Electrical, AC & DC. The purpose of the two pole breaker is to insure that if a fault occurs it trips both Although I would run a 120/240 volt feeder, you could run a 120 volt feeder protected by a 50 amp single pole breaker. Tx. Another wiring practice, using a single two-pole breaker to power a split circuit which uses a shared neutral, such as may be installed in kitchens in some areas, is nearly certain to have each leg of the circuit loaded independently and thus subject to single-leg overloading and subsequent breaker jamming. Now take just one hot leg with respect to ground. Another circuit can be ran off the other leg, provided that the neutral, white wires, are separate on the ground bus bar, which they all are. the phases of a 3 phase are 120 degrees, or 1/3 second apart. Electronic Equipment and Computers, http://www.mjobee.com/projects&news/...rt%20210.4.pdf, Zinsco breakers: slims vs standard, single vs 2 pole, 120 vs 240. Unless that "fused" disconnect is not "fuses" but is a "breaker". Using one side of a two pole circuit breaker would work but it is not proper. They are normally installed in situations where the breaker box is alr… Is sealing old wood floor necessary before carpet tiles? I'm putting a 60amp subpanel out in my shop. Can a SQ-D double pole breaker with single lever be used for two 110 volt circuits. There is a small piece of plastic that connects the trip mechanisms. The black wire will connect to a 20A breaker. AxV=W. The breaker must be able to trip before the wires connected to it can become damaged. The handle tie is there so that it will trip the other breaker is one is tripped - if the handle tie does not provide that function, then the handle tie is not appropriate for those single pole breakers. A two-pole breaker consists of two breakers. They are constructed with one hot wire and one neutral wire. I have two 3-way switches that operate a pool light. Jerry, as long as a fused disconnect is legal for the circuits in question, and they still are, there is no requirement that the over current device open both ungrounded conductors at the same time. On todays inspection, there was a double pole, 30 amp. This kind of breaker stops the current during overloads and short circuits to prevent wires from overheating. The two phases disconnects are tied together inside the breaker itself so that if one phase trips it kills power to both. Then went to the main panel and checked the conducter coming out of the breaker that feeds the subpanel. You can use one half of the 2-pole breaker. So you need TWO separate double-pole … Because this is NOT the way handle ties work is the reason that handle tied single pole breakers are restricted in 240.14. Just run another wire to a single pole breaker and a neutral wire for your 110v supply. i'm using a single pole 30 amp breaker. Circuit breakers come in several styles, including the standard single-pole breakers that serve 120-volt household circuits and double-pole breakers that take up two slots in a breaker box and serve 240-volt appliances. I forgot to mention, that per ABYC, you can use SP breakers for you AC circuits IF, and only if the master AC breaker is a DPDT and as BB noted there is a reverse polarity indicator on the panel that lights if there is voltage on any leg other than the hot leg. Two Pole Breakers With One Switch A two pole breaker that has only one switch is called an internal trip breaker. How to get 120/240v from generator into my house. A three-pole 100A breaker will draw 33A on each leg.>People have funny concepts about electricity , the above is totally false. The language of the code that covers multiwire circuits and 120/240 volt circuits is quite specific as to under what circumstances individual handle tied breakers are permitted. It sounds, though, as if this water heater requires TWO separate 40A 240V circuits -- 80A total. High leg only matters if you're using a hot leg and neutral. Hi, Thanks! DO NOT GO TO TWO 40A. If that was the case, you could pull an infinite amount of current on one leg through a subpanel as long as the other leg remains less than the rated current of the OCPD. So here's the situation. Anyway, with the handle tie you only loose the circuit with the problem in a tripped situation. Nawww. In what situations would a 120/240 two-pole GFCI breaker be recommended? I'm guessing a 30A single pole would be fine, but perhaps someone else can give you a better number with more info. Breaker let power run to sub panel on one leg. i'm using a single pole 30 amp breaker. Here is what happened. The AWG wire was # 10 awg. The neutral does not remain "hot" but what the double pole breaker does is make sure the current from the other leg of the multiwire circuit also stops flowing through the neutral, otherwise you could disconnect the neutral and have a lot of current flowing through it, making for one large arc, and resulting affects, which could include fire, electrical shock, etc. You may freely link Or must it exceed 30 amps? As noted, the breaker is supposed to be marked 240, not 120/240 but the vast majority will use a basic 120/240 breaker. Without commenting on your installation there you would use a 60 amp breaker. We never use high leg to neutral and always use 2 pole breakers on a high leg for motors, etc. My contractor is telling me they do not meet code in IL since they are not contained in a metal box. I've installed double-pole breakers to bring 240v to a dryer before, and the breaker simply snaps into two places on one leg inside the panel, not both legs at one time, and each hot wire on the