I’ll start out by saying that I am not an electrician, do not want to teach anyone how to wire anything and don’t want to come across as sounding like I know anything about the subject. I do want to share some of the wiring ‘mistakes’ that I have recently uncovered with the help of my electrician and I do want to get input from you all as I’ve noticed that there seems to be a lot of good knowledge here. So please, correct me as needed! A few definitions; Hot wire – usually black but could also be red or other colors such as when using THHN – The ungrounded conductor. Neutral – usually white, could be grey, especially if there are multiple voltages present- The grounded conductor. Provides a neutral current return path to the source. Ground – the earth – like, what we live on. Grounded – attached to the earth. As the XO terminal on the utility transformer is grounded to the earth. Ground wire – usually bare copper or aluminum but can be green as with THHN. Creates the Effective Ground Fault Path. Bonding – Not sure how this is different than grounded, but every metal bit in a system, like work boxes, panel housings, emt pipe, motor housings, etc…, needs to be bonded together. Circuit Breaker – Provides a means to shut off the flow of electricity in the event of an overload and or a ground fault such as the hot wire coming in contact with any grounded metal part. Service entrance – The first circuit breaker panel on a property. Power comes from the transformer through the meter to the service entrance. First one; This is a sub panel in a customer’s garage. Notice that the green ground screw is still bonding the neutral buss bar to the metal housing and the ground wires and the neutrals are mixed together in the neutral buss bar. This is not correct. The only place that neutrals and grounds are to be mixed is at the service entrance. Mixing neutrals and grounds in a common neutral buss bar at a sub panel creates many parallel neutral current paths returning to the source. That’s what the electrons want to do, return to their point of origin. If there are multiple parallel paths to follow, the electrons will take all available routes, like through the cold water bond and copper plumbing, the housing, and thus the gas line to your boiler, into the earth through a ground rod, etc….. OR… through the worker who inadvertently comes between the neutrals during work on the system. Grounding, ground rods and bonding are NOT to be used for neutral current flow back to the source.
The fix here is to install a separate ground buss bar, move all the grounds to it, and to remove the bonding screw that was bonding the neutral buss bar to the metal housing.
Not an electrician either but been doing it for 30 years and have been guided by 2 very good E1’s. The purpose of bonding is to make a situation where there is no voltage potential between any objects. All objects are to be bonded to each other and this all leads back to one point at the ground lug in the panel. The terms bonding and grounding are often mistakenly interchanged. Bonding is a hotly debated topic and doing it properly is a common question. A bond allows things to be at the same potential and have a path to the same ground if needed. This is why steel frame buildings are bonded. No potential if someone touches a machine and the frame. It all needs to be done right and in some unique cases not bonded, like that sub panel. Not a fan of the cable ties in that panel. Zip ties are allowed, usually for circuit grouping as in 210.4(D), but personally I don't like the potential for hot spots. I see a Rotophase breaker there. Generated 3-phase systems create special bonding and ground situations. Makes a difference if delta or wye system also. 3 wire floating delta creates special considerations. If 480v is created via a transformer be really careful and understand arc flash. Do those aluminum connections have Noalox on them? Just my 2 cents. Take it, leave it or correct me if needed.
Ct Farmer, I appreciate your input. What I've heard about bonding is that it's primary purpose is to protect against lightning strike and utility failure. When there is a lightning strike, a tremendous magnetic pulse can travel through the metal parts of a structure and it's contents. Bonding these items together allows that magnetic pulse to travel from one point to another. Without proper bonding the magnetic pulse can flash between items, causing fire, personal injury or death. Cable ties - I appreciate your point. Noalox on all aluminum connections - YES! Thanks again.
Ehhh, If that box bothers you, you must not get out much. I found an add on box from the fuse box days. It had the standard 60A fuse box, but somebody had added another box to the side with two rows of four fuses each row, no busses, all wired individually on each side of the fuse. Couldn't run two things in the kitchen, I figure it's too much on one fuse, pretty common right? There was no neutral bus in the add on box, they had run all the white wires to one fuse with the neutral feed on the other side of that fuse. Fused neutral, new one to me. Of course, it wasn't one neutral per hot, it was that one neutral for the seven hot fuses and seven circuits.
found this in a commercial freezer room at a food plant. box is a 12x12x6. Cover was hanging like that when i found it. Gotta love the globs of silicone. 240v or 480v not sure, plant had both.
