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dochisholm
just to put it out there does anyone else feel that in a periodic that the neutral continuty should be tested on all circuits as a loose neutral is normaly the cause of heat and ultimately fire.
Re: gs3 flaws
I always test it, even did on the 2391 practical and wasn't penalized for it. Can't see why it isn't mentioned explicitly.
I always test it, even did on the 2391 practical and wasn't penalized for it. Can't see why it isn't mentioned explicitly.
Re: gs3 flaws
GN3 is for guidance.
Verification of polarity cannot be confirmed if some tests (for example R1&RN) are not carried out.
It's probably not mentioned so much for this reason, as polarity is normally worded with regard to ES lampholders (except for E14 & E27) and other things like switching of line conductors only etc..
GN3 is for guidance.
Verification of polarity cannot be confirmed if some tests (for example R1&RN) are not carried out.
It's probably not mentioned so much for this reason, as polarity is normally worded with regard to ES lampholders (except for E14 & E27) and other things like switching of line conductors only etc..
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Re: gs3 flaws
I suspect these may be reasons
Neutral continuity will have no effect on short circuit protection
Neutral continuity is not part of the earth fault path
I think a loose neutral will cause overheating until perhaps the rising resistance breaks the continuity,but whether it overheats to the point of causing a fire before the continuity is broken ?It may be more difficult trying to keep the circuit loaded
I suspect these may be reasons
Neutral continuity will have no effect on short circuit protection
Neutral continuity is not part of the earth fault path
I think a loose neutral will cause overheating until perhaps the rising resistance breaks the continuity,but whether it overheats to the point of causing a fire before the continuity is broken ?It may be more difficult trying to keep the circuit loaded
Re: gs3 flaws
beg to differ des. neutral continuity does have an effect on short circuit protection, if the short is across L and N. a 5ohm resistance on a neutral connection for example would give rise to a short circuit current of 46A, which would not cause a 32A mcb TO trip for an hour.
beg to differ des. neutral continuity does have an effect on short circuit protection, if the short is across L and N. a 5ohm resistance on a neutral connection for example would give rise to a short circuit current of 46A, which would not cause a 32A mcb TO trip for an hour.
Re: gs3 flaws
Fair comment,I should have used the word "little effect" on short circuit protection
In that a short circuit doesn't exist, where a resistance either a load or a high resistance connection is in circuit
In a double fault situation, your example is correct (where a L_N short and a loose neutral connection exist )
I suspect that the loose connection resistance of the neutral would in most circumstances,rise to such a point that the load resistance coupled with the loose connection resistance would stop current flow
As you rightly say, the second fault would affect the short circuit protection if it occured before the loaded circuit gave up the ghost
Fair comment,I should have used the word "little effect" on short circuit protection
In that a short circuit doesn't exist, where a resistance either a load or a high resistance connection is in circuit
In a double fault situation, your example is correct (where a L_N short and a loose neutral connection exist )
I suspect that the loose connection resistance of the neutral would in most circumstances,rise to such a point that the load resistance coupled with the loose connection resistance would stop current flow
As you rightly say, the second fault would affect the short circuit protection if it occured before the loaded circuit gave up the ghost
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