In Service Inspection and Testing of Electrical Equipment

Ian Gardner
Member - 31 posts

There's a quite instructive discussion in progress at the moment, on the IET (publishers of the IEE CoP) forum, regarding this subject:
http://www.theiet.org/forums/forum/messageview.cfm?catid=205&threadid=22359&enterthread=y

Malcolm Wallace
Member - 14 posts

To Dave Smith re hard wired appliances.

The IEE have sat on the fence for years over this. Fixed wiring is done every 5 years which is too long a period for hard wired appliances such as hand dryers etc. The problem for PAT Testers is that it is easy to ask for a PC or a few PCs to be switched off, but when it comes to hard wired appliances, who do you ask to switch off the mains. Also some radial mains circuits are very long and you do not know what will go off. All this means is that the only way to test a hard wired appliance is live. I refuse to disconnect a hard wired appliance which is live so I compromise. I remove the spur and with an isulated screwdriver check that all the scews are tight. I look for the normal damage, overheating etc. If the appliance is a class 1 ie there is an protective conductor in the cable going to the appliance, I check for earth continuity from the spur to the appliance chassis, using a battery continuity tester. If I get continuity and the appliance functions ok I pass it.

It is what an electrician would call a limited pass without an insulation or earth leakage test. At the end of the day, is the appliance safe and is it better than no test or check which has been the situation for years.

Lyn Thomas
Member - 3 posts

The IEE tests are not 5 yearly the time period varies depending on the use of the building, are members of the public using the building etc.
IEE testing requires 10% initial testing of hard wired circuits, with increased testing if faults are found. A major part of the periodic testing is visual. Regards testing long radial circuits that cannot be isolated, the only test that may be carried out to comply with the regulations is an earth loop impedance test. This confirms the continuity of the phase conductor and cpc (earth) conductor. There is a formula which electricians use to confirm wiring is correct using the Zs (earth loop) reading, Zs= (Ze + r1 + r2) x t
Where Zs is the impedance of the circuit
Ze is the impedance at the incoming service
r1 + r2 is the continuity of the phase conductor and cpc
t is the usual operating temperature (not needed generally)
From this formula an electrician can work out r1 + r2 which is a requirement of the periodic test certificate that can be calculated.
As regards who is allowed to test hard wiring, BS 7672 and electrical safety rules state that the person should be competent. This is seen as a person who is familiar with the systems to be tested and a person who is qualified to carry out the testing. The person must be qualified (C &G 2391) so as to be able to diagnose test results on site and make safety determinations whilst testing amongst other H & S reasons.
All the relevant information can be found in IEE Testing and Inspection, IEE On Site Guide or BS 7672 electrical wiring regulations.
In short there is very little open to interpretation as every test and period of test is laid out.

Malcolm Wallace
Member - 14 posts

To Lyn Re testing of hard wired appliances.
I am coming at Ian's enquiry from a PAT Testers point of view. Having run a PAT Testing company for 11 years and tested thousands of portable appliances, I have to say that his concern over the testing of hard wired appliances is very valid. I was at a meeting at Faraday House when an IEE inspector said that he could not see how the average PAT Tester could be competant to deal with fixed wiring, without extra training. I have assisted a Periodic Inspection of a company that 80 circuits. Before we could make a start we had to identify where every circuit went and what every outlet was connected to. In some rooms there were 2 or 3 different circuits. To do that identification, every circuit had to be turned off, effectively turning the company off. If you or Ian or I want to test a hard wired appliance, as per the CoP, then it should be disconnected from the spur and connected to an instrument. This means the mains must be turned off. Without knowing who is connected to the circuit, turning it off is just not a practical solution and that is the situation with about 99 out of 100 companies who I PAT Test. My live testing is not perfect, but it is practical and better than no test, which has been the reality for many years.

Ian Gardner
Member - 31 posts

It was David's enquiry, not mine, but I'll let it go this time ;-)
I agree with your post, BTW.

Lyn: I don't think you've quite understood the initial question.

Phill S
Member - 69 posts

Lyn.

I agree with Malcolm.

When I was at the pat testing course the trainer (who is a fully qualified electrician) told us all that "if it has a flex, an electrician is very unlikely to carry out any test on it"

Another electrician that was also doing the course agreed with him.

Its a bit of a gray area.

And thankyou to Ian, I followed your link and found this quote;

"we find that certain items such as those above have been overlooked (whether intentially or not) by electricians in the PIR; the end result is that these appliance can go untested."

Graham Kenyon
Member - 43 posts

At the end of the day, it's not up to the PAT Tester or the Electrician to make this decision, it's the organisation. They may consult the Electrician or PAT Tester, or maybe a H&S Practitioner, for advice, but at the end of the day, this testing must be a response to a Risk Assessment. Otherwise, it's a waste of time, or you may be wasting money.

