does this comply?

[ADS]

this is ghetting really boring now, please admin or the mods would someone close this thread as its getting tiresom. !!

Stop reading it then

oh and just for the record it doesnt comply with regs, :^O :^O

Another random statement with nothing to back it up - I rest my case

 

[ianmacd]

Actually I want this to stay open until I get a response from the IET about it. The rest is just filler

 

[Andy™]

Nah they were stupid enough to stick their fingers in but now our cable is melting and causing the house to burn.

and if this happened on a spur from a ring main......?

 

[ianmacd]

You are covered by reg 433.1.5

 

[Lee321]

I actually think ian can see the light but he's in too deep to admit so is standing ground ROTFWL

:Applaud

 

[Lee321]

Nah they were stupid enough to stick their fingers in but now our cable is melting and causing the house to burn.

no the body burning on the floor causes the fire :^O

how the electrocuted dead div who rammed his fingers into a shuttered socket has the exact chemical make up to cause the current to flow at 31 amps when he's crisp and dry not tripping the breaker but causing an over current condition on the cable that would run at that for 4 million years anyway :_|

 

[Andy™]

You are covered by reg 433.1.5

so just because its connected to a ring main it suddenly complies, even though that part of the circuit has not been changed in any way.

 

[ianmacd]

[quote name='Andy

 

[ianmacd]

[quote name='Lee

 

[Nicky Tesla]

433.1 Every cct shall be designed so that a small overload of long duration is unlikely to occur.

Now 433.1.5 is a paragraph which is a progression from the above reg. So can a small overload of long duration be created by sticking your very tiny thin fingers in a socket?

433.1.1 the protective device shall not be less than the design current of the cct

This design current will be 13amp (to a s/f/s)

433.1.5 is just a reg specific to ring main ccts, with a bit in it that says "under intended conditions of use, the LOAD current in any part of the cct is unlikely to exceed FOR LONG PERIODS the current carrying capacity of the cable"

This reg being to do with ring ccts has nothing to do with the radial scenario, even though it supports it.

433.2.2 The protective device, protecting a conductor against overload MAY be installed ALONG THE ROUTE, provided it fulfils AT LEAST ONE of the following conditions.

This means that it doesnot have to comply with both.

(1) it is protected against FAULT CONDITIONS with requirements of section 434

(2) its length does not exceed 3M AND is installed in such a manner to as to reduce the risk of fault.

Section 434 protection against fault current

434.1 The PFC shall be determined at every point of the cct.

434.5.2 For a fault of VERY SHORT duration KsqdSsqd shall be greater than the value of let through energy for the protective device.

After checking through the BRB at the above regs, I am now convinced the radial scenario is acceptable, as long as the MCB protecting it, is within the range for protecting the cable under fault conditions.

come on......can anybody do the calcs to show that a 32A mcb will infact protect a single 2.5t&e cable under fault conditions

 

[Lee321]

come on......can anybody do the calcs to show that a 32A mcb will infact protect a single 2.5t&e cable under fault conditions

yes this would be good i'd say it would be shockingly large

 

[Riggy]

[quote name='Lee

 

[Lee321]

^would be good to see the equation worked out + the device for fault protection only will be bigger than 32a

 

[m4tty]

Sorry to get involved and tell me to jog on but I thought a 13a fuse could take more than 13a for a period of time so if a double socket outlet (spur) can take more than 2 x 13a ie maybe 32a then this is more than the 2.5 can take. Can someone explain if I'm talking rubbish. I'm not getting involved but thanks everyone for this thread it's been good viewing and I'm learning loads from it. Cheers

 

[Andy™]

and a 32a MCB can take more than 32a.....

and a 20a mcb can take more than 20a

etc

 

[Lee321]

[quote name='Andy

 

[Lee321]

Sorry to get involved and tell me to jog on but I thought a 13a fuse could take more than 13a for a period of time so if a double socket outlet (spur) can take more than 2 x 13a ie maybe 32a then this is more than the 2.5 can take. Can someone explain if I'm talking rubbish. I'm not getting involved but thanks everyone for this thread it's been good viewing and I'm learning loads from it. Cheers

the fuses have a margin matty and so will the cable :x

i.e 13a fuses don't blow at 13.00000001 amps the same as a 2.5 that can carry 27a will do more for short times i.e it might be ok at 1000a for a nano second but be fine for 32a indefinately

obviously we design to the givens tho not what ifs

 

[ianmacd]

Nicky I am not going to argue against that for a FCU but a socket does not contain a fuse and 433.2.2 clearly says (although you have omitted it) that (paraphrased) sockets can not be BEFORE the protective device.

 

[Lee321]

but ian you cannot connect to the socket without introducing a fuse

 

[ianmacd]

[quote name='Lee