrical Cable Insulation `resists` [?] - and even then I would guess that prolonged contact would degrade the [PVC ?] Insulation ? [at 70 Degrees]

On Conventional Open Vented Heating Systems the Copper Heating Flow Pipe from the Boiler reaches approximately 80 Degrees C - on a Sealed System this can be slightly higher - approximately 82 to 85 Degrees C.

Hot Water Pipes are unlikely to exceed approximately 60 Degrees C - but when they are that Hot I would still be concerned that damage could be done to the Cable Insulation by prolonged contact.


I would definitely state that Electrical Wiring / Cable should NEVER be allowed to come into contact with Central Heating - Hot Water or Gas Pipework.

And because of the Gas Regulation regarding this it should be that Electrical Cables should NOT be in contact with ANY Heating - Plumbing or Gas Pipework - Electricians should NOT be trying to Identify `Cold Pipes` as being O.K. for their Cables to touch.

The Gas Regulation of a MINIMUM of 25mm to a Gas Pipe should be exactly that - a Minimum - I would always Try to be at least 50mm away from ALL Pipes - If this can be achieved I would view it as `Good Practice`.

I have read on this Forum that it would be acceptable to `Shield` the Cables from the Hot / Gas Pipes by using Foam Pipe Insulation - so I expect that `Bob` may well suggest that as opposed to You pulling out the Cable and re-running it ?


I hope that I have NOT aggravated any of My Electrician Colleagues on here with these comments - although I doubt whether any would state that Electrical Cables contacting Pipework is completely acceptable [?].


Regards,


Chris