Shower change

[Foxmeister]

I have been asked to price a shower swap in a flat. Existing board with fuses is still in place and its 6mm on 30amp. The reason the shower is getting changed is that after running for around 10mins it trips the fuse, i have heard that the "compensator" or "condensor" unit acts like this when its starting to go, sorry but i dont know much about shower parts, is this the case? Either that or the cabling might need looking at, will do a quick test on that anyway to be sure its still up to said job.

So, the real problem is now with regs stating that all bathroom power circuits to be RCD protected, whats the best(easiest and cost effective) way of installing the new unit with the required protection to suit regs that doesnt require a new CU, i personally will recommend the landlord to think of upgrading CU but obviously they dont want to hear more cost on top of what they dont want to pay out now!

 

[tonksie]

i would put it on a 32a rcbo mate

 

[SPECIAL LOCATION]

I would find out more info first..

like..

What is the power rating of existing shower?

How old is existing shower?

By your own admission you have minimal knowledge of shower parts..

double check the obvious basic first..

A failing cord pull isolator can cause the symptoms you describe..

lose connections arcing & sparking while under load

Like - 4- Like maintenance replacement is NOT installing or modifying supply cable. You are just replacing an accessory attached to the installation!.

 

[Foxmeister]

I would find out more info first..like..

What is the power rating of existing shower?

How old is existing shower?

By your own admission you have minimal knowledge of shower parts..

double check the obvious basic first..

A failing cord pull isolator can cause the symptoms you describe..

lose connections arcing & sparking while under load

Like - 4- Like maintenance replacement is NOT installing or modifying supply cable. You are just replacing an accessory attached to the installation!.

True i havent got all the info.

Will obviously check power of shower etc but with it being hassle free for last x amount of years i dont think the shower is to large for the fuse.

Have seen some loose connections in my time also, with bad consequences so will check that also.

If its a simple solve then fine, but the problem is if it needs changed and fitting RCBO to an old style board, or will i need to add a spereate enclosure for the RCBO?

Cheers for replies lads.

 

[m4tty]

Is a rewirable fuseboard mate?

If so you could split the tails and put a small cu in for the shower.

As specs says its like 4 like but if it says in manufacturers instructions that it requires rcd protection then youll have to fit it.

Question: Them small powerbreaker 30ma RCDs (same size as single socket outlet) .. will they fit 6mm cable in them?

Cheers

 

[kme]

Yeeeees, although they`re generally only rated at 13A IME...

Seperate enclosure alongside DB would be best option - after verifying state of shower circuit....

I don`t think the shower is too large for the circuit

but you don`t KNOW,

Just because it worked for some time doesn`t make it right.

KME

n.b is a "speareate" enclosure anything like the individual ones you can mount a din-rail RCD or RCBo in?

 

[batty]

Could be that its always been on the border line and voltage has dropped slightly causing the problem now or if its a rewirable fuse box maybe a bad connection in that remember a lot only had 60 amp main switches.

 

[Lurch]

Like - 4- Like maintenance replacement is NOT installing or modifying supply cable. You are just replacing an accessory attached to the installation!.

Although it should have had an RCD from day 1 and the new one will definitely state that it requires an RCD so I wouldn;t just be swapping it like for like.

 

[Foxmeister]

Batty-Hear what your saying there, as most operate well within their total demand stated, hence why i will check this just to be sure, and do a quick test on cable.

KME- As stated, i dont know shower size for sure as havent checked that particular problem yet but only have previous knowledge of house electrics due to working in the property before, i will obviously look into the simple cures first....as they say, assumption is the mother of all f%$k ups!!!!!!!!

And yes, as seperate enclosure i mean the small 1 or 2 way units that has a din rail installed and ready to go. This is the method i would think best, but now think i may have a problem isolating main supply to install it, sure its just meters above CU with no means of isolation, it never ends some days!!!

Thanks for info and replies lads.

---------- AUTO MERGE Post added at 19:35 ---------- Previous post was at 19:25 ----------

How would this do for it, looks like just the part for it?

http://www.screwfix.com/prods/90026/Electrical-Supplies/Consumer-Units/Wylex-Consumer-Units/Wylex-Fully-Insulated-RCD-Shower-Consumer-Unit

Or does anybody use any better units???

 

[batty]

Batty-Hear what your saying there, as most operate well within their total demand stated, hence why i will check this just to be sure, and do a quick test on cable.KME- As stated, i dont know shower size for sure as havent checked that particular problem yet but only have previous knowledge of house electrics due to working in the property before, i will obviously look into the simple cures first....as they say, assumption is the mother of all f%$k ups!!!!!!!!

