# Electric Converter - Will this work?

#### krhodus

##### Member
I am in depirate need of a Edison to Stage-Pin electric converter and don't have the time to order one for our upcomming show. So I decided to take a stab at making one. I had a power cord from an old power strip that I wasn't using. I crimped eye-holes on the ends of each wire. I then took an old Stage Pin connector and connected the eye holes to it in the corresponding points. Our theater director wasn't sure if it would work or not. I plugged the cord (with no light plugged in the end) into an outlet and it didn't blow up. Will this provide enough power to power a light? This is just going to be used to see if the light works, so the light will be running a maximum of a few minutes.

Should I expect sucess or fire?

Thanks,
Kevin

#### JP12687

##### Active Member
Its a hot-patch.

I make things similar to this all the time. As long as all your wires match up, and the gague wire your using will support the load then you should be good.

#### techieman33

##### Well-Known Member
What size of cable, that would be your only problem as long as it's wired correctly. And just to let you know, that plugging in a light like that is hard on the lamp, and will reduce it's life. And actually it would be called a jumper.

#### Mayhem

##### Senior Team Emeritus
Aside from the cable gauge that you are using, which is important and has been mentioned above, I would ensure that your crimping is of a good quality. Should one or more of the wires pull free, you will have a serious risk.

I assume from your description, that the stage pin connector is male and therefore plugged into a receptacle. If so, you may think that if a wire pulls free from the power source, it is no big deal, as you will break the circuit and no power will flow.

Whilst this will happen, the wire that has pulled free could be come in contact with another terminal, causing arcing inside the plug, presenting a serious risk.

Now I will be the first to admit that we don’t use stage pin connectors in Australia and that I have only ever seen one in pictures, so I cannot really comment on whether or not crimp connectors are the correct way to wire up such a plug. What I do know however, is that there isn’t a lot of room in these plugs for error.

Be very careful and I would get it checked out by someone with more experience in this area. Also, if you do burn down the theatre with this, you will be held liable.

#### bdesmond

##### Active Member
This isn't kosher if I'm following your description right. There have been at least a few discussions of how to go about wiring a stage pin here before.

Thee long and the short of it goes like this: you strip a certain number of mm of insulation off the ends of each conductor (read the directions that come with the connector, they usually spel this out), put the ferrule on, crimp teh ferrule, slide the ferrule covered conductor into the pin and finally crank down the set screw so its nice and snug.

My interpetation of your description is that you took three crimp on eyelet connectors (like this, right -
?) and then proceeded to anchor them to the top of the pins with the set screws.

This is definetely not he intended mode of wiring, and I'm surprised the plug closed gracefully - closing it should require no extra force. What happens if these eyelet connector screws loosen a bit via vibration or the temperature of the metal and now you've got two of these eyelets spinning around and they short out?

The cable you use and the preexisting edison style connector need to be rated for the load they'll be carrying for this to even be legal as far as the cabling goes. You may only be planning to use this thing for ten seconds to make sure the lamp works, but some other guy might come along and hook something up with this cord you have and end up having a small fire because he's running a large load on a cord and plug rated for a fraction of it.

The actual task of installing the connector is trivial once taught to do it properly. In your situation, I'd be more inclined to tell you to get a stage pin extension you already have and fit it with the appropriate edison connector you pick up at the local hardware store.

Hopefully Mr. Ship will be along with a more colorful explanation of this. He does this for a living and explains it well.

#### krhodus

##### Member
I know for a fact that this will NOT be a perminant cord because when it is not being used for testing, it will be locked away in a place where only the PAC manager and I will have keys to. Yes the eye hole picture is correct. The crimping is pretty strong, I tested it by yanking on it and seeing if it would come off and it didn't. The only think I am worried about is the guage of the wire since I don't know what it is.

We are planning on using this to inventory what is working and what isn't and hopefully we need to use it once or maybe twice on a light. How can I make it better for the light than just plugging it in and then unplugging it? The only other solution we have which is possible but requires alot of work is to get out around 100ft of stagepin extension cable and plug it in up on the catwalk and drape it down to the ground and then run it to the lighting shop. This is not only dangerous but we are still plugging the light in and out and being rough on the light.

Thanks,
Kevin

#### propmonkey

##### Well-Known Member
im glade all our intsruments and circiuts still are edison plugs.

##### Well-Known Member
Personally the only thing wrong I find with this is that the wire being from a power strip that probably handles 4.5 amps or so, might not handle some of the higher wattage lamps. Assuming the crimps are hi-temp, they should work fine. Some of the plugs we used before we upgraded to the bates recommended in the instructions to use crimps, if I remember correctly.

#### krhodus

##### Member
Does anyone know how easy it would be to install a wall outlet that is stage pin and then have a normal light switch dimmer that would allow us to dim up the light and then dim it down, therefore being a little more gentile on the light?

Can a theater light even run off of a regular outlet or would we have to have special wiring for it.

AH THE PAINS OF STAGE-PIN.

Kevin

#### bdesmond

##### Active Member
Kevin-

I'm nto familair with teh style of plug which uses the eyes. I've always dealt with the sort I described. Assuming you've got a brand of connector that is designed to be wired in the manner you described w/ the eyelets then assuming you did the crimp & assembly properly you're likely OK as far as the conencotr goes.

