two radials on 16 a mcb

[ac/dc]

Hi All
Today I came across 2 x 2 radials on 16 a mcb's. Both on 2,5 mm .
One is for KTCH and the other for the 2 bed flat .
They were suppose to be rings , but for some reason they are radials .
If you do T & I , what would you put on a test sheet for R1 + R2 and ZS
Thx

 

[davesparks]

What is a KTCH?

What do you mean when you say they were supposed to be rings?

You put down the measured values in the appropriate boxes for the circuits you have tested


Sent from my iPad using Tapatalk

 

[ac/dc]

Hi DS
THx .for your replay .
I was checking the elect. certs . from 10 yers ago and there were 2 rings on that 2 bed flat.
One for kitchen and one for the rest of the flat.
There were on 32 a mcb.
Now there are no 32A mcb , there are 16 a mcb .
After testing them , ther is no connt . on both rings.
They are radials .
there is no space for an extra mcb's .
If you do T & I what would you do .
THx

 

[telectrix]

as the cables cannot be overloaded, there is no apparent potential danger, but probably will give rise to nuisance tripping.therefore, i'd code it C3. remedial works are to be discussed with customer. give them the options and let them decide. ( i am assuming the circuits are RCD protected ).

 

[Simonslimline]

They cant be 2 radials if they are on the same OCPD.

 

[davesparks]

Hi DS
THx .for your replay .
I was checking the elect. certs . from 10 yers ago and there were 2 rings on that 2 bed flat.
One for kitchen and one for the rest of the flat.
There were on 32 a mcb.
Now there are no 32A mcb , there are 16 a mcb .
After testing them , ther is no connt . on both rings.
They are radials .
there is no space for an extra mcb's .
If you do T & I what would you do .
THx

Your post is still very confusing, could you please take the time to write in a more coherent manner and proof read your posts, there is no time limit to how long you take to make a post and you will get far more help if you can communicate clearly.

At the moment it sounds like there is nothing wrong and nothing to do, presumably a fault has occurred and the only way this could be solved was to cut out the bad section and make the circuit a radial with two branches. Though it is very odd for similar faults to happen to two different circuits.

 

[davesparks]

as the cables cannot be overloaded, there is no apparent potential danger, but probably will give rise to nuisance tripping.therefore, i'd code it C3. remedial works are to be discussed with customer. give them the options and let them decide. ( i am assuming the circuits are RCD protected ).

I would have said no code to be given if this is an EICR, unless talking to the occupier reveals that a serious nuisance tripping problem is occurring

 

[Octopus]

Hi DS
THx .for your replay .
I was checking the elect. certs . from 10 yers ago and there were 2 rings on that 2 bed flat.
One for kitchen and one for the rest of the flat.
There were on 32 a mcb.
Now there are no 32A mcb , there are 16 a mcb .
After testing them , ther is no connt . on both rings.
They are radials .
there is no space for an extra mcb's .
If you do T & I what would you do .
THx

You've lost me.

How many MCB's are you referring to?

How many cables are in the MCB's?

 

[ac/dc]

Hi
I wanted to separate those radial circuits but there is no space for extra mcb .
My only problem is the R1 + R2 and Zs.
Would you consider them as a 2 radials circuits .
Even regs is confusing when it comes to those situations.
thx

 

[Octopus]

Hi
I wanted to separate those radial circuits but there is no space for extra mcb .
My only problem is the R1 + R2 and Zs.
Would you consider them as a 2 radials circuits .
Even regs is confusing when it comes to those situations.
thx

No they are not.

Please answer post # 8

 

[ac/dc]

You've lost me.

How many MCB's are you referring to?

How many cables are in the MCB's?

Hi M
There are 2 mcb , both at 16 A.
in both of them there are 2 wires .
First thought would be there is a ring in there , but there is no contin. on L- L and the rest.
Both are radials.
IMO there is no problem as there are on 16 A mcb .
Would you consider them as one radial circuit or two radials.
Would you write the highest reading for r1 + r2 after you test both cables .
THx

 

[Simonslimline]

Look up definitions of a circuit in BS7671 (in definitions)

Then carry out testing as normal.

 

[davesparks]

Hi M
There are 2 mcb , both at 16 A.
in both of them there are 2 wires .
First thought would be there is a ring in there , but there is no contin. on L- L and the rest.
Both are radials.
IMO there is no problem as there are on 16 A mcb .
Would you consider them as one radial circuit or two radials.
Would you write the highest reading for r1 + r2 after you test both cables .
THx

1x ocpd = 1x circuit regardless of the number of conductors connected.

Why on earth would you assume a circuit connected to a 16A mcb is a ring final circuit when the standard ring is a 32A circuit?