Lyn Thomas
Member - 3 posts

Hi guy's I'm sorry if I misunderstood the original question.
However I am a Qualifying Manager and a JIB Approved Electrical Technician.
If the question was simply how do you test a circuit that has an appliance which is connected via a fused spur, then it is not part of the PAT test, Portable Appliance Test, as it is fixed equipment. Therefore it should be treated like any other circuit with fixed equipment, i.e pumps or air conditioning units, and should be tested under Periodic Inspection at the the furthest part of the circuit (for instance the spur).
The periodic test would be made at the fused spur unit without the need for isolation by an electrician and as I previously stated, he could carry out an earth loop impedance test. This as I previously pointed out will meet all relevant tests for a periodic inspection. But I would also carry out an earth loop test to the fixed appliance if it is metal using the earth probe and the supply at the spur unit. The above assumes the equipment cannot be isolated and is not as per D/B schedule
The connecting flex or wiring should be visually inspected, that is all the regulations call for. You are correct no electrician will separately test a flex connecting the appliance.
Where circuits are not correctly marked at the D/B, or there is no schedule of circuits at all, then yes, there is a problem. You are quite right in that you need to trace circuits, this would be an agreed added expense to the client but the client should be made aware that this is work required anyway to comply with IEE electrical regulations, and electricity at work regulations. The only alternative is to isolate circuits indiscriminately which could cause loss of supply to the clients equipment, which will be at the clients risk and still result in advisories on the periodic certificate.
The regulations and HSE make provisions for live testing and working by competent persons, i.e electricians, and this would be highlighted in any risk assessment etc.
I hope this clarifies any misunderstandings and covers most scenarios

Malcolm Wallace
Member - 14 posts

Hi Lyn.
As I stated earlier, The IEE has sat on the fence for years regarding appliances connected to fixed systems via a spur. This year a new Code of Practice has brought appliances 'I Quote: "equipment connected by means of a flexible cord or cable to a fused or unfused connection unit or isolator" unquote, into the realms of PAT Testing, hence the dilemma. Periodics are too infrequent.

If companies would treat PAT Testing seriously and not just an overhead, life for us quality contractors would be easier. They just want us in and out with the minimum of problems and the cheapest cost.

I should like to start a new discussion regarding RCDs.
In the Code of Practice para 15.10.1 it states that extension leads (reels) 1.5mm exceeding 15metres in length should be fitted with an RCD. Not used via, or plugged in but be fitted with. Why is it that the sheds and lots of other suppliers are selling 25 metre reels, without an RCD but with a British Kitemark.

To try and cope with the new Cop, we now carry wireable RCDs and RCD Test equipment so that when we come across a relevant reel we can replace the plug and test the trip time of the RCD. What may I ask is everyone else doing.

Graham Kenyon
Member - 43 posts

The equipment should be tested using a procedure recommended by the manufacturer, or, alternatively, the original installer.

It is not possible for the IET to provide guidance that is suitable for each and every item of fixed equipment - there are literally 100s of standards covering the electrical safety of equipment.

If you wanted to build up a general knowledge of equipment safety, ERA used to run a course that covered equipment safety, something like "Safe Design of Electrical and Electronic Products".

Kelly Mansfield - Workplace Law Network
Online advisor - 62 posts

Mahendra Mistry,
Electrical Engineering Specialist,
Bureau Veritas UK Ltd:

Stationary equipment supplied by a fused spur should be inspected and tested as part of the fixed wiring installation. The general definition of a portable appliance is a equipment that has a flexible cord and is supplied by a plug. In this case equipment is supplied by a spur unit which cannot be physically disconnected from the electrical installation. There are some PAT testing companies that allow their engineers to test these items and are placing the engineers at risk.
In order to fully test an appliance supplied by a spur unit, the spur unit has to be opened which exposes live electrical parts which increases the risk of electrical shock. If engineers do not understand the dangers of electricity and have not recieved the appropriate training then they should not be working on or near live equipment. The Electricity at Work Regulations 1989 clearly states the for a person to work on electrical equipment and installations they must be competent to do so and competency is defined as a person who has the theoretical knowledge of electricity, has recieved the necessary training, is familiar with the class of installation and equipment to be worked on, understands the dangers that could arise and knows when to stop working. Hence to work on spur units an engineer would need to be a qualified electrician. Further more the ELectricity at Work Regulations 1989 say that a person should only work on live equipment if 1) it is unreasonable in all circumstances to switch it off AND 2) it must be reasonable for him to work on the equipment live AND 3) where following a risk assessment it has been decided to work on live equipment then appropriate safety measures must be in place ie procedures, PPE, barriers, notices etc.

