View Full Version : fuse box query
Guvnaar
3rd September 2007, 04:16 PM
What is my fuse box rated at?
Main switch is labelled 80A
The usage meter itself is labelled as 60A
Power company tells me all houses in the street are 55A and the fuse on the outside of the house is 55A
A sparky tells me he thinks it may only be 35A
If it helps the cable between Mains and fuse box that runs thru the roof is a black color 10mm in diameter labelled "OLYMPIC REG 250 VOLT INSULATED NEUTRAL SCREENED"
House was built in 1960, original wiring is the rubber stuff, house has had a recent renovation with safety switch installed.
What is the correct answer? :?
NCArcher
3rd September 2007, 04:45 PM
If you still have the neutral screened cable then the house is probably limited to the current rating of that cable which I would guess to be 35A.
If you intend to continue renovations and add additional power points and appliances (air cond, stove, hot plates etc.) then the consumer mains will need to be upgraded by your electrician. It would be a good idea to have the house rewired as well. Get all that rubber insulated cable replaced.
It's generally ok as long as it isn't disturbed but it is well past it's use by date.
outback
3rd September 2007, 04:49 PM
The answer is 42, the question what is the REAL queation.
thatirwinfella
3rd September 2007, 06:06 PM
if the 55 amp fuse is the smallest before you reach your fuse board, than your house can draw 55 amps.
the cable may only be rated to x amps, but that doesn't mean the house can't draw more than that... the cable just needs to be protected to x amps.
if the sparky is saying 35 amps, he may have his own reason; there is possible a smaller fuse before the fuse board, or that the cable is now rated to 35 amps and if you want anything more you'll have to upgrade.
i'd get rid of the black rubber wiring as soon as you can afford to, and upgrade the fuseboard to a circuit breaker panel. if you don't have rcd's, get them.
the ratings on your meter and mains switch are only an indicator of how much current draw they can handle and still safely operate.
Guvnaar
3rd September 2007, 07:01 PM
Great info. thanks so far.
Already have RCD's (40A) and circuit breakers. Although I am wondering if the current setup is a disaster waiting to happen.
Phone Pole -> 55A main fuse -> 35A "Insulated screened main cable" -> 80A Main cct breaker
So let me get this straight - If a device in my house decides to draw 50A for example. The fuse outside and the main cct breaker will happily pass it and fry the main cable which is rated at 35A :no: :no: :no:
Circuit breakers are
Main 80A
Wall oven 16A
RCD 40A
lights 16A
lights 16A
lights 16A
lights 16A
Power 10A
Power 10A
Do I need to get this cable looked at? Reason is I may be installing a aircon capable of drawing 15-17A, already have an electric oven, IXL's, spa, downlights etc.
Ausyuppy
3rd September 2007, 07:54 PM
Proceed with caution Guvnaar.
I recently moved into my new 1970's home in Brissy. Went and bought four airconditioners after checking the main breaker and seeing that it was 80A, therefor all good.
When the sparky came to install the A/C's he burst my bubble. Some dodgy sparky soldered 10mm cable onto the 6mm cable running through the roof from the street mains to my meter box. There should have only ever been a 40A fuse for the house.
To make the long story short, I ran 16mm cable from the eave of the house to the meter box, then had a sparky come in and connect the new mains cable to the Energex lead in cable and my already "upgraded" switchboard.
Im pretty handy with Electricity as I have worked with it for years in the Navy, however when it comes to the safety of my family and house, its worth taking the advice from the sparky.
Cheers
Steve
peter_sm
3rd September 2007, 08:40 PM
Our 1950's house had all original box, wiring, fuse etc.
When we bought it, first thing on the list was the fusebox. As we were going to build the garage and required a 40A sub board for what I wanted, the Sparky fitted new fusebox with 80A main fuse etc. The power company came out and fitted new standards cable from pole to house. I don't think I was charged for that part of it.
The power wiring was all replaced. The lighting wiring was left in place as it was still in good condition, and low amperage.
Sideshow
3rd September 2007, 09:36 PM
One thing to consider is that the fuse carrier at the point of attachment is rated at 55 A, but the fuse inside may be 35 A. This may be what your sparky saw. Where did you get 55 A from? If this is printed on the fuse carrier then that is the maximum fuse that the carrier is rated for, not necessarily what's inside it. If the mains is rated at 35 A, then your fuse is oversize and should be replaced.
Have fun.