That's interesting Delmer.... All the hots were fused... and because all the neutrals were tied together the neutral return current was too much for the fuse when more that one appliance was used and the fuse burned. Kinda confirms the point that Ct Farmer made about not zip tieing the neutrals in the panel, There can be a fair amount of neutral current and thus heat... Thanks for the comment!
Nice!
More definitions; Service entrance ( I’m gonna add something to this one) – The first circuit breaker panel on a property. Two Hot Wires, one Neutral, and one ground come from the utility company’s transformer, through the meter and to the service entrance. The two hot wires are said to be opposite phases, think like sine wave. The sine waves don’t line up with each other, they are opposite to each other. Single pole breaker – An over current protection device that has one switch on the front, one screw on the side to attach one hot wire. Output 120 volts. Two pole breaker – An over current protection device that has one switch on the front and two screws on the side to attach two hot wires. These two hot wires will be on opposite phases. Can be used for both 120 volt and 240 volt appliances. Multi wire branch circuit – 3 wire circuit – Edison circuit. Can be 120 volts or 240 volts. Sometimes an electrician will run a 3 wire romex ( two hot wires, one neutral and one ground) to say something like a bathroom heat-a-vent a- light. That will allow two hot wires to feed separate appliances while sharing a neutral. The advantage here is less wire to run and a reduction in neutral current. It is important to remember that the two hot wires need to be on the opposite phase to one another. In doing so the neutral amperage will cancel. So if the heater is drawing 12 amps and the fan light is drawing 5 amps, the neutral amperage will be 7 amps. If the two hot wires are improperly installed on the same phase, the neutral amperage will increase, easily to unsafe levels, in this case 17 amps. Now what if someone tied in a bathroom outlet to this same circuit and the hair drier and the fan and the heater were running? Also, the over current protection device - circuit breaker - MUST shut off BOTH hot wires in a Multi wire branch circuit simultaneously. Additionally, I think, and would like some confirmation on this, that the neutral current cancelling thing is how a motor can be wired with no neutral. Just two hot wires and a ground. As long as the motor is working as it should, each winding is drawing the same amps and therefore no neutral return current. Maybe?
So here's one.. The red wire is the give away. Follow it back and find that it is part of a 3 wire romex. Both hot wires on one single pole breaker.
The fix, rearrange the breakers and add a two pole 15 amp breaker. Transfer the two hot wires to the new 2 pole breaker.
Here's another.. 3 wire circuit, two hots on separate breakers next to each other therefore the two hots are on opposite phases, that's good but, in a multi wire branch circuit, the over current protection device MUST turn off BOTH hot wires simultaneously, something about series circuits or something... ?
The fix, tie the breaker together.
I don't see anything wrong with the photo in #10, the red and black on the same screw is allowed on QO breakers, and they're not overloading the neutral because they're on the same breaker. Looks bad, and no reason to have the two wires, but I'm not sure it's illegal. A 240 motor is no different than any other 240 load, there is no neutral required. Like a water heater, or 240 baseboard heater, the ground is connected to the frame, and the hots go to the load. If the motor is able to be connected to either 120 or 240, then you can think of it as two 120v light bulbs, wired in series for 240, or parallel for 120. For 120, one lead from each winding will be connected to neutral. I never thought of the multiwire circuit being the logic behind the mess I described, maybe that's what somebody was thinking? For the record, NEVER fuse the neutral, OR GROUND.
Every box I've ever been in looks like your original photo with shared neutral and ground. I've never seen one with a separate ground buss. I've only worked within the county that I've lived in all my life, could this be a regional thing? Also, on 220 circuits the neutral is the ground and vice versa. At least that's how it's done around here.
But hey! It is labeled.