If access is not made available to any part of the equipment during inspection and testing then this must be clearly stated in the report and the client advised accordingly. The client must then make the necessary arrangement to make all parts of the equipment accessible, this could be removing shelves, moving heavy filing cabinets, unlocking rooms etc.

Regards
Mahendra Mistry
Electrical Engineering Specialist
Bureau Veritas UK Ltd

Phill S
Member - 69 posts

"The general definition of a portable appliance is a equipment that has a flexible cord and is supplied by a plug"

Is that why it is not called Personal Appliance testing (except as a nickname) any more?

"The Electricity at Work Regulations 1989 clearly states the for a person to work on electrical equipment and installations they must be competent to do so and competency is defined as a person who has the theoretical knowledge of electricity, has recieved the necessary training, is familiar with the class of installation and equipment to be worked on, understands the dangers that could arise and knows when to stop working."

To what level? if someone has attended a course for 'PAT' testing, and has then passed the exams, arent they then competent to a certain level.

I'm not deliberately picking holes in what you say, because I largely agree with what you are saying, as does most people here.

But it is, in my opinion, not clearly defined and as Malcolm said before it's the IEE sitting on the fence.

I have spoken to other Electricians, and none of them are absolutely sure when it comes to testing.

Phill S
Member - 69 posts

"as does most people here"

wheres me grammar?

Malcolm Wallace
Member - 14 posts

I have just carried out a PAT inspection of a hotel where 3 out of four appliances in every room were hard wired to a fused or unfused spur. My method of live testing worked very well and I was brought in because the electrical company who had just carried out a full periodic inspection of the hotel did not and never had tested anything past the spurs. I consider myself a high quality PAT Tester who is trying to do the right thing and my clients look to me for advice.
Mahendra says these appliances are fixed wiring, electricians appear to consider them portable appliances, Graham says its not up to the PAT Tester but up to the organisation as a result of a risk assessment and the new CoP (para 5.5) lists them with all other catagories of appliance.

Does the IEE have the part number of a crystal ball because I will need to order one - in the meantime I shall carry on with the method I outlined in an earlier post.

Regards

Graham Kenyon
Member - 43 posts

In response to Kelly Mansfield, reference information provided by Mahendra Mistry, Electrical Engineering Specialist, Bureau Veritas UK Ltd., which I believe to be mis-leading.

FIrst, the fixed Electrical Installation may include "fixed equipment". However, periodic inspection and testing of the installation, as defined by Chapter 62 of BS7671: 2008, and associated IEE Guidance Note 3, only covers testing for the fixed wiring.

BS7671, against which the installation is inspected and tested, only covers the SELECTION of equipment - it does NOT deal with safety of the equipment itself which must comply with appropriate standards. It also specifically excludes equipment (or assemblies or systems) classed as "Machinery".

When a "periodic inspection" is booked, it is arranged against the current version of BS7671. If the customer wants fixed equipment inspected and tested, this should be identified BEFORE the inspection and test, and listed separately with any relevant standards that apply (e.g. IEE's Code of Practice for In-Service Inspection of Electrical Equipment). Please see Section 3.6 of Guidance Note 3 on BS7671: 2008.

The IEE's CoP for In-Service Inspection of Electrical Equipment does NOT preclude its use for "fixed equipment", and adequately fills the gap.

If you don't specify inspection and testing of fixed equipment when you procure a Periodic Inspection of the electrical installation, then then only a cursory visual inspection of the outside of the equipment will be made by the electrical inspector.


I think this is quite plain, and it's up to the person responsible for the electrical installation to agree an appropriate scope with the electrical contractor for the periodic inspection - including getting competent persons to inspect and test. THIS MAY MEAN DIFFERENT PEOPLE ARE REQUIRED TO INSPECT THE FIXED EQUIPMENT, TO THE FIXED WIRING INSTALLATION, ESPECIALLY IN THE CASE OF "MACHINERY".


Second, the Electricity At Work Regulations doesn't care whether the electrical equipment (or "system") is "portable" or not. The Regulations simply require adequate maintenance to ensure safety. The difference arises simply in that, if you carry out a risk assessment, you may decide that Portable Appliances carry more risks, therefore require more frequent inspection and testing, than fixed equipment and installations. To carry this illustration further, it is possible to have "mobile or transportable equipment" (generators and exebition/show equipment) which is equipment that's typically "fixed", but is arranged for transport to different locations: that would require more frequent inspection and testing than "fixed equipment" that never moved throughout its life.

Third, on the definition of "Portable Appliance". It is possible to remove the plug of a "portable appliance" and connect the appliance to a fused spur - regardless of whether it remains hand-portable (such as a hair-dryer in a hotel room), or becomes "fixed". It is also possible to have "fixed equipment " connecting via normal plug and socket - here, I'm not only talking about a washing machine (which is "movable" or "transportable", rather than "portable" or "hand-portable"), but about things like IT Servers, that are permanently bolted into racking systems except when they are being maintained.