Yes you can run a theatrical light off a wall outlet. The deciding factor is what the outlet on the wall is rated for and how much load your light plus anything else on the circuit is generating.

The way to figure this out is Amps = Watts / Volts (I=W/V). If you look at a circuit breaker, you'll see it has a number stamped on it, usually on the arm - this si the number of amps its rated for. Your wiring from the breaker to anything on the circuit is sized accordingly.

Its unlikely the power strip cord you plucked is setup for a 20A load, but, a 750W lamp is 6 amps and change, you should be OK, though again, no idea what kind of a mickey mouse cord the power strip might have.

THat site you linked to has some good basic info along these lines, as far as the math goes.

#### ship

##### Senior Team Emeritus
Given your description, and the description of the supervison your director is able to provide I would recommend that you do not use this item before it’s inspected by at least the head of the maintenance staff at the school.

Here is the reasons or causes of my concern.
First as JP12687 says, it’s a “hot patch” you are describing in plugging a fixture into a receptacle to see if it works. Is this just one fixture or potentially many of them or is such an item expected to be frequently used? It’s an adaptor not a jumper, a jumper has both ends the same.

If this is a one time only thing, and the most experienced electrician on staff certifies that your strain relief for the stage pin plug is properly installed, and the “ring terminals” are properly crimped on - by way of tugging them at least to see if they pull out, yes use it this once than cut off the stage pin end and don’t use it a second time. This given most power strip cords are made of 14/3 SJT wire which has the rated capacity of 1,800 Watts.

Normally on a adaptor, you say the male end, than the female end thus and especially given the description of the whip off a power strip it is assumed this is a molded Edison style 15 amp plug with a female stage pin connector mounted on it’s opposing end.

Bdesmond, this crimp depends upon the type of plug, if using a old style Union stage pin connector, than this ring terminal might be correct in style for the ground, but you need a flag style right angle terminal for the hot and neutral. Much less, given 14ga wire from the power strip cord, a standard ring terminal provided with a stage pin connector will be the wrong size to be using with this size of conductor. Way too much room in the crimp terminal to be able to close down on the wire correctly.

Beyond this, I think your description is in thinking it’s a Bates style of stage pin connector that normally uses ferrules to sleeve the conductors in the set screw holes. Hmm, a ring terminal in a Bates plug... could work... possibly, but your point is correct but only given he is using this or a knock off of this specific brand of connector. Many other styles of connector on the market using different systems. Look into Union, Rosco, Peachtree (sp) amongst others that use ring terminals instead of ferrules.

So here is some questions in “it did not blow up.” Were you to reverse the hot and neutral, given a bi-pin lampped fixture, it won’t blow up, nor even on a screw base. Your fixture will even work, but should you touch the shell of the screw base or pre-focus base fixture, it instead of being neutral thus no shock, will become hot. Should you on this adaptor reverse neutral and ground, it won’t blow up either, should you plug a fixture into it, chances are it also won’t blow up, but every piece of metal in your electrical system will have the return path from the hot. Should you plug a adaptor in with a hot ground reverse, and up until the point you plug a fixture into it, it won’t blow up either. As long as the inner conductors are not touching, there is no current flow thus by description, just because it did not “blow up”, does not mean it’s wired correctly. In other words, just because it did not blow up when plugged in without a load attached to it, does not mean it’s wired properly or safe. Never plug stuff in you are not absolutely sure about.

Thanks in further reading your post Brian, but being inclined to install any plug when not trained or properly supervised no matter the type is dangerous. By description, and on the whole krhodus, it sounds as if you did everything right and correctly. Don’t get any of us wrong, our interest is in your safety and out of concern for the lack of instruction you have in this. We absolutely are not trying to make it seem as if a closed club of trained tech people only. I take people just about off the street who last week were flipping burgers and train them in how to properly install Socapex plugs on a 19 pin multi-cable. Everyone can install plugs on cable if they have the ability to follow instruction. Short of this, and even on - line, it’s chancy because we have no way of seeing what you have done in verifying it’s safe.

So also in what you have done, because 14 ga cable is fairly standard for a power strip as a wire gauge, it should be more than sufficient for the loading you place on it as long as it’s under 1,800 watts. Were there a way to know that your circuit breaker powering up this Edison socket was rated at 15 amps, and in good working condition, one might also assume that given the cable gauge and Edison plug on it, most problems with it or the fixture would trip the circuit breaker before the cable had a problem with capacity. However many 15 amp receptacles are linked together around a building and powered by a 20 amp or even at times 30 amp circuit breaker. Hopefully it will trip, given a overload condition, but not always dependant upon the problem. Many things will not cause this circuit breaker protection to trip.