Tying those breakers together like in #13, is that best practice? I've always thought that was just jerry-rigging, but, some double breakers are only connected at the handles, though, aren't they? What if one of those breakers was a center trip, and one tripped all the way off? Do they both have to be the same model?
The neutral and ground are connected at the SERVICE ENTRANCE only (not on any sub panel). I've never seen a ground come from the transformer, just the neutral, you supply the ground to the panel and feed it to the meter socket. Maybe that's new, and I'm out of date. Since 94? the new four prong dryer and stove cords are required in new construction, separate neutral and ground. It's been that way for way longer for mobile homes. Other 220 loads would have no neutral, or separate neutral and ground, not shared, even though they were connected to the same terminal (must be a separate terminal now apparently, first pic has a couple shared)
Your facts are mostly correct, and other electricians will argue with me. As you are working with AC, half the time the neutral is "hot". Current passes from the transformer, and returns to the transformer. It connects to the center of the transformer winding. It is the device we use to get half voltage. Typically in USA, 120 volts. This center tap is grounded in one place only, in the service disconnect. It is legal to have up to 6 service disconnects, therefore, up to 6 bonding jumpers, but ALL in service disconnects. The reason to ground the center tap is you need a point of contact in + a point of contact out to get a shock. Connecting something of the hot transformer to earth, in turn plumbing, appliances, wet concrete, and all other conductive objects people might contact, is to limit points of contact to provide shock to a person. Choosing the center tap conductor to ground limits the potential to 120 volts should a person contact on of the other transformer leads. Breakers once only reacted to current. These days many circuits are required to have ARC FAULT CIRCUIT INTERRUPTERS. They sense arcing by recognizing ripples in the sine wave of ac power. Here, they are required in most rooms where people live. Another type is GROUND FAULT CIRCUIT INTERRUPTER. It monitors the current balance in two, or three conductors.
No ground upstream of the service disconnect. You can have a switch or breaker upstream from the service disconnect. It is not a service disconnect. In example, my home has a breaker on the power pole 150 feet from my home. The service lateral supplying the house is three conductors all the way from the transformer to the service disconnect in the basement. Bonding is in the service disconnect only. From the disconnect, to the generator transfer switch is 4 conductors, No neutral to ground bond in the transfer switch. Four conductor feeder to the main breaker panel. No bonding in the main breaker panel. A four wire feeder supplies a sub panel in a different part of the cellar. No bonding jumper there either. From this sub panel, a four wire underground feeder goes to the garage (detached). At the garage, there is no bonding jumper either. The ground system at garage includes the reinforcing steel in the footing, and buried ground rods.
Forever, a range, or dryer not originating in service equipment have been required to be four conductor. Service equipment ends at the enclosure where the service disconnect is. In some cases, this includes circuit breakers for branch circuits. In a mobile home, the service disconnect is outdoors. The breaker panel(s) are all sub panels.
From Post #14, Delmer "I don't see anything wrong with the photo in #10, the red and black on the same screw is allowed on QO breakers, and they're not overloading the neutral because they're on the same breaker. Looks bad, and no reason to have the two wires, but I'm not sure it's illegal." That’s a good point there Delmer. Lets look at the scenario I presented in post 10 again. When I look at these issues, the first and foremost points of concern; Is it safe? Can the person using, or working on the circuit do so safely? Is it a fire hazard? As Delmer pointed out the having both hot wires in a multi wire branch circuit on the same single pole breaker is safe. In this case the breaker will limit the maximum amperage flow between the two hot wires to 15 amps. That’s not 15 amps each, that’s 15 amps total so the neutral current will be 15 amps max. So no, it is not a fire hazard. There is also a proper ground fault current path to protect the user and as long as a worker shuts off the breaker before performing any work, there is no chance of injury to the worker from shock. But, from a design standpoint, the benefits associated with a 3 wire circuit (one less wire to run, reduced neutral current) are not realized and therefore it would have been better to just run a 2 wire romex from the start and branch off at the work boxes if the intention was to use a single pole breaker. I think that in this case they might have just run out of space in the panel and doubled up on the single pole breaker. I stand by the fix of replacing the single pole breaker with a 2 pole breaker.