Guvnaar
4th September 2007, 10:47 AM
One thing to consider is that the fuse carrier at the point of attachment is rated at 55 A, but the fuse inside may be 35 A.
<snip>
Have fun.
Fuse inside is definately 55A - Power co guy took it out and had a look.
I assume the best thing to do is upgrade the mains cable to >55A and change the main circuit breaker to 55A also?.....
What should the main cct breaker rating be changed to :?
NCArcher
4th September 2007, 11:01 AM
The individual circuit breakers will protect the cable and equipment installed. The 80A Main 'breaker' is actually a switch and has no automatic operation. Manual switch on and off only.
You are only likely to blow the supply authority fuses with a major fault in the board or the consumer mains. The 55A SA fuses protect the mains from the connection point to the switchboard and limits the total current that your house can draw.
Your electrician will recommend upgrading the consumer mains to 16mm cable before installing any further outlets or appliances. Shouldn't be too expensive. Leave the main switch as it is.
Guvnaar
4th September 2007, 12:24 PM
Ok makes sense. :D
Looks like my sparky will have to run a 10m length of new mains wire.
This will bump the power rating up from 35A to 55A.
So does this mean I will be able to install a separate circuit for a 15 or 20A inverter (split - reverse cycle) air con without any problems?
another termite
4th September 2007, 12:35 PM
You might see the lights dim a little when the air con is running flat out. Why not get a quote on getting three phase run to the house (An air con is a legitmate reason) and seeing as the sparky is aleady doing it anyway. Just think of the tools you could have then...(your meter will have to be changed tho)
Guvnaar
4th September 2007, 12:54 PM
I see your point but my budget at this point wont cover it. I just got off the phone with my sparky and he informs me that in order to replace the mains cable the power co will need to be booked as the mains cable is not high enough off the ground and they charge a fortune. The wooden box the meter is housed in needs to be replaced with a metal one as it is located outside.
Does this sound right? I just want to bump the mains up get the 55A capacity to supprt an air-con and leave it at that without spending a fortune...
NCArcher
4th September 2007, 03:20 PM
Yes, what he is telling you is correct.
Any work done on the mains or meters means the rest of the installation must be upgraded to conform to current regulations. As you had new CB's I thought that may have already been done.
Not sure if it applies in Vic. but you can use an Accredited Service Provider rather than the Supply Authority. Much cheaper.
Sideshow
4th September 2007, 07:44 PM
Unfortunately there's no way out of this one without spending more money than you'd like. As pointed out by NCArcher, the job will snowball quite quickly in order to bring it up to current standards.
As for the supply authority, I think you need to have them come out to identify where your new point of attachment will be (cost to you for the visit) then your electrician does most of the work and finally on the day your new switchboard is energised you need to get the supply authority in at least once, possibly twice (disconnect/reconnect - depends on whether your electrician is authorised to disconnect supply and remove meter).
Great info. thanks so far.
Already have RCD's (40A) and circuit breakers. Although I am wondering if the current setup is a disaster waiting to happen.
Phone Pole -> 55A main fuse -> 35A "Insulated screened main cable" -> 80A Main cct breaker
So let me get this straight - If a device in my house decides to draw 50A for example. The fuse outside and the main cct breaker will happily pass it and fry the main cable which is rated at 35A :no: :no: :no:
Circuit breakers are
Main 80A
Wall oven 16A
RCD 40A
lights 16A
lights 16A
lights 16A
lights 16A
Power 10A
Power 10A
Do I need to get this cable looked at? Reason is I may be installing a aircon capable of drawing 15-17A, already have an electric oven, IXL's, spa, downlights etc.
One thing that I noticed when I had a bit more time to read your post properly is that you have 4 x 16A light circuits and 2x10A power circuits. (a) it's probably the other way round and (b) that's a lot for an old installation with the equipment you specify. With all that reno work it really doesn't make sense that the mains remained original. It suggests to me that the electrical work was done illegally (and therefore dodged the need to have the mains upgraded) and you should probably have it all checked by your electrician anyway. I'd be most worried about the load going through the old mains with the oversized fuse affording a lesser degree of protection.
peter_sm
4th September 2007, 08:37 PM
When our power box was upgraded it was changed to a new metal box, and the mains cable had to go on an extension rod on the roof as there is a minimum height requirement.
another termite
5th September 2007, 01:05 AM
In nsw as long as the sparky has all the required licences he can do the lot and the service provider doesn't need to attend. Have a look and see if it works where you are they can be a lot cheaper.
peter_sm
5th September 2007, 10:37 PM
I only had to have the service provider to connect the new cable to the mains on the pole out in the street.
