Pir test

[danny7299]

Just a quick one chaps , went and did small pir on house , (80a main fuse 16mm tails with 10mm earth.... that's all good) but it has a 4mm bond , no rcd's , what code do you put down ?

Cheers

 

[sparkytim]

Code 2 IF it is 4mm, are you sure its not 6mm,(more common size) if it is then that would be code 4

 

[danny7299]

looked to small for 6mm ... its an old installation

 

[a1spark]

Code 4. unless TNCS .then it may have to be Code 2. meethinks danny mate !

 

[Andy™]

also code 2 if the earth shows any signs of thermal damage

 

[a1spark]

[quote name='Andy

 

[Andy™]

Does that particular reference to thermal damage from circulating network currents also apply to the Earthing conductor Andy ?a1spark.

i would say yes. but if either are hot at the time of PIR, then possibly code 1 if there is a risk of fire

 

[a1spark]

Yes, I suppose The Earthing conductor should be inspected for thermal damage as you rightly say ,andy as any potential circulating currents may well be flowing through it,.and damage could occur epecially if the earthing conductor was undersized......I tended to only think of the Main bonding conductors as being subject to heat damage...thanks for highlighting the issue.

a1spark

 

[sparkytim]

Code2 if it does not meet adiabatic equation calc.

 

[initforthemoney]

Perfectly ok for TT, but should have RCD.

 

[a1spark]

Code2 if it does not meet adiabatic equation calc.

Hi ST. mate ! yes that could be true if the op was referring to the Earthing conductor but his concern was with the protective Bonding Conductor,

--adiabatic equation not applicable in that context.

a1spark.

 

[a1spark]

Perfectly ok for TT, but should have RCD.

Hi Info mate ! same comment as I made above for ST..i.e. the op was referring to the Protective Bonding ,not the Earthing conductor. The Bonding should be sized to be not less than half the Earthing conductor csa. with a mimimum of 6mm [ unless PME ,where it would usually be 10mm in domestic install ]

a1spark.

 

[spinlondon]

The adiabatic equation is applicable, in so far as it should be used to determine the required CSA of the Earthing Conductor.

In the OP's case, the required CSA is less than 8mm

 

[sparkytim]

As often is the case sorry mis read opening post

:Blushing

However

BRB Pg 134 544.1.1 appears to answer the question.