From Post #14 again, Delmer "A 240 motor is no different than any other 240 load, there is no neutral required. Like a water heater, or 240 baseboard heater, the ground is connected to the frame, and the hots go to the load. If the motor is able to be connected to either 120 or 240, then you can think of it as two 120v light bulbs, wired in series for 240, or parallel for 120. For 120, one lead from each winding will be connected to neutral." Thanks for adding the '240' to 'motor'. That's what I meant in post #9, last paragraph. (I wish we had more freedom with editing our posts) From Post #14 again, Delmer"For the record, NEVER fuse the neutral, OR GROUND." This bears repeating. For the record, NEVER fuse the neutral, OR GROUND. Thanks Delmer!
I think it could be a regional thing, I've heard that up until recently there were still odd systems in place throughout the US. I think that states and municipalities accepting the National Electrical Code (NEC) that there is an effort to standardize everything. Also it could be a holdover from past practices. Are there still Electrical inspectors that have there own ways, sure. Are there still guys out there that say,"That's the way my daddy did it!" Sure. Thanks for the comment Steve!
mitch, I would not call it best practice. I would call replacing the two single pole breakers with a single 2 pole breaker best practice. But, if NEC article 210.4b calls for "simultaneous disconnects" for all multi wire branch circuits and lists possible options as single pole breakers with handle ties, who defines handle ties? (Not me) I'm sorry but I cannot answer your other questions. Maybe someone else.... Thanks mitch.
Willie B, that's gonna take me a while to digest... Thanks for the input!
Bonding is 100% about equipotential. Take a 9 volt battery. Hold one terminal to your tongue, (be sure it doesn't have Corona Virus on it). You feel no shock. You have to touch at least two conductive objects to feel electricity. Now connect the terminals to each other, and repeat the test. You will feel no current. You stop being a path. That is the essence of bonding.
The electrical box CT Farmer posted looks like a lot of boxes I see. When I come across those my standard procedure is to pickup the phone and call a buddy of mine, tell him I have a rats nest that needs attention and take care of the issue. I do enough of my own wiring to know when to call a professional or to ask questions from someone who does know. The biggest thing we have going on now is to replace the old fuse panels with circuit breaker panels. We don't mix white and green wires on the same strip, white wires go on one side and the green all go on the bottom set of screws, been told dozens of times why, but tomorrow I'd not remember all the technical terms anyhow, so we do as my electrician buddy advises. Whoever invented those ground fault outlets should be in charge of keeping them working at no charge to the owner for as long as that law is on the books. When my folks remodeled their house a while back, everything inside had to be up to code, for fire safety issues, so after a half dozen inspections it finally passed. But those that know me were not surprised I had words with the inspector over some of the things he wanted done. I was told it was for fire safety concerns involving wiring. Apparently to ask the inspector that since he's been on the job now [due to the law change at that time] from that day forward no house fire will ever be from the wiring or he'd be canned for not doing his job correctly isn't the thing to ask? The electrician told me maybe I shouldn't be around much till AFTER the house passes inspection.
If you are paying an electrician, and it takes 6 inspections to pass, be very worried. An inspector only has minutes to notice problems. Therefore, you NEED a qualified electrician. No! An inspection can't be thorough enough to rule out all hazards. A code book is several inches thick. Some amateurs it seems, figure out how to violate most articles.
Having worked on many job sites around the country I've seen a lot electricians and inspectors come and go. Every electrician knew exactly what the local inspector had for quirks beyond NEC. Every inspector is a little different but any electrician who requires 6 inspections scares me. What really scares the crap out of me is the people in the big box stores buying electrical hardware for diy projects. How many fires are caused by these folks. If you need directions to put a plug on a cord you better just not try it.
How 'bout the guys in the big box stores that give you that dumbfounded look and say, "are you an electrician?" "No sir, I just pretend to be one on the internet!"
