Installing a new Circuit BreaKer


  #1  
Old 11-19-06, 08:31 PM
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Installing a new Circuit BreaKer

I have done some electrical work around my house, wired up Lights , switches, shed wiring etc. The only thing that conserns me is adding a 20A circuit breaker in the main box for my new split system air conditioner which requires a separate circuit.

If I switch off the main breaker and unscrew the panel will there still be any live wires behind there? also do I run the wires for the new circuit breaker directly from the main or from the closest circuit etc?

I have plenty more slots to add more breakers, can one just be added with out modifying anything?

SuperH
 
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Old 11-19-06, 09:05 PM
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run the wire from where you want to put in your outlet directly to your panel (only this way can you get a dedicated circuit, otherwise you are just tapping off another circuit). The only "modifiction" you will have to do is to break out one of the spaces for the new breaker. If you turn the main breaker off, YES, there will still be hot wires in there, these will be the two very large hots that come in from the meter. The rest of the panel SHOULD be dead. Just do it carefully and don't touch any of the copper bussing (even though it technically should not be hot after you've kicked the main). Remember, for a 20 amp circuit, you need #12 wire. If you install a single recepticle, it MUST be a 20 A recepticle. If you install a duplex recepticle, it can be either 15A or 20A. Make sure to put a grommet in the panel where you run the wire into it, this way you won't risk damaging the insulation on the wire, plus, it's code.
Hope this is clear, if not, ask again.
jeff
 
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Old 11-19-06, 09:59 PM
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Thanks for your reply,
Im not sure about duplex etc which you mentioned.

I have run a direct cable from the A/C to the fuse box,
I can only say thats its a 4mm, not sure about #12 etc

I will take a look inside/behind the main box to see how it is all connected and I will just try to copy that,

Thanks for your help

SuperH
 
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Old 11-19-06, 10:38 PM
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a duplex recepticle is probably the one you are used to seeing, it has two places to plug something into on it. Your wire should be marked, are you using nonmetallic sheathed cable? It should say AWG followed by a number on it. If it's less than 12, don't hook it up to a 20 amp breaker.
 
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Old 11-19-06, 11:37 PM
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Here is a picture of my main box, my wire is the one on the bottom waiting to be connected.

http://itfocus.dyndns.biz:8880/mainbox.jpg

The earth wire looks easy, first copper plate, the black neutral I would guess the third copper plate in the number 9 screw spot and the red live wire would connect to the top of the new circuit breaker. How do I connect the new circuit breaker at the bottom? Would I go back to the Safety switch ? or Main switch?

SuperH
 
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Old 11-20-06, 10:56 AM
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I've never seen a panel like this before, but I'd say you're right about the ground and neutral connections. Very strange wire colors too. What country are you in? It might be a good idea to wait for someone else to respond, possibly someone who is familiar with a panel like this. In the meantime, I'll try and do some research.
 
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Old 11-20-06, 11:04 AM
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I'm sitting here just looking at the picture. There doesn't appear to be a neutral. I'm guessing you are in Australia...is everything 240 volt over there?
 
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Old 11-20-06, 11:24 AM
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alright, I understand a little better now, I think. Those safety switches must be GFCI breakers. So the black wires should be neutrals. I'd say you were right about where to connect the black and green wires, for the hot wire, I'd think you would come off the bottom of the second safety switch (gfci breaker), as the first one already has three wires coming out of it. It might be wise to wait for some aussie advice, as, like I said, this is pretty unfamiliar to me. All I know is what I've obtained by looking at those pictures.
 
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Old 11-20-06, 11:30 AM
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Furthermore, the neutral needs to be connected to the same bar as the neutral is on for the GFCI breaker, so if you connected your red wire to the GFCI breaker that has only one red on the bottom of it, you'd need to connect your black wire to terminal #14 up at the top. Does this make sense?
 
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Old 11-20-06, 01:39 PM
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Originally Posted by jmchargue
I'm sitting here just looking at the picture. There doesn't appear to be a neutral. I'm guessing you are in Australia...is everything 240 volt over there?

Yes I am from Australia, everything is 240v
Thanks for your explanation,

The 2nd Circuit Breaker (next to the main) is wired for my electric wall oven and it doesnt go via the safety switches? Would there be a reason for this?

