Electricians....question For You?

[rude]

Hey Polk how many GPO fuses are there 2? (if you are a sparky & work on it you are suppose to bring it up to standards ie RCD )

Probably 1 fuse for lighting

Thats if its an older house most homes these days have more ccts due to derating factors on insulation of the cable due to many circumstances such as cables installed in groups or within 150mm of cieling space deemed to be in insulation

The SAA Wiring rules what a pusser

If I was over there mate Id give you a hand but you do null void insurance if it is bodgie

Having said all that if you are half handy & ask around this seems a very easy job of paralleling another GPO on to this cct

 

[Dunno]

Hey Pok

As several in the know have suggested, I would get a licensed sparky on the job if only to cover your arse. There are too many variables to look at and if you are not aware of them it can cause problems. eg The wires to the existing outlet for your fridge are only designed to handle a rated current, usually 10amps max load per standard outlet. Some fridge outlets are wired individually from the switchboard - so if another appliance trips a circuit breaker, your fridge keeps running. Therefore the wiring may only be there to cater for a 10amp load. Piggybacking off this outlet may be fine for the fridge to run normally as the 2 fridges will use less than 10amps. However problems can occur randomly, eg if a master dropout fuse on the HV distribution network blows, you can be left with power supply but at a very low voltage. As Lethal mention earlier, Voltage, Current and Resistance are related. If a fridge motor is getting reduced voltage, it will draw more current to compensate, ie if the volts drop by a power of 10 (240 down to 24), the current will increase by a power of 10. This can lead to the wiring drawing too much current and heating up/burning out/catching fire. Before this point a circuit breaker or fuse should go. If this is the wrong size in the first place, then you may have a problem.
For the record, I'm not an electrician but work in an office where everyone else is either an electrician or an electrical engineer, I'm just their bitch. But this is what they tell me so I understand why to tell members of the public to call a sparky. If there are any qualified tradies about, please feel free to let me know if I'm off the mark.

Dunno

 

[Screwtop]

Guys, please stop the pissing contest about voltage versus current. None of you (except newguy) know what you're talking about, and you're speaking as though you think you do.

Those years of study..........wasted..............I'm gutted....learn't nothing. Think I'll throw myself off a bridge (rectifier) :lol:

Screwy

Edit: To Qualify: Not a sparky, worked with much higher voltages/current.

 

[Back Yard Brewer]

Those years of study..........wasted..............I'm gutted....learn't nothing. Think I'll throw myself off a bridge (rectifier) :lol:

Screwy

Relax, don't worry - have a homebrew craftbrew!!




Now who was it that said that <_<

BYB

 

[Screwtop]

Relax, don't worry - have a homebrew!!

<_< You know there are still 4 days to go :angry:

Screwy

 

[Zwickel]

Those years of study..........wasted..............I'm gutted....learn't nothing. Think I'll throw myself off a bridge (rectifier) :lol:

Screwy

hahaha...Screwy.....no way, dont do that.....not for that reason

Just take this thread for entertainment, lay back, relax and enjoy it.....where are the chips?

:lol:

 

[Screwtop]

hahaha...Screwy.....no way, dont do that.....not for that reason

Just take this thread for entertainment, lay back, relax and enjoy it.....where are the chips?

:lol:

They're in the Wave :lol:

Last OT post promise, having too much fun.

Screwy

 

[rclemmett]

If there is a hole in the wall and there will be a fridge on either side, why don't you use an extension cord?

 

[LethalCorpse]

Voltage schmoltage, how does a little 30,000V - 50,000V static discharge feel when exiting your car in dry windy weather. It's the current that kills!

Screwy

sorry, screwy, but this one earnt you a place in my last post. You were probably taking the piss, but it's still rubbish.

 

[LethalCorpse]

If a fridge motor is getting reduced voltage, it will draw more current to compensate, ie if the volts drop by a power of 10 (240 down to 24), the current will increase by a power of 10.

Nope, this doesn't happen. If you halve the voltage, most things will draw half the current. They don't have the brains to compensate. The general exception is switchmode power supplies - if designed to do so, switchmode supplies will draw twice the current to keep their outputs constant with a reduced supply.

 

[yardy]

Fomr my experience of aussie leco's (only 1) it would be safer to do it yourself.

classic, this thread has it all :lol:

thanks for the laugh pok, start one on thermal lancing so i can get involved

cheers

 

[rclemmett]

Nope, this doesn't happen. If you halve the voltage, most things will draw half the current. They don't have the brains to compensate. The general exception is switchmode power supplies - if designed to do so, switchmode supplies will draw twice the current to keep their outputs constant with a reduced supply.

Wow... Wrong. LC whats going on?

When electric motors are subjected to voltages, below the nameplate rating, some of the characteristics will change slightly and others will change more dramatically. A basic point is, to drive a fixed mechanical load connected to the shaft, a motor must draw a fixed amount of power from the power line. The amount of power the motor draws is roughly related to the voltage times current (amps). Thus, when voltage gets low, the current must get higher to provide the same amount of power.

Of course that is assuming that the load on the compressor is fixed... I'm not a fridgie.

 

[QldKev]

Wow... Wrong. LC whats going on?