Vermont first recognized a problem, and decided to license electricians effective 1968. There was a grandfather clause. You didn't have to have any knowledge, only $25 dollars every three years, you could buy a master electrician's license. I was 12. I applied for mine. A thinking member of the electricians licensing board returned my application. I'd be able to receive a Master's License, or Vermont was about to embark on a State financed training program. Free of charge, I was eligible for a four year education. In my case I knew everything, so I was annoyed. My father saw it differently. He saw opportunity. I went through the program. It was a six year apprenticeship with education at night. I had the privilege of four of the most brilliant electrical minds I'll ever know. I was the kid awestruck with these brilliant, caring, generous people. They all seemed to enjoy a kid sucking up knowledge. My first year teacher is still involved in teaching. The down side of this is trained electricians weren't universal until those licensed in 1968 aged out. Resistance from slum lords, and the governors they supported ruled out inspections of residential buildings. Even now, an unscrupulous landlord finds loopholes around inspection law. Owner occupied single family homes are still exempt from inspections. Years ago, a bill in VT Legislature nearly passed, requiring paid electricians to be licensed. You could still wire your brother in law's cousin's neighbor's rental for marijuana or beer. The Governor killed the bill. His biggest supporter was a slumlord.
When the house was remodeled, electrical inspections for remodel jobs was the first year it was required. The guy was a complete dick, every time he came, he got paid, so instead of telling us and the electrician, all the old dry wall needed to be removed so he could see the wiring, he'd tell us just this portion needed to be removed and since it was fine, he said, don't worry about the rest. But he required the sheet rock to be removed in precision cutting as to not damage the wires, which was no big deal, but since it wasn't done when he got there, he'd have stop back by. Took only a couple times to figure out we'd better remove all the sheet rock to the entire house so every wire could be seen. Then he changed his through process, some wires "looked" too old, those had to be replaced, so again he'd have to come back. By the end we rewired the entire house top to bottom and the last two times he had to come, apparently there was a law change from the first time to the last time, so we had to tear all the new wiring out of the basement, [from where he told the electrician he wanted it put in the first place] to where he wanted it put for the final inspection. My buddy didn't wire my folks house, so I called him to ask why he turned down the job, after about two visits with from the inspector and he asked, have you met the inspector yet, told him yes, he then asked, have you got the whole house rewired top to bottom twice yet with new, told him at that point, not yet, he said just wait, you will end up doing it, a few remodels have had to do it three or four times before they passed final inspection. He told me the guy's impossible to deal with, he's been tape recorded and video tapped on his walk through inspections to prove what he's said in the past and been reported for telling electricians several different things on the same issue, just so he can come back again due to forcing unneeded changes in wiring. My buddy works in a different inspectors area and at that time refused to come into this inspectors area at all, so he turned us down for the wiring job on the house. I'd later found out the inspector was fired and his certification pulled from my state. There was nothing unsafe about any the wiring that had been in the house, but if it all needed to be new, no issues with me, just replace it with new, there was nothing wrong with how it was wired the first time in the new addition, due to being told by the inspector how it was supposed to be done, it certainly didn't need to be torn back out to redo it the second time and there certainly was no change in the code in two weeks time and each and every time he was there, there was nothing wrong ever, he just wanted to boss everyone around and treat all electricians like they were complete idiots and have the homeowner pay for it all in the end. It certainly wasn't the electricians fault because I was there for the first four or five inspections and I know what the inspector had said and how he wanted it done, the last couple times I refused to be there, thought I'd deck the guy, which is what someone should have done. The theory behind inspections are fine, to have someone else besides the electricians look over the work, but when there is nobody above the inspector to make sure the inspector is doing his job correctly, there can be abuse of power, which is what was the case with this guy.
