Fixed Wire Testing

[IrishSparks]

Hi All

I've been asked to tender for a fixed wire test for a hotel group here in Ireland.
They sent me documentation to read through before I tender.
The hotel group is UK based so therefore the regulations would also be British standard rather than the Irish standard I work to.
I would assume it's pretty similar anyway but if you wouldn't mind helping me with a few questions I have?

My question first is about the Earth Loop Impedance.This is part of what they sent me.
12.1 Earthloop impedance

Earth loop impedance tests to be carried out at locations indicated below: -


(a) At the origin and at each distribution board.

1. All socket outlets.
2. Any location, which is exposed to exceptional damage or deterioration or represents a special hazard.
3. Whilst 100% of fixed equipment is tested for Earth Continuity, a further 10% sample will be checked for Earth Loop Impedance.

My reading of that is I don't have to do an earth loop test on every lighting circuit? There is no mention of it in the above,all they mention are sockets. Is this the norm in the UK? I would have always done an earth loop test on every circuit.


Here then then mention Only a sample of lighting circuits need to be continuity tested.I presume they mean the R1+R2 test here?

11.1 Continuity testing of protective conductors to include: -

(a) Earthing Conductors.
(b) Main Equipotential Bonding Conductors.
(c) Supplementary Bonding Conductors.
(d) All circuit protective conductors (sample lighting circuits).
(e) Exposed conductive parts on installed machinery/fixed equipment.

Also,they only request 20% of all circuits need to be Insulation resistance tested. Is this also the norm for a fixed wire test in the UK?

Really sorry for the long post,any advice or help would be appreciated,especially about the earth loop testing on lighting circuits.

 

[Brightspark2]

It's quite standard on large condition reports to calculate Zs, carrying a R1+R2 on every circuit.

There isn't really a norm it depends on the installation and limitations. In a hotel I would except to carry out an R1+R2 on every circuit as I imagine they're all accessible off step ladders, where as you may sample in large warehouse where you need powered access equipment to get to the lighting. So it's all down to the agreed limitations they have give you.

I don't agree with the 20% of insulation testing though, that isn't industry standard at all. you should be carrying it out on each circuit you do.

 

[IrishSparks]

It's quite standard on large condition reports to calculate Zs, carrying a R1+R2 on every circuit.

There isn't really a norm it depends on the installation and limitations. In a hotel I would except to carry out an R1+R2 on every circuit as I imagine they're all accessible off step ladders, where as you may sample in large warehouse where you need powered access equipment to get to the lighting. So it's all down to the agreed limitations they have give you.

I don't agree with the 20% of insulation testing though, that isn't industry standard at all. you should be carrying it out on each circuit you do.

Hi brightspark thanks for the reply.Can you see what I say though about they only request a sample of Lighting circuits or am I reading it wrong? They first say this regarding earth continuity testing :
(d) All circuit protective conductors (sample lighting circuits)
and then in another section they specifically say:
Whilst 100% of fixed equipment is tested for Earth Continuity, a further 10% sample will be checked for Loop Impedance.
That to me is a contradiction of saying only a sample of Lights need earth continuity tests.

Have you any advice re the Loop test also and if they want all the lighting circuits done,as they haven't mentioned them? Normally I would but maybe British standard is different?

Also here's what they said re Insulation Testing

12.2 Insulation Resistance Testing
Insulation Resistance tests must be carried out at the discretion of the inspecting engineer with regards to age, condition and visual inspection,approximately 20% of the circuits will be tested.


Hope nobody mind all the questions,it's just this will affected my pricing depending what what does or doesn't need to be tested according to the documents they sent me.

 

[IrishSparks]

Rather than posting parts of the documentation do you mind if I just post the whole thing? And if anyone has any advice on what they do or don't actually want tested that would be a big help to me.
Normally I would preform every test on every circuit,But they seem to be asking for something different here.
10.PERIODICINSPECTION AND TESTING OF ELECTRICAL INSTALLATIONS

(20%Testing & Verification of Circuits and 100% Inspection of everyboard in every property in a 12 month period [100%over 5 years])

10.1 PURPOSE


To verify as far as is reasonably practicable within the limits of this specification that the electrical installation is in a safe condition and thereby complies with the fundamental requirements of BS 7671 IEE Wiring Regulations (current edition) and the Electricity at Work Regulations(1989)/Electricity at Work Regulations (Northern Ireland) 1991.



