The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Industrail Control Panel bonding per 409.108
by sparkyinak
12/09/16 06:29 PM
Calling all Non-US members!! (Non-US only)
by aussie240
12/07/16 02:39 AM
Photo Upload Tutorial
by DanK
12/06/16 11:35 PM
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
On Delay Relay with Auto Reset
by Potseal
12/01/16 09:59 AM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 13
HotLine1 10
sparkyinak 9
Texas_Ranger 8
Trumpy 6
Who's Online
1 registered (brsele), 230 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#138013 - 08/09/03 07:01 PM Overloading?
ryanj Offline
Junior Member

Registered: 08/01/03
Posts: 3
Loc: N/A
First off, I'm sorry if I have posted this in the wrong forum, I'm new around here.

My question was, "Is it safe to have all a houses sockets wired into only one fuse?"..

I was looking around my house earlier today and discovered all of my houses sockets (except 4) were wired into a 30amp fuse.

Is this a fire hazard?

Top
Test Equipment:

Large Selection of Test Equipment For Electrical, HVAC, Test & Measurement
Large Selection of Test Equipment For Electrical, HVAC, Test & Measurement

#138014 - 08/10/03 10:38 AM Re: Overloading?
j a harrison Offline
Member

Registered: 05/22/02
Posts: 112
Loc: southampton, england
ryanj,

First off, welcome to ECN.!
next, where are you from ?
what type of property are you in?
age of equipment? (approx)
type of panel (distribution board)
how many outlets on this 30amp fuse

if you can give a bit more information we can see if we can point you in the right direction.

John

Top
#138015 - 08/10/03 02:07 PM Re: Overloading?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Hi Ryan,

You've posted in the non-U.S. area, so are we to assume that you are outside the United States?

As John has said, we really need to know where you're located to give an answer to this. If you're in the U.K., it would not be at all unusual for a small-ish house (especially one wired back in the 1950s/60s) to have a single 30A ring feeding all the sockets.

Top
#138016 - 08/10/03 02:49 PM Re: Overloading?
ryanj Offline
Junior Member

Registered: 08/01/03
Posts: 3
Loc: N/A
Thanks

Sorry about the lack of information.

I'm from the UK (south-west Scotland), and I live in a reasonable sized two-story house, I think the equipment could be pre 1960.

I counted up the outplets, and there in 27.

Here's a pic of the unit... (sorry about the junk in the way :O)

Everything:


Top fusebox:


Fuse 2: 40amp Circuit Breaker - Shower

The other four do single sockets! (They used to be some kind of storage heater outlets, but they got changed to sockets). Is having 15amp per socket, safe?

Bottom Fusebox:


Inside that there are six fuses..

Fuse 1: Most Lights
Fuse 2: Two Lights (couldn't they be halfed over each of them?)
Fuse 3: Another 15amp fuse to only one socket
Fuse 4: Old Immersion Heater
Fuse 5: All the rest of the sockets and the central heating (the problem??)

Fuse 6: Cooker

RCD:



Meter:


Something: (any idea what this is?)



It's label reads: "100A Series 7 Type II. b. 415v. BS. 1361."


That's all.


[This message has been edited by ryanj (edited 08-10-2003).]

[This message has been edited by ryanj (edited 08-10-2003).]

[This message has been edited by ryanj (edited 08-10-2003).]

[This message has been edited by ryanj (edited 08-10-2003).]

Top
#138017 - 08/10/03 04:22 PM Re: Overloading?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
O.K., thanks for the pics. There are no surprises there.

The distribution panels are Wylex standard range, very common in many British homes, although the all-insulated versions were probably more common in residential work than these metal-clad types.

From your notes, I would guess that the top fusebox was originally wired on the Economy 7 timeswitch so that it was energized over night to charge the storage heaters. The individual 15-amp circuit to each heater is standard.

Clearly the metering has now been changed to a regular single-tariff type (presumably when the storage heaters were removed and central heating installed), and somebody decided to fit sockets where the heaters used to be.

A standard BS1363 (rectangular pin) fused plug is rated for 13A maximum, so there's no safety issue with having a single socket on a 15A circuit. (This arrangement would be considered non-standard with 13A sockets, but it's not that uncommon where wiring has been modified and it was convenient to do this.)

