Having a debate with a coworker:
He says the MEC has to be continuous throughout its length ie, has to be fully replaced if it is cut; cant be jointed/repaired
I say thats an old electricians wives tale, MEC joints are fine
Can anyone clarify?
Joints in MEC
Re: Joints in MEC
I believe you are correct
5.5.1.1 doesn't use the word continuous at all, just that it must be run as directly as possible from MSB to electrode (doesn't say there can't be joins along the way)
3.7 covers Electrical Connections and has nothing that says a MEC can't be joined
5.5.1.1 doesn't use the word continuous at all, just that it must be run as directly as possible from MSB to electrode (doesn't say there can't be joins along the way)
3.7 covers Electrical Connections and has nothing that says a MEC can't be joined
Re: Joints in MEC
Joints are fine as long as they are done correctly. I prefer crimp links, but soldering is also acceptable. 3.7.1.11
As Jamie said, the wording is "run in as direct a manner as possible" and the earliest I can find that wording is 2000. But that doesn't prohibit joins of course.
There doesn't seem to be any rule prohibiting joins that I can see in any rules or regulations right back to 1976.
As Jamie said, the wording is "run in as direct a manner as possible" and the earliest I can find that wording is 2000. But that doesn't prohibit joins of course.
There doesn't seem to be any rule prohibiting joins that I can see in any rules or regulations right back to 1976.
Re: Joints in MEC
Yes it's a myth spread by people (including some "inspectors" who never bothered to read the actual words.
1976 R 154 "separate & independent earthing lead"
1993 R 76 & 1997 R 86 both said "a separate lead"
Since 2010; all the specific rules have been in "3000"; and under '93 & '97 Regs, compliance with first ECP 25 and later "3000" was 'deemed to comply' but not mandatory.
ECP 25 (1995) specifically allowed joins, provided they were electrically & mechanically sound.
3000: 1997 repeated this wording, and listed some acceptable types of connections
3000: 2000 said "in as direct a manner as possible"; and same rule applies still.
I seem to recall the word "continuous" having been used at some stage, and that this was the source of the incorrect interpretation.
I can't now find where that word was used (if it was); but "continuous" cannot mean "no joins" ; it can only mean "electrically continuous".
What you can't do is connect the MEC to any fitting / enclosure; other than at one end to the main earthing terminal bar, and at the other end to the electrode.
But you can connect other things to the MEC.
For that, good practice would be too use a form of connection that doesn't require cutting the MEC, eg a line tap
1976 R 154 "separate & independent earthing lead"
1993 R 76 & 1997 R 86 both said "a separate lead"
Since 2010; all the specific rules have been in "3000"; and under '93 & '97 Regs, compliance with first ECP 25 and later "3000" was 'deemed to comply' but not mandatory.
ECP 25 (1995) specifically allowed joins, provided they were electrically & mechanically sound.
3000: 1997 repeated this wording, and listed some acceptable types of connections
3000: 2000 said "in as direct a manner as possible"; and same rule applies still.
I seem to recall the word "continuous" having been used at some stage, and that this was the source of the incorrect interpretation.
I can't now find where that word was used (if it was); but "continuous" cannot mean "no joins" ; it can only mean "electrically continuous".
What you can't do is connect the MEC to any fitting / enclosure; other than at one end to the main earthing terminal bar, and at the other end to the electrode.
But you can connect other things to the MEC.
For that, good practice would be too use a form of connection that doesn't require cutting the MEC, eg a line tap
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