Generator supply

[Eddiesparks]

Lovely bloke I am pricing a job for wants a feed coming UP from the shed to his house for a generator to power his heating if there is a power cut.

I'm assuming running swa in the garden (i will do sizing calculations etc), commando plug in shed but not sure what would best idea be for the heating side of things in his utility room. Bloke will be having a combi boiler and was gonna be on an FCU....

BUT if power cut he needs something he can just plug in. Should I put 'permanent' boiler feed on a DP socket from kitchen ring and have another DP integrated rcd socket next to it going down to genny?! Does genny socket in house even have to be rcd protected seeing as he is a skilled enough to have a genny and plug it in (!) so assume he is a 'skilled operative' - actually if i label it as 'boiler only' then that's ok too isnt it??

Ideas/thoughts?! Any glaring omissions?!?!

Thanks all

 

[not clever]

Ideas/thoughts?!

Yes
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.
.
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Transfer switch?

 

[MDJ]

Lovely bloke I am pricing a job for wants a feed coming UP from the shed to his house for a generator to power his heating if there is a power cut.

I'm assuming running swa in the garden (i will do sizing calculations etc), commando plug in shed but not sure what would best idea be for the heating side of things in his utility room. Bloke will be having a combi boiler and was gonna be on an FCU....

BUT if power cut he needs something he can just plug in. Should I put 'permanent' boiler feed on a DP socket from kitchen ring and have another DP integrated rcd socket next to it going down to genny?! Does genny socket in house even have to be rcd protected seeing as he is a skilled enough to have a genny and plug it in (!) so assume he is a 'skilled operative' - actually if i label it as 'boiler only' then that's ok too isnt it??

Ideas/thoughts?! Any glaring omissions?!?!

Thanks all

How are you going to earth the genny? how are you going to seperate the house supply to the heating from the genny supply to the heating?

 

[Knobhead]

Use site search, this subject has been done to death.

Ideas/thoughts?! Any glaring omissions?!?! Yes but I’ll get banned for swearing.

 

[shanky887614]

do not do this without a changeover switch.

otherwise it might kill someone one day

 

[not clever]

Well I was going to go with.......

Ideas/thoughts?!

Yes call somebody who knows what they need & how to install it!!

But thought that was a little harsh

 

[Eddiesparks]

Ok, I am learning, I have not done this before, we have all been in that situation before. At least I'm not just running an extension lead up the garden eh? lol!

I understand a transfer switch is something i will need. Although surely if I am running the genny feed up to one socket only then there is no danger of that socket powering anything else or the genny backfeeding to the DNO's property. I am NOT planning on having the generator power a sub main or indeed the main board. This is only for that one heating socket so if power failure is apparent then the bloke unplugs boiler and plugs into this socket(combi on 3a supply - NOT >3kW), does this not get rid of the necessity for a transfer switch?

Earthing is something I must consider, does that one socket need its own earth rod then?

Some helpful replies in here already, anyone else with a bit of patience got some time for me?

Thanks a lot

 

[Eddiesparks]

Ps tony thanks for advice re: searching. I found some good stuff using the search once I jumped on my computer. Tapatalk is a bit clunky...

 

[not clever]

If your going to do it do it properly.

install a change over switch between the dno supply/ genny supply /CU, will save lighting up any dno operative working up the road.

That way your customer can then isolate non essential circuits but leave on the heating & lights.

 

[not clever]

A pictorial guide for you.
Power Transfer Switch

 

[snoopydo]

remember a generator will produce carbon monoxide. Running one inside a shed could be deadly. its quite common in the usa to see deaths from generators which get used after bad weather resulting to power problems. Normally being used in hurricane shelters/sheds and tents.

 

[shanky887614]

If your going to do it do it properly.

install a change over switch between the dno supply/ genny supply /CU, will save lighting up any dno operative working up the road.

That way your customer can then isolate non essential circuits but leave on the heating & lights.

he isnt connecting it to supply/ccu

he is talking about having another socket next to boiler

with supply from genny so no chance of crossover, not the way I would do it but he isnt modifying existing circuits

 

[MDJ]

A can of worms though, the boiler will be bonded to the PME house supply and when the boiler plugged into the genny there will be a different earth potential then on all pipe work in the house, what happens when the power comes back on and it takes a few minuites to get back up to the garden shed to switch off the genny? 2 supplys connected in theory to pipe work, a change over switch isolating the whole pme supply must be the way forward IMO, I await others input but I see a can of worms with just adding a socket next to the boiler.

 

[davesparks]

You need a transfer switch arrangement of some sort, and proper earthing. Otherewise who knows what potential difference is going to exist between the generator supplied socket and the DNO fed socket.

Connecting the generator to the boiler will effectively connect all of the metal pipework to whatever earth the generator has got, and therefore all of the bonding in the house which is at some point connected to the supply neutral, either at the cutout or at the substation star point. Not quite so isolated from the DNO supply now is it?

 

[Eddiesparks]

Of course MDJ, that is spot on advice right there, I had not thought of that, as I said not used to putting in generators.

so basically I would need (to do properly)

proper genny for job (NOt site generator!) rated for supplying full house's electrics or "emergency CU" genny supply in swa up garden capable of said load and voltage drop, transfer switch between meter and CU

What about earth rod? Is there a place to connect it to the earth on the transfer switch's genny side only??

Thanks again

 

[davesparks]

What terminals the transfer switch has will depend entirely on which transfer switch you buy. If you are planning on installing a switch in to any earth connection then you need to be 100% certain you know exactly what you are doing and that it is 100% safe and compliant. Other options are converting the whole place to TT or adding an earth rod to the existing earth arrangements.

 

[Knobhead]

Ps tony thanks for advice re: searching. I found some good stuff using the search once I jumped on my computer. Tapatalk is a bit clunky...

If you’ve looked at some of the past threads you will see that earthing is a bugbear. The reason I’m so keen on it is I was trained by EMEB on distribution systems. They were a bit twitchy about generators being connected willy nilly to the system. they seem to have a thing about cable jointers getting fried.
PhilD is phoning me soon I’ll get him to look in here, he came across one of the most dangerous situations I’ve ever heard of with a generator. I’ll leave it to him to tell.

 

[Knobhead]

What about earth rod? Is there a place to connect it to the earth on the transfer switch's genny side only??

Thanks again

Short of sawing the boiler in half there’s not much you can do to isolate the two earths. BUT you must not rely on the DNO earth for the generator. You must supply an effective earth for the generator and the neutral earth link.

 

[Eddiesparks]

Thank you Tony. Very useful advice. You're not ALWAYS a grumpy old git as your profile says!

And Davesparks I will mate. Thank you

 

[Eddiesparks]

Ps Tony i'm interested to hear phild's story.