I'm almost always dealing with State Inspectors. They either last less than a month, or twenty years. My second year in school the instructor was also the State Inspector I had most often. In my early years their districts were separated by county. I live near the county line. One inspector was a pleasure to work with/learn from. The other was AWFUL! He allowed some terrible workmanship to pass that had been done by inexperienced employees of high roller electrical contractors. My work, he spent as much time as it took to find a minor violation, then he would fail the job. I believe he was taking bribes to sign off. I refuse to play that game. A long time customer of mine bought a property with several units for small businesses. The former owner went bankrupt before the place was finished. On the wall in the big mechanical room was a certificate of approval signed by this inspector. Violations were numerous, and major. I took lots of pictures, and called him on it. He demanded I give him the certificate. I refused, "I'll give you a photocopy." He never again gave me a hard time on an inspection. An inspector is a valuable ally in the event of a lawsuit. An expert signing off that all is correct in my work, available to go to court, and testify is good insurance. I wish all my work was inspected, along with all other electricians work.
I have one more issue that I want to cover regarding multi wire branch circuits. For starters, let’s say that whomever initially wired the circuit attached the two hot wires to two single pole breakers without tying the handles together. Just like in the example above in post #12.
Then they used the wiring device at a junction box to provide neutral continuity. Kinda like this.
This is the remains of two temporary work boxes that an electrician set up for one of my jobs. He used 12/3 romex and GFCI receptacles, but he used one of the wiring devices to provide neutral continuity for both hot wires. In the event of a problem with the first work box, it is easy to see how an unsuspecting worker could turn off one breaker while others continued to use the second breaker, and then in an attempt to diagnose and repair a problem at the first workbox, inadvertently become part of the neutral return circuit. This could easily result in a life threatening shock.
For this reason, neutrals in a 3 wire circuit should be pigtailed together in the back of the box with a jumper to the wiring device(receptacle or switch). This is a picture that I stole off the innernet. It's not truely indicative of our situation as it is not a 3 wire circuit but it does clearly show how to pigtail.
Nearly all equipment used must be "LISTED" as in example UL. Laboratory listing is contingent on following manufacturer's instructions. Those wire nuts are not tight enough to earn listing. Many manufacturers instruct tighten until two full spirals of twist are visible outside the wire nut. Three wire circuits were once more common. Now in residences most circuits require ARC FAULT CIRCUIT PROTECTION. Until an AFCI unit is developed to look upstream, three wire circuits are a problem. There can still be three wire circuits installed where AFCI protection is not required. Three wire circuits do not require internal common trip double pole breakers, but a "LISTED" handle tie is scarcer than hen's teeth. Internal common trip breakers are easy to find & cheap. Pigtailing is required wherever neutral conductors are shared, by two, or more hots. In post 13 the copper wire handle tie is not "LISTED" therefore not acceptable.
Or fire anywhere in the circuit. The neutral is the device used to get 120 volts from a 240 volt source. In the event of neutral failure 240 volts will be divided unequally. 120 volt loads might get 200 volts, or 40 volts. 40 volts in a motor will give weak magnetic field, little magnetic impedance, very high amperage, likely the motor won't turn, locked rotor will make for high amperage and subsequent meltdown. High voltage ruins electronics, and lighting.
"Nearly all equipment used must be "LISTED" as in example UL. Laboratory listing is contingent on following manufacturer's instructions. …..In post 13 the copper wire handle tie is not "LISTED" therefore not acceptable." Good points there Willie B. This would be a better solution;
"Those wire nuts are not tight enough to earn listing. Many manufacturers instruct tighten until two full spirals of twist are visible outside the wire nut." Another good point. I should of looked closer at that picture before I stole it! I generally group my conductors together, grip the bare ends with my linemans, and twist together as you said 2 or 3 twists, and then add the wire nut. That way the integrity of the splice is not dependent on the wire nut.
I'm pretty sure this is what you mean? It can be seen by the circuits that with any multi wire branch circuit, if the neutral is opened, the series circuit then becomes a parallel circuit and the voltage divides in a different manner. Quickly resulting in appliance damage or possibly fire.