double pole breaker brings 120v to the outlet to equal 240v. If you don’t know what you are doing you should call a licensed electrician or consult an experienced electrical engineer. The dryer outlet is not in use. A "neutral" or "return" line is connected to appliances and outlet receptacles to complete the circuit. (The bottom 3-way switch - left side of pic - operates the kitchen lights.) (adsbygoogle = window.adsbygoogle || []).push({}); All answers based on unamended National Electrical codes. Single-phase power in NOT just one leg of a 3-phase feed. The advantage of the two pole breaker is that it completely. Both breaker types are considered common trip breakers because if one leg trips the other is forced off as well. Put a cover on the junction box? There is a small piece of plastic that connects the trip mechanisms. If the breaker should trip it will simply also trip the unused leg. 4 pole seems to be an IEC thing. And then two others could easily be taken up by two 13-15amp machines running concurrently (band saw and table saw for example). Those two poles of the 200 amp breaker are in a series circuit at 240v. But that does NOT mean there is "20A" in the circuit. Do you agree? A double pole breaker is a circuit breaker that allows two poles in your circuit breaker panel to feed one circuit as in a 240VAC air conditioner or electric stove. The other remains on except for the momentary interruption when you reset the tripped breaker. When I'm working with a high-leg system, I will always use the high leg and another phase unless there's a valid reason not to. Never for MWBC involving a neutral of course. the reason is that I don't get quite what I want with either of them. So in order to do that I'd need a 60amp breaker in the house panel. A circuit breaker controls one "hot" leg of a circuit. There shouldn’t be a 120V circuit created from one leg of the two-pole. We’re replacing it in a few months, but in the mea... Hello. Don't know about double pole DC breakers, but in double pole AC breakers, both trip if either exceeds the rated current for a single leg. Another scenario is to take an unused 240/120 30A #10 4-wire ( two ungrounded hots + neutral + ground ) and turn it into a multi-wire branch circuit, MWBC for short. Yes, they may not all be using 15amps at once, but it's possible. A 2 pole breaker will trip when either pole (or both) is (are) overloaded as the trip mechanism for both breakers is tied together internally. If the full load amps are that close to 15 amps then they should be 20 amps with #12 wire. I got 121.5V on both legs. systems a two pole breaker is used, with one pole on each leg of the supply circuit. A "hot" wire, that is, the one that supplies the power, is fed through a circuit breaker before it goes through a building's wiring to wall outlets and appliances. Technical Topics For Home, Commercial & Environmental Inspections, Electrical Systems: Home Inspection and Commercial Inspection, 2 pole breakers used for 2 single pole circuits, Double pole 220 volt breaker used for 110 circuit, www.ConstructionLitigationConsultants.com, If this is your first visit, be sure to Occam's eraser: The philosophical principle that even the simplest solution is bound to have something wrong with it. One is by a transformer having four wires coming out of the secondary, the three phases, plus a neutral connected as a center-tap on one of the windings. It could actually be a single circuit. 01-28-2017, 05:37 PM #3. If a 30 amp double pole breaker was 15 amps on each leg, then a 20 amp double breaker would be 10 amps on each leg. I had two inspections for the wiring of a new shop and walked away with an okay... My fuse box is full and I would like to add some lights in our basement along wi... Silllites - are they allowed per code in IL? .....and letters from any other manufacturer will say the same thing. There is a junction box (located outside) that the light's wires go to before running to the outside switch. Previous advise I rec'd from an electrician I cornered at Lowes did not work, and he examined the pic I'm about to upload. But, if you only hook up one … Remove the outlet and tie the individual wires from the breakers to their respective circuits with wire nuts (in the outlet junction box). If this is a MWBC the 2 pole CB or two single poles with a handle tie is. ... because the "B" phase (breaker #3 and #4) and every third breaker afterwards will be either a three-pole breaker or a blank. These are usually small services under 400 amps. Any assistance is greatly appreciated. If you say so, Justin. Each one connects to one of the hot bus bars in the panel, which makes the voltage of the circuit 240 volts. mgt. I was hoping to use Silllite outlets in my kitchen island. This can take place when a hot wire contacts a ground wire, another hot wire or a neutral one. When single-pole breakers are installed, they snap into one pole to receive 120 volts.Double-pole breakers snap onto two poles for a total of 240 volts. Kenton, you only have one of the two measurements needed for the formula. The largest one I can remember building was 1,600 amps. Just lost power a few moments ago. check out the. so you're saying they moved the white to the neutral bar to make it a single pole circuit and then added a circuit to it? A single pole breaker is typically used with 120-volt circuits, 15-20 amps. Now that leg can draw 200amps on that side and current returns on the mid tapped neutral for half the cycle and 200 amps can be drawn on the other leg similarly. The current in the two wires is not additive. Q: I have a 240-volt electric job-site heater, which is required by the NEC to be GFCI protected. Even more fun, when you have a 400amp breaker blow, causing the other phase to blow out that side. A 50 amp breaker will easily handle the load on 4 - 15 amp circuits. Somewhere between your main service disconnect and the transformer one of the legs is open. I don't believe the NEC expresses a preference. Double pole breaker being used for 110 circuits. This causes the other half of the breaker to trip at the same time because the two halves are tied together by the single breaker bar or toggle. Only if you have two circuits on one device, as a split receptacle with one circuit on top and another on the bottom, do you need to use a 2 pole circuit breaker. Pic #2 is [COLOR="#0000FF"]the outside 3-way switch for the pool light[/COLOR]. A special kind of circuit breaker is the tandem breaker, which is designed to allow two 120-volt circuits to be fit into a single slot in the circuit breaker box. Breaker let power run to sub panel on one leg. 3 pole breaker in place of 2 pole breaker. There is no 10 amp circuit breaker or 7.5 amp breaker made for residential breaker box. Either run a 4-wire 240V supply or use a single-pole breaker. The installer would remove the 30A breaker and install a double pole 20A breaker and relabel the breaker to its corresponding loads. Here’s a little bit more about both single-pole and double-pole breakers: Single-Pole Breakers Nashkat, a 2-pole breaker does not trip through the handle. I only get 6V on the other leg. Licensed electrician suggested replacing an existing 30Amp double pole breaker for the garage with the 50Amp breaker, then double tap from the same breaker to feed both the 50amp range, and the garage. One is located inside the house & the other is located outside by the pool. That's why they're usually connected together with a metal bar, such that you have to throw both breakers at the same time. Circuit Breakers Control One "Hot" Wire. We have a Zinsco style panel. Since you’re asking about the service coming in off the utility pole, the only breaker is the fuse at the transformer, or the wire itself. My panel is maxed out, and I need to install an 240V-50Amp outlet for an electric range. Easiest way to replace pressure regulator valve. Another posting in this forum didn't have the same color wires, so I was reluctant to try that. Safety First. If you put a current meter one leg, it reads 10A; if you put it on the other leg, it also reads 10A. Is this correct? The old dryer was connected to the panel via a double-pole breaker except that there was no clip or tie between the poles. That's what I was afraid of. That's basically a resistor so I had a voltage drop and now we get 46v feeding back across the dead leg to the building and the lights. However, 220 volt devices require the rated amperage for each leg. That language says only that a disconnect has to turn off both ungrounded conductors simultaneously, but says nothing about the overcurrent device being required to do so. No, a 15 amp load will not trip a 30 amp breaker. It sums the current of the load and uses that as a reference as the current leaves one leg of the breaker. Single-pole breakers I want to convert the outside switch to an outlet (GFI). the two pole or double pole thermosat do have off postion so it will shut off complety. Replace the 30 amp double pole with a pair of 15 amp single pole breakers. I'll say one thing Jerry, when you decide to dig holes they're deep. ' DoItYourself.com®, founded in 1995, is the leading independent If the panel is tight on space, you may be able to use Twin Breakers for a few of the 120 volt circuits to free up some space, this would depend on the panel make and model. In theory, the current coming back should be the same. Using a Double Pole Breaker to feed two circuits [ 11 Answers ] I have 40' run from the main panel with BX and want to use 14/3 instead of two runs of 14/2. For a 240 volt breaker, it will be the size of two 120 volt breakers, and hook on to each 120 volt leg making a 240 volt total. Most of these situations are where a person converted an AC receptacle from 240V to 120V, but instead of removing the two pole and using a single pole they just use the two pole and leave the other leg open. It will break both side of that circuit .,, the other reason why it may be stuck on it dont matter if single or double pole if the concants are welded shut ( that do happend … Questions of a Do It Yourself nature should be They are constructed with one hot wire and one neutral wire. Two Pole Breakers With One Switch A two pole breaker that has only one switch is called an internal trip breaker. Nice fourth of July action. However, the two-pole breaker should be dedicated for whatever appliance (most likely a dryer) it protects. All information is provided "AS IS." Re: Using a two-pole breaker to interrupt a single-leg circuit Yep, correct on both counts. A “double-pole” circuit breaker is clipped into both 120 buses at the same time, so the voltage to the circuit is doubled. Will it resolve the issue if I: 1. With a 240 volt two wire system, that is- 120v - 120v to feed a high current (power) system, both circuit breaker inputs will be feed with 120 volts (first phase) the the other 120 volts from the other phase to the other pole. It is this switch that I want to convert to an outlet. Certainly they would not be at maximum capacity. This will not protect the wiring you have. of the same type, or install a 20 A. two pole breaker . If that's the case then all the MWBCs on 2-pole breakers are accidents waiting to happen. submitted to our "DoItYourself.com Community Forums". 