220V Light off of compessor

[ehauptma]

Hi,

I saw someone else on the forum run a light directly off the compressor, so when the compressor was powered (not necessarily running) the light would be on. Purpose of light was just to remember to turn the compressor power breaker off for the night, week, etc.

Here are a couple of pictures that were posted. I would like this same setup, but my electrician says I need to have the light run at 220Volts, just like the compressor, as the wiring will come off of it. I think the pics are pretty self explanatory.

Where would I buy such a 220V caged light (like the green color too)! Thanks all.

Eric

 

[OccupantRJ]

Here's a much cheaper version.

http://www.topbrands.jedishops.com/index.php?case=product&proddb=4&pid=7553

 

[mrb]

ive got these LED based 22mm panel mount indicators, pretty sure i have 240v ones. You could mount one in a blank cover on a junction box.

If you want to do what is pictured, here is the fixture shown (and you can get colored glass for them) but I think you will have trouble finding a 240v colored lamp for it. Maybe use a 240v relay to switch a 120v circuit for the light. (is your compresor wiring romex or conduit where you could pull a neutral in?)

http://www.e-conolight.com/Product/EProductDetail.asp?ProductFamilyID=7&FGNumber=E-MT3A101G

 

[ehauptma]

I don't need to do exactly what the pics show...just want to visual indicator that power is on. Where is the link to the 22mm LED lights? thanks

Eric

 

[JustBob]

I don't need to do exactly what the pics show...just want to visual indicator that power is on. Where is the link to the 22mm LED lights? thanks

Eric

Here is a place that has the 22mm indicator lights for a good price, you will need an indicator and a light block. Light blocks come in led, neon, and incandescant from 12volts to 220 volts.

http://www.factorymation.com/s.nl/sc.2/category.151025/.f

 

[mrb]

I don't need to do exactly what the pics show...just want to visual indicator that power is on. Where is the link to the 22mm LED lights? thanks

Eric

I sell them. Would be $5 shipped for a 220v one. PM me on monday.

 

[Yardgoat]

I dont do wireing and this question will prove it. 220 VOLT IS TWO 110 VOLTS ? Isay yes.Now how come you cant go to just one wire thats 110 volt and put a reg/std light there ?.....................YG

 

[MrMark]

Because you need a return path for the current to flow back to its source. And you can't use the ground wire for that. Well, you could, but it would be somewhat dangerous and then you wouldn't have a ground.

 

[PassnThru]

Could you pigtail off one hot leg, the neutral leg, and the ground?

 

[mrb]

Could you pigtail off one hot leg, the neutral leg, and the ground?

yes except the compressor isnt going to have a neutral, and you cant run a neutral by itself from somewhere. It would have to be in the conduit / cable going to the compressor.

 

[PassnThru]

yes except the compressor isnt going to have a neutral, and you cant run a neutral by itself from somewhere. It would have to be in the conduit / cable going to the compressor.

I'm confused. It happens often by the way. Let's say I run the 240 to a box on the wall next to the compressor. Then I pigtail two wires to one hot leg, two wires to the neutral, and two wires to the ground. I run the undisturbed hot to the compressor along with one tail from the other hot, one tail from the neutral, and one tail to the ground. I run the remaining pigtails to the light. In that scenario, I don't see how the compressor loses it's neutral?

 

[MrMark]

The 240 volt compressor doesn't need the neutral and therefore doesn't usually have wiring with a neutral. I did run three wires to my compressor plug, but most don't. So, the problem here is the lack of a neutral. Without a neutral (grounded conductor tied to the centre tap of the transformer) you can't get 120 Volts. The neutral wire (just another white wire) needs to be run from the panelboard to the outlet. It needs to be in conduit if there is conduit. If this is romex, the person would have two choices 1) run another romex just for the white wire (if this is legit) , 2) run three conductor romex and remove or abandon the original romex. There's probably ten other ways to do it, but those come to mind.

I think the LED light is a very cool idea. but exposed wiring looks like ***.

