some random questions about testing...

[Thomas123]

Hi guys,

I've got alot of questions that i'd like to be answered.

1) Is a double socket counted as 1 point served or 2?

I count it as one, and have read somewhere on here that its one, but a few people in work are adamant that its classed as 2. Is there any hard evidence that its classed as one that i can show them? What is the reason for number of points served?

Light switches? Are they counted?

PIR's? are they counted?

Spurs - do you count them or what they are feeding? or both?

Isolator - do you count them or what they are isolating? or both?

Is there any documentation on number of points served? as it seems to be quite a few people including myself are unsure about it.

2) PFC

Scenario: Lets say there is a pfc of 25KA at the mains which is protected by bs-88's, thats fine right. But then I have a pfc at a DB in that installation of 19ka, it is covered by 60898 breakers (10ka rating) I know these breakers would not be sufficient for the KA, but if that kind of fault current was flowing that the 60898 breakers could not operate the bs-88's at the mains would operate and cover the DB, so would that be a valid arguement that the board is covered?

Am I making any sense?



Outside Lights - they dont have to be covered by an rcd right? if they are out of reach fair enough, but what if it is low level surely it should be covered? it says in the regs that all mobile equipment for use outdoors is to be covered by an rcd, so spurs do not have to?



Periodic inspection:

Lets say the installation your testing does not conform to the 17th edition,

For instance if you have sockets that are not covered by an rcd, what do you do? does this mean it fails? Do you right it down as a recommendation? Or is it acceptable, because im guessing it conformed to the regs at one point...


No cpc on circuits, just trunking and conduit as an earth, is this ok? does it fail? do you right it down as a recommendation, because again at one point this conformed with the regs.

No rcd on circuits in bathrooms/swimming pools etc, is this ok? does it fail? do you right it down as a recommendation.

This guy in work said that having live parts showing in the board (old c50 type) was a fault and he gave it a code 2? I said to him, its a board, it's meant to? Is he right? Surely not?

Do sockets have to have a flying earth lead to the back box? I always do it, would you right it down as a fault on a new installation?

Ceiling grid, does it have to be bonded? the lights that sit in it are earthed, would this be sufficient?

******EDIT**********

Another question i forgot to post

Water and gas bonding, how do you calculate the size of the cable used? does the size matter as long as its under 0.05 ohms? or am i getting mixed up?

Another scenario, 300mm2 singles feeding a 3 phase main DB, neutral is 150mm2, the MET is not in the board but on the wall at the side of board. a 75mm2 earthing conductor is coming from the cut out, which is ok yeah? half the size of neutral, but then it only had a 35mm2 coming from MET to board? is that ok? as the regs only says about the earthing conductor from cut out to MET, not from MET to board.

*****edit****



I know its a lot of questions, but i would be grateful if anyone can answer them.

Cheers,
Aaron

 

[ezzzekiel]

1) Is a double socket counted as 1 point served or 2?

1


Light switches? Are they counted?
no

PIR's? are they counted?
yes
Spurs - do you count them or what they are feeding? or both?
count them
Isolator - do you count them or what they are isolating? or both?
no

Is there any documentation on number of points served? as it seems to be quite a few people including myself are unsure about it.
no except minimum advised per room

2) PFC

Scenario: Lets say there is a pfc of 25KA at the mains which is protected by bs-88's, thats fine right. But then I have a pfc at a DB in that installation of 19ka, it is covered by 60898 breakers (10ka rating) I know these breakers would not be sufficient for the KA, but if that kind of fault current was flowing that the 60898 breakers could not operate the bs-88's at the mains would operate and cover the DB, so would that be a valid arguement that the board is covered?

Am I making any sense?
dunno, the pfc taken at incoming side less than the rated pfc of service fuse or pfc taken from circuit less than pfc of mcb, either way covered by the main pfc



Outside Lights - they dont have to be covered by an rcd right? if they are out of reach fair enough, but what if it is low level surely it should be covered? it says in the regs that all mobile equipment for use outdoors is to be covered by an rcd, so spurs do not have to?
lighting fixed equip so no but cables buried yes



Periodic inspection:

Lets say the installation your testing does not conform to the 17th edition,

For instance if you have sockets that are not covered by an rcd, what do you do? does this mean it fails? Do you right it down as a recommendation? Or is it acceptable, because im guessing it conformed to the regs at one point...

should be covered by rcd by current standards

No cpc on circuits, just trunking and conduit as an earth, is this ok? does it fail? do you right it down as a recommendation, because again at one point this conformed with the regs.
either class2 and recorded or rewire

No rcd on circuits in bathrooms/swimming pools etc, is this ok? does it fail? do you right it down as a recommendation.
code 1 special locations require rcd

This guy in work said that having live parts showing in the board (old c50 type) was a fault and he gave it a code 2? I said to him, its a board, it's meant to? Is he right? Surely not?

