Contactor help

[mk1rob]

Hi guys

Ive just done a EICR at a doctors surgery. Theres a single phase rewireable fuse board for the main circuits (lights, rings etc) and a separate 3 phase board for the electric convector heater radials. This 3Ph board is supplied from another enclosure with a contactor in it (see pic)



Ive not had a lot of experience with commercial/industrial installations or 3 phase for that matter. Apart from the obvious IP rating problems and lack of grommets etc. Does this look right to you? The two small 2.5mm cables go to a time clock which i'm guessing bring the heaters all on together hence the reason for a contractor but should they be fused down?

If I'm asked to do the remedial work to make it comply would it be acceptable to remove this set up completely and have all the circuits including the 6x 16A heater radials on one 1 phase consumer unit (or 3phase to spread the load between phases). I dont think the time clock is used and they switch each heater on individually.

Would really appreciate any help and advice on this.
Thanks

 

[Hants-Spark]

From the picture and your description I would say that the contactor actually brings in the 3 phase board rather than the heaters themselves, I would be surprised if the heaters are not individually protected within the 3 phase board. If you wanted to reduce the amount of boards etc you have within the premises you could fit a new/or re-use the existing 3 phase board, bring in all the circuits from the other board and feed out to your heater circuits and have individual smart stats adjacent to them. Just an idea, not having seen the job its hard to give a definitive answer to questions. Hope this helps

 

[JeanGenie]

From the picture it looks like the time clock feed needs to be fused down, but is there any reason to change this set up? It may be that they want the clock to bring the heaters on during the day so they're not left on over night.

 

[Sintra]

Can I just ask 2 things
1. What is the in line fuse at the bottom doing.
2. Why are you doing an EICR on an installation that you are not comfortable with.

 

[mk1rob]

Thanks for the replies!

Hants-Spark - Yes the contactor does bring in the whole 3Ph board. Liking the idea of having the lot in one 3Ph board and individual timers next to each heater. That way the whole installation would be neater and more straight forward.

Sintra - The bottom horizontal fuse is for the Neutrals. Although I've not done an EICR before or worked with 3Ph very much, I can test competently and know how to do that side of things. I feel the only way to get comfortable with it is to get experience. Theres got to be a first time for every thing right?

 

[Sintra]

Think I would be concerned about the neutrals being fused tbh. My personal opinion on testing especially periodics in commercial or industrial is that you should have had previous experience in installing these systems. I liken it to a bicycle repairer carrying out an mot on an HGV.

 

[Deleted member 72666]

The bottom fuse holder may just house a removable link. Hoping it does, but not the way I would have done it as it can still give rise to danger if it was inadvertently pulled !

 

[hasel5]

Tbh if you are asking questions on here then maybe you should leave the eicrs to people who understand what to do and look out for and interperate the existing install

 

[SPARTYKUS]

Hi mk1rob

deffo get a second, experienced, opinion on this.

no disrespect, it is important & you will learn from a master as a result & therefore be a bit better

 

[Marvo]

I'd agree you can't competently test or pass judgment on a panel unless you know it's exact function. This panel could be for control purposes but it could also be for any number of other purposes such as load shedding for example. You need to investigate the entire system as a whole long before there's any talk of upgrading or replacement. I'd suggest you might seek assistance on this job from someone more familiar with commercial controls if you're lacking in experience.

 

[Knobhead]

If you’re doing an EICR claim to be competent, why are you asking these questions?

You clearly don’t know what the panel does, how can you test it?

 

[pjcomp]

Various threads on this forum bemoan the lack of training, the skinflint levels of pay (agencies offering £7 an hour etc), and the difficulties new starters face getting into the business. The world's changed, maybe not for the better, but nowadays this, here, is where people turn for advice and the benefit of others' experience. If the OP had some wise old man, a village elder of electrics, to turn to he wouldn't have asked the question here. The internet and forums such as this are the new "wise old men".

I've learned things on here, and I'm happy when I can pass them on to others. If you can't respond without resorting to trashing a complete stranger it might be better not to respond at all.

PJ

 

[dansk]

^^ I second that, at least the questions are been asked and trying to do the job right, we are all still learning every day.

 

[SPARTYKUS]

Understood pj (& i think I am not guilty of said trashing) but in this case, getting someone in is the only option. Surely you can see the danger & futility of it...?

At the same time as demonstrating said respect for individuals this does not negate the need for Rhino skin of the individual and accepting harsh yet sensible, realistic advice.

 

[SPARTYKUS]

As an example I quoted to PIR a service station. It was my find but I asked a commercial tester who does these things (I dont) to do the work with his team- he was prepared to let me help & learn under supervision.

 

[mk1rob]

Thanks pjcomp! Reading through other threads I have noticed once 1 person says 'you dont know what your doing' etc etc others seem to jump on the band wagon and it starts to get insulting.

Sorry I probably shouldn't have said ive NEVER done a EICR as ive done the 2391 course so know the theory and have tested a 3Ph installation filling out a EICR in the practical exam however this doesn't contain contactors etc and as im sure your all aware things are a lot different out in the field.

I asked the question on here to get a second opinion from people that are more experienced in commercial/industrial installations. I know its hard to give advice with out seeing the job in person but any advice (apart from 'i shouldnt be doing it') would be helpful! Some of the earlier replies in this thread have been so thanks for that

 

[mk1rob]

Spartykus - I understand where your coming from and agree that little knowledge is dangerous but the ONLY bit im not 100% sure on is this particular enclosure. The rest of the property/installation is all single phase individual circuits that are common in domestic situations. Id be silly to turn this job down in the current climate just because of an enclosure i'm not familiar with. The idea of asking the question is to get more familiar with it Thanks

 

[SPARTYKUS]

Cool man, I never mean to belittle or dig. As you say it is hard to advise via a forumfor something like that but I catch the drift. Just that bit in the piccy is the chewy bit.

hope it goes well.

 

[Sharpend]

So who of the experienced ones are going to put their time where their mouth is and offer to go with him to allow him to learn? Or do we leave all that to someone else?

 

[Brightspark2]

Check the requirements for over current protection in BS7671. It feeds a time clock, a switch basically. Is this likely to cause overcurrent?.

Although is the cable liable to damage and how far is the timeclock away?. Have a poke around the section (oh er).

Check the neutral to make sure theres no fuse in there!.