fused spurs

[stratplus]

Interested to know where you guys take you fused spurs from and how do you size the cable/fuse at the board to it?

 

[ShaunCorbs]

if you need to ask and you arnt part p reg you shouldn't be doing it from the board

 

[IDCHAPPY]

No Part P up here 😀

 

[ShaunCorbs]

No Part P up here 😀

no your lucky 😀 im sure they get money out of you another way tho?

 

[stani]

If there is a ring main close by I would take the spur from the ring main, the cable should be the same size as the ring main I.e. 2.5 mm t&e, the ring main protective device would suffice, and then the spur should be fused to protect the appliance as required.
Should I have to go back to the board for a new circuit then again 2.5 mm t&e, protective device for this would be 16amp then again fused at the spur to protect the appliance.

 

[ShaunCorbs]

If there is a ring main close by I would take the spur from the ring main, the cable should be the same size as the ring main I.e. 2.5 mm t&e, the ring main protective device would suffice, and then the spur should be fused to protect the appliance as required.
Should I have to go back to the board for a new circuit then again 2.5 mm t&e, protective device for this would be 16amp then again fused at the spur to protect the appliance.

it might not be 16amp maybe 32 amp depends on what type of main they have used

 

[stani]

If you read the text you will see that the 16 amp is to protect 2.5mm t&e, 32amp is to big to protect 2.5mm as a single circuit.

 

[ShaunCorbs]

If you read the text you will see that the 16 amp is to protect 2.5mm t&e, 32amp is to big to protect 2.5mm as a single circuit.

depends on what circuit type it is 😉

 

[stani]

depends on what circuit type it is 😉

???

 

[ShaunCorbs]

???

if you dont know you dont need to 🙂 but since its been a good day have a look at this

Converting a radial circuit to ring circuits

 

[stratplus]

That was why I asked the question. 2.5mm from the board on a 15amp 3036 rewireable fuse to the immersion. Then a 1.5mm from the spur to the boiler with a 3 amp fuse at the spur. Just thought the 15amp at the board should be changed to a 6amp. Wasn't sure with the 2.5mm t+e.

 

[stani]

He's not converting a radial into a ring he was asking where we take a spur from, and how we size the cable,

 

[ShaunCorbs]

That was why I asked the question. 2.5mm from the board on a 15amp 3036 rewireable fuse to the immersion. Then a 1.5mm from the spur to the boiler with a 3 amp fuse at the spur. Just thought the 15amp at the board should be changed to a 6amp.

quick question does it need rcd protection and whats the bonding like 4mm on water 😉

 

[ShaunCorbs]

He's not converting a radial into a ring he was asking where we take a spur from, and how we size the cable,

no but you need to know what your spuring from else you might overload a circuit

and that link was for you as you said 32 amp was too big for 2.5mm

 

[stratplus]

So the 15amp at the board will protect the 2.5mm and the 3amp will protest the 1.5mm from the spur.

 

[stani]

As a single circuit, I.e. From the board to the appliance (not a ring main) then the maximum current carrying capacity of 2.5 mm t&e is 27amps when ref.method C is used, a 32amp breaker would therefore be too big.

 

[stani]

So the 15amp at the board will protect the 2.5mm and the 3amp will protest the 1.5mm from the spur.

No, the 15amp protects the circuit the 3amp protects the appliance fitted, in this case the boiler

 

[ShaunCorbs]

As a single circuit, I.e. From the board to the appliance (not a ring main) then the maximum current carrying capacity of 2.5 mm t&e is 27amps when ref.method C is used, a 32amp breaker would therefore be too big.

yes but he didnt say what type it was and you suggested it was a ring post 5 and my post refers to yours

 

[ShaunCorbs]

No, the 15amp protects the circuit the 3amp protects the appliance fitted, in this case the boiler

which he has said (1.5mm flex)

 

[joni os]

Good example of how a simple question can involve complex considerations. Next someone will ask is the cable surface mounted or surrounded by rockwool.

 

[ShaunCorbs]

Good example of how a simple question can involve complex considerations. Next someone will ask is the cable surface mounted or surrounded by rockwool.

or chased in 😀

 

[stani]

Sorry, I thought the 1.5mm was also t&e, 1.5mm flex is very big for a boiler,

 

[stani]

or chased in 😀

That's why I said ref.method C

 

[ShaunCorbs]

Sorry, I thought the 1.5mm was also t&e, 1.5mm flex is very big for a boiler,

nope always use 1.5mm for boilers

 

[ShaunCorbs]

That's why I said ref.method C

again that post wasnt to you 😀

 

[joni os]

My missus been threating diversity for years.

 

[ShaunCorbs]

My missus been threating diversity for years.

😀 keep with it im sure she will come round one of these days 🙂

 

[stani]

nope always use 1.5mm for boilers

0.75mm is more than big enough for a boiler, it's rated at 6 amp capacity

 

[stratplus]

No, the 15amp protects the circuit the 3amp protects the appliance fitted, in this case the boiler

Always thought the fuse was there to protect the cable so the fuse melts before the cable.

 

[ShaunCorbs]

0.75mm is more than big enough for a boiler, it's rated at 6 amp capacity

yea doesnt mean i agree with it

 

[stani]

Always thought the fuse was there to protect the cable so the fuse melts before the cable.

As above thought the 1.5 was t&e to the spur not from the spur to the appliance, you are right,

 

[stratplus]

Sorry, I thought the 1.5mm was also t&e, 1.5mm flex is very big for a boiler,

Was t+e to the boiler.

 

[ShaunCorbs]

Was t+e

why would you use t+e from a fused spur to a boiler

 

[stani]

So have you taken 1.5t&e into the boiler

 

[Best]

Cables are often oversized. I never use any heavier cable to a boiler than 1.0mm and that is more than plenty.
Fuses are for protecting cable to appliance and, perhaps slightly less importantly, the appliance itself.