Yes. A series circuit divides voltage applied. The greater resistance takes the greater share of voltage. Whether your resistors are light bulbs, heaters, or motors, the half circuit with most load, (least resistance) gets less voltage. Add an identical resistor in parallel with the bottom resistor your sketch is correct. Add one in series with the top resistor, your sketch will be correct. As drawn, with equal resistance, each gets 120 volts. It is very common in overhead services to lose the neutral. It is exposed to weather, and corrodes. It is the cable used to support the other conductors, so storm damage, it is the first to go. Underground services; frost lifts the post a meter might be mounted on a little each year. Eventually, it stretches the conductors, pulls them out of the terminal. Neutral failure is pretty common. 50 years ago we mostly had incandescent lighting. Damage was often limited to blown bulbs. These days electronics are plentiful. They do not do well!
what would be wrong with this ? I want to run a 240 volt under ground feed under my driveway to approx. a 140' beyond. since i already have 240 going under to the well why could i not tie in to the well feed line and not have to dig a trench across the drive? well feed is substantial wire
As long as your sleeve under the road is big enough to pull wire through, and has ample space , it shouldn't be a problem
What is the gauge of the existing well pump conductors? Is there 2 hots, one neutral and one ground? What new appliance do you want to feed? Will it be running at the same time as the well pump?
We bond Neutral (I wish it was called center tap) to Equipment ground & in turn earth for a couple reasons. A It creates an equipotential plane. Can't get a shock if everything you touch is electrically bonded to everything else. B It provides a fault current path completing the circuit to transformer. Typically, a fault current path with low impedance will flow sufficient amperage to trip a circuit breaker. Equipment grounding paths should not carry everyday current. We want all current to flow over intentional paths. If you bond at more than service disconnect some portion of that center tap current will flow over equipment ground paths. Current flowing over equipment grounding paths is dangerous. Connections in equipment ground paths are numerous, they are prone to inadequate connections. I've seen several places where conduit enters a box. They are burned away from current over a high resistance connection. Electrical inspector tells the cautionary tale of an appliance delivery "installer" putting a three wire cord on a range. This one is real common. He discarded the jumper strap required in the exceptions allowing three conductor circuit cable. Since the strain relief supplied with these cords never fit, he discarded it too. He then shoved the range against the wall pinching the cord against a sharp sheet metal edge. I'm not shure where the sheet metal cut into the cord insulation, but it did. For a year Mrs. Jones used the range with the frame energized by a "hot" conductor of the cord. With no ground path jumper, no circuit was completed, breaker didn't trip. After a year, the plumber was there addressing a problem, happened to touch sink & range. He was killed. Bond neutral to equipment ground only in service disconnect. Rules are circumstance specific, usually, do not bond in outbuildings. Outbuildings in new installations require both neutral & grounding conductors & driven ground rods, concrete ground or substitute.
The well only gets power when the pump needs to run. Despite the safety reasons not to do it, it wouldn't work.
Depends on where the pressure switch is, whether the well has power all the time or only with the pump running. Everything else in post #49 is reason to be careful.
"Yup, got my new compressor hooked up in the shed, gotta flush the toilet to turn it on!"
But if the jumper required in this installation had been in place, it'd trip the breaker.
Great thread. We are on a 5 acre split up into 1.25 acre lots with a group B well. The original fellow who put it all together had moved on, and left me with the pieces. One day well quit working. I get out my meter and find ~70 volts on one leg. The other 50 are leaking away somewhere LOL. Nothing to do but dig in a new service to the wellhouse, and along the way figure out the problem. He had direct buried the wire to the wellhouse in the giant potato rocks we have, no bedding, then brought his log truck home every night across it. Needless to say it went back in conduit and hand bedded. IF that post above is wire out to the well house, you could use the run as long as you turned off or otherwise disconnected the pump load when you wanted to use it. That would be the only way I could see that would be safe, as your loads and breakers need to be sized correctly to protect you and your equipment. If you want simultaneous operations, then you'll need to pull separate wire all the way to a panel, or put in a sub panel at the well house and wire accordingly. My wellhouse has a 100 amp panel and enough wire to do the 100 easy, far in excess of the loads. A neat trick I used was a 4 wire 50 amp twist lock connector on both the well pump and the pressure pump, and outlets on the wall. I have enough 240 volt generator to run one or the other, and a 500 gallon storage tank. In an extended power outage I can make sure the storage tank is full and then run the pressure pump by plugging it into the generator. No transfer switch needed. After about a day of that I plug in the well pump and fill the tank. It has happened only once since I set it up but still worth the trouble for 4 families to get to flush the turlet etc.