 

[DuaneMHunt1976]

As far as I can read this.
Past the old EIC said there was two rings
Now there is two radial on each of.the two mcb guess down rated to 16A from the 32A it problerly was when they where rings

R1+R2 is the far point in the radial which every is the worse case ie the highest
Both radials on both circuits will need to be tested and not the far point for any one else

 

[Pete999]

Hi M
There are 2 mcb , both at 16 A.
in both of them there are 2 wires .
First thought would be there is a ring in there , but there is no contin. on L- L and the rest.
Both are radials.
IMO there is no problem as there are on 16 A mcb .
Would you consider them as one radial circuit or two radials.
Would you write the highest reading for r1 + r2 after you test both cables .
THx

r1 and r2 on a radial? as far as I knowr1 and r2 are readings required for a RFC

2 16A cbs both have 2 cables, confused.com

 

[hightower]

r1 and r2 on a radial? as far as I knowr1 and r2 are readings required for a RFC

Oh no pete! Don't confuse the OP even more, I thought we were getting somewhere there. [emoji38]

 

[Pete999]

Oh no pete! Don't confuse the OP even more, I thought we were getting somewhere there. [emoji38]

What What??

 

[Jake1992]

What What??

Why cant you carry out R1+R2 readings on a radial ? .... I can??

 

[Pete999]

Why cant you carry out R1+R2 readings on a radial ? .... I can??

The OP mentioned r1 + r2 did he mean R1+R2?? see post 11

 

[Jake1992]

The OP mentioned r1 + r2 did he mean R1+R2??

....I am now with you Pete ! .... haha.

 

[DuaneMHunt1976]

Also said on the last report these radials where rings
So on the last report on the system they would of had the r1 r2 rn
As far as I can read these rings have been broken and places on 16A breaker
So what was once two rings have become four radials over two circuits

 

[telectrix]

to clarify. each 16A MCB has 1 radial circuit consisting of 2 branches. ​

 

[Octopus]

to clarify. each 16A MCB has 1 radial circuit consisting of 2 branches. ​

So OP:

Step 1 - locate the sockets / outlets on "both" branches.

Step 2 - I & T each branch

Step 3 - record the higher readings however if, for example 1 leg is short and has low IR and the other is long and has good IR I would be inclined to record both sets of readings on the schedule of inspections..... and add a note in the inspection comments section.

 

[Paul.M]

What is the possibility of finding the ends of these two radials and making them back into two RFC's?

 

[polo1]

So OP:

Step 1 - locate the sockets / outlets on "both" branches.

Step 2 - I & T each branch

Step 3 - record the higher readings however if, for example 1 leg is short and has low IR and the other is long and has good IR I would be inclined to record both sets of readings on the schedule of inspections..... and add a note in the inspection comments section.

At last, a straightforward answer to (an initially befuddled) question.
Truth is, I've come across many electricians who don't know exactly how best to test & record such a scenario, so let's not be too hard on the OP. And yes, electricians mixing up their r1 & R1 etc, gets me too!

 

[telectrix]

At last, a straightforward answer to (an initially befuddled) question.
Truth is, I've come across many electricians who don't know exactly how best to test & record such a scenario, so let's not be too hard on the OP. And yes, electricians mixing up their r1 & R1 etc, gets me too!

some guys just don't know their arse (r's ) from their elbows.

 

[Paul.M]

some guys just don't know their arse (r's ) from their elbows.

:frown2::frown2::frown2:

 

[telectrix]

:frown2::frown2::frown2:

you been on that peroxide again?

 

[Paul.M]

Thread going way off track now so I've edited a couple of posts and made it into a new thread. http://www.electriciansforums.co.uk/chit-chat-off-topic/110111-arse-elbow.html

Lets see how many of us know our arse from our elbow? (we are all grown ups and this is just a bit of banter taken away from this thread).

 

[Paul.M]

Trying to get this thread back on topic:- You can not have have 2 circuits from the same OCPD. You can have one radial socket circuit with a spur from the MCB if feeding only one point!

Discuss?

 

[telectrix]

Trying to get this thread back on topic:- You can not have have 2 circuits from the same OCPD. You can have one radial socket circuit with a spur from the MCB if feeding only one point!

Discuss?

no, you can have unlimited branches. it's only that you can have 1 unfused outlet from a RFC, tapped off at theOCPD.

 

[Paul.M]

no, you can have unlimited branches. it's only that you can have 1 unfused outlet from a RFC, tapped off at theOCPD.

Branching off a radial is fine from a socket. Branching from a MCB?...... I was thinking along the lines of separation of circuits but at the end of the day, if it was a RFC in the first place it would serve the same floor/area so no difference really.

 

[telectrix]

welcome to my world.


https://www.youtube.com/watch?v=QHmH1xQ2Pf4

 

[Andy78]

no, you can have unlimited branches. it's only that you can have 1 unfused outlet from a RFC, tapped off at theOCPD.

But remove the RFC leaving the 2.5mm radial with one double outlet on the 32A MCB and it suddenly becomes dangerous and against the regs, much in the same way that an insulated consumer unit will inevitably catch on fire now it's not to regulations.

 

[Deleted member 26818]

Just measure Zs at each socket on the circuits, and record the highest value for each circuit.
I wouldn't bother with measuring R1 or R2.