 

[mrb]

The 240 volt compressor doesn't need the neutral and therefore doesn't usually have wiring with a neutral. I did run three wires to my compressor plug, but most don't. So, the problem here is the lack of a neutral. Without a neutral (grounded conductor tied to the centre tap of the transformer) you can't get 120 Volts. The neutral wire (just another white wire) needs to be run from the panelboard to the outlet. It needs to be in conduit if there is conduit. If this is romex, the person would have two choices 1) run another romex just for the white wire (if this is legit) , 2) run three conductor romex and remove or abandon the original romex. There's probably ten other ways to do it, but those come to mind.

I think the LED light is a very cool idea. but exposed wiring looks like ***.

you cant run an additional romex and just use the white. All the circuit conductors need to be together, cant have the neutral in a different cable from the hots.

what exposed wiring?

 

[MrMark]

you cant run an additional romex and just use the white. All the circuit conductors need to be together, cant have the neutral in a different cable from the hots.

what exposed wiring?

That's interesting and I believe you. I am too lazy to look it up right now. The reason it is interesting is because an electrician I hired when I first bought my place did that and although he did almost everything he could possibly do unsafely and half-*** I never really thought that was one of his transgressions. I was like, typical, but I didn't realize it was illegal.

The *** wiring is in the original picture.

 

[PassnThru]

I understand that some of the older 240 plugs were missing a wire - but I thought that it was the ground. I have one here - 2 hots and a neutral - no ground for the dryer. How is the air compressor different from something like a dryer or a stove? I'm not sure where we lost the neutral here?

 

[mrb]

That's interesting and I believe you. I am too lazy to look it up right now. The reason it is interesting is because an electrician I hired when I first bought my place did that and although he did almost everything he could possibly do unsafely and half-*** I never really thought that was one of his transgressions. I was like, typical, but I didn't realize it was illegal.

The *** wiring is in the original picture.

NEC 300.3 Conductors
(B) Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors and bonding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord, unless otherwise permitted in accordance with 300.3(B)(1) through (4).

I never enlarged the original picture. That doesnt look very good at all. Shoulda been piped.

 

[mrb]

I understand that some of the older 240 plugs were missing a wire - but I thought that it was the ground. I have one here - 2 hots and a neutral - no ground for the dryer. How is the air compressor different from something like a dryer or a stove? I'm not sure where we lost the neutral here?

Air compressor (240v model) requires two hots and a ground. Connecting the frame of the compressor to the neutral would not be a good thing. The old type dryer outlets with two hots and a neutral should not be used to power anything in a garage.

 

[MrMark]

I understand that some of the older 240 plugs were missing a wire - but I thought that it was the ground. I have one here - 2 hots and a neutral - no ground for the dryer. How is the air compressor different from something like a dryer or a stove? I'm not sure where we lost the neutral here?

I believe you are correct that the older plugs were missing the ground, I have read that here.

The difference is that the electric dryer must be a dual voltage device like most ranges - they need 240 and 120. We generally don't use electric dryers where I live so I am just assuming they are dual voltage, 240 for the heating elements, and 120 for the control panel. Just an educated guess.

 

[MrMark]

So the answer to your question is that the compressor doesn't need 120, hence no neutral and most people don't plan ahead and run spare neutrals just in case the need for 120 comes up later.

This is a perfect example of why it is always good to run the 8/3 for the compressor.

 

[mrb]

another way to do the 120v light (I do like the use of a vaportight light as an indicator, im going to have to remember that one) if there is a 120v circuit nearby you could use a 240v coil ice cube relay to switch the light which would be powered off the 120v circuit. (this arrangement should never be used where safety could be a concern if the light shows a false off since the light could lose power with the other circuit still energized)

 

[ehauptma]

Wow guys, I had no idea there were so many ways to look at this issue. I will confirm with my electrician how the conduit was run from the breaker, though I do remember us pulling 3 cables through the blue conduit, which I believe were 2 hots and a ground. So, from what I understand, there is no neutral in a 240 Volt installation.

We did the same thing when we ran power to my 240V Dayton heater a few months ago.

MrMark, I didn't understand what this meant:

This is a perfect example of why it is always good to run the 8/3 for the compressor. .

thanks all...I think I'm learning something

 

[PassnThru]

So the answer to your question is that the compressor doesn't need 120, hence no neutral and most people don't plan ahead and run spare neutrals just in case the need for 120 comes up later.

This is a perfect example of why it is always good to run the 8/3 for the compressor.

