An Awful Feeling This

[gap30]

notes to table 3.3

4. the earth fault loop impedance test my be used to confirm the continuity of protective conductors at socket-outlets and at accessible exposed-conductive-parts of current-using equipment and accessories.

guidance notes 3 page 74

in what instance would this method be used? if i was just carrying out a Zs ie a lighting circuit then i could just tick polarity and leave r1/r2 blank (which i have often done in the past) but i would leave all other fields n/a or blank

this is sampling on a pir

 

[IQ Electrical]

The use of appropriate codes are found by searching for the particular location in BS7671:2008 eg. marina, sauna etc.

 

[Deleted member 26818]

where are the ip codes located, there is a table for them somewhere, i got bs7671, gn3 and osg in front of me and cannot find it

Pages 323 and 324.

 

[gap30]

IP codes. NOT PIR codes.

IP Codes

The first number signifies protection from solids
0: No Special Protection
1: Protected against solid objects up to 50 mm in diameter
2: Protected against solid objects up to 12 mm in diameter
3: Protected against solid objects up to 2.5 mm in diameter
4: Protected against solid objects up to 1 mm in diameter
5: Dust protected
6: Dust tight

The second number signifies protection from liquids
0: No special protection
1: Protected against dripping water
2: Protected against dripping water when tilted up to 15° from normal position
3: Protected against spraying water
4: Protected against splashing water
5: Protected against water jet spray
6: Protected against heavy jet spray
7: Protected against the effects of immersion
8: Protected against submersion

where is this information please pal?

 

[IQ Electrical]

Now does that make me feel real daft! Thanks IQ, I've no idea where I's going with that one!

Hey, that guide's still well worth downloading!

 

[gap30]

Pages 323 and 324.

cheers could you look at the other post i just made regarding sample testing please

 

[gap30]

guidance note 3 page 74 detailed periodic testing

the use of an earth fault loop impedance tester is often the most convenient way of continuity testing

again i take it this is carrying out 'live' tests and it will confirm polarity at the same time without the need to isolate or dismantle the circuit or equipment

 

[Deleted member 26818]

state in sequence the first three tests to be carried out on completion of a newly installed three-phase motor circuit

continuity of protective conductors
insulation resistance
polarity

ignore the three phase motor bit and treat it as a new circuit?

I think I would check continuity of phase conductors, before polarity.
I don't know if polarity would really be an issue.

 

[gap30]

I think I would check continuity of phase conductors, before polarity.
I don't know if polarity would really be an issue.

on a side note page 76 gn3

motor circuits

loop impedance tests on motor circuits can only be carried out on the supply side of isolated motor controlgear. Continuity tests between the circuit protective conductor and motor are then necessary.


where would i connect to the motor? would this literally be just clamp on the main body? this is a test i have never done but i have never tested any motors before

 

[IQ Electrical]

I think I would check continuity of phase conductors, before polarity.
I don't know if polarity would really be an issue.

Do you mean phase sequence?

If so, why would you be interested in that before polarity?

 

[Deleted member 26818]

on a side note page 76 gn3

motor circuits

loop impedance tests on motor circuits can only be carried out on the supply side of isolated motor controlgear. Continuity tests between the circuit protective conductor and motor are then necessary.


where would i connect to the motor? would this literally be just clamp on the main body? this is a test i have never done but i have never tested any motors before

You'd have to open up both the motor termination box, and the motor control gear box, and then perhaps with a wander lead test between each termination of each conductor.

 

[Deleted member 26818]

Do you mean phase sequence?

If so, why would you be interested in that before polarity?

No not phase sequence, I've never really bothered with that. If the motor runs backwards, I just swop over two of the conductors.
I'd check continuity of the phase conductors, because if one is broken, or not terminated, you can burn out the motor on energization.
As for polarity, does it apply? There's no neutral.

 

[gap30]

Areas i need to cover big time - ip codes, testing earth electrodes, factors that can affect conductor/insulation resistance, terminology

 

[gap30]

An installation has been seriously overloaded and requires investigation. State
a) the type of inspection and test that would be required. (1 mark)
b) two areas which require close inspection as a result of the overloading. (2 marks)

could this be any 2 from the scope ie SADCOW

Safety,ageing, deterioration, corrosion, excessive overloading, wear and tear

 

[Deleted member 26818]

Overloading of a conductor will cause insulation deteriation and increased resistance.