Really old memshield 3 phase board. New install.

[cateringENGINEE]

Hi
I have a 3 phase cooker range to install on unbalanced loads 47a / 9a / 9a.
Apparently.... I need to confirm that..
it needs a new supply that is rcd protected.
My problem is the board that it is coming from is a old memshield board 3 phase with all individual bs88 fuse carriers and no main switch isolator.
ive not come across one of these before. Usually it's a new mcb in the board and job done.
looking on the fuse carriers they mostly say 30a which I'm thinking I can't put a 50a fuse in them so would I need a new carrier?
my original idea was to put an ad box mounted to the side of the board and bring tails from the 3 phases neutral and earth through to a 3 phase rcd/mcb set up.

50a bs88 fuses - rcd - mcb - rotary isolator - appliance

i have pictures of the board and fuse carrier but don't know how to put the pics on here..?

any help or guidance would be appreciated.

thanks

 

[D Skelton]

im not here to aruge with anyone, i was just after information on a distribution board that i have come across and a setup i was proposing with an unfamiliar board thats all.. maybe ive gone into too much detail.

Nope, detail is a good thing. It allows us not only to see the level of problem you're facing, bit with your suggested solution it allows us to see your current level of skill. At present it is below the level required of someone messing around with three phase commercial ovens.

You aren't paying attention to the crux of the response.

Get someone qualified to do the job!

 

[cateringENGINEE]

Nope, detail is a good thing. It allows us not only to see the level of problem you're facing, bit with your suggested solution it allows us to see your current level of skill. At present it is below the level required of someone messing around with three phase commercial ovens.

You aren't paying attention to the crux of the response.

Get someone qualified to do the job!

ok firstly you say the op hasnt got a scooby doo because it cant possibly be right that an oven can be 50a per phase when there are plenty out there and and some the are higher per phase. i know, because thats what i do.

whats wrong with what i proposed to do in your opinion?

do you personally have experience with boards like this?

i dont, as in the inprinted writing on the fuse carriers, is that the maximum the carrier can take? the answer is more than likely yes. but there is no carriers with 50 amp on them does that mean that old board set up is not designed to take loads larger than 30a max? i dont know because ive not come across it before.
i could ring eaton memshield up and they could give me information on it, but ive come on here instead to see if anyone could help with some information.

keep saying get someone qualified in isnt answering the questions that im asking is it, weather im to do the job or not.

 

[snowhead]

I used to install those MEM boards.
You can't change the Carriers (pair) for larger ones, their max rating is as identified on the carrier.

If the spec of the oven IS as stated unbalanced, which I doubt, then as is being suggested above you need a lot more thought into the design of the new installation.

.

 

[D Skelton]

ok firstly you say the op hasnt got a scooby doo because it cant possibly be right that an oven can be 50a per phase when there are plenty out there and and some the are higher per phase. i know, because thats what i do.

whats wrong with what i proposed to do in your opinion?

do you personally have experience with boards like this?

i dont, as in the inprinted writing on the fuse carriers, is that the maximum the carrier can take? the answer is more than likely yes. but there is no carriers with 50 amp on them does that mean that old board set up is not designed to take loads larger than 30a max? i dont know because ive not come across it before.
i could ring eaton memshield up and they could give me information on it, but ive come on here instead to see if anyone could help with some information.

keep saying get someone qualified in isnt answering the questions that im asking is it, weather im to do the job or not.

I give up!

As per the wise words of my Jock pal Mr Bannatyne, "I'm out!"

 

[telectrix]

anyone who designs an oven with the loads that far out of balance should take up plumbing. can't see those figures being correct.

 

[Flanders]

Yes you are orrect the ratting on the fuse holder is the maximum size fuse you can put in it, it may be the case that you have to replace the db that is there or fit a seperate switched fuse and rcd , have you checked that the supply can take the additional load?

 

[cateringENGINEE]

I used to install those MEM boards.
You can't change the Carriers (pair) for larger ones, their max rating is as identified on the carrier.

If the spec of the oven IS as stated unbalanced, which I doubt, then as is being suggested above you need a lot more thought into the design of the new installation.

.

thanks for your informative post, that helps. i doubt it is that far out of balance myself but that is the information i got given weather it turns out to be right or not.
either way if the highest rating carrier in that board is a 30a then its a no go.

 

[shanky887614]

thanks for your informative post, that helps. i doubt it is that far out of balance myself but that is the information i got given weather it turns out to be right or not.
either way if the highest rating carrier in that board is a 30a then its a no go.

sounds to me like the figures they gave are for different sections of the oven and not total load per phase etc

 

[telectrix]

first job is to get the correct figures (A/phase) for the oven. only then can you start calculating cable size, fuse sizes, etc.

 

[cateringENGINEE]

yes quite true that will be my first job, i am there on monday i know total load is 64A but been given the information of 47a 9a 9a, im hoping it is false information. not done a load test on the board as of yet just been given all the information. Now i have a better understanding of this board and what my limits are ive got something to work with.

thanks

 

[davesparks]

Right, it's an MEM EXCEL fuseboard, which is still a current product (apart from the colour they still make them identical). The carriers are rated for a max of 30A each if it is a 30A board, this should be on the label fixed to the inside of the door, along with other useful information about the board.

 

[shanky887614]

yes quite true that will be my first job, i am there on monday i know total load is 64A but been given the information of 47a 9a 9a, im hoping it is false information. not done a load test on the board as of yet just been given all the information. Now i have a better understanding of this board and what my limits are ive got something to work with.

thanks

i cant be arsed to help someone like this and i don't want to block them

ill edit stuff out

 

[D Skelton]

it will be 64a spread across tp then.

the 47,9,9 will be a brakedown of the different sections of the appliance not the amount it will draw on each phase.

Why are you still conversing with this guy?!

It was clear from the outset that he didn't have a clue and you're still helping him!

 

[cateringENGINEE]

Why are you still conversing with this guy?!

It was clear from the outset that he didn't have a clue and you're still helping him!

64a equally spread over 3 phases? is that ho it always works?

i already told you from the start i have been "given" the information of the phases, what more can i give you apart from the information ive been given until i can confirm it for myself..
not all three phase appliances are balanced loads. you cant just say oh 63a total that means 21a per phase.
if you got 8 elements 2 running at different wattages to the other 6 split over 3 phases it wont work out equal.
D SKELTON do you have any electrical knowledge because you put about 10 posts on here and not one of them have shown any electrical experience? are you a 5 week wonder as well?

thanks

 

[Flanders]

Here we go tin hat on :tank: