# Need a Simple Solution Basic Electricity



## speedre9 (Oct 2, 2014)

I need a quick answer to this, almost ready to start her up. 
I want to add a simple on and off s.p.s.t. switch to my spindle power supply. It has the standard two wire conductors, L, N,  and a ground. I am not sure how to do it. I think I should install the switch in the line in wire, being the white wire. I am correct in thinking only one wire, the white one, must be interrupted to cut the power thereby shutting off the supply? I know it's electricity 101 but I do not use it that much to be sure of it. Have I made my question clear?. Thanks guys


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## JimDawson (Oct 2, 2014)

Normal color code for 120VAC is:

Hot = Black, or Brown
Neutral = White, or Blue
Ground  = Green, Green w/Yellow stripe, or bare.

Normally you would break the Hot to turn on and off.

On a power cord plug, or wall socket:

Hot connects to the Gold terminal
Neutral connects to the Silver terminal
Ground connects to the Green terminal


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## Terrywerm (Oct 2, 2014)

I always remember which one is the 'hot' this way:  Brown and Black both start with 'B' just like 'BZZZZZZZZZZZZZZZZap!

Green and Ground both start with G, leaving white by itself, which is a very 'neutral' color in a room.

Sounds silly, but it has worked for me ever since high school, and that was a long time ago!


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## John Hasler (Oct 2, 2014)

terrywerm said:


> I always remember which one is the 'hot' this way:  Brown and Black both start with 'B' just like 'BZZZZZZZZZZZZZZZZap!
> 
> Green and Ground both start with G, leaving white by itself, which is a very 'neutral' color in a room.
> 
> Sounds silly, but it has worked for me ever since high school, and that was a long time ago!



In the USA anything other than white, grey, green, green/yellow, or bare can be hot.  White and grey can only be used for grounded neutral.  Green, green/yellow, and bare can only be used for protective ground.  Blue is neutral in Europe.  http://www.allaboutcircuits.com/vol_5/chpt_2/2.html

In practice it's rare to see anything other than red and black used for hot in single phase circuits in the USA.


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## Al 1 (Oct 2, 2014)

Speed,   
               Make sure the housing on your motor is not hot when you do the hook up.

Al.http://www.hobby-machinist.com/images/icons/omg.gif


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## jgedde (Oct 2, 2014)

speedre9 said:


> I need a quick answer to this, almost ready to start her up.
> I want to add a simple on and off s.p.s.t. switch to my spindle power supply. It has the standard two wire conductors, L, N,  and a ground. I am not sure how to do it. I think I should install the switch in the line in wire, being the white wire. I am correct in thinking only one wire, the white one, must be interrupted to cut the power thereby shutting off the supply? I know it's electricity 101 but I do not use it that much to be sure of it. Have I made my question clear?. Thanks guys



With a 120V supply, only the hot needs to be switched.  That is the BLACK wire _not _the white one.   My understanding, though, is your motor has the white wire connected to the L terminal on the motor.  That's a conundrum you'll need to figure out because something's a bit amiss if that's the way it is.  Let us know and we can tell you how to dig deeper....

Getting back to your 101 question:  Not to confuse you further, but either the white or the black could be switched to shut off the motor.  However, switching the white (neutral) leaves the motor windings HOT even though it's off.  That's not a safe condition.

With a 220V motor, both hots are usually switched with a dual pole switch.  To confuse this further, I've seen my share of 220V motors wired using black and white wires for each hot - especially on imported machines.  If you're at all in doubt, switch both the black and white with a dual pole switch and be safe.  Make sure the GROUND wire is n_ot s_witched.  This may just be the best solution for you even at 120V since we don't know for sure what you have there.

John


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## John Hasler (Oct 2, 2014)

Don't expect the wires inside the motor to conform to the NEC color codes.  At best they will conform to the NEMA ones, which are different.


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## Hawkeye (Oct 2, 2014)

There are several signs I see on the job that a home handyman has been doing his own wiring. Tape wrapped around the wire nuts tells me he doesn't trust his own connections. He should listen to that advice. Wires barely extending out of the box are another giveaway. Here at least, code calls for 6" of wire out of the box. A definite sign that someone is in over his head is a switched neutral (white) wire, followed closely by two whites connected to a light fixture.