not if its enclosed

Do sockets have to have a flying earth lead to the back box? I always do it, would you right it down as a fault on a new installation?

no bit of a myth but good practice

Ceiling grid, does it have to be bonded? the lights that sit in it are earthed, would this be sufficient?
should have an earth connection if steel


I know its a lot of questions, but i would be grateful if anyone can answer them

 

[gamblor6]

my view, defo 2, its 2 outlets. light switches no,pirs yes,spurs, only what they are feeding ditto isolators, ipf yes the bs88s cover it, outside lights, depends on when they were installed, if they conformed then they do now, sockets, depends if they can be used outdoors really,trunking and conduit earths are fine as long as there is no breaks,rcd in bathroom id recommend strongly,the board? do u mean with the cover off? flying earth nope, no need as long as there is 1 fixed lug, ceiling grid no.

 

[i=p/u]

aaron your going places

 

[Deleted member 9648]

Hi guys,

I've got alot of questions that i'd like to be answered.

1) Is a double socket counted as 1 point served or 2?I dont have the info to hand but it always used to be "each outlet counts as one point"...so a double would be two,this was for the pupose of establishing that the number of spurs does not exceed the number of outlets on the ring.....but for the puposes of a schedule of circuit details each point counts as 1...double or single.

I count it as one, and have read somewhere on here that its one, but a few people in work are adamant that its classed as 2. Is there any hard evidence that its classed as one that i can show them? What is the reason for number of points served?

Light switches? Are they counted?I count the number of loaded points...ie with a lamp...ignore switches.

PIR's? are they counted?As above

Spurs - do you count them or what they are feeding? or both?The spur point only

Isolator - do you count them or what they are isolating? or both?Isolator only...one point

Is there any documentation on number of points served? as it seems to be quite a few people including myself are unsure about it.Not that I am aware of...I've been doing as above for years without any comeback

2) PFC

Scenario: Lets say there is a pfc of 25KA at the mains which is protected by bs-88's, thats fine right. But then I have a pfc at a DB in that installation of 19ka, it is covered by 60898 breakers (10ka rating) I know these breakers would not be sufficient for the KA, but if that kind of fault current was flowing that the 60898 breakers could not operate the bs-88's at the mains would operate and cover the DB, so would that be a valid arguement that the board is covered?

Am I making any sense?



Outside Lights - they dont have to be covered by an rcd right? if they are out of reach fair enough, but what if it is low level surely it should be covered? it says in the regs that all mobile equipment for use outdoors is to be covered by an rcd, so spurs do not have to?In non special location situations on TN systems there is no requirement to provide rcd protection to fixed equipment outdoors..411.3.3



Periodic inspection:

Lets say the installation your testing does not conform to the 17th edition,

For instance if you have sockets that are not covered by an rcd, what do you do? does this mean it fails? Do you right it down as a recommendation? Or is it acceptable, because im guessing it conformed to the regs at one point...If that socket was liable to supply equipment outdoors or in another hazardous situation that would warrent a code 2....if it was not liable to supply equipment outdoors code 4.


No cpc on circuits, just trunking and conduit as an earth, is this ok? does it fail? do you right it down as a recommendation, because again at one point this conformed with the regs.As long as tests were satisfactory and the system was sound a code 4 might be appropriate

No rcd on circuits in bathrooms/swimming pools etc, is this ok? does it fail? do you right it down as a recommendation....bathrooms are only a recent requirement to rcd,you cant condemn all installs prior to 2008,so a code 4...swimming pool more serious as rcd protection has been a requirement for equipment in the zones for a long time,code 2 or even 1

This guy in work said that having live parts showing in the board (old c50 type) was a fault and he gave it a code 2? I said to him, its a board, it's meant to? Is he right? Surely not?As long as the live parts can only be accessed with a tool and the board was labelled "exposed live parts within" no code...if the live parts can be accessed without a tool code 2 or even 1 if in a situation where accessible to unskilled/unsupervised persons

Do sockets have to have a flying earth lead to the back box? I always do it, would you right it down as a fault on a new installation?As long as the socket has earthed metal screwholes and the box has at least 1 fixed lug...no......if there is no separate cpc(conduit earth)...yes.

Ceiling grid, does it have to be bonded? the lights that sit in it are earthed, would this be sufficient? No..it is unlikely to be an extraneous conductive part...see the definition of an extraneous conductive part in the BRB



I know its a lot of questions, but i would be grateful if anyone can answer them.

Cheers,
Aaron

...................

 

[Sparky Ninja]

I believe that a twin socket is still considered as 1 point of utilisation.

 

[gamblor6]

ive been told its 2. it is 2 outlets.

 

[Sintra]

Agree with Widdler one point of wiring.


