What are the risks of an electrical setup like this.

D.sebens said:
Let me preface that I “can” do it right I’m just being cheap and lazy. My new to me lathe is wired in 220 no neutral. It came with an articulating 110v lamp. The previous owner just had it plugged in to a wall outlet. The way I have it orientated that’s not really feasible.

The two easy options are an extension cord hanging around (not what I really want to do). And the real question here, how wrong will it be if I used the ground supplied to the lathe and added a 110 box for the lamp?

I know this against code and unsafe but can someone explain why I shouldn’t and what the potential scenario is that would lead to the unsafe situation?
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A small step down transformer might work.
 
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Maybe this is late but, for years this was done with no issue at all, in a four wire system the white and the ground are landed at the potential anyway back at the box. While this may not be current code there is nothing electrically wrong with that circuit and the wiring is on/in the lathe box anyway.

Phil
 
Phil_C said:
Maybe this is late but, for years this was done with no issue at all,
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That is like saying "for years we had no seatbelts or airbags, no issue at all." I think they call that "survivor's bias" - kind of hard to get a second opinion from those who didn't make it.
Phil_C said:
in a four wire system the white and the ground are landed at the potential anyway back at the box.
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if everything is wired correctly, no rat-chewed wires, etc., yes. But the practice of separate neutral and ground was developed to address those situations where things become not 100% optimal.
Phil_C said:
While this may not be current code there is nothing electrically wrong with that circuit
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I beg to differ.
 
It’s fine guys. I ended up twisting coat hanger wires together to carry the electricity. I stapled them to a 2x4 about a foot above my head so I don’t bump my head on them. All good. I know when I have a really good cut going as it smells like a wood engraving shop.








(Fyi this was a lie, machine is wired and runs good with appropriate power considerations)
 
When I first moved into our current residence the 240 volt mains feed to the house came from the barn via two overhead wires. The 60 amp fuse box at the barn was bonded to ground via a ground rod and the meter head was also bonded to ground via a separate ground rod. At the 60 amp fuse box in the house, the neutral was bonded to a ground rod and to the iron pipe plumbing supply. The neutral wiring between the the house and the barn consisted of the galvanized pipe supplying water to the barn. Some years later, the galvanized pipe was replaced with polyethylene, effectively destroying the neutral circuit. The symptoms were that if there was an unbalanced load on the lights on one side would dim while those on the other side would brighten. Short bulb life was another . The third symptom was if there was an imbalance and one were to touch the faucet while touching the sink one would get a mild shock.

At one time I measured the voltage between the house neutral and earth ground at 40 volts. Discovering that, I convinced the landlord to spring for triplex. Being a lawyer, it didn't take much convincing. Years later after I bought the property, we replaced the 60 amp service with 200 amp service and ran an underground feed.
 
D.sebens said:
My new to me lathe is wired in 220 no neutral. It came with an articulating 110v lamp. The previous owner just had it plugged in to a wall outlet. The way I have it orientated that’s not really feasible.
Click to expand...
A lot has been written here, but I will contribute a few facts about how power is delivered and a few other comments. I have wired several houses and always try to apply common sense to the process. Yes, I do feel one needs to understand these few facts in order to know if you are being safe or not. People do not always understand why the code is written as it is and in some circumstances blindingly following code can actually be a mistake!

Codes are ever evolving documents and can be different for each municipality as they do not have to adopt the entire book. Things do improve, but the main reason for this is that when a city adopts the new parts of the code book then the electricians must use the new devices which cost more. Hence manufacturers who have patents try to push their newer devices into the code book. At the same time the Code books, which are massive, are always published by the same folks and they like to sell their books so they like to see new additions that can cause a professional to have to purchase them. Some code requirements are either not useful or are actually a hazard. For example, here, one is required to use child proof outlets, but these things which have a spring loaded plastic internal cover require that what is inserted must be a pair of terminals not just a childs rod. However, they do not work well and it is not uncommon that a plug will be pushed part way out leaving the terminals somewhat exposed! Also they commonly push the terminals out far enough that the plug comes loose, but does not quite fall to the floor. They are a pain in the xxxx. A second example is the electrical arc/spark arrestor. These very expensive breaker replacements are suppose to monitor if there is a frayed wire that is arcing and break the circuit, sort of like a ground fault interrupter. But the arc is probably between power and neutral, like a lamp cord. They are suppose to control the outlets in the bed rooms to prevent fires from starting while one is asleep. However, brushed motors (like a vacuum cleaner motor) can set these off and so once again a pain in the xxxx as you have to go to the breaker box to reset them.