OK. Yes - a stove definitely needs a 120 supply. Don't know for sure about the dryer but that is definitely possible. This is the first I've ever heard of any circuit not needing a neutral. So I'm hearing that 2 120 hots don't need a neutral to complete the circuit? If so, thanks for the education.

 

[BioHazard]

How 'bout you just buy a european 230v light bulb?

 

[MrMark]

OK. Yes - a stove definitely needs a 120 supply. Don't know for sure about the dryer but that is definitely possible. This is the first I've ever heard of any circuit not needing a neutral. So I'm hearing that 2 120 hots don't need a neutral to complete the circuit? If so, thanks for the education.

That's right. The two hots (2 different phase legs 240 volts apart, each of opposite polarity which makes them look to be 180 degrees out of phase with each other on an oscilloscope) complete the circuit with the current switching directions 120 times a second.

 

[MrMark]

Wow guys, I had no idea there were so many ways to look at this issue. I will confirm with my electrician how the conduit was run from the breaker, though I do remember us pulling 3 cables through the blue conduit, which I believe were 2 hots and a ground. So, from what I understand, there is no neutral in a 240 Volt installation.

We did the same thing when we ran power to my 240V Dayton heater a few months ago.

MrMark, I didn't understand what this meant:

This is a perfect example of why it is always good to run the 8/3 for the compressor. .

thanks all...I think I'm learning something

Just meant that the 8/3 gives you the two hots AND the neutral and thus 120 volt capability. It's added flexibility for very little additional cost. There have been countless situations come up where someone wants 120 volt capability but only has 2 wire 240 volt wiring. It is a little trick to deal with unforeseen possibilities, if that makes any sense.

 

[BioHazard]

Or how about two 120v bulbs wired in series? Is that legal?

 

[OccupantRJ]

OK. Yes - a stove definitely needs a 120 supply. Don't know for sure about the dryer but that is definitely possible. This is the first I've ever heard of any circuit not needing a neutral. So I'm hearing that 2 120 hots don't need a neutral to complete the circuit? If so, thanks for the education.

The #8, 3 conductor CABLE w/ground, will have two power conductors and a neutral, along with a bare equipment ground. Therefore you can obtain 240 volts by using the two hot conductors together, (they use each other for return path), or 120 volts by using one hot conductor and the neutral. (standard return path). Two 120 volt conductors must be on opposite phases to appear as 240 to the unit. Still referred to as single phase, which can confuse a beginner. 3 phase has 3 hots, each using each other for return paths, no neutral needed. Each phase will measure as voltage to a ground. A simple 240 device needs only 2 opposing phase hots to operate. Hopefully this will help someone just getting into wiring.

 

[PassnThru]

That's right. The two hots (2 different phase legs 240 volts apart, each of opposite polarity which makes them look to be 180 degrees out of phase with each other on an oscilloscope) complete the circuit with the current switching directions 120 times a second.

The sound you hear is me slapping my forehead. It should have occurred to me since I only have to hit the hots with my meter to get a voltage reading. Of course, I can hit a neutral and a hot and get 120. To get a reading on a 120 circuit I have to have a neutral. The mere fact that I can get a voltage reading from the hots alone on a 240 circuit should have told my thick brain that the circuit was completed.

 

[Norcal]

How 'bout you just buy a european 230v light bulb?

------ -----

Because the NEC prohibits it, one is not allowed to have lighting in excess of 120 volts in a dwelling see article 210.16(A)

All the major industrial control manufacturers make 240V pilot/indicator lights, I cannot see any code issues in using them, unlike 240V light bulbs or 2-120V lamps in series. One source to find indicator lamps on the cheap is Ebay, there are 2 sizes of them, 22 MM & 30MM, 22MM fits a 1/2" (7/8") knockout, I do not know the KO size of the 30MM ones & am too lazy to go outside to get one & find out.That being said, I prefer 30MM components, they are more rugged then 22MM IMO.

 

[Aceman]

------ -----

Because the NEC prohibits it, one is not allowed to have lighting in excess of 120 volts in a dwelling see article 210.16(A)

All the major industrial control manufacturers make 240V pilot/indicator lights, I cannot see any code issues in using them, unlike 240V light bulbs or 2-120V lamps in series. One source to find indicator lamps on the cheap is Ebay, there are 2 sizes of them, 22 MM & 30MM, 22MM fits a 1/2" (7/8") knockout, I do not know the KO size of the 30MM ones & am too lazy to go outside to get one & find out.That being said, I prefer 30MM components, they are more rugged then 22MM IMO.

