Rewiring Shed

[mdbalson]

The way I am going to now rewire the shed is:

Change the 16 MCB to a 32 amp MCB, in the House ccu

Change the 2.5mm T+E to 6mm T+E, which runs from the ccu to the Metal app. box

Change the 2.5mm 2 core SWA to 6mm 3 core SWA, which runs from the Metal app. box in the House to the Shed ccu

Change the Terminal block in the Metal app. box, to a 30Amp one

Change the old Metal Wylex 2 way ccu (Rewireable Fuses), to in a New Metal Wylex 5 way Consumer Unit with a 100A Dp Isolator Sw (MCBs), in the shed

Put in a Metalclad DP double socket for the Tumble Dryer, and Freezer, which will be on a Radial, on its own MCB in the shed ccu (16 amp or 20 amp )

Put in three Metalclad DP double sockets along the worktop, which will be on a Ring Main, on its own 32amp MCB in the shed ccu

Have the pond pump and an outside socket on a Metalclad RCD FCU which will be on its own 16amp MCB in the shed ccu

Put the LV Garden lights (x2), outside floodlight, and outside shed light (light above shed door) on a Metalclad RCD FCU on a 6 amp MCB in the shed ccu

Put the shed light on a 6 amp MCB in the shed ccu

Have the 2kW Heater wired into a switched Metalclad FCU, connected to the Ring Main Sockets.

Run the Cables in the Shed in Round 20mm PVC Conduit.

Clip up the 6mm SWA with cable cleats

Put in a 8 Gang Metalclad MK Grid System for:

The Shed Light (A 10Amp 1Way SP Switch)

The Outside Shed Light (A 10Amp 2Way SP Switch)

The Outside Floodlight (A 10Amp 2Way SP Switch)

The LV Garden lights (Top of Garden) (A 20Amp DP Switch)

The LV Garden lights (Side Garden Path) (A 20Amp DP Switch)

The Pond Pump (A 20Amp DP Switch)

Have the Outside Shed Light, and The Outside Floodlight, on a two way switched system. (One of the Switches will be in the shed, and the other Switch will be in the Kitchen)

The Run of SWA is 13m from the Metal app. box in the house to the shed ccu

I have all ready bought 13m of 6mm 3 Core SWA, 1m of 6mm T+E, and a 30 Amp Terminal Block


1) So would this be ok


2) What Size SWA Cable Cleats do you use for 6mm SWA


3) Is it 20mm Large SWA Glands, that are used for 6mm SWA

 

[Steve]

I have written my replies in red within this quote:

The way I am going to now rewire the shed is:

Change the 16 MCB to a 32 amp MCB, in the House ccu ok

Change the 2.5mm T+E to 6mm T+E, which runs from the ccu to the Metal app. box ok

Change the 2.5mm 2 core SWA to 6mm 3 core SWA, which runs from the Metal app. box in the House to the Shed ccu ok

Change the Terminal block in the Metal app. box, to a 30Amp one ok

Change the old Metal Wylex 2 way ccu (Rewireable Fuses), to in a New Metal Wylex 5 way Consumer Unit with a 100A Dp Isolator Sw (MCBs), in the shed ok but the 100A isolator is just that, its not an MCB

Put in a Metalclad DP double socket for the Tumble Dryer, and Freezer, which will be on a Radial, on its own MCB in the shed ccu (16 amp or 20 amp ) right, now the fun begins. Dont use sockets here. Get a couple of FCUs for these appliances, otherwise they need to be RCD protected. FCUs dont.

Put in three Metalclad DP double sockets along the worktop, which will be on a Ring Main, on its own 32amp MCB in the shed ccu RCD protection required. Use an RCBO instead of the MCB.

Have the pond pump and an outside socket on a Metalclad RCD FCU which will be on its own 16amp MCB in the shed ccu why not put this on the ring main with the sockets above? Negates the need for more RCDs

Put the LV Garden lights (x2), outside floodlight, and outside shed light (light above shed door) on a Metalclad RCD FCU on a 6 amp MCB in the shed ccu no need for an RCD here, or an FCU. Outside lights dont need to be RCD protected, and a 6 amp MCB is sufficient protection.