Could I come of the bottom of the main like my wall oven switch for my A/C,
Would this be better ?

The 3 after the first saftey switch is for my power points
The single switch after the 2nd safety switch is for my lights?


SuperH
 

Last edited by SuperHornet; 11-20-06 at 01:52 PM.
  #11  
Old 11-20-06, 11:27 PM
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Unfortunately, I'm not really familiar with electrical codes in Australia. All I can do is look at the picture and say what I think about it. I'd love for some others from the forum to chime in, because I know there are people on here who have more experience than me, maybe even some Aussies. I think you should probably wire your new circuit through the safety switch. Did you understand what I was saying about the black wire being connected to the same bus as the safety switch you wire your circuit through?
 
  #12  
Old 11-21-06, 08:11 AM
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Hello

I've found this thread very interesting and frankly had to spend awhile looking around to get a better understanding of what that panel is doing.

I understand this as follows..... Red is hot, black is neutral and green/yellow is earth. The power cable from the meter is entering from the bottom knockout below the main breaker The far left breaker is your main switch (breaker) the power cable red hot wire (240 volts) line side (from meter) is feeding in at the top of that main breaker, the power source neutral then connects to the neutral buss at the top of the panel. Earth and power source neutral are bonded in this panel...but only the ground bar and the next neutral bar to it are so bonded. Notice the green/yellow jumper between these two bars. The grounding electrode conductor is connected to terminal 11 of the ground bus at top left. At the bottom terminal (load) of the main switch 3 (red) hot wires feed the two safety switches (gfci here in the US) and the non-safety breaker immediately to its right...so there are three load wires coming off the bottom terminal of the main breaker. There isn't a hot bus like here in the US electrical panels...just a mounting rail. The three center breakers with black toggles are all safety protected by the most left saftey switch. Notice there are three wires from the load terminal of that safety switch going to the three circuit breakers in the center. So this tells me these are branch circuits that require ground fault safety circuits according to Aussie electrical code. The other thing I notice is that it would appear it doesnt matter what terminal you feed the non safety switches line/load would appear to not matter. I'm not sure on the saftey switches themselves.

The farthest right 40 Amp saftety switch protects the 10 amp switches branch circuit at the far right so it is also a required safety protected branch circuit.

So as far as I can tell the safety switches are not both overcurrent and ground fault capable. You need both a safety switch for ground fault and a non-safety switch for overcurrent protection for those required circuits.

So as I see this to add your air conditioning breaker you need to connect a red wire of the right gauge to one of the red LINE side connections of a saftey breaker or the LINE side of the non saftey breaker next to the main. Or the LOAD side of the main switch if that terminal will accept more than three wires. Then connect to either of the terminals of your new switch/breaker. Then from the other terminal connect the red of your cable going to your a/c, then black to to the neutral bar that the power source neutral is connected to...not to the two farthest right neutral bus bars. It appears that the two safety switches and their protected branch circuits have their specific neutral bars so that return neutral current from all the branch circuits protected by safety switches will return thru the correct safety switch for that branch circuit.
If the a/c is required to be safety protected then you will have to run a red wire probably from the far right safety switches LOAD terminal to your new switch for the a/c. Then connect the black of the cable to the a/c to the far right neutral bar because that neutral bar serves the farthest right safety switch. Notice the large black wire from the load side of the safety switch connects to that specific neutral bar. So these two farthest right neutral bars are specific to the safety switch connected to them. The neutral bar that is next to the ground bar is the only earth bonded neutral bar because all return current flows to it from all the branch circuits. Evidenced by all line side safety switches neutral wires are connected to this one neutral bar as is the neutral coming from the load of the non-safety switch branch circuit.

Of course I am not a electrician in australia so best be sure that is a correct analysis of what you have there.

Some helpful links ........

http://www.accesscomms.com.au/reference/powerplug.htm

http://www.clipsal.com.au/consumer/products/DandC_Elec/power/miniature_circuit_breakers

Roger
 

Last edited by Roger; 11-21-06 at 10:44 AM.
  #13  
Old 11-23-06, 05:24 PM
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Thanks Roger,

I ended up installing the cirucuit breaker to the far Right Saftey Switch and my Dakin Airconditoner is working very well,

SuperH
 
 

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