What did I do wrong? Electrical help please!

[Anonymous No.805496]

/diy/ I need your help.

I decided to change type B electrical outlet because the old one started to burn. It was 30 years old and corroding so it was arcing and it needed to go.

I bought a new one and decided to remove old one and connect wires just like they had been connected before. But when I did that and when I put my apartment's circuit breaker into ON position, it blew the mains fuse on the building and I had to ask superintendent to flip it back.

What I noticed is that I had 4 wires in this old outlet: bare (ground), white (neutral) and also a red & black wires. Old outlet had red & black wire connected next to each other but I don't think they're connected to each other. I think upper and lower receptacles have different hot wires (one gets red, other black). The new outlet has these two connected by a piece of metal.

1) To fix this, I just used one hot wire and insulated the other one and left it in the box. Is that the right thing to do? Or are there outlets that work with two hot wires?

2) When you connect two hot wires, why does it blow the fuse?

tl;dr: I managed to trip a mains fuse on the apartment building when changing the outlet.

[Anonymous No.805501]

break off the tab between the two brass screws so you can hook both circuits to the outlet.

[Anonymous No.805502]

>>805501
ah... had no idea that could be broken. looked thick though... I think I need a hacksaw to make enough gap between the two.

[Anonymous No.805503]

>>805502
No. A pair of needle nose pliers will do it.
Also, a screwdriver in the slot in the tab will work.

[Anonymous No.805504]

>>805503
OK! thanks. is there any harm in just using the setup like I have now? Only use one spot on the outlet for the microwave anyway.

[Anonymous No.805509]

>>805504
Not really but you have a loose wire in the box and everything plugged in to that outlet goes through one breaker instead of two.

[Anonymous No.805512]

>>805509
OK! Thanks. I'll remedy this then.

[Anonymous No.805513]

>>805504
Also, you mentioned a super and apartment. It was wired the original way for a reason and anyone who works on it after you will expect it to be wired like it was.

[Anonymous No.805516]

>>805512
Me again. It's possible that one side is hot all the time and the other is connected to a switch (probably the red).
If this is the case it was too bad the switch was ON when you wired it up.

[Anonymous No.805518]

>>805516
both red & black were not hot when I disconnected them. I have a tester. but when they connected... the crap hit the fan.

[Anonymous No.805542]

>>805513

I'm wondering why the landlord isn't handling this in the first place.

OP: Did you ask your landlord to fix it? My experience is that landlords don't want you to fix things because they'd rather have their own people do it anyway.

>Be me in apartment
>Want to hang a flat panel TV on the wall. Have to drill 1/4" holes through the wall for lag bolts.
>Get landlord's permission contingent on me filling the holes when I move out.
>Put TV up
>a year passes...
>Time to move out.
>Landlord tells me not to fill in holes.
>He doesn't have anything against me, but he knows for sure that he won't screw it up.
>He just wanted to make sure I really wanted to hang the TV before I started putting holes in the walls.

Fixing up apartments is a cost of renting property. You're already paying for that shit with your rent, there's no reason OP should be doing something like this.

[Anonymous No.805548]

>>805542
landlord said that if I can replace it he'd cover the costs and kick in some cash. So I took his offer.

[Anonymous No.805568]

>>805496
The extra wire most likely ran somewhere else in the wall, daisy-chaining or something to another outlet. Or it was linked to a switch. It's 'safe' to cap it with a wire nut and leave it there, but it won't be doing whatever it was before. Make sure all the stuff in your apartment still works right.

TBH, I suddenly realized why so many apartments have wall switches that don't seem to do anything....

[Anonymous No.805571]

>>805568
I don't understand how it can connect to anything else. Where exactly would it complete a circuit? You have this all wrong.

Think about it... if it went anywhere, that other place would have power if you plugged and appliance into the other receptacle.

[Anonymous No.805577]

>>805571
Not every socket has the same connections in the same place.

Literally yesterday I replaced a twin socket with another that had the live and the neutral on opposite sides to the one that came out.

If you tie the live to a neutral, bang.

If you tie a switched live to a neutral, nothing, switch, bang.

If you tie a switched neutral (which shouldn't exist, but sometimes does) to a live, bang.

If you swap live and neutral, and some appliance ties neutral to ground, bang.

There's a lot of ways that you can wire a socket that differ from the correct way and result in bang.

[Anonymous No.805580]

>>805571
>I don't understand how it can connect to anything else.
Outlets comes with a little tab you can cut or remove that electrically isolates the two receptacles from each other. That way you can hook only one plug up to an electrical switch to control a lamp, without the switch turning the other receptacle on or off.

[Anonymous No.805609]

>>805496
It's 14/3 wire instead of 14/2.

It can be for a switch somewhere to turn on one of the outlets (floor lamp)...

[Anonymous No.805681]

>>805496
>2) When you connect two hot wires, why does it blow the fuse?

Short circuit.

[Anonymous No.805682]

>>805681
>Short circuit.
Explain. How can it be short circuit?

[Anonymous No.805686]

>>805682
Red and black are always in opposite polarities.

[Anonymous No.805688]

A typical group of wires for an outlet is ground (exposed wire), hot (black wire) and neutral (white wire)

Red and black wires are typically found in setup for three or four way light switches. Why are black and red wires going to your outlet?

[Anonymous No.805693]

I just changed a bunch of these outlets in my kitchen.
Bare copper = ground
White = neutral
Black = HOT1 +120 VAC
Red = HOT2 -120 VAC

As previous poster mentioned, break off tab on short side of plug. Black goes to top one, red to the bottom one. If you measure the AC voltage between black and red, you should measure 240VAC. If you connect black and red together, big poof.
Reason is voltage between neutral and HIT1 is +120V and

[Anonymous No.805694]

premature post. Anyways, the reason for this is if you look in the panel, there should be 2 breakers for this circuit. If you have a toaster plugged into the top plug and a microwave in the bottom, you can have both going at the same time without blowing a fuse.

[Anonymous No.805695]

>>805688
>Red and black wires are typically found in setup for three or four way light switches. Why are black and red wires going to your outlet?
It could have originally wired as a 240v single outlet for some appliance. (medium sized window air conditioner, etc.)

When it was no longer needed as a single 240v outlet, it was replaced as a dual 120v using both phases.

I've done this many times.

[Anonymous No.805787]

>>805693

> Black = HOT1 +120 VAC
Red = HOT2 -120 VAC

There's no such thing as a + or -120 volts alternating current. Any AC signal varies from + to - throughout its cycle.

What you're probably talking about is, in the US, you have 2 120VAC lines coming into your house from the transformer in the street, these are 180 degrees out of phase. If you connect these lines together you get 240 V.

OP said something about a microwave, so there probably used to be a powerful 240 V microwave there. Then someone replaced it with a regular 120V microwave, and attached 1 phase to 1 screw of a split receptacle and the other phase to the other screw. This way you get 120 at each outlet on the duplex, but if you connect black and red you get 240.

A problem with this setup, besides blowing up if you handle it wrong, is that now you have what's called a multiwire branch circuit, with two hots sharing a neutral. If the load on each phase aren't balanced, you can get more current on the neutral than the insulation is rated for and it might start to turn brown over time.

Tl;dr for your own sake just call an electrician if you don't know what you're doing

[Anonymous No.805864]

>>805787
>There's no such thing as a + or -120 volts alternating current. Any AC signal varies from + to - throughout its cycle.
Not that anon but I use that analogy myself.
No point in confusing someone wanting just to wire an outlet properly with info about phase differences. At a given point in time this is correct and enough info to understand the difference and how it can give you 240V with both only 120 from ground.

[Anonymous No.805879]

did it really take 20 replies to get to phase difference?
i'm disappointed in you /diy/

be careful op, depending on what you flipped at the breaker panel one of the outlets could have still been live even if the other was dead. bear this in mind if you plan on replacing any more sockets.
sometimes its a pain flipping your main breaker if you need light to work.

[Anonymous No.805914]

>>805695
ok mr. smarty pants that makes sense I guess

[Anonymous No.805921]

>>805682
>>805686
bullshit, not opposite.

you have 3 hot wires with 120 degree phase shift
while 1 phase has 0 degress the voltage is 0V (a*sin(0)) the other ones have a voltage of a*sin(120) or a*sin(240)

i=u/r

[Anonymous No.805922]

>>805921

You wouldn't have a three phase supply in the house though, unless someone seriously fucked up.

[Anonymous No.805935]

>>805921
>you have 3 hot wires with 120 degree phase shift
OP posted a pic of a USA type socket.
In USA three phase is almost never used in a home.
Farms and business owners are willing to pay the extra service fees associated with providing three phase service (which uses four wires)
Homes and apartments use two 180° phases supplied on three wires.

[Anonymous No.805949]

Do you have a metal box or pic? If metal did you wrap the outlet with tape? If not then is the hot coming into contact with the metal box?

[Anonymous No.805978]

>>805496
>What I noticed is that I had 4 wires in this old outlet: bare (ground), white (neutral) and also a red & black wires. Old outlet had red & black wire connected next to each other but I don't think they're connected to each other. I think upper and lower receptacles have different hot wires (one gets red, other black). The new outlet has these two connected by a piece of metal.
Check the old outlet: Is the tab on the hot side broken, and the tab on the neutral side was in tact? Just do the same OR cap off either the red or black wire with a wire nut so it's unused (be sure no metal is exposed to touch anything in the box.).

[Anonymous No.805988]

>>805879
180 degree, two phases is only a thing in merkia.

[Anonymous No.806012]

>>805978
>Recommending wirenuts

The only country in the world that still uses these is america, they are banned for residential use everywhere else in the world on account of being staggeringly dangerous, but hey, knock yourself out!

[Anonymous No.806015]

>>806012
>they are banned for residential use everywhere else in the world on account of being staggeringly dangerous
They're only dangerous if:
1. Your country proceeds to make millions of shitty ceramic ones that fall apart.
2. Your tradesmen are dumb enough to use them to splice aluminum and copper wires together. Something you can also do safely with the side-by-side connectors or solder.

[Anonymous No.806031]

>>806012
Curious Murrikan here, what's so dangerous about them? Seems a better solution than electrical tape. Surround conductive, potentially hazardous live wire end with non conductive plastic.

[Anonymous No.806033]

>>806031
They're also a better solution than blutack.

[Anonymous No.806039]

>>806012
>Although very much the connector of choice in North America, the twist-on wire connector remains a largely untapped resource in the UK electrical market. Unfortunately many electricians still associate them with the poor-quality ‘screw-it’ wire nuts from the 1970s; manufactured from ceramic, these had a tendency to crack very easily and expose the wires, leading to safety hazards

yuropoors :)

[Anonymous No.806040]

>>805787
For any given peak in the cycle, one will be +120V and one will be -120V with respect to neutral/ground. It's not entirely accurate, but it's simple to understand.

As for overloading the neutral, I don't see how that could happen. If anything, the neutral is taken LESS current (assuming that you have something plugged into and using power on both legs of the phase). Neutral would only handle the imbalance of those two loads. Using a normal circuit with a single hot and neutral, the neutral has to handle all of the current all of the time.

[Anonymous No.806082]

>>805787
>A problem with this setup, besides blowing up if you handle it wrong, is that now you have what's called a multiwire branch circuit, with two hots sharing a neutral. If the load on each phase aren't balanced, you can get more current on the neutral than the insulation is rated for and it might start to turn brown over time.

Circuit breakers prevent that from ever happening.

[anus presley No.806085]

>>806082
>Circuit breakers prevent that from ever happening.

except there are no circuit breakers on the neutrals. see pic.

what actually happens, as mentioned in >>806040, is that the two loads are effectively put in series across the 240V lines, and if they're of diff wattages, the neutral takes away any excess current so that they each have exactly 120V each.

e.g. two loads of 10A and 8A wont put 18A on the neutral, only 2A. coz math.

[Anonymous No.806088]

>>806031
Foreigners are too stupid to use them.
/discussion.

[Anonymous No.806093]

>>806085
You are an idiot, and I invite you, and your fully insured company to come wire my new home.

[Anonymous No.806103]

>>805571
do you have a light on the ceiling cuz it kinda sounds like that outlet is where you attach your light

[Anonymous No.806106]

>>805787
>A problem with this setup, besides blowing up if you handle it wrong, is that now you have what's called a multiwire branch circuit, with two hots sharing a neutral. If the load on each phase aren't balanced, you can get more current on the neutral than the insulation is rated for and it might start to turn brown over time.

This is incorrect, the neutral conductor cannot EVER carry more current in a split phase or 3 phase system than any single largest current flowing in any active conductor.
For example you have 8 amps on "red" line and 8 amps on "black" line your neutral current, in ideal conditions, is 0 amps.
Some would think that it'd be 16 amps but its not because instead of thinking we have two parallel 120v loads @ 8 amps each we have two 120v 8 amp loads in series to form one 240v load @8 amps because they are 180 degrees out.
If the load is unbalanced say 12 amps on "red" line and 6 amps on "black" line only the excess current flows through the neutral conductor not the whole current, in this case due to being 180 degrees out of phase the neutral current is 6 amps.

[anus presley No.806116]

>>806093
> You are an idiot

Circuit simulator says I'm right.

[Anonymous No.806117]

>>806116
>e.g. two loads of 10A and 8A wont put 18A on the neutral, only 2A. coz math.
Yes you're right. Had to draw up a simple battery and resistor circuit to see it myself.

> You are an idiot
This just means "I have no counter argument", Ignore those posters along with namefags... err, shit.

[Anonymous No.806209]

>>805864
ok, if everyone wants to use + or - to talk about AC like its DC, be my guess. But at least know that if you were to look at these signals on an oscilloscope, the phases are relative to each other horizontally, not vertically as +/- suggests. Also fun fact each phase is technically 120 VAC RMS.

>>806040
Sorry i botched that somewhat. The neutral can only carry excessive current if the red and black are attached to the same leg in the breaker panel. Then you don't get 240 V, but the current from each line now adds together on the neutral, instead of cancelling like when the phases are separate. As mentioned elsewhere the neutral has no current limiting device. So if you have 14-3 rated for 15 A, and one leg on phase A is carrying 12A, and the other leg is also on phase A and is carrying 10A, the neutral will carry 22A with insulation intended for 15A. The insulation will brown at the panel.

This is why multiwire branch circuits, sometimes called edison circuits, aren't as common as they used to be. If legs are phased together, you can overload the neutral. If legs are phased separate, you risk getting 240 and blowing your tv up if the neutral wire is disconnected.

[Anonymous No.806230]

>>806033
now this is podracing