And yes, as seperate enclosure i mean the small 1 or 2 way units that has a din rail installed and ready to go. This is the method i would think best, but now think i may have a problem isolating main supply to install it, sure its just meters above CU with no means of isolation, it never ends some days!!!

Thanks for info and replies lads.

---------- AUTO MERGE Post added at 19:35 ---------- Previous post was at 19:25 ----------

How would this do for it, looks like just the part for it?

http://www.screwfix.com/prods/90026/Electrical-Supplies/Consumer-Units/Wylex-Consumer-Units/Wylex-Fully-Insulated-RCD-Shower-Consumer-Unit

Or does anybody use any better units???

That picture looks like an RCD in an enclosure so no overload protection. Most manufacturers make shower consumer units.

 

[Foxmeister]

That picture looks like an RCD in an enclosure so no overload protection. Most manufacturers make shower consumer units.

Pretty much as you've described it, but that is all that is required i believe, only RCD protection for bathroom circuits??? Please correct me if im wrong, dont have my red bible to hand.

 

[sparkytim]

It will still need Over current protection in the form of a Fuse or MCB.

This can be in the Original Consumer Unit

RCD only provides ADDITIONAL shock protection.

:|

 

[Foxmeister]

Oh right, misunderstood that, sorry.

So my initial thought of small enclosure with 30mA main RCD and circuit protected by 32a mcb the best solution?

 

[PC Electrics]

I have been asked to price a shower swap in a flat. Existing board with fuses is still in place and its 6mm on 30amp. The reason the shower is getting changed is that after running for around 10mins it trips the fuse, i have heard that the "compensator" or "condensor" unit acts like this when its starting to go, sorry but i dont know much about shower parts, is this the case? Either that or the cabling might need looking at, will do a quick test on that anyway to be sure its still up to said job.

Have you checked the running current against the appropriate device curve in 7671? Might be the device is tripping as it's supposed to with the level of overload it's seeing (depending on th erating of the shower).

---------- AUTO MERGE Post added at 20:07 ---------- Previous post was at 20:02 ----------

How would this do for it, looks like just the part for it?

http://www.screwfix.com/prods/90026/Electrical-Supplies/Consumer-Units/Wylex-Consumer-Units/Wylex-Fully-Insulated-RCD-Shower-Consumer-Unit

Or does anybody use any better units???

I fit loads of these to add RCD protection where the existing ocpd & board are not being changed. Perfect for the job. You might get another brand a little cheaper from your wholesaler though (I use the Hager version from Edmundsons).

 

[sparkytim]

Depends on how you want to configure it.

Option 1 Provide independant 1 Way CU with 30m A RCD + MCB

Option 2 Still use Fuse or MCB in existing CU and THEN go thru STAND ALONE 30 m A RCD (FOR SHOWER ONLY)

Option 3 Replace EXISTING CU complete

 

[S60TEM]

Depends on how you want to configure it.Option 1 Provide independant 1 Way CU with 30m A RCD + MCB

Option 2 Still use Fuse or MCB in existing CU and then go thru STAND ALONE

30 m A RCD

Option 3 Replace EXISTING CU complete

Option 2 is what I would do......

use existing CU for overload protection, split the tails and put in a 30mA RCD to feed the original CU which would cover all the circuits for shock protection. Complies to regs and cost effective.

 

[batty]

Option 2 is what I would do......use existing CU for overload protection, split the tails and put in a 30mA RCD to feed the original CU which would cover all the circuits for shock protection. Complies to regs and cost effective.

I would think having one RCD for whole installation is a serious no no who trained you?

 

[Foxmeister]

I would think having one RCD for whole installation is a serious no no who trained you?

Agreed, the rule of thumb now is to segregate to reduce nusiance tripping etc that would take whole board out.

Think he meant to RCD that circuit maybe and got confused while typing, ahem???

Ok, option 2 sounds the better choice then, but excuse my lack of domestic intelligence in carrying out this type of method(Industrial spark by trade) but what is meant when you say "split the tails"?

I imagine going this route will involve me disconnecting the shower circuit from existing CU, installing the single enclosure with 30mA RCD, connecting the shower to the bottom of the RCD and installing new cable(tails) from the RCD back into existing CU and connect to existing fuse and neutral connection?

 

[Zeespark]

Why not have a small four circuit board, a main switch and an RCBO? take the tails from a Henley block?

AndyGuinness

 

[sparkytim]

I have ammended my earlier post to try and make it clearer

"Splitting tales" means installing a double pole Henly type connection block to enable supply to two or more seperate Consumer Units from the existing Meter.

This would require temp disconnection of the supply.

Feeding the shower from an existing Way in the Consumer Unit would be the simplest solution, and would require only an additional RCD and enclosure and could be wired with the same size cable as the shower.