Put the shed light on a 6 amp MCB in the shed ccu

Have the 2kW Heater wired into a switched Metalclad FCU, connected to the Ring Main Sockets.

Run the Cables in the Shed in Round 20mm PVC Conduit. if you want this to look good, use metal conduit, but this requires specialist tools. Otherwise, use some SWA to link it all together, but this will be time consuming to do.

Clip up the 6mm SWA with cable cleats

Put in a 8 Gang Metalclad MK Grid System very nice for:

The Shed Light (A 10Amp 1Way SP Switch)

The Outside Shed Light (A 10Amp 2Way SP Switch)

The Outside Floodlight (A 10Amp 2Way SP Switch)

The LV Garden lights (Top of Garden) (A 20Amp DP Switch) why 20 amp?

The LV Garden lights (Side Garden Path) (A 20Amp DP Switch) why 20 amp?

The Pond Pump (A 20Amp DP Switch) why 20 amp?

Have the Outside Shed Light, and The Outside Floodlight, on a two way switched system. (One of the Switches will be in the shed, and the other Switch will be in the Kitchen) how will you accomplish this?

The Run of SWA is 13m from the Metal app. box in the house to the shed ccu

I have all ready bought 13m of 6mm 3 Core SWA, 1m of 6mm T+E, and a 30 Amp Terminal Block exactly 13m? you will invariably need more. for example, I measured the distance to my shed as 20 metres. I bought 25 metres of SWA, had about 3 metres left.


1) So would this be ok sounds like a robust installation, just the technicalities above need dealing with


2) What Size SWA Cable Cleats do you use for 6mm SWA cant remember, but the ones TLC recommended were too big


3) Is it 20mm Large SWA Glands, that are used for 6mm SWA yes, IIRC

hope this helps you
regards.

 

[mdbalson]

I have written my replies in blue within this quote:

I have written my replies in red within this quote:

The way I am going to now rewire the shed is:

Change the 16 MCB to a 32 amp MCB, in the House ccu ok

Change the 2.5mm T+E to 6mm T+E, which runs from the ccu to the Metal app. box ok

Change the 2.5mm 2 core SWA to 6mm 3 core SWA, which runs from the Metal app. box in the House to the Shed ccu ok

Change the Terminal block in the Metal app. box, to a 30Amp one ok

Change the old Metal Wylex 2 way ccu (Rewireable Fuses), to in a New Metal Wylex 5 way Consumer Unit with a 100A Dp Isolator Sw (MCBs), in the shed ok but the 100A isolator is just that, its not an MCBI put MCB down to show that it is a ccu with MCBs, and not Rewireable Fuses

Put in a Metalclad DP double socket for the Tumble Dryer, and Freezer, which will be on a Radial, on its own MCB in the shed ccu (16 amp or 20 amp ) right, now the fun begins. Dont use sockets here. Get a couple of FCUs for these appliances, otherwise they need to be RCD protected. FCUs dont.There is RCD protection on the ccu in the house, which the shed circuit is on

Put in three Metalclad DP double sockets along the worktop, which will be on a Ring Main, on its own 32amp MCB in the shed ccu RCD protection required. Use an RCBO instead of the MCB.There is RCD protection on the ccu in the house, which the shed circuit is on

Have the pond pump and an outside socket on a Metalclad RCD FCU which will be on its own 16amp MCB in the shed ccu why not put this on the ring main with the sockets above? Negates the need for more RCDsI was going do it like this, so that it would not trip the RCD in the house, because if it did it would knock out the power to the Freezer

Put the LV Garden lights (x2), outside floodlight, and outside shed light (light above shed door) on a Metalclad RCD FCU on a 6 amp MCB in the shed ccu no need for an RCD here, or an FCU. Outside lights dont need to be RCD protected, and a 6 amp MCB is sufficient protection.

Put the shed light on a 6 amp MCB in the shed ccu

Have the 2kW Heater wired into a switched Metalclad FCU, connected to the Ring Main Sockets.