nuff said to make me scratch that idea
Here's one. Last weekend I was installing a new window at my house. In order to accomplish this I had to remove 2 receptacles on two different circuits. The first receptacle had been for a wall AC unit, only appliance on that circuit. I tested for voltage, identified the breaker, shut it off and to be on the safe side I tested for voltage again, with my meter set to AC voltage, between the hot wire and the neutral and then again between the hot and the ground. ***!!! I still had 1.4 volts! This lead me to consider that I may have stray current on my grounding system;
So then, just for shats and gurggles, I decided to shut off the surge suppressor that I have for my home theater. Voltage reduced to 0.85 volts. So I turned the surge suppressor back on. Still 0.85 volts. Hmmm... Now I'm still thinking stray current. Time for the next receptacle. Different circuit with multiple receptacles. Same test. Meter set to AC volts. Shut off the breaker. Probe the hot wire and the neutral. 0 volts. Probe the hot wire and the ground. 0 volts. Whatcha all think?
Cables run close to each other will induce voltage in the one that's not connected from the one that's live. That's what I assume when an UNHOOKED wire has voltage. Your ground and neutral should still be connected at the box. If they're not, you got bigger problems.
Induced voltage? I was thinking bad breaker... In the main panel (or sub panel if that's where it came from). Yes.
easy enough for you to loosen and pull the wire out of the breaker and go re-test.
https://www.jadelearning.com/blog/t...020-nec/#:~:text=Equipment Grounding Conducto Worth reading, makes your hair hurt too. Joe H
I really wish Code hadn't chosen such similar names for very different use conductors. I offer center tapped for white, neutral, instead of grounded. It connects to the center point of the secondary winding of the utility transformer. Grounding could be left, or labeled fault conductor. I think it'd make for less confusion. Current on center tapped conductor is fine. Current on fault conductor is to be avoided.
The trouble is, it is not always center tapped. There are still 120 volt only systems out here. One conductor is grounded, the other is hot. Or you might have a 240 delta or 480 corner ground 3 phase system with only 3 wires. One of the 3 phases happens to be a grounded conductor, not a center tap or neutral. I do agree that the wire we color green or bare should be called something other than a "ground" wire, though. I like the term bonding, because its purpose is not really to take things to earth. More that it is to bond everything metal to everything else.
Yeah, but I imagine those other systems are most commonly used by trained electricians. The neutral grounded residential single phase used universally in USA is where I see do it yourselfers screwing it up. I do a lot of standby generator installations. One step in the process is separating grounded from grounding as the new service disconnect is in the transfer switch. I see atrocious messes. Often I see bare conductors carrying current.
Regarding 240 volt, 2 wire vs. 3 wire. My well pump service cable, from the panel to the pump control, is what I call 12 gauge 3 wire. It has 2 hot conductors, 1 neutral conductor and one bare ground/bonding conductor. Then, at the pump control there is a 12 gauge 2 wire service cable to the submersible pump. It has 2 hot conductors and one bare grounding/bonding conductor. My question is; "What should the neutral conductor be connected to? Nothing? It terminates at the pump control."
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Again
Wow! Those pictures are horrible! Sorry.
The pump doesn't need a neutral, so 12-2 wire with ground would have been enough. Technically, the white wire should have a wire nut on it I believe, and the white wire connected to the red should be identified with black electrical tape (or other colors).
Thanks for the reply Delmer. So I believe the answer is "Yes, the neutral conductor in the 12/3 that comes from the panel should be connected to nothing, on either end, not connected to the neutral bus bar in the panel and not connected to anything at the pump control." "and the white wire connected to the red should be identified with black electrical tape (or other colors)." And yes Delmer, the white conductor in the UF cable is being used as a hot conductor and should be color coded accordingly. Thanks again.
I’ve seen those neutral-ground bonding mistakes in subpanels cause big problems. Always keep them separate except at the main panel.