Now normally and why I say to use it once if built and approved by someone with basic electrical knowledge use it, you instead of wanting the cable jumping between the Edison male and the stage pin female to be of the largest amperage load rated for the plugs instead of the smallest. Since the Edison plug is rated for 15 amps, but the stage pin plug is rated for 20 amps, you than would want a 20 amp rated cable in the adaptor which is 12AWG. (American Wire Gauge.) You might look into the http://www.hstech.org/index.html how to section, there might be some photos there about how to install this plug to compare what you have done with it. While these photos are often student done and not ideal in how to or examples of what you should be seeing, they will at lest be safe in how it’s done. If you were using a new connector also, dig out that instruction sheet that came with the plug, verify you did all it showed in telling you how to wire the plug and apply the strain relief, than present it also to the person inspecting the plug so they will have reference also given they are not that familiar with a stage pin plug either. Were something mis-wired, I would still feel more comfortable with it being mis-wired within the stage pin plug. It’s both more beefy and has a larger body to separate conductors, and given the molded Edison plug from the power strip, there is little to no chance of it not being correct and very safe.

If possible in testing this lighting fixture, instead of plugging it into a common receptacle, you might take it to a washroom with a GFCI receptacle in it, or have this maintenance crew inspector of it also install a GFCI outlet where you will be checking the lighting fixture. This will often do a better job of ensuring the fixture is safe than just a circuit breaker. A circuit breaker given appropriate rating of it, just trips when it senses an overload or at times current traveling thru it too fast dependant upon the type. A Ground Fault Current Interrupter on the other hand compares the current load between hot and neutral and trips when this loading is out of balance in a dangerous way - given it can be fooled at times by things like computers and dimmers. For the most part, on a fixture test type of thing, first having a circuit breaker dedicated just to that circuit, and rated for the maximum loading safe for the plugs and cable, than the GFCI is ideal in protection.

This is what I use at work and often if there is a problem such as someone forgetting to install the mica insulation on a S-4 fixture’s lamp base, the GFCI will trip well before you know what happened, much less given a dedicated circuit breaker, that in my case is thermal magnetic in type will also trip. In any case, you now have both over current protection and a sensing of the current flow as opposed to just over current protection of the maximum allowable loading on the often over-sized circuit breaker.

For my own tester box that sits on my work table, I have all components of it rated for at least 20 amps, with all others rated at 30. I have power coming into a 30 amp switch, than going to a thermomagnetic circuit breaker rated at 20 amps, than going to a plug fuse that can go down to 5 amps in current rating - given also that a circuit breaker and a fuse will have different trip ratios, it than goes to a high quality GFCI receptacle. My life at times depends upon this box tripping if something is wrong. After the GFCI, the other types of receptacle I test on the box are wired. Even if I leave a 20 amp plug fuse in, there is still lots of circuit protection in many forms of it here. I also have indicator lights to indicate at which stage the circuit tripped. I’m on my third GFCI receptacle in six years now. GFCI receptacles need especially as a lamp test receptacle to have their monthly test to them done. This is one outlet that is used more than any washroom receptacle thus the necessity of it being tested and infrequently replaced.

Also above with the testers at the shop and my own, you will not all have at least 20 amp switches installed in-line between either power coming to the box in my own tester, or in the Leko Land prep area, where 20 amps is all they have in power available, each of three work stations has a lighted switch installed of which I’m constantly wandering by the aisle and yelling at everyone in the area “Why’s this on?” This is a constant fight both because at the current shop, the switches are flipped on by accident or because people are hot patching as described earlier.

The hot patching is a very bad thing to do and what I constantly fight people doing at work. The heck is a hot patch? This is a term for what happens when you plug a electrical load into a live circuit. Given a potential for something to draw current, when you just simply plug it in, it will tend to do so immediately. This means that those points of a plug that contact first - at the tip of the plug will than arc to the other receptacle in allowing this current to jump. Lots of current over a small surface area means even at times sparks of light dependant upon the load but in any case, this means that lots of current will start flowing as soon as there is contact. Even on stage pin plugs and industrial rated receptacles, this amount of current in going instantly “hot” or live will be far too much current for such a small amount of contact in conducting the electricity. Much less should your finger stray into the plug that’s being plugged in, you will also get shocked. For this reason, a switch installed before the outlet you intend to plug into will prevent such a arcing that destroys both plug and receptacle - given it’s in the off position. For a school’s test circuit, have the maintenance staff at very least give you a Switch powered GFCI receptacle to test fixtures with. This will at very least if not a dedicated circuit to the maximum loading of the equipment you will test, prevent this hot patch condition. It should be either a internal pilot light 20 amp switch, or a dual purpose GFCI with switch that has indicator light to show power on. In using this switch to turn on the fixture once the plug is fully installed, it also ensures that your hand is not touching the plug if mis-wired. If mis wired, it’s possible the short will than melt the plug and injure you while holding it.

Kevin

#### bdesmond

##### Active Member
krhodus said:
I tried the converter today and it worked. Keep in mind I used it for at most a minute plugged into the light. I had no sparks or anything come from it or the light. I am looking for a professional converter. The best price I can find is from a local theater company, Brite Lites. They say \$17. Does anyone know a online store that has it cheaper?

Kevin

Sounds decent if you're only buying one ... keep in mind that the shop has labor cost in addition to parts when they sell you one.

#### techieman33

##### Well-Known Member
Sounds like a pretty reasonable price to me as well.