11.0 TESTINGSCHEDULE


11.1 Continuity testing of protective conductors to include: -


(a) EarthingConductors.
(b) Main EquipotentialBonding Conductors.
(c) SupplementaryBonding Conductors.
(d) All circuitprotective conductors (sample lighting circuits).
(e) Exposed conductive parts on installed machinery/fixed equipment.

1. Polarity & Load Testing

(a) The Polarity is correct at the meter, consumer units/distribution boards.
(b) Single pole control and protective devices are connected in the phase conductors only.
(c) Conductors are correctly connected to all socket outlets and a 20% random sample ofother accessories/equipment.

1. Multi-pole devices are correctly installed (20% random sample to be taken).
2. 20% of boards are to be tested for load balance across phases.

12.1 Earth loop impedance


Earth loop impedance tests to be carried out at locations indicated below: -


(a) At the origin and at each distribution board.

1. All socket outlets.
2. Any location, which is exposed to exceptional damage or deterioration or represents a special hazard.
3. Whilst 100% of fixed equipment is tested for Earth Continuity, a further 10% sample will be checked for Earth Loop Impedance.

12.2 Insulation Resistance Testing


Insulation Resistance tests must be carried out at the discretion of the inspecting engineer with regards to age, condition and visual inspection,approximately 20% of the circuits will be tested.
Based on the results found from the testing engineer more circuits may require testing if high failure rates are found.

1. 1. Operating devices for isolation and switching

These are to be checked for effectiveness and to ensure adequate and correct labelling without.


12.4 Operation of Residual Current Devices (RCD’s)


100% of RCD’s will bet ested for tripping time at half rated, full rated and five times rated tripping current across positive and negative cycles.


12.5 Prospective fault current


Tests to be carried out at the origin and at each distribution board.


12.6 Overcurrent circuit breakers


A manual operation of overcurrent circuit breakers to be completed.


13.REPORTING


Reports to be completed using the Electronic reporting system.


The reported defects and remedial actions are to be prioritised as follows:


C1- Danger present.Risk of injury. Immediate remedial action required.
C2- Potentially dangerous - urgent remedial action required.
C3 - Improvement recommended.


N/V - Not verified.Further investigation may be required.

1. LIMITATIONS

The inspection andtesting will be carried out where practicable at the discretion ofthe Engineer, taking into account availability and accessibility.


Cables concealedwithin trunking and conduits, or cables and conduits concealed underfloors, in inaccessible roof spaces and generally within the fabricof the building or underground, will not be visually inspected.


Insulationresistance tests will not be carried out on circuits and/or sectionsof the installation, which contain electronic or similar sensitivecircuitry.

 

[Brightspark2]

It's asking for 20% to be carried out a year.

Then treat fixed equipment and lighting separate.

Fixed equipment. 100% earth continuity, 10% of that measure earth fault loop impedance.

Lighting circuits sample earth continuity.

20% of the circuits covered to be insulation tested at your discretion.

That's how I make it out.

 

[Farmelectrics]

insulation testing is very important as its this test that tells you if there is any deteration in the installation. so i think the 20% test is wrong it should be a 100% have you any previous test sheets to compare your readings with.

 

[IrishSparks]

It's asking for 20% to be carried out a year.

Then treat fixed equipment and lighting separate.

Fixed equipment. 100% earth continuity, 10% of that measure earth fault loop impedance.

Lighting circuits sample earth continuity.

20% of the circuits covered to be insulation tested at your discretion.

That's how I make it out.

So no loop test on any lighting circuits?
I'm sure by fixed equipment they mean circuits supplying isolators and spurs?

 

[IrishSparks]

insulation testing is very important as its this test that tells you if there is any deteration in the installation. so i think the 20% test is wrong it should be a 100% have you any previous test sheets to compare your readings with.

I know yeah but this is what they are asking for. Normally I would test every circuit.

 

[Farmelectrics]

well if thats what they want and youve got it in writing bat on lol

 

[Pete999]

So no loop test on any lighting circuits?
I'm sure by fixed equipment they mean circuits supplying isolators and spurs?

Might be barking up the wrong tree "fixed equipment" that is surely power consuming apparatus, fridges, hand driers etc which require testing under Portable Appliance testing

 

[Richard Burns]

A few thoughts:
Surely this specification is stating that 20% of the installation is tested every year such that 100% of the installation is tested after 5 years.

The purpose of testing I would query as you should be testing to ensure it is safe, not necessarily compliant with BS7671 or the electricity at work regulations, although it really would be a good idea to be complaint with the EAWR, as it is unlikely to be safe otherwise!