Yes, house outlets used to be wired without a ground, but they did have a neutral. (two openings for two prong plugs for a 110 circuit)

Grounds are meant to be a safety feature and current is not suppose to flow in them unless there is a problem to protect us from.

From the outside world (power company) the feed provides three wires. +-110 = 220, plus a wire that is usually the same size and is considered a neutral. I am sure it is grounded somewhere in the power systems that deliver the power.

When this arrives at your house breaker/fuse box a separate ground is created via connection or a long grounding rod that is driven into the earth (ground) ... or water pipe that is shorted around the meter so that is makes contact with the earth. A ground wire it attached to this rod and the grounding bar inside the breaker box. So, yes, at the breaker box the ground and neutral bars are tied together. In concept, in your house your current usage draws an equal amount from each of the 110 sides of the 220, but if not, this must be averaged over a large number of homes so that is is eventually balance. The imbalance flows in the power companies neutral and eventually to its ground. Any current that flows into the ground from your home must travel through the earth and back to the power company via the earth (ground).

So while your lathe should have been wired up so that two terminals carry the 220 current to the motor etc, the third wire should be a neutral (not a ground). A forth wire should be a ground, but you did not get one with the lathe. You should add it to the lathe. Even the motor windings of the 220 motor are not perfectly balance when new and this imbalance should travel back down this neutral. If this is the case you can just wire up your 110 lamp between one side of the 220 and the neutral (not the ground) and all will be within codes. However, the lamp should also have a ground wire or be made so that you cannot come into contact with a metal housing that might contact a neutral or power wire. So simply look at your wiring to the lathe and make sure that that third wire is a neutral and not a ground. Then run a separate ground wire back to the breaker box. (see comment below) At a modern breaker box you will find the two sides of the 220 attached to the breaker, the third wire should be connected to the neutral bar, and a ground wire should be tied to the ground bar. If this breaker box is actually a sub box, then the neutral and ground bars should NOT be tied together at this sub-breaker box, but will be tied together at the main breaker or switch box. (code).

As learning experience you can go to a distant point, from the breaker box, in your home and using a VOM (volt ohm meter) measure the voltage at the outlet terminal between the neutral and the ground. You will commonly find a volt or two difference, while the voltage between the power terminal and the neutral or the ground should be approximately 110 on a 110 outlet. (you may do the same experiment on a 220 outlet if you have one at some distance from the breaker box.) This 1-2 volts difference represents the voltage drop along the neutral wire as it returns the current back to the main breaker box.

If it is really difficult for you to run an additional wire for the ground then the next best thing is to take it to another earth ground rod. If this is not possible then I suggest you spend a few bucks as @verbotenwhisky suggested and buy a step down transformer 220 to 110 which is rated for the current load of your light. I.e. step down of 2:1 with a 220 rating. This isolates the circuits, but does not provide a ground to the lamp, which you would still like to have. Or there are a few LED lamps which are rated for 220. Some one mentioned the drills and other hand appliances which doe not have a ground plug on there feed cord. These are rated as doubly insulated, are usually made of plastic rather than metal and so meet code. But a ground wire is still a safety feature.

Lastly, if you ever notice when you purchase romex wire, the ground lead is not even insulated. This is because it is not "suppose" to carry current.