Run the Cables in the Shed in Round 20mm PVC Conduit. if you want this to look good, use metal conduit, but this requires specialist tools. Otherwise, use some SWA to link it all together, but this will be time consuming to do.The PVC Conduit does look good when done probally

Clip up the 6mm SWA with cable cleats

Put in a 8 Gang Metalclad MK Grid System very nice I know for:

The Shed Light (A 10Amp 1Way SP Switch)

The Outside Shed Light (A 10Amp 2Way SP Switch)

The Outside Floodlight (A 10Amp 2Way SP Switch)

The LV Garden lights (Top of Garden) (A 20Amp DP Switch) why 20 amp?The DP Switches ownly come in 20Amp, and the switch will be switching a socket on/off

The LV Garden lights (Side Garden Path) (A 20Amp DP Switch) why 20 amp?The DP Switches ownly come in 20Amp, and the switch will be switching a socket on/off

The Pond Pump (A 20Amp DP Switch) why 20 amp?The DP Switches ownly come in 20Amp, and the switch will be switching a socket on/off

Have the Outside Shed Light, and The Outside Floodlight, on a two way switched system. (One of the Switches will be in the shed, and the other Switch will be in the Kitchen) how will you accomplish this?By having a 2 Gang Switch in the Kitchen, which is connected to the two switches in the shed, and link them with strappers,run within a run of PVC Conduit

The Run of SWA is 13m from the Metal app. box in the house to the shed ccu

I have all ready bought 13m of 6mm 3 Core SWA, 1m of 6mm T+E, and a 30 Amp Terminal Block exactly 13m? you will invariably need more. for example, I measured the distance to my shed as 20 metres. I bought 25 metres of SWA, had about 3 metres left.The run from the house to the shed is 10m, then I added 3m to be safe


1) So would this be ok sounds like a robust installation, just the technicalities above need dealing withWould what I have just said, deal with the the above techicalities


2) What Size SWA Cable Cleats do you use for 6mm SWA cant remember, but the ones TLC recommended were too big


3) Is it 20mm Large SWA Glands, that are used for 6mm SWA yes, IIRC

hope this helps you
regards.

 

[securespark]

Have the pond pump and an outside socket on a Metalclad RCD FCU which will be on its own 16amp MCB in the shed ccu why not put this on the ring main with the sockets above? Negates the need for more RCDsI was going do it like this, so that it would not trip the RCD in the house, because if it did it would knock out the power to the Freezer

Surely if you have the shed circuit protected by RCD at the house, any earth fault in the shed will trip that RCD?

The best layout would be to have RCD protection (or RCBO's, John!!) in the shed, then a fault would only trip that device, not affecting the house.

I can see the logic ('scuse pun) of using DP switches. If there were a problem in future, it is very handy having total isolation.

 

[Steve]

OK, i was assuming you werent having it on the house RCD. I wouldn't do it. Start RCD protection at the shed, using a couple of RCBOs for certain circuits. Assuming you have a 30mA RCD at the house, you dont need ANY RCD protection at all at the shed, but this is not the way to do things. Also another point is that having two RCDs in series, of the same rating (30mA) is wrong, because in the event of a fault, EITHER or BOTH could trip. There is never a guarantee that one WILL trip first.

The freezer and tumble dryer? dont need RCDing for a start, so take a couple of FCUs on their own MCB-only circuit for these.

All sockets at the shed need RCDing, so put these on an RCBO.

If those 20A DP switches control sockets, these should be on a 20A RCBO too, NOT the lighting circuit, as anything could be plugged in to these sockets. Then, what I said about the lighting circuit not requiring an RCD still applies.

Point taken about the PVC conduit, but metal conduit looks better with metal fittings.

I think the main thing you need to realise is that only the sockets need RCD protection, and you shouldn't have RCDs in series (2 RCDs protecting the same load).




Another thing I wasn't sure about was the PVC conduit for the kitchen switch. I'd rather see a length of 1.5mm² SWA for the outdoor run.

 

[mdbalson]

I have put my replies in red

OK, i was assuming you werent having it on the house RCD. I wouldn't do it. Start RCD protection at the shed, using a couple of RCBOs for certain circuits. Assuming you have a 30mA RCD at the house, you dont need ANY RCD protection at all at the shed, but this is not the way to do things. Also another point is that having two RCDs in series, of the same rating (30mA) is wrong, because in the event of a fault, EITHER or BOTH could trip. There is never a guarantee that one WILL trip first.

