View Full Version : Electrical Inspections of Refrigeration Plant.

08-01-2011, 11:56 AM
Can Anyone please advise?
I was on a site yesterday where the site engineer mentioned that they were having a Electrical Survey done.
To comply with their Fire Insurance (Required every 3 years?).
I always thought it was 5yrs, but Hey it may of changed?

My dilemma is that the Electrician who is carrying out the work appears to be shall we say overzealous?

Apparently He advised the site engineers that the Screw comps were wired up incorrectly. as the phase wires don't match the dist boards?

My question is how far does an inspecting Electrician need to go into the control side of a plant.
This guy has gone right through to disconnecting and checking the wiring on the Liquid line solenoid Valves.
Every last electrical component is being labelled up
Incorrectly I may add.
The PM valve Solenoid Valves are designated M.V.
Pressure switches are Gauges etc.

I have never seen any Electrician go into this much detail before.
Is this necessary?
More importantly He has advised the customer that some of the control circuits need re-wiring?

I thought Regs were not retrospective?


08-01-2011, 01:22 PM
I would like to know who is paying him and ask them for a job anyone can go over the top for a few quid

If the plant has a written PPM that include electrical and visual inspections (and is carried out and recorded) then this replaces periodic electrical inspection and is not required to be done separately or periodicaly.

08-01-2011, 02:15 PM
Is this necessary?

More importantly He has advised the customer that some of the control circuits need re-wiring?

I thought Regs were not retrospective?


I would agree with you on that. Once installed and so long as the system is "safe" there should be no need to rewire. The original install would have been done to the regs at that time and remain so. Obviously any alteration or additional work would be done to the current regs standard plus any other remedial work.

I recon your Sparky is just laying it on thick to get more work out of the job.

08-01-2011, 05:27 PM
One might also ask - is he allowed to work on that equipment without an F-Gas Certificate?

08-01-2011, 05:42 PM
It's my understnding of BS7671 - 2008 that it relates to the mains supply only.

If I am wrong....has he looked at and checked the internal wiring in the canteen's Microwave oven?

Same Sh*t. :D

charlie patt
08-01-2011, 05:42 PM
if someone other than a ref engineer is checking and redoing wiring ie on a mag valve and he has no knowledge of system and how it works then bigger fool the customer and brian good question any answers out there i was told that any work carried out that could lead to ref leakeage had to have a f gas engineer so if sparky by mistake bypassed hp switch and fans failed and prv opened and dumped the ref is he liable

08-01-2011, 07:50 PM
As said earlier, your installation would have been certified originally before mains connection, no retrospective works are needed unless a dangerous fault has occured.

Control wiring in dictated by the manufacterer, not for a sparks to dictate or change at a whim, it could invalidate warranty or lead to improper function, eggs and grannies may come to mind but have you tried talking to this guy before he goes too far?

I've met these folks before, they used to be called consultants!


08-01-2011, 09:22 PM
A big thank you Guys.
I have spoken to one of the Company directors.
He has instructed his guys to tell this Electrician.
To complete the works he has started.

Because he has removed Bulkhead lights and installed new emergency lighting ECT.
As well as carrying out the so called inspection.
Anything else is to be put in writing and only then will decisions be made as to what is to be done.

I have also pointed out that these lights should be wired so that when the Ammonia alarm trips the main incomer, they should also loose power.

You have given me something solid to go on there.

A rouge electrician messing about with fridge circuits and controls scares me somewhat.
Can anyone else clarify just how far these inspections should go.
Thanks also to everyone Else's valid comments they are really appreciated.

It's a small world then Al. we get the same in U.K. (consultants)
The Aussies call them FIGJAMS.
F**ck i am good just ask me!

I guess we all know when someone knows what they are talking about just by listening what is said.
I did not have to hear a lot about this situation before I became concerned.
Thankfully the customer listens to us!

09-01-2011, 01:35 PM
Very good and very valid points. Testing of machinery and plant has always been a grey area, even on a domestic/residential periodic inspection report. it is unclear whether any equipment connected through a fused spur should be included in the report. Sometimes you get a spec to work to, other times you don't. Then your on your own and the spec and method is down to you.

So maybe this is the case here, and the sparky is used to just working on and testing fixed wiring and equipment, and out of his comfort zone. And it is reflecting in his judgement and what he is construing as non compliances. You would expect to find code four non compliances on anything installed within the last three or four years. Due to the change over from the 16th to the 17th edition. If he is using the 17th testing methods to the core, and he's finding code one's and two's, then it could be through accidental damage or incorrect selection of materials.