When electric motors are subjected to voltages, below the nameplate rating, some of the characteristics will change slightly and others will change more dramatically. A basic point is, to drive a fixed mechanical load connected to the shaft, a motor must draw a fixed amount of power from the power line. The amount of power the motor draws is roughly related to the voltage times current (amps). Thus, when voltage gets low, the current must get higher to provide the same amount of power.

Of course that is assuming that the load on the compressor is fixed... I'm not a fridgie.

You both are correct... but you must understand what you are saying.

If the voltage drops then yes the current flowing will also drop, basically as LC describes, it is know as Ohm's Law.
BUT... if you need to achieve the same output, in the case of driving the fixed mechanical load at the same speed, then at a lower voltage you would need to exceed the original current to achieve this. To do this a reduced resistance would need to be introduced.


Also in the how many GPO per line debate, in Australia it is illegal to use cabling that is capable of carrying a current less than that of the protection circuit (fuse/circuit breaker). So the idea of a fridge circuit being less than that of the circuit breaker is not realistic. By adding more GPO in line you can never damage the wiring as the circuit break should trip prior to the wire being overloaded. The more GPO inline the more of a load, so you may result in the breaker tripping more often. An electrician *should* determine the current load of a circuit prior to adding more load; and if necessary run a separate circuit for the new GPO.


I would consider using an electrician to install the new GPO as by doing it your self is not only illegal; but should a fire be caused by incorrect wiring your insurance will have a way out of paying.

EDIT: I am not an electrician, the above is my understanding of loads from working with many electrcians over the years.

QldKev

 

[technocat]

classic, this thread has it all :lol:
thanks for the laugh pok, start one on thermal lancing so i can get involved
cheers

Yep the laws of Gaus, Maxwell, Lenz, Kirchoff, Ohm, going down the path of no return. Going on memory I think five double GPO's max on each circuit.

<_<

 

[wakkatoo]

subscribed

Not a leccy, don't know one (wish I did), vaguely remember some electrical stuff from high school and I have a house with power points in it. Guess that makes me as qualified as many others on here :lol:

Not going to offer any opinion other than to say this thread seems to be running close to point 4 in the new guidelines that everyome is supposed to have read....

carry on....this thread will make my planning day much more enjoyable!

 

[LethalCorpse]

oops, posting before coffee, and too long since I dealt with AC motors. Yep, the current goes up if you drop the voltage,. Not true for a whole lot of other things, though, certainly not anything with a resistive load (a motor is a largely inductive load). plenty of people assume that, in all situations, if voltage goes down, current goes up, hence my reaction

 

[komodo]

Interesting thread...

IMO if you need to ask questions your not competent enough to be doing the job call in the professionals. I've done minor electrical works in my house - but mostly its just been changing over a light fitting, updating GPOs to clipsal 2000 series (every room seems to have a different brand / style of power point and light switch - and some rooms have several different styles) as I paint/renovate each room.
Also being that you are in a rental property consult the landlord / real estate agent.

As for north america I believe that some of their kitchen and laundry circuits are 220/240V? And in the UK I believe that on commercial building sites the voltage is all 115V? I know in most new houses there is dedicated circuits for fridges and freezers. and I believe down here in Vic they are supplying 3 phase to most new houses 43amps a phase. oven and light, shed and general power, ac. r w b respectively. its only starting to come in because they cant keep up with the demand and dont want to upgrade the suppy because of cost factor. so limitting customer is easy and cheap. I know my parents place has 3 phase 120amps per phase and it cost them a fortune and thats how its wired. Causes some confusion though when theres been something happen to the lines and only one phase has gone out - lights are on but no TV for example.

Newguys post has me interested as doing renos on my place I'm finding concealed junction boxes all over the place like a mad womans shit. I can tell exactly where the original wiring was done because its mickey mouse. Everything is perfect - then someone who thought they were an electrician has gone up there and installed ceiling fans and down lights and additional power points (and ran power to an out building by running the power cable about 200mm deep without even conduit!)... Lets just say that its "interesting" and I've had an electrician mate come and disconnect anything that was dangerous and he is going to come back when he gets 5 minutes to install a safety switch and tidy up all the add on wiring.

 

[pokolbinguy]

Wow this thread got damn indepth over night.

 

[Frank]

Pok
Lots of good points to take in.
But first things first, it's not your house. Call your agent and ask them to pay for it, it is a reasonable request. It is all tax deductible to the owner.

 

[pokolbinguy]

Pok
Lots of good points to take in.
But first things first, it's not your house. Call your agent and ask them to pay for it, it is a reasonable request. It is all tax deductible to the owner.

Good idea. I think in the short term I will just run an extension lead around the corner, I'll fix it to the top of the skirting board with some of those "3M" stye cable clips to keep it neat and tidy...will save me modifying anything at all. Putting the GPO in was a sort of spur of the moment idea considering that there is a hole in the wall that needs to be fixed....then again it was here when we move in so not my responsibility.

As for it not being my house....thats a damn good point guys, I had forgotten this...so used to being in my family home where I can do what ever the hell I want. Last thing I want is to piss off the landlord etc...so will stick to the ext lead...and it will be cheaper anyway!!

Cheers, Pok