RCBO's would cost too much, and also the reason I was going to put the Shed on the house ccu is, the shed is on it at the moment, and there is no room on the older non-RCD protected ccu in the house.

The freezer and tumble dryer? dont need RCDing for a start, so take a couple of FCUs on their own MCB-only circuit for these.

All sockets at the shed need RCDing, so put these on an RCBO.

They would be RCDed by the house RCD

If those 20A DP switches control sockets, these should be on a 20A RCBO too, NOT the lighting circuit, as anything could be plugged in to these sockets. Then, what I said about the lighting circuit not requiring an RCD still applies.

I am now going to, connect the LV Garden Lights to Waterproof JBs, controled by the 20A DP Switches.

Point taken about the PVC conduit, but metal conduit looks better with metal fittings.

The PVC conduit is easier to work with and costs less, and the tools to work with the PVC conduit are cheaper to buy.

I think the main thing you need to realise is that only the sockets need RCD protection, and you shouldn't have RCDs in series (2 RCDs protecting the same load).

So that means that the Outside Waterproof Socket in the courtyard is wrong, as it has a built in RCD, and the ccu in the house has a RCD as well.

Another thing I wasn't sure about was the PVC conduit for the kitchen switch. I'd rather see a length of 1.5mm² SWA for the outdoor run.

I have not seen 8 core 1.5mm SWA, and I would probally cost a lot.

 

[Steve]

You CAN RCD protect anything you want! Doesn't mean you SHOULD, or that the regs require it! The only thing you NEED RCD protection for is sockets that could reasonable be expected to provide power outdoors!

And there is NO point whatsoever in having 2 RCDs protecting the same socket/circuit/wiring. All you need is the RCD at the house, you dont need any more RCDs at the shed. At all. full stop.

The only problem with this is resetting the RCD if it trips - you've got to go all the way back to the house to reset it, and then it might trip again. It will also take out whatever circuits it protects in the house! Which is why we keep telling you to have the shed on the non-RCD wiring in the house, and have a local RCD for the shed!

EDIT: http://www.myonlineimages.com/Members/mdbalson/images/Both Consumer Units.JPG

Any reason why the new shed circuit cannot go on the MEM CU? That contactum one will probably disintegrate when you open it anyway. Talk about cheap.

And your installation has no single point of disconnection, which you might want to address, as the regs require this.

 

[mdbalson]

You CAN RCD protect anything you want! Doesn't mean you SHOULD, or that the regs require it! The only thing you NEED RCD protection for is sockets that could reasonable be expected to provide power outdoors!

And there is NO point whatsoever in having 2 RCDs protecting the same socket/circuit/wiring. All you need is the RCD at the house, you dont need any more RCDs at the shed. At all. full stop.

The only problem with this is resetting the RCD if it trips - you've got to go all the way back to the house to reset it, and then it might trip again. It will also take out whatever circuits it protects in the house! Which is why we keep telling you to have the shed on the non-RCD wiring in the house, and have a local RCD for the shed!

EDIT: http://www.myonlineimages.com/Members/mdbalson/images/Both Consumer Units.JPG

Any reason why the new shed circuit cannot go on the MEM CU? That contactum one will probably disintegrate when you open it anyway. Talk about cheap.

And your installation has no single point of disconnection, which you might want to address, as the regs require this.

The New Power Supply to the shed cannot go to the MEM CU, as you cannot buy the MCBs for it any more, and at the moment the old power supply to the shed goes to the Contactum Cu, so I was going to disconnect the Old Shed supply, and connect the New Shed supply to the same way in the Contactum CU, but change the B16 MCB for a B32 MCB.

Why would the Contactum CU disintegrate when I open it It didn't when I opened it to check the wiring in the CU

By a Single point of disconnection, do you mean to put in a DP Isolator switch to isolate both CUs. By putting the DP Isolator switch between the Meter and the two MK Service Connector Blocks, and would it need to be mounted on a block of wood, like the Service Head, Meter and the MK Service Connector Blocks, are mounted on.

