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.