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## Wheresmywrench? (Oct 3, 2014)

Hawkeye said:


> There are several signs I see on the job that a home handyman has been doing his own wiring. Tape wrapped around the wire nuts tells me he doesn't trust his own connections. He should listen to that advice. Wires barely extending out of the box are another giveaway. Here at least, code calls for 6" of wire out of the box. A definite sign that someone is in over his head is a switched neutral (white) wire, followed closely by two whites connected to a light fixture.



_*I installed and wired lot of machines when I worked as my companies Idustrial Electician and ALL connectors HAD to be taped. Why, machnine vibrations will cause the twist on Marr conectors to vibrate off. We had so much work to do when we moved into a new plant the company hired an outside contractor to help with the wiring. Well they did not tape there connectors. And after the machines where running a few weeks the connectors stated falling off and the sparks started to fly. Had to find all the contractors connections and redo them. I tape ALL trwist on connectors even at home. It's a matter of safety.*_


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## John Hasler (Oct 3, 2014)

Wheresmywrench? said:


> _*I installed and wired lot of machines when I worked as my companies Idustrial Electician and ALL connectors HAD to be taped. Why, machnine vibrations will cause the twist on Marr conectors to vibrate off. We had so much work to do when we moved into a new plant the company hired an outside contractor to help with the wiring. Well they did not tape there connectors. And after the machines where running a few weeks the connectors stated falling off and the sparks started to fly. Had to find all the contractors connections and redo them. I tape ALL trwist on connectors even at home. It's a matter of safety.*_



I assume that you tape with self-vulcanizing rubber tape?  Vinyl electrical tape always eventually dries up and falls off.

Of course the Cadillac way to go is compression connectors and heat-shrink boots, though I've never had problems with properly installed wire nuts.


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## speedre9 (Oct 3, 2014)

My eyes have been opened, I got all wrong ! First I must add my connections are all new ones, no tape yet. My spindle has one black and one red wire, so the black is hot. That should be the same throughout my circuit, correct?. Red should transform to white, neutral, also throughout the circuit. So to add a switch I should add it to the black wire, correct?. I have saved all your responces and will add the information to my list of tips I keep handy in the shop. Thank you all so much. I really do like it here.


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## mzayd3 (Oct 3, 2014)

Always break the ungrounded conductors, otherwise you will have voltage on equipment that is turned off.  This is the reason for polarized plugs and multi-pole switches.  A three phase motor will not turn with one phase missing.  A single phase high voltage motor will not turn with only one phase.  With that said, with one phase being interrupted, the equipment will not work as intended, but will still have voltage on them- a real safety concern.


Sent from my iPhone using Tapatalk


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## jgedde (Oct 3, 2014)

speedre9 said:


> My eyes have been opened, I got all wrong ! First I must add my connections are all new ones, no tape yet. My spindle has one black and one red wire, so the black is hot. That should be the same throughout my circuit, correct?. Red should transform to white, neutral, also throughout the circuit. So to add a switch I should add it to the black wire, correct?. I have saved all your responces and will add the information to my list of tips I keep handy in the shop. Thank you all so much. I really do like it here.



Speedre, Is this thing wired for 220V or 120V?  It matters...

John


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## Wheresmywrench? (Oct 4, 2014)

_*I also say go with a double pole switch just to be safe.*_


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## speedre9 (Oct 4, 2014)

Actually I have this kind of stuff, a power supply to provide 12 VDC to the spindle motor. It is wired for 120 AC, to a grounded socket at the rear panel by three wires, L, N, and G. I want to install a sitch to it on the front panel so I can turn the power on at every operating session. So to do this I will add, that switch to the Black wire to interrupt the Hot line current to turn it on and off. So, it is wired for 120 AC, to provide 12VDC for my spindle.


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## stevemetsch (Oct 4, 2014)

First thing to do is verify what you have. Use a multimeter or test light.
Start with the 120 v side.
Check the "hot" leg to the machine. You should get 120v. Now check it to the "ground"; terminal. Should get 120v. Now check it to the" neutral". Should get 120v.
Now connect "neutral" to  "ground". Should get nothing.
Now you know what's what.
 ALWAYS switch the Hot leg or legs if 220.
Stevemetsch


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## stevemetsch (Oct 4, 2014)

Safety first. Make sure you are not grounded while fiddling with live wires.
 Also, interrupt the hot wire before it gets to the machine if you want to kill power to it.
Get fancy and use a switch with a pilot light so you know when the machine is "Hot".
Stevemetsch


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## speedre9 (Oct 9, 2014)

Thank you issues resolved.


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