What age roughly is this board

[m4tty]

Hi,

Been to look at a job today in a shop. The mainfuse blew today on one of the phases.

The board been out and replaced fuse and said it was overheating. I clamped each phase and phase 1 was 80A, phase 2 0.35A and phase 3 21A. It looks like the board in the picture is fed off one phase and the pyro which goes upstairs to another board.

I didnt have a lot of time at the place today and am going back to test the installation and then go from there.

Just wanted to know roughly how old this board is. This place is a real mess but the owner wants it done in stages so I suggested testing it all out and upgrade the boards first then upgrading circuits as and when needed.

Thanks for reading and ive remember to post the link this time lol

Cheers

Also whilst posting. The lighting circuits have about 20 switches with all lights being switched individually. He wants one switch for back of shop lights and one switch for front. Ive never dealt with contactors before and if anyone had any useful links where I could learn how they are rated etc i would appreciate it.

 

[ProDave]

That's a pretty normal Wylex metal clad rewireable fuse box, probably from the 1960's

If it's all wired on 1 phase, and it's drawing 80A, and you have a 3 phase supply there, then surely it would be best replaced with a 3 phase DB and split the loads between the 3 phases.

Contactors are just in effect big relays. The two important ratings are the switching current of the contacts, and the operating voltage of the coil.

Are contacts in use already? or are you proposing adding contactors to achieve the grouped switching that the customer wants?

 

[Sidewinder]

That looks well dodgy from that I can see with my poor peepers!

Is it TN-C-S or TN-S?

Not keen on the 951 on the pyro.

Is the g/y coming down with the incomer the main E or not, where is it coming from/going to mate?

As far as contactors go, there is a little more to rating them but not much more than rating an mcb really!

One thing you need to watch with 4 pole is that you get 4 fully rated poles not 3 + an aux!

You need to decide with contactors if you want the lighting to come back on automatically in the event of a power failure or not?

This will have an affect on how you control the main contactors.

 

[m4tty]

That's a pretty normal Wylex metal clad rewireable fuse box, probably from the 1960'sIf it's all wired on 1 phase, and it's drawing 80A, and you have a 3 phase supply there, then surely it would be best replaced with a 3 phase DB and split the loads between the 3 phases.

Contactors are just in effect big relays. The two important ratings are the switching current of the contacts, and the operating voltage of the coil.

Are contacts in use already? or are you proposing adding contactors to achieve the grouped switching that the customer wants?

Contactors not in use currently as all lights are switched individually and some of the switches are the really old type. Like a stick poking out with a round base which you switch up and down. It may be called a toggle switch. I was thinking that contactors will be needed if switching 2 banks of 25 floursecents?

 

[Sidewinder]

m4tty they will!

You will need also to think about the supplies and a few other things too!

I'm sure you can do it.

In the words of the song "I'll get by with a little help from my friends"!!!

 

[m4tty]

That looks well dodgy from that I can see with my poor peepers!Is it TN-C-S or TN-S?

Not keen on the 951 on the pyro.

Is the g/y coming down with the incomer the main E or not, where is it coming from/going to mate?

As far as contactors go, there is a little more to rating them but not much more than rating an mcb really!

One thing you need to watch with 4 pole is that you get 4 fully rated poles not 3 + an aux!

You need to decide with contactors if you want the lighting to come back on automatically in the event of a power failure or not?

This will have an affect on how you control the main contactors.

Thanks SW. I was only there 5 mins so didnt get a good chance to investigate but when I go back ill post my findings. Also as this is a shop which doesnt have any emergency lighting at present. I should really recommend them getting some?

Thanks

 

[Sidewinder]

EM ltg and probably smokes or even a fire alarm.

The fire brigade are going though the City Centre at the moment issuing their own kind of improvement notices on premises for REM ltg, FA, Smokes, PIRS, PAT etc.!!!

 

[ProDave]

If you are planning to install the contactors for master control of banks of lighting, that's going to require some pretty major alterations to what's there.

Judging by the use of round toggle switches, I'm willing to bet the lighting circuits would benefit from a rewire anyway, so that's probably the best line of approach.

Ditch the round toggles and group all the lighting together with banks of grid switches, and wire in your contactors for master switching of banks as required. But given you can get 20A grid switches, do you actually need contactors for the master switches, or can you persuade the customer to group them in small enough groups to be within that 20A rating? it would make things a lot simpler.

And I agree with all the other comments about EM lighting and fire alarms etc.

I would start by suggesting to the customer you carry out a PIR first, and from that you can then advise the extend of remedial work needed to facilitate the CU upgrade and lighting upgrades.

 

[Sidewinder]

^ true

 

[steptoe]

^+2

good call prodave

quite a lot of lights on a 20A load, you just need to sort out how much current the cable will carry though,

if its only 1mm it doesnt help much, but if its 1.5 in the right installation method you have 16A to play with.