Current Balance! It is perfectly fine to run 220, neutral +ground to an outlet box and then only hook up one side of the 220 so that you have a 110 outlet. I did this in a portion of my shop. (4 wires to each outlet box along the wall of the shop). Then I installed two 110 plugs with one of each using one side of the 220. This way I had two separate 110 circuits. but only had to run one 4 wire romex, not two 3 wire romex lines. If I plug in two similar 110 loads then current returning to the breaker box mostly flows in the two 220 wires and the neutral carries very little current. However, if I only use one of the outlets then the return current flows in the neutral and one side of the 220. On the other hand if I decide I want to use this service for a 220 appliance I just have to replace the 110 outlets with a 220 outlet and wire it as such. The 220 breaker at the breaker box has two sides, one for each of the 110 halves of the 220. The breaker is actually just two 110 breakers mechanically tied together. If the current through either leg of the breaker exceeds its rating then both sides trips open. (You should not use two separate breakers to service 220 loads as only one side may open leaving the other side supplying power.)

By the way, if you really want to understand how old house power systems were wired you will need to study Knob and Tube installations. These had two fuses in them one for the 110 going out and one for the neutral (ground) coming back. This is because there was only one wire being run every where. There was no romex or other style where there was two wires in once outer case. For example, the electrician would run one wire to a switch followed by a similar wire from the switch to a lamp, followed by a single wire to a neutral, any neutral that is near by would be handy. So commonly, at the fuse box, an amount of current would flow out one fuse and wire, but the current could come back via multiple return wires. Or more likely the current returning in any given return wire would carry more. This was called knob and tube because the wires only had one layer of insulation, usually cloth and tar, and so it was not nailed to a stud but was held off of the stud by a ceramic clamping knob and when it needed to go through a joist or stud one inserted a ceramic tube in the hole of the wood and then put the wire through this tube. There was no insulation in the walls of the old houses so these wire could be quite hot without starting a fire. Hence, the wire sizes for a given fuse size was smaller than it is for today's romex where two wires are right next to each other and the romex is stapled against flammable wood which must run cooler. It was not unusual to find the knob and tube wires to be 14 gauge and be fused at 30 amps! Where as standard romex 14 gauge wires are fuse/breaker-ed at 15 amp.

Good night.
 
This has been an interesting thread, and has made me think back on some of my decisions. Recently, I added a sub panel to the garage. According to the Internet, it is OK to connect the sub panel to the main panel with two hots and a ground (no neutral) as long as the sub panel is only driving 240 volt loads. Since the garage is already wired with 120, and there are no dryers or such which use the neutral, this is kind of OK. But, it is frowned upon, and supposedly requires some convincing if the inspector is picky. I originally thought that this sub panel would only power large machine tool motors and welders, both of which do not use the neutral, it should be in principle OK. Now, after reading this thread, I realize that it is not really OK, even if allowed by code. Somebody coming along later with a load requiring a neutral will have a strong temptation to jury rig some non-code compliant wiring, either flowing current through the ground wire or bonding a neutral to the sub panel ground bar. Would I have done something wrong? In a sense, yes. I will have introduced a temptation and channeled a future amateur electrician into doing something unsafe. I kind of realized this, so I shelled out for the extra white wire, fully sized, that will never carry any current as long as I'm here. In a sense, it is sort of like a responsibility to society. My colleagues in the world of software engineering call this "defensive coding", and it is a firmly established good practice.
 
I'm with the safety folks here. After many years of experience with electrical wiring under code and lots of conversations with my electrical engineer friend, I've learned to be overly cautious. Modern rules/code are there for a reason. Most old wiring needs to go. Last thing I want is to die from some stupid wiring issue that someone left for me, or have my shop burn down like too many others have. Overkill is good where electrical circuits are concerned. If I find an issue and it means an expensive new circuit or switch, I go there. Doesn't pay to save money on electrical.
 
When my wife and I were house shopping about 8 years ago, we were shown a piece of property I really likes. 3+ acres, separate shop building, private pistol range, large ranch with a huge master bedroom. Then I took a peek inside the one storage room (semi-attic space) door. There was wiring lying on top of the insulation, unsecured. Some of it was spliced and just wrapped in electrical tape. I took a closer look then at the panel in the basement. Previous occupant did some kind of sketchy stand-by generator setup. We passed. The rewire would have probably cost $20k and the asking price was not good enough for me to take that risk. That house was a death trap.
 
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