The continuity of cpcs appears to be able to be reduced for the lighting circuits, not one I would agree with.
The addition of exposed conductive parts on machinery or fixed equipment is going into the realm of ISITEE so would be (a lot) more work.
Sampling of internal inspections is expected and appropriate.
They seem to be mixing up earth continuity and earth fault loop impedance:
Earth continuity is confirmed if you do a successful EFLI test, however I think they mean R1+R2 or R2 for earth continuity as a dead test.
This could take a considerable time.
10% testing for EFLI would be OK if you have done the dead earth continuity testing on all points.
I would expect from context that fixed equipment means all fixed point of use and hard wired equipment (ISITEE).

Limiting the insulation resistance testing does not sound good unless the 20% is per year (not according to the context), since it should take very little time to do a L+N - E IR test which is acceptable under the guidance I cannot see why this should be limited, but if it is then that is just one of the limitations, and I would note that this is inappropriate.
The limitation for sensitive equipment is one I would accept considering the nature of the premises, so long as it was not used as a reason not to test anything!

I assume the RCDs are only 30 mA RCDs as 5 times testing on higher values would be inappropriate.

 

[IrishSparks]

A few thoughts:
Surely this specification is stating that 20% of the installation is tested every year such that 100% of the installation is tested after 5 years.

The purpose of testing I would query as you should be testing to ensure it is safe, not necessarily compliant with BS7671 or the electricity at work regulations, although it really would be a good idea to be complaint with the EAWR, as it is unlikely to be safe otherwise!

The continuity of cpcs appears to be able to be reduced for the lighting circuits, not one I would agree with.
The addition of exposed conductive parts on machinery or fixed equipment is going into the realm of ISITEE so would be (a lot) more work.
Sampling of internal inspections is expected and appropriate.
They seem to be mixing up earth continuity and earth fault loop impedance:
Earth continuity is confirmed if you do a successful EFLI test, however I think they mean R1+R2 or R2 for earth continuity as a dead test.
This could take a considerable time.
10% testing for EFLI would be OK if you have done the dead earth continuity testing on all points.
I would expect from context that fixed equipment means all fixed point of use and hard wired equipment (ISITEE).

Limiting the insulation resistance testing does not sound good unless the 20% is per year (not according to the context), since it should take very little time to do a L+N - E IR test which is acceptable under the guidance I cannot see why this should be limited, but if it is then that is just one of the limitations, and I would note that this is inappropriate.
The limitation for sensitive equipment is one I would accept considering the nature of the premises, so long as it was not used as a reason not to test anything!

I assume the RCDs are only 30 mA RCDs as 5 times testing on higher values would be inappropriate.

Thanks Richard Burns thats an excellent response and I agree fully with it.
As I said I would usually do 100% of tests on all circuits. As this is a British based group (but with hotels in Ireland) I wondered was the British standard different.
Just on the EFLI test, would you also agree they don't ask for this to be done on any of the lighting circuits or am I reading it wrong?
As far as I can see they just want a sample of lights circuits tested for earth continunity ( I agree they probably mean r1 r2 test) but they have no mention of EFLI test on lighting circuits.

 

[Richard Burns]

I would say that the continuity of the cpc should be checked for a sample (presumably 20%) of the lighting circuits and that from 12.1 (a) fourth paragraph I would expect that 10% of the lighting circuits should be checked for EFLI as lighting is fixed equipment.

Normally for this sort of job I would expect testing of 20% of the installation and inspection of the same 20% of the installation, internal inspection of say 20-40% of the accessories that are accessible (withing the parts of the installation that are being tested).
This would repeat annually for five years with different areas being tested each year.

 

[IrishSparks]

Thanks again Richard that's a great help.

 

[Risteard]

Hi All

I've been asked to tender for a fixed wire test for a hotel group here in Ireland.
They sent me documentation to read through before I tender.
The hotel group is UK based so therefore the regulations would also be British standard rather than the Irish standard I work to.

Presuming that the hotels in question are in the south of Ireland, is it actually lawful for them not to comply with ET101 (ETCI National Wiring Rules)? I am not aware of any allowance for buildings to be wired in the south of Ireland to BS7671. Inspection, Testing & Certification of an existing electrical installation in the south of Ireland, even in a non-domestic premises, will come within the remit of Controlled Electrical Works - view CER Decision Paper CER/09/009.