 

[mdbalson]

The way I am going to now rewire the shed is:

(The House CCU has a RCD)

Change the 16 MCB to a 32 amp MCB, in the House ccu

Change the 2.5mm T+E to 6mm T+E, which runs from the ccu to the Metal app. box

Change the 2.5mm 2 core SWA to 6mm 3 core SWA, which runs from the Metal app. box in the House to the Shed

Change the Terminal block in the Metal app. box, to a 30Amp one

Change the old Metal Wylex 2 way ccu (Rewireable Fuses), to in a New Metal Wylex 5 way Consumer Unit with a 100A Dp Isolator Sw (MCBs), in the shed

Put in a Metalclad DP double socket for the Tumble Dryer, and Freezer, which will be on a Radial, on its own MCB in the shed ccu (16 amp or 20 amp )

Put in three Metalclad DP double sockets along the worktop, which will be on a Ring Main, on its own 32amp MCB in the shed ccu

Have the pond pump and an outside socket on its own 16amp MCB in the shed ccu

Put the LV Garden lights (x2), the light in my little brother's playhouse, and he outside shed light (light above shed door) on a 6 amp MCB in the shed ccu

Put the shed light on a 6 amp MCB in the shed ccu

Have the 2kW Heater wired into a switched Metalclad FCU, connected to the Ring Main Sockets.

Run the Cables in the Shed in Round 20mm PVC Conduit.

Clip up the 6mm SWA with cable cleats

Put in a 8 Gang Metalclad MK Grid System for:

The Shed Light (A 10Amp 2 Way SP Switch)

The Outside Shed Light (A 10Amp 2Way SP Switch)

The light in my little brother's playhouse (A 10Amp 2Way SP Switch)

The LV Garden lights (Top of Garden) (A 20Amp DP Switch)

The LV Garden lights (Side Garden Path) (A 20Amp DP Switch)

The Pond Pump (A 20Amp DP Switch)



Have the Outside Shed Light on a two way switched system. (One of the Switches will be in the shed, and the other Switch will be in the Kitchen

I will accomplish this by having a 1 Gang Switch in the Kitchen, which is connected to the switch in the shed, and link the two switches with a length of 3 core 1.5mm SWA



For the two sets of LV Garden lights, and the pond pump and the light in my little brother's playhouse, I was going to use two lengths of 4 core 1.5mm SWA, to power them.

One length would be to power the pond pump, and one of the sets of LV Garden Lights. (By using two of the 4 cores for each thing = Two sets of Live & Neutral cores, and use the Steel Armor as the Earth.)

The Other length would be to power the Other set of LV Garden Lights, and the light in my little brother's playhouse. (By using two of the 4 cores for each thing = Two sets of Live & Neutral cores, and use the Steel Armor as the Earth.)



The Run of SWA is 13m from the Metal app. box in the house to the shed ccu

I have all ready bought 13m of 6mm 3 Core SWA, 1m of 6mm T+E, and a 30 Amp Terminal Block

The run from the house to the shed is 10m, then I added 3m to be safe


1) So would this be ok

2) What Size SWA Cable Cleats do you use for 6mm SWA

 

[RF Lighting]

Sounds OK, but personally I would feed the shed from the non RCD side of the house CU, and then in the shed have either a CU with an RCD main switch, or better still (but more expensive) RCBOs for the circuits which require RCD protection.

Can I just double check how many MCBs will supply your grid switch?

The cleats I'm not sure about size.
I would go the the wholesaler and ask for cleats for a 6.0mm² 3 core SWA.

 

[mdbalson]

Sounds OK, but personally I would feed the shed from the non RCD side of the house CU, and then in the shed have either a CU with an RCD main switch, or better still (but more expensive) RCBOs for the circuits which require RCD protection.

Can I just double check how many MCBs will supply your grid switch?

The cleats I'm not sure about size.
I would go the the wholesaler and ask for cleats for a 6.0mm² 3 core SWA.

There is no room on the Non-RCD CCU (Consumer Circuit Unit), but there is on the old CCU, as that is what the shed is connected to at the moment.