There is a definition of "portable appliance" on page 18 of the IEE Code of Practice for In-Service Inspection and Testing of Electrical Equipment, that does NOT include the definition of having a plug.

Please be careful about trying to define what a "portable appliance" is by yourself: definitions already exist in many equipment safety standards as well as the IEE CoP (which seems to accord with the safety standards in general), and therefore you are leaving yourself open to being challenged.


Hope this is useful, but to summarise:

1. "Portable Appliance" does NOT mean "has a UK plug" (or similar definition).

2. Your "fixed" or "permanently-wired" equipment won't be inspected or tested adequately by the contractor carrying out the Periodic Inspection to BS7671, UNLESS you specifically include this in your requirements. Expect to be charged more for this, or to seek advice from relevant specialists in the equipment itself (e.g. for "Machinery").

Graham Kenyon,
Chartered Electrical Engineer.

Malcolm Wallace
Member - 14 posts

Graham, I think that everyone reading your post, cannot but be impressed by your efforts on bringing together all these standards and definitions in what clearly is a difficult subject. It is a pity that your post cannot be published such that all ordinary electricians, old & new could read it and be aware of what should be required of those proposing to do periodic inspections.

I suspect that the Portable/Fixed Appliance, hard wired via a spur to a Fixed Installation will continue to create a grey area, especially for contractors like myself, who come in between periodics and who try to pick up the pieces of what should have been sorted out previously.

From a PAT inspectors point of view, all I see is are clients who are trying to comply with an avalanche of regulations and want it done as cheaply as possible. To advise a client that he should have arranged to get his fixed appliances tested at the time of the last periodic is probably correct but unhelpful. In the real world he wants it done now and if you can't or wont do it, there are scores of professional label fitters out there, ready to take the job and your income with it.

The best that I can come up with is the live test but I would prefer not to do it at all as it carries some risk and takes much longer.

Regards

Malcolm Wallace
Senior PAT Inspector
Safetest Electrical

Graham Kenyon
Member - 43 posts

Malcolm,

I understand the problem you've got trying to ascertain safe isolation procedures for equipment. But in actual fact, it's still the "Employer's" problem:

Regulation 12 of the Electricity at Work Regulations (http://www.opsi.gov.uk/si/si1989/Uksi_19890635_en_3.htm#mdiv12) requires suitable means for isolation to ensure safety. I believe that this Regulation is mandatory unless the device being isolated is itself a source of supply (such as a tranasformer UPS or generator), in which case Regulation 12 Para (3) applies, to still require danger is prevented SFARP.

Therefore, if a fixed appliance is to be regularly inspected and tested, and the test procedure necessarily involves opening up the connection unit (as is normally the case) there must be adequate means of isolation to allow this to be carried out safely.

If this means that the means of isolation (e.g. 2-pole keyswitch for small appliances) is separate to the connection unit, i.e. you can isolate all conductors to the connection unit before opening up, proving dead, and testing the appliance, then that is what is required.

Alternatively, if the means of isolation is at the Distribution Board, then the Employer must give you access to isolate and lock off before opening the connection unit.

This is, of course, part of the Fixed Electrical Installation. Hopefully, more Designers (of fixed electrical installations) will begin to take periodic inspection procedures into account from the outset - it's required under CDM Regulations, if nothing else.

Malcolm Wallace
Member - 14 posts

I think a fused spur going into a 2 pole keyswitch, to isolate small appliances, would be an excellent way to overcome the safe isolation procedure. It might be a bit tricky with towel rails in the bathroom, or similar but if the circuit was protected with an RCD or MCBO it would work. Maybe a new design of fused spur with well insulated input connectors, feeding a 2 pole isolator keyswitch via the fuse, is needed - designers take note please!.

Until all this comes to pass, I am paid to PAT Test all electrical appliances which come under the heading 'Portable' and which now appears to include fixed appliances connected to a spur or switch. I generally try to test 100 items a day, a few more if it is IT only, including repairs such as replacing plugs with RCDs where required etc. etc. The problem of isolation is not so much that of method, thanks to your posts, but more to do with time. By the time it would take to identify a spur, and any other users connected to the circuit; then switch off the said circuit, having got agreement with those other possible users; then dropped the spur, disconnected the appliance, fitted flying leads for connection to the PAT Test instrument , then tested the appliance, then reconnected the appliance to the spur - well you get the idea. It would not take many hard wired appliances to cut my 100 items a day down to 50, effectively putting me out of business.

I say 'roll on' to isolator switches but in this current economic climate I cannot see companies fitting them retrospectively although I will try to encourage it.

Regards