Sent from my iPhone using Tapatalk.

 

[gamblor6]

agreed i may be wrong but i think, i cant find the paperwork, the niceic say its 2 points of utilazation ,spelling, on a circuit.

 

[gpz900jim]

i vote 1

 

[ian.settle1]

ive been told its 2. it is 2 outlets.

Does that mean you count a twin fluorescent as 2 because it has two tubes?

 

[gamblor6]

fair point

 

[Deleted member 26818]

Originally Posted by Aaron123
Hi guys,

I've got alot of questions that i'd like to be answered.

1) Is a double socket counted as 1 point served or 2?I dont have the info to hand but it always used to be "each outlet counts as one point"...so a double would be two,this was for the pupose of establishing that the number of spurs does not exceed the number of outlets on the ring.....but for the puposes of a schedule of circuit details each point counts as 1...double or single.

I count it as one, and have read somewhere on here that its one, but a few people in work are adamant that its classed as 2. Is there any hard evidence that its classed as one that i can show them? What is the reason for number of points served?

Light switches? Are they counted?I count the number of loaded points...ie with a lamp...ignore switches.

PIR's? are they counted?As above

Spurs - do you count them or what they are feeding? or both?The spur point only

Isolator - do you count them or what they are isolating? or both?Isolator only...one point

Is there any documentation on number of points served? as it seems to be quite a few people including myself are unsure about it.Not that I am aware of...I've been doing as above for years without any comeback

2) PFC

Scenario: Lets say there is a pfc of 25KA at the mains which is protected by bs-88's, thats fine right. But then I have a pfc at a DB in that installation of 19ka, it is covered by 60898 breakers (10ka rating) I know these breakers would not be sufficient for the KA, but if that kind of fault current was flowing that the 60898 breakers could not operate the bs-88's at the mains would operate and cover the DB, so would that be a valid arguement that the board is covered?

Am I making any sense?



Outside Lights - they dont have to be covered by an rcd right? if they are out of reach fair enough, but what if it is low level surely it should be covered? it says in the regs that all mobile equipment for use outdoors is to be covered by an rcd, so spurs do not have to?In non special location situations on TN systems there is no requirement to provide rcd protection to fixed equipment outdoors..411.3.3



Periodic inspection:

Lets say the installation your testing does not conform to the 17th edition,

For instance if you have sockets that are not covered by an rcd, what do you do? does this mean it fails? Do you right it down as a recommendation? Or is it acceptable, because im guessing it conformed to the regs at one point...If that socket was liable to supply equipment outdoors or in another hazardous situation that would warrent a code 2....if it was not liable to supply equipment outdoors code 4.


No cpc on circuits, just trunking and conduit as an earth, is this ok? does it fail? do you right it down as a recommendation, because again at one point this conformed with the regs.As long as tests were satisfactory and the system was sound a code 4 might be appropriate

No rcd on circuits in bathrooms/swimming pools etc, is this ok? does it fail? do you right it down as a recommendation....bathrooms are only a recent requirement to rcd,you cant condemn all installs prior to 2008,so a code 4...swimming pool more serious as rcd protection has been a requirement for equipment in the zones for a long time,code 2 or even 1

This guy in work said that having live parts showing in the board (old c50 type) was a fault and he gave it a code 2? I said to him, its a board, it's meant to? Is he right? Surely not?As long as the live parts can only be accessed with a tool and the board was labelled "exposed live parts within" no code...if the live parts can be accessed without a tool code 2 or even 1 if in a situation where accessible to unskilled/unsupervised persons

Do sockets have to have a flying earth lead to the back box? I always do it, would you right it down as a fault on a new installation?As long as the socket has earthed metal screwholes and the box has at least 1 fixed lug...no......if there is no separate cpc(conduit earth)...yes.

Ceiling grid, does it have to be bonded? the lights that sit in it are earthed, would this be sufficient? No..it is unlikely to be an extraneous conductive part...see the definition of an extraneous conductive part in the BRB



I know its a lot of questions, but i would be grateful if anyone can answer them.

Cheers,
Aaron



...................

It's the NICEIC that counts double sockets as two points, but then again you're probablly using their test sheets.
Conduit used as CPC warrents no code at all, as it complies with current Regulations. Of course if Zs are too high that's another matter.
I would agree with everything else above.
I would point out, that the ESC and NICEIC do not consider the lack of RCD protection for special locations, warrents any code at all.

 

[IQ Electrical]

Yes, I agree with the conduit/trunking cpc point, it should not have a code applied if it meets the requirements of 543.2.2

It was mentioned briefly above but if conduit is used as the sole cpc then regardless of the lug-type on boxes, a fly lead MUST be used to the accessory 543.2.7

 

[Deleted member 9648]

Agree with second thoughts on the conduit point....you are quite right,no code if all tests are good.