(I could put the shed on the Non-RCD Side of the New Split-Load CCU, when I change the old Non-RCD CCU, to a Split-Load CCU. And then put in a Split-Load CCU in the shed.)


There will be three MCBs Supplying the grid switch

 

[mdbalson]

So will this be OK

 

[mdbalson]

So would what I was thinking of doing be ok

 

[mdbalson]

The way I am going to now rewire the shed is:

(Put the shed on the RCD CCU, for now & then move it over to the non-RCD side of the 9way Wylex split-load board am going to put in, to replace the old 6way MEM CCU with.)

Change the 16 MCB to a 32 amp MCB, in the House ccu

Change the 2.5mm T+E to 6mm T+E, which runs from the ccu to the Metal app. box

Change the 2.5mm 2 core SWA to 6mm 3 core SWA, which runs from the Metal app. box in the House to the Shed

Change the Terminal block in the Metal app. box, to a 30Amp one

Change the old Metal Wylex 2 way ccu (Rewireable Fuses), to in a New Metal Wylex 9 way Split-load Board Consumer Unit, in the shed

Put in a Metalclad FCU for the Freezer, which will be on a Radial, on its own MCB on the non-RCD side of the shed ccu, on a 16 amp MCB or a 20 amp MCB

Put in three Metalclad DP double sockets along the worktop, & a Metalclad switched FCU for the 2kW Heater, which will be on a Ring Main, on its own 32amp MCB on the RCD Side of the shed ccu (Plug the Tumble Dryer into one of these sockets),

Have the pond pump and an outside socket on its own 16amp MCB on the RCD Side of the shed ccu

Put the LV Garden lights (x2), the light in my little brother's playhouse, and the outside shed light (light above shed door) on a 6 amp MCB on the RCD side of the shed ccu

Put the shed light on a 6 amp MCB on the RCD side of the shed ccu

Run the Cables in the Shed in Round 20mm PVC Conduit.

Clip up the 6mm SWA with cable cleats

Put in a 8 Gang Metalclad MK Grid System for:

The Shed Light (a 4ft Tube) (A 10Amp 2 Way SP Switch)

The Outside Shed Light (A 10Amp 2Way SP Switch)

The light in my little brother's playhouse (a 3 or 4 ft Tube) (A 20Amp DP Switch)

The LV Garden lights (Top of Garden) (A 20Amp DP Switch)

The LV Garden lights (Side Garden Path) (A 20Amp DP Switch)

The Pond Pump (A 20Amp DP Switch)

(3 MCBs are going to fed the grid switch)

Have the Outside Shed Light on a two way switched system. (One of the Switches will be in the shed, and the other Switch will be in the Kitchen

I will accomplish this by having a 1 Gang Switch in the Kitchen, which is connected to the switch in the shed, and link the two switches with a length of 3 core 1.5mm SWA



For the two sets of LV Garden lights, and the pond pump and the light in my little brother's playhouse, I was going to use two lengths of 4 core 1.5mm SWA, to power them.

One length would be to power the pond pump, and one of the sets of LV Garden Lights. (By using two of the 4 cores for each thing = Two sets of Live & Neutral cores, and use the Steel Armor as the Earth.)

The Other length would be to power the Other set of LV Garden Lights, and the light in my little brother's playhouse. (By using two of the 4 cores for each thing = Two sets of Live & Neutral cores, and use the Steel Armor as the Earth.)

Will 1.5mm 4 core SWA be alright for this Or should I use 2.5mm 4 Core SWA


The Run of SWA is 13m from the Metal app. box in the house to the shed ccu

I have all ready bought 13m of 6mm 3 Core SWA, 1m of 6mm T+E, a 30 Amp Terminal Block, & 50m of "Cable Below" Warning Tape.

The run from the house to the shed is 10m, then I added 3m to be safe


So would this be ok

 

[mdbalson]

Here is a picture of the old metalclad rewireable CCU that is in the shed at the moment:

http://i167.photobucket.com/albums/u125/mdbalson/P9150109.jpg


And here is a picture of the old 2.5mm SWA coming in through the back of the shed:

http://i167.photobucket.com/albums/u125/mdbalson/P9150108.jpg


(P.S. All the rubbish that is in the shed was left by the old owners of the house)