When I had an electrical contracting business some years ago, I was an niccy member (15th &16th edition days). I once asked them whether or not a central heating system should be included in the report and tested up to the spur, or beyond it. One answer I got from their help desk was "Yes it should be included in the report, but with limited test results recorded".

Another time was regarding a burglar alarm connected from a ring main through a spur, and I got the reply "No it doesn't come under the category of fixed wiring? so just disconnect the wiring from the spur and perform a limited insulation test along with the other tests". When the area inspecting engineer came for his annual visit, he looked at both jobs where the confusion was, and just said mmm, just stick to testing up to the fuse spur.

Like the other poster states has he checked the wiring of the microwave? Even when pat testing is done they only record a limited insulation test along with the other main three, and the other ones that don't neccesary amount to the safe operation of the appliance.

Digressing slightly

Recently I spoke to an old customer who had some wiring tested that I'd done in his business, (a cafe inside Leeds market) by another niccy electrician. And he told him that with the amount of code one non compliances, he needs a rewire. The premises were only upgraded back in 2002, so me being me I asked to look at his report. On the results page of non compliances, here are some of the things he'd recorded as code ones.

1. No 16mm2 earth/ground cable run with 63 amp 4 core 25mm2 submains feeder.

SWA cable 30 meter run with R1+R2 reading of 0.07 ohms, earth/ground loop test of 0.18 ohms recorded on the original installation certifcate, and inspected and passed by the niccy area engineer.

2. SWA gland not bonded to enclosure/panel via earth/ground monacle/ring.

Gland is secured with surrated washer both sides of enclosure/panel and paint scraped away inside giving exellent metal to metal contact.

3. No rcd protection on any final circuit.

Its a commercial premises so requirement, and premises are inside a building and no exit from the premises leads outside the building.

4. No equipotential bond/ground to airconditioning and refrigeration pipes.

Pipes have 4mm supplementary bond/ground inside the condensing unit, and from nearby circuits supplying lights and sockets, similar to a special location method. An O.T.T method but there were no further information and I was on my own with my judgement on a grey area. Also they do not make up part of an incoming utility, metal constructive, or extraneous metalwork likely to become live in the event of an earth/ground fault occuring of such magitude that will not cause the main incomming fuse to rupture and maintain danger.

5. 32amp BS 7831 type 3 mcbs protecting 4mm/imperial sized pyro feeding cooker points and socket outlets.

BS 7831 is now an obsolete standard but it is still OK to keep on using it in existing installations and does not even construe a code four, let alone a code one. Plus 4mm pyro is rated to about 32-50 amp.

6. A standard 8 KW Crabtree motor starter having a 415v coil and 415v potential difference across stop and start buttons, when it should be 110v?

This kind of starter can still be found today and is as safe now as it has always been. If were meant to have an 110v coil, and 110v across the stop and start buttons for safety? then 240v at a light switch or a socket outlet would be dangerous and non compliant with the 17th and any of the previous editions.

7. No supplementary bond to metal tables in food prep area.

Again not a requirement, if earthing/grounding requirement is found to be needed, then main equipotential bonding should be considered and not supplementary bond.

I have told the customer to hang fire on letting him carryout any remedial work, as he is getting a second opinion from me. As I do find it makes me look bad after I looked after him for a number of years. He may even withhold payment to him, if my report differs from him, I honestly think it will, and if there's an arguement. Then it will be reported to the niccy that one of their members isn't complying to their rules and maybe lacks the competency to carryout testing especially periodics.

Maybe its the same electrician doing the testing on your job Griz. Or maybe he has done a testing course and misconstrues the non compliance codes. As long as it doesn't make you look bad let him get on with it. But if you see something you think he's missed, make a note of it and consider letting your customer know, and whomever else.

Sorry for waffling on but thought I'd get my tuppence 'a' penny in

09-01-2011, 04:46 PM
There is one other point to note, after reading the previous post.

When conducting a Periodic Inspection, the first thing that has to be agreed with the person ordering the Inspection is the "extent" of the Inspection.

I suppose that if the person ordering the Inspection wants the inside of the chiller, A/C unit or Microwave inspected, then he should get what he is paying for.

But, if that is the case, then we must ask "is the guy doing the PI qualified to inspect the inside of such equipment"?