I was not charged for this by the service provider. It may have something to do with it being a standard upgrade to current specifications.
Guvnaar
6th September 2007, 10:55 AM
One thing that I noticed when I had a bit more time to read your post properly is that you have 4 x 16A light circuits and 2x10A power circuits. (a) it's probably the other way round and (b) that's a lot for an old installation with the equipment you specify. With all that reno work it really doesn't make sense that the mains remained original. It suggests to me that the electrical work was done illegally (and therefore dodged the need to have the mains upgraded) and you should probably have it all checked by your electrician anyway. I'd be most worried about the load going through the old mains with the oversized fuse affording a lesser degree of protection.
FFS you mean I've gone from the untouched but legal setup and forked out $4k so far to make it illegal.... Im not happy :(( :(( :((
I think its time to switch my sparky. This time I will do my research (unfortunatley I cant rely on the professionals) get my facts straight talk to the power co find out what the standards are, what they can do and what it will cost me.
chrisp
6th September 2007, 12:41 PM
FFS you mean I've gone from the untouched but legal setup and forked out $4k so far to make it illegal.... Im not happy :(( :(( :((
I think its time to switch my sparky. This time I will do my research (unfortunatley I cant rely on the professionals) get my facts straight talk to the power co find out what the standards are, what they can do and what it will cost me.
Check with your electrician, but it is likely, as SideShow pointed out, that you have 4 x 16A power circuits and 2 x 10A light circuits rather than the other way around. Have you checked the circuit breakers to see what they are rather than just rely on the stickers underneath?
Also, switchboard upgrades with old incoming mains can be a sign of a LEM (Licensed Electrical Mechanic) but non-REC installation. The electrician legally needs to be a REC (Registered Electrical Contractor) to charge for his/her services. And I suspect they need to have the REC to have the incoming supply replaced.
It is quite possible that the electrician is technically qualified (i.e. a LEM), but may not be a REC (legally able to charge for work) doing a cash job.
Ask your electrician if they are a REC, and if they are, ask why they didn't have the incoming mains upgraded as well. If they are not a REC, ask if they are a LEM!
Sideshow
6th September 2007, 07:33 PM
If you've paid for the work and it's not up to standard, then report it to the regulator/supply authority. They will investigate and if the sparky has not done the work to standard they will issue a fault rectification order and repairs will have to be made. If the sparky isn't legit, they may seek to prosecute and you may have recourse to a compensation order of some type.
Alternatively just ask the electrician who you paid to do the work and get the full story. There may be a genuine misunderstanding or another explanation. At least you're armed with a bit more understanding of what should have been done. If what you hear doesn't sound right, get a second opinion. It's difficult to give you a 100% correct answer here without opening the switchboard and having a first hand look.
One thing - different states have different regimes. In the ACT there is no distinction between an LEM and REC as in Victoria (as outlined by Chrisp) and some other states. A licensed electrician is a licensed electrician - authorised to do work anywhere as long as regs are followed and paperwork is submitted.
Let us know how you go!
nev25
23rd September 2007, 02:15 AM
Yeah this REC LEM this can be really confusing for the layman
I'm a REC in Vic and have to carry with me 2 licenses
"REC" (Register Electrical Contractor) and "Electricians license A CLASS"
To get my Electricians License I had to do an apprenticeship as a LEM (Licensed Electrical Mechanic) Now called LEA (License electrical assessment)
(Confused yet)
This has evolved as there used to be electrical mechanics, Electrical Fitters and Armature winders.
Only electrical Mechanics could Become REC with no further electrical training.
They have done away with Fitters and Armature winders.
To become a REC you have to have passed the LEM (LEA) which in Vic is a 4 year apprenticeship, have a registered business. have done a Electrical business course and have the relevant public liability Insurance,
An A-class electrician can do any work but cannot be payed for it.
The question there is if something goes wrong he wont have the insurance to cover it
So to get an electrician thats not an REC and pay him cash (as someone has quoted) is rather silly and IMO stupid and you will have no comeback for shoddy work
So always get an REC
An REC will (or is supposed to) have his REC number in ALL Advertising included on the vehicle, business cards etc
And always insist on a certificate of Electrical safety.
Its your safeguard
http://www.esv.vic.gov.au/ForConsumers/Choosingandusingatradesperson/Electricitytradesperson/tabid/333/Default.aspx