Changing meter tails, and cable size inquiry
Posted: Mon Jul 16, 2007 11:37 pm
by I_spark
Hello,
Is an electrician allowed to change meter tails?
If yes, How can he get the sealer to seal the fuse and the meter?
If on the test certificate it says for 1mm cable 5 amp supplying to lights "Fuse very high rated for cable size" How can this problem be rectified?
Thanks for any help.
Re: Changing meter tails, and cable size inquiry
Posted: Tue Jul 17, 2007 9:39 am
by BLAKEY1963
[quote="I_spark"]Hello,
Is an electrician allowed to change meter tails?
If yes, How can he get the sealer to seal the fuse and the meter?
If on the test certificate it says for 1mm cable 5 amp supplying to lights "Fuse very high rated for cable size" How can this problem be rectified?
Thanks for any help.[/quote]
I SPARK
THE ELECTRICITY BOARDS CUSTOMER MUST INFORM THE
ERERGY SUPPLIER OF A REQUIREMENT FOR A CUSTOMERS
ELECTRICIAN TO CHANGE METER TAILS, BECAUSE OF THE NEED TO INTERUPT SEALS . IN SOME CASES NOW THE ELECTRICITY BOARDS
ARE FITTING KMF ( ISOLATION SWITCHES ) BETWEEN METER TAILS IN ORDER TO ACHIEVE ISOLATION AND AVOIDANCE OF BREAKING SEALS.
YOU STATE 1 MM2 CABLE FOR LIGHTS AND COMMENT : FUSE VERY HIGH
RATED FOR CABLE SIZE : WHICH IS STATED ON YOUR TEST FORM
YOUR 1 MM2 CABLE HAS A CURRENT CARRYING CAPACITY OF
FROM TABLE 4D1A , BS7671, PAGE 220 , 11 AMPS WHEN ASSUMING
INSTALLATION METHOD 4 FOR CABLE DERATING.
THE 5 AMP FUSE HAS BEEN SELECTED TO PROTECT THE 1 MM2 CABLE,
WHICH IS LOWER THAN THE CABLE RATING OF 11 AMPS .
THE FUSE IF BS3036 REWIRABLE HAS A FUSING FACTOR OF 2 WHICH
WILL DRAW 10 AMPERES TO OPERATE FOR OVERLOAD PROTECTION.
THIS COMES CLOSE TO THE RATING OF THE CABLE.
M.C.B , S HAVE A LOWER FACTOR OF I.I TIMES THIER RATING AND THIS
COULD REDUCE OVERLOAD CURRENT CAPACITY. ( TO REPLACE FUSES )
OTHER THAN THAT THE CABLE SHOULD BE UPGRADED TO 1.5 MM2
THIS HAS A RATING OF 14 . 5 AMPS.
BLAKEY1963