hi all, we are currently doing an audit of our electrical panels as on a dept inspection I identifed some very poor conditions of 415v panels in a remote location. This is being dealt with now by 3rd party to rectify.

What I have found recently is that on a number of 415v panels the main panel door isolator switch has been disengaged and removed allowing access into the panel without it being isolated. On investigation with the senior electrican on site it was stated that the set up of the panels does not allow for any type of maintenance of the equipment. The majority of panels (newer types) contains multiple items of equipment (e.g. >6 -7 pumps, motors, etc). If one trips or one has to be removed the main panel isolator configuration requires all 7 items to be isolated. This is simply not practical as it requires a total shut down of a section of production process to attend to 1 item. This appears to the reason for disengaging the main isolator. All internal sections of the electrical panels are insulated and protected and each item of equipment can be isolated individually and LOTO for any work. The panels are only accessible to electricans. The main issue i have is would this be classified as 'live working' as per the EAW Regs as the panel is still live when main panel doors are opened. I can't see a practical solution of reinstating the main panel isolator switch- only option is complete redesign of all panels to the older style on site that is a individual panel for each item - this will be very costly. I'm i misunderstanding the requirements of the regs?? My next stop after this advice request is to contact our local HSE Inspector for some advice but i would prefer not to go that far yet.

Thanks

What is the compartmentalisation like in the panels?
Are they built to 60204, or 60947?
Your 3rd party remedials, to what standard are they being completed to?
There should be no reason to remove the interlock, the isolator should be able to be defeated under controlled conditions.

As far as the comment by alistair.r with regard to tagging out an isolator to find it does not isolate the system I find hard to correlate with removal of the door interlock.

Oh and the panels may be labelled as 415V however, we do not use 415V in the UK any more the nominal voltage is now 400V in the UK.

If the isolator has been totally defeated, find the guy that did it and shoot him. well perhaps sack him for gross industrial misconduct.

Electrical panels such as this MUST only be accessible to competent persons.

Without knowing what section of the isolator was defeated, and, how, and the details of the panel design I cannot comment further.

HOWEVER, please understand that it is VERY doubtful that this panel is, or should be designed and built to BS 7671, so the 3rd party undertaking the works, MUST have competence in the standards to which the panel IS designed and built.

Most general electrical contractors do not have this competence, nor are they ever assessed on their competence in 60204 or 60947 by ANY of the known certification bodies, ECA, NICEIC, NAPIT etc. (there are others) as these bodies ONLY assess to 7671.

7671 does not apply to machinery, nor does it apply to motor control centres, which this panel sounds like it could well be classed as.

There is MUCH more to this electricity thing than first meets the eye, and BS7671 is a minor part of it, in fact it is one of the most BASIC parts of it!

Bottom line is-
the device you are talking of is called a mechanical interlock on the main isolator spindle and is in place to prevent access to the panel whilst it is live. If the panel is for pumps etc i am sure that there will be relays, PLC's and DIN rail in there for terminations. These components all have exposed conductive parts which pose risk to life for anyone waving conductive kit around whether it be a screwdriver or a finger.
In simple terms BS 7671 talks of prevention of "Direct Contact" with live parts-particularly important with 400v equipment where an individual is unlikely to survive a belt at that voltage. That is what your interlock did until it was overridden.
The electrician clearly knows what its purpose is for the interlock by the sounds of it i.e. safety. Did he bring this to the managements attention first with no response?? If not-why not?

alistair,
I did not read the OP as relating to the link between the operating handle and the isolator, I read it as the door interlock being removed.
These can ans should be possible to defeat anyway when installed for controlled testing and fault finding.



Remember that HSE DO allow live testing and fault finding, there are occasions when it is only possible to undertake the testing or fault finding live.

It is doubtful that anyone would get a shock at 400V as this would necessitate contact between 2 phases.
The risk is more likely along the lines of a phase to earth fault shock risk at 230V, still however, lethal.

There is no issue with working in a live panel for fault finding.
Again I come back to the build standards and the compartmentalisation.

BS7671 will almost certainly not apply to this panel, well at least not any version of it I have seen anyway!
It certainly will NOT apply if it has a PLC in it!

Safetyman,

You have my sympathy with this one... Whilst I will not try to provide any more advice (Others know far more than me) this does serve as an object lesson in why "safety" needs to be built into all business processes. I bet the project engineer who specified this kit did not consult maintenance engineers or techs on the need for access should just one machine trip. I bet the procurement person bought the kit in the most efficient (cost wise) package they could get - with no acount of the through life costs and maintenance / defect requirements. I bet the production manager does not know there is an access problem regarding interlocks but does know exactly what the loss is costing when a machine trips.

I bet the maintenance guys are just trying to get the kit to work whilst fending off the production manager and anyone else who just looks at the bottom line. The procurement guy? - he's already spent his bonus. The project engineer? - recruited into a bigger project on the basis of his enhanced, "delivered on time to cost" CV.

Let's not forget, the guys on the tools are the last link in this process but they are the one's who have to deal with the fallout of other peoples poor management and decisions...

Anyway, That was fun, can't stop - Easter Eggs don't eat themselves.....

Jim