I don't see how a garage is considered a dwelling unit. I looked in the definitions for dwelling and garage. Seems like if it's attached, I could see the inspector making a judgement call since it's a bit of a gray area. A detached garage, no way could it be considered a dwelling unit. The code article is 210.6(A)

I also don't see how you can hook a small LED up to a compressor circuit 30 amps and above due to 210.23(B). You'd have to fuse down the lighting wires.

 

[Norcal]

I don't see how a garage is considered a dwelling unit. I looked in the definitions for dwelling and garage. Seems like if it's attached, I could see the inspector making a judgement call since it's a bit of a gray area. A detached garage, no way could it be considered a dwelling unit. The code article is 210.6(A)

I also don't see how you can hook a small LED up to a compressor circuit 30 amps and above due to 210.23(B). You'd have to fuse down the lighting wires.

If it's on a residential property, it's residential, if the shop/garage is zoned otherwise or on a farm I would agree w/ you.

 

[Torque1st]

Just an idea... Use two 110 bulbs in series in a dual bulb fixture??? Pick your own colors.

 

[BioHazard]

------ -----

Because the NEC prohibits it, one is not allowed to have lighting in excess of 120 volts in a dwelling see article 210.16(A)

I believe the last time we argued about this it was pointed out that is limited to branch circuits with a maximum of 15 amps. (1440 VA)

I'm pretty sure this guy's compressor isn't in his dwelling, and the compressor is on more than a 15 amp circuit. Further than that, has anyone ever seen an inspector unscrew a light bulb to check the voltage?

 

[BioHazard]

Problem solved:
http://www.1000bulbs.com/9274/?utm_...=google_base&gclid=CJOUqZKst6ACFRsVawodw0_XTA
$0.59

 

[mrb]

Problem solved:
http://www.1000bulbs.com/9274/?utm_...=google_base&gclid=CJOUqZKst6ACFRsVawodw0_XTA
$0.59

thats a small inch and a half tall candelabra base bulb......good find, but how is this any better than the 220v LED indicator?

 

[truckn_r]

by the looks of it, there is a junction box under the light ,and also a conduit going to the junction box from the compressor, and from the j-box to somewhere else, my thoughts on this is that in the j-box there is a 220v relay, that closes a contact when energized, the other conduit is a 120v source for the 120v light bulb, probably brought from a light switch.........

 

[BioHazard]

thats a small inch and a half tall candelabra base bulb......good find, but how is this any better than the 220v LED indicator?

Just another option. I'd be willing to bet 1000bulbs has bigger bulbs that would work in that vapor light fixture too in 230v, but I didn't look.

I think the question here has already been answered - several ways you can do it, a 220v indicator(bulb, neon, LED) or a standard 220v light bulb of whatever sort you like.

 

[mrb]

by the looks of it, there is a junction box under the light ,and also a conduit going to the junction box from the compressor, and from the j-box to somewhere else, my thoughts on this is that in the j-box there is a 220v relay, that closes a contact when energized, the other conduit is a 120v source for the 120v light bulb, probably brought from a light switch.........

no. The box under the light is a square D QO 60 amp disconnect with a molded case switch. He probably has a neutral in his circuit to supply the light.

 

[srmofo]

I also like the idea of an indicator lamp and my compressor/switch will be right next to the man door so it will be easy to see. So to some things up, when I run my wiring for my compressor in a few weeks I should just go ahead and run 8-3 now. That would eliminate all this confusion about the easiest way to do it.

 

[ehauptma]

OK, I spoke to my electrician today and here is the plan. He is going to run a 240 volt seal tight connection out of the junction box coming off the circuit breaker (can see it in picture below) to a 240V light (in 2nd picture). He will add a 240 switch to the junction box, so when the switch is ON the light will be on and the compressor will have power; when the switch is OFF, the light will be off and the compressor will have no power.

Sounds pretty straight forward, so I'll go down to Grainger tomorrow and get the parts.

Thanks all for such a lively discussion...I sure have learned a lot.

Eric