The British IEE Wiring Regulations specify that a 30A ring can supply any number of sockets over a floor area of 100 square meters (1076 sq. ft to you and me).

These days it is more usual to split the sockets onto two or more circuits, but a 30A circuit can supply up to 7.2kW of power, so you'd need a lot of high-power equipment plugged in to approach that, especially now that the house has central heating so that you're not likely to be using big electric heaters in every room.

The wiring may not be ideal, but so long as everything's in good condition and installed correctly (which we couldn't tell without actually examining it) you most likely don't have a problem.

The only area where I would have concerns would be the kitchen/utility if you have washing machine, dryer, and dishwasher plus all your other high-power kitchen equipment running on the ring. But that's very much my personal view, and many new homes still have all of this stuff on a single ring.

Are the fuses in the lower box the rewireable types? (i.e. the same type as the four 15A ones we can see in the upper box).

Most people would recommend that these be replaced by cartridge fuses or circuit breakers for improved protection. Fortunately, the Wylex range have interchangeable carriers which would allow you to replace these very easily (just like that 40A MCB which has been fitted for the shower).

The gray box in your last picture is the main fuse and connecting block between where the service enters the house and the meter.




[This message has been edited by pauluk (edited 08-10-2003).]

Top
#138018 - 08/11/03 12:36 AM Re: Overloading?
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Ryan,
Welcome to ECN!.
Thanks for the pics.
I notice that the top fuse-box is missing a bushing where the meter tails enter the box.
Paul,
Is it normal to parallel(sp?) up Consumer Units, like this, with using multiple Meter Tails?.
Hmmm, 100A Single Phase supply?, is this a normal supply size in the UK?, I'm just comparing this to our 63A Single phase over here, which is 230V.
What size Mains carry this 100A?, considering that Mains are looped between buildings, or is there a different system used in the UK?.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

Top
#138019 - 08/11/03 03:21 AM Re: Overloading?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
The bushing doesn't appear to be a problem: If you look closely you'll see that there's a black rubber/PVC grommet where the cables enter the top panel.

It's not unusual to parallel two or more units like this, but I've just noticed that the two sets of tails both go directly into the top of the RCD. I'm wondering whether someone has trimmed off some of the strands on each tail in order to squeeze two cables into each terminal.

There are still plenty of 60 and 80A (and even some 40A) services still in use, but 100A is pretty much the norm these days. It's not standard practice to loop the mains building to building here; each house usually has its own spur from the mains under the street or to the pole. The service cables are probably 25 sq. mm.

Top
#138020 - 08/11/03 12:35 PM Re: Overloading?
j a harrison Offline
Member

Registered: 05/22/02
Posts: 112
Loc: southampton, england
Trumpy,

It is not reccommended or advised to run two sets of meter tails to the feed side of the RCD (or ELCB Earth Leekage Circuit Breaker) the correct way to actually do this is take the meter tails from the load side of the meter then to a 100Amp services block (big bits of terminal block in a rather largish enclosure) then two sets of tails to each service panel.

100Amp is the standard size single phase to a domestic property in the uk.

ryanj.
one thing i would also advise is that you have a qualified electrical contractor perform an Inspection and Test and produce a report on the installlation for you, this will give you a better insight into the condition of the installation, as Paul has said, changing the re wireble fuses to MCBs (miniture circuit breakers) would be a good idea, and testing the RCD would also be a good idea, but if you are unsure consult a Qualified Electrical Contractor.

if you need any further advice just post.

John H

Top
#138021 - 08/11/03 05:09 PM Re: Overloading?
ryanj Offline
Junior Member

Registered: 08/01/03
Posts: 3
Loc: N/A
Guys, thanks for all the replies!

Paul,
It did used to be wired with some kind of economy timer, and the fuses in the bottom box are the same rewireable type as in the top box.

I believe this service is acctually 80A, the markings on the RCD say this.

And around here a lot of houses share a spur from the mains, I share one with the house next door, but I've even seen one sharing four or five houses...

-Ryan

Top
#138022 - 08/12/03 02:43 AM Re: Overloading?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
THe 80A marking on the RCD is just the rating of the RCD itself -- It has nothing to do with the actual capacity of the service.

As John has sad, it wouldn't be a bad idea to get a test and inspection on the wiring if there are any doubts. It's not uncommon to find a few areas for concern where things have been altered like this over time.

Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals