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Author Topic: new 220vac line for final  (Read 6331 times)
W1QJ
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« Reply #15 on: February 13, 2013, 11:43:25 AM »

Your hot water tank had a 3 wire feed to it?
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AA4PB
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« Reply #16 on: February 13, 2013, 11:54:41 AM »

If you are wiring a sub-panel you need 10-3 with ground (total of 4 conductors) because the sub-panel needs to have an isolated neutral.
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N4CR
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« Reply #17 on: February 13, 2013, 02:52:28 PM »

Your hot water tank had a 3 wire feed to it?

It did. 30 amp at 240 volts. Fairly typical from what I've seen.

I added a ground wire. The old wiring was white/red/black. New wire is white/red/black gnd.
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73 de N4CR, Phil

Never believe an atom. They make up everything.
N6AJR
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« Reply #18 on: February 19, 2013, 09:17:08 AM »

I too had an electrician run a couple of lines for me.  I have 120 v plugs from 2 existing circuits in the shack plus a new 240 line (20 amps) and a new 110 line ( 20 amps), and the 240 goes to 3 boxes in the shack, and the new 110 v goes to 4 new boxes in the shack. At one time I had 8 hf rigs and 6 or 8 mobiles running at the same time. the only thing is that I have to ttransmit on only one amp at any time. I used the multiple boxes so I did not have to plug and unplug the amps all the time.  it works for me.
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W1QJ
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« Reply #19 on: February 19, 2013, 03:50:47 PM »

Your hot water tank had a 3 wire feed to it?

It did. 30 amp at 240 volts. Fairly typical from what I've seen.

I added a ground wire. The old wiring was white/red/black. New wire is white/red/black gnd.


When we talk about "building wire" like Romex a "3 wire" cable is (black, red, white, and ground)  the ground is taken for granted.  A 2 wire cable like 12-2 Romex is (black, whitle, ground).  Now, a hot water heater ONLY needs a 2 wire feed. (black, white, ground).  If your hot water heater had a 3 wire feed (black, red, white, ground) Where was the extra wire connected?  The hot water heater only requires 2 wires (2 hots, black, white and of course ground)  So where did the extra wire connect to since there is nothing to connect the extra wire to?
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N4CR
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« Reply #20 on: February 19, 2013, 10:20:04 PM »

3 wires Red, Black, White. White is common, no safety ground.

New wire is 4 wires. Red, Black, White is common, with safety ground.

Red to Black is 240 volts. White is the center tap.

10-2 has 3 wires. (my old hot water tank)
10-3 has 4 wires. (my new 30 amp feed)

Thinking that the third wire in 10-2 is ground is wrong. It's common. It goes to the center tap on the line transformer. If it was installed to code, it's also earthed at the pole and earthed at the entrance panel, but 240 volts with a common (classic old school 240 wiring) will work just fine and deliver full power (and 2 legs of 120) without any relationship with earth ground.
« Last Edit: February 19, 2013, 10:32:45 PM by N4CR » Logged

73 de N4CR, Phil

Never believe an atom. They make up everything.
W1QJ
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« Reply #21 on: February 20, 2013, 03:29:53 AM »

3 wires Red, Black, White. White is common, no safety ground.

New wire is 4 wires. Red, Black, White is common, with safety ground.

Red to Black is 240 volts. White is the center tap.

10-2 has 3 wires. (my old hot water tank)
10-3 has 4 wires. (my new 30 amp feed)
Thinking that the third wire in 10-2 is ground is wrong. It's common. It goes to the center tap on the line transformer. If it was installed to code, it's also earthed at the pole and earthed at the entrance panel, but 240 volts with a common (classic old school 240 wiring) will work just fine and deliver full power (and 2 legs of 120) without any relationship with earth ground.




 This is not entirely correct!.  When speaking of Romex wire for example.  A Romex wire which is termed 14-2 or 12-2 or 10-2 has 2 insulated wires.  Black and white.  There is a bare ground wire included but it is NOT called a 3 wire.  It is a 2 wire with ground.  A Romex wire that is termed 14-3 or 12-3 or 10-3  has 3 insulated wires, black, red and white  and a bare ground. It also is called 3 wire with a ground. They are not called 3 or 4 wires.  Dedicated 240v loads like a ham amplifier or a hot water heater only require a 2 wire circuit and of course a ground, commonly called a bond.  A dedicated 240v load does not require a neutral. Now, unless you have some sort of electronic high tech water heater, you only need 2 hot wires and a ground. ANY load that uses 240v and requires a neutral is NOT a dedicated 240v load.  A load that uses 240v and a neutral is called a 240/120v feed, not a dedicated 240v load.  This is how an electrician knows what type of wire to run to a location for a load when they rough a house.  So I would like to know how you wired your hot water heater with 3 wires and a ground if it only requires 2 wires and a ground. Of course if you have some sort of fancy unit that requires a neutral then I can see, but most HW heaters are dedicated 240v loads. You said "thinking that the third wire in 10-2 is a ground is wrong"  That is not true al all.  ANY cable that has 2 insulated wires and a bare or green wire is most definetly a ground.




T
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N4CR
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« Reply #22 on: February 20, 2013, 06:48:27 AM »

Quote from: WiQJ
The hot water heater only requires 2 wires (2 hots, black, white and of course ground)

That is called DEAD MAN wiring. White is NEVER hot and if you choose to abuse wiring colors that way, the next guy can make a terrible assumption that white is neutral. And end up a DEAD MAN. Please tell us you NEVER will do such a stupid thing!

ANY cable that has 2 insulated wires and a bare or green wire is most definetly a ground.

Well, you can call that bare wire not a wire if you want to, but in my book, a long thin copper conductor is a wire even if it doesn't have any insulation. (not to mention you just called it a wire)

And any cable that has 2 insulated wires and a bare or green wire is either a dedicated 240 only circuit or 120 v with common. Which is not what I had connected to my hot water tank.

If you read carefully, I stated that my hot water tank (wired by an electrician long before I bought this house) had 3 wires. All three are insulated and none of them were safety ground. The white wire, like all white wires in every panel I've seen, is neutral. It is not a safety ground and should not be referred to as ground.
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73 de N4CR, Phil

Never believe an atom. They make up everything.
AA4PB
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« Reply #23 on: February 20, 2013, 07:06:45 AM »

Hot = black or red
Neutral = white
Safety Ground = bare copper or green

The white wire in romex cable can be used for a secondary hot conductor if both ends are marked with a piece of black electrical tape or colored black or red with a marker pen. That lets some future electrician know that the wire is being used as a hot rather than a neutral.

The safety ground and neutral wires connect to two separate wiring busses in the panel box. If the panel box is the primary box then a grounding screw on the neutral buss connects the neutral and grounding buss bars together. THIS IS THE ONLY POINT WHERE THE NEUTRAL AND GROUND GET CONNECTED TOGETHER. If the panel box is a piggy-back box then the screw is removed during installation so that the neutral and ground buss are insulated from one another. In that case the neutral buss should have a wire connecting it the the neutral buss in the primary panel. Again, the only place in the system where the ground and neutral get connected together is in the primary panel box.

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N3QE
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« Reply #24 on: February 20, 2013, 07:17:39 AM »

I think some localities/inspectors will insist on 3-wire Romex for 240VAC hot water heaters. They will not let "red tape" on the white wire of 2-wire "black and white" Romex pass their inspection (despite the allowance for remarked wires in NEC) and I kinda see their point.

I thought that two-wire 12-gauge or 14-gauge Romex with red and black existed but the local electrical supply places tell me they never heard of it, that red-black 2-wire Romex is only much thicker gauge and only for HVAC usage. I was surprised. I swear I've seen it in old work for water heaters. I don't know if it was abolished at the same time as the old "ground is neutral" dryer plugs (90's?) or what.
« Last Edit: February 20, 2013, 07:20:18 AM by N3QE » Logged
AA4PB
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« Reply #25 on: February 20, 2013, 08:07:27 AM »

I guess if your inspector won't permit remarked wires then you'd have to install 12-3/w gnd (black, red, white and gnd) and just leave the white unconnected if you don't need it. Around here remarking is common practice although sometimes rules are different for different inspectors, even in the same jurisdiction - and each one seems to have their own "pet peeves". Cheesy


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N4CR
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« Reply #26 on: February 20, 2013, 08:25:26 AM »

Many people have been killed or put in the hospital by dead man wiring. All of them should have checked voltage for safety first.

I'm not an electrical inspector but it would certainly be my pet peeve if I saw a hot white wire being installed in new wiring, marked by tape or not. Tape falls off. Wires get shortened. It's easy to understand how it might cease to be marked.
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73 de N4CR, Phil

Never believe an atom. They make up everything.
AA4PB
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« Reply #27 on: February 20, 2013, 08:40:55 AM »

You might have a clue if you saw the white wire connected to a breaker in the panel, even if the tape fell off  Grin

You see it most often in switch legs for lights. You need two hots and a ground but you can't buy 14-2 or 12-2 with black and red wires. Any electrician worth his salt would recognize what is going on if he removes the light switch and sees only a black and white wire connected to the switch terminals, even if the tape fell off. It really isn't that big of a deal. Your only other option is to spend more money and get 14-3 or 12-3 and just don't connect the white wire.


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N4CR
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« Reply #28 on: February 20, 2013, 09:08:50 AM »

You might have a clue if you saw the white wire connected to a breaker in the panel, even if the tape fell off  Grin

You might, assuming it wasn't spliced in somewhere.
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73 de N4CR, Phil

Never believe an atom. They make up everything.
W1QJ
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« Reply #29 on: February 20, 2013, 10:36:22 AM »

There is no rule in the NEC book that has anything to do with what color wires can be used for.  The only rule is that a green or a green gray striped or bare wire can not be used for current carrying purposes except for fault current.  When using THHN in conduit most electricians will only stock black wire.  When running any circuits, even 3 phase, they will mark the wire on both ends with colored tape appropriately.  Even black wire can be used as a ground.  It will get a green piece of tape on both sides.  If for some reason the wires go through a pull box or pass through a JB, they must be marked there as well.  Usually when this happens often, an elcetrician will surely use the different color wires.  But many electricians that only do smaller residential work and mostly use Romex will use all black THHN when using condiut so they only stock one color wire on their van.  If a feed begins at a panel and ends at a disconnect most will use all black wire and just mark them on both ends with colored tape. As long as a green wire or bare wire is not used as a current carrying conductor  any color can be used as long as it is marked.  ALL electricians I know of including myself, yes that's right, I do electrical work,  use 12-2 Romex for example to feed all sorts of 240v loads like pumps, air conditioners, ham amplfiers, and the list goes on.  it is perfectly legal to mark the white wire with tape red or black.  I know of no inspector who will challenge this.  if he does he will be called up by the state electrical inspector who is a friend of mine.  He was one of my teachers when I went to electrician school.  He likes his students very much.  Although some inspectors insist on certain things they should make it known at the time you take out a permit.  As I do work in different areas I may on occassion ask an inspector just what he likes to see.  If he does not specify something up front, one would assume he goes by the prevailing NEC code book for the year that has been adopted.  Some inspectors if you are new to the locale will hand you a sheet of what he likes to see if it is over and above the code.  I know of what I say.
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