3. I guees I don't completely understand the reply. If it was a single pole breaker, there would be no problem. However, the problem is that the largest single pole breakers that are made for my panel are 40amp. so any two legs supply one phase only, just like residential. A single pole breaker is typically used with 120-volt circuits, 15-20 amps. home improvement and repair website. Your instantaneous water heater or other 220 volt loads that you apparently don't miss are most likely able to feed back from one leg to the other. The purpose of the breaker, is just to ensure that should any of our equipment short, break, get hit by lighting etc that the breaker will trip, and not affect other the main power in a negative way. ... High-leg delta service is supplied in one of two ways. two breakers in one housing with two separate switches tied together from the factory; two separate breakers with a tie connector field installed. A two-pole 100A breaker will draw 50A on each leg. If 3 wire romex is used as a branch circuit to supply two 120V circuits (Black, Red, and White wire) a two pole breaker must be used so all ungrounded wires in the multi wire branch circuit are disconnected simultaneously. Nashkat, a 2-pole breaker does not trip through the handle. Double-pole breakers: Provide 240 volts, 20-60 amps and have two hot wires that share one neutral wire. In some circumstances a 120V circuit requires a double pole breaker. In all cases one leg only can be used. correct a wise man and you gain a friend... correct a fool and he'll bloody your nose'. View our Privacy Policy here. A 2-pole breaker only loaded on one half is likely to have too much mechanical resistance to do that. The 480v (or higher) 3-phase distribution line powers a delta-configuration primary pole transformer and the complex-connected secondaries of that step-down transformer are what feed the 1-phase drops to the homes/businesses. legs a-b,b-c,c-a are 240 … Ignore the label that says "hot tub" there's not one installed. A "hot" … The 4th I probably won't use now, but want just in case we need it later. Current flows from one point to another through the CIRCUIT, and the circuit consists of those two wires. how to get 120 volts out of 208 3 phase using a tandem breaker 2 circuits in a single slot breaker consult with codes before doing electrical wiring A 3-phase breaker used in place of a 2-pole breaker on a 3-phase system, such as a 2-pole breaker used in a branch circuit that is actually two legs of a 3-phase system, is acceptable without the 3-pole breaker being specifically marked. wiring a G 73, have 2 wire with ground, L1 to white wire, L2 to black wire, copper to ground wire. The NEC requires the simultaneous disconnect and, I. This current shutoff prevents electrical fires. You can use one half of the 2-pole breaker. Either replace the bad 20 A. single pole breaker with another . The sublanel had a breaker for a 220v heater. Illinoyance liked this post 01-28-2017, 08:06 PM #8. I have 120V to each leg, L1 and L2 but the heater won't come … read more We welcome your comments and When operated, the breaker will open both the neutral and the live wire, isolating the load from the circuit. https://www.thespruce.com/what-are-double-pole-circuit-breakers-1152727 The neutral does not remain "hot" but what the double pole breaker does is make sure the current from the other leg of the multiwire circuit also stops flowing through the neutral, otherwise you could disconnect the neutral and have a lot of current flowing through it, making for one large arc, and resulting affects, which could include fire, electrical shock, etc. If you disconnect all 220 volt loads (flip the breaker) you will likely find one leg goes dead. to this site, and use it for non-commercial use subject to our terms of use. Any 240v / or double pole breaker - should be not splitting / or sharing loads - they should be a dedicated single 240v device . If a 30 amp double pole breaker is used for two 110V circuits, will it trip if one of those circuits exceeds 15 amps? A 40-amp double-pole breaker is 40 amps on each leg. A breaker will clip or hook on to one of them in various ways, depending on the type you have. And includes the entire circuit - no added loads to one leg … Will a 120/240 two-pole GFCI breaker provide protection for a 240-volt load with no neutral? Here is what happened. That is, a 30 amp double pole breaker isn't 15 amps for each leg, it's 30 amps per leg (same as a switch). disconnects all power to the circuit. The sublanel had a breaker for a 220v heater. Additionally, change out the double pole breaker for a single pole breaker and fill the empty space with a panel blank. A double pole breaker is primarily used with a 240-volt circuit, 20-60 amps and consists of two … A 2-pole breaker is normally used where you're hooking up a 240-volt service. Just because you have two poles on a breaker, one pole can go bad, while the other still works fine. (4) 15 amp breakers in the shop subpanel shouldn't require a 60A main. The first, a single pole breaker and the second, a double pole breaker. With two singles, one can open, stopping the pump, The beatings will continue until morale has improved. So you will use all 3 wires, all of which are required for a 120V circuit. Regards, Mike Entering the subpanel,I get 120V on one leg. In this case you cannot break the handle of a 2 pole breaker. Thanks. Or perhaps he's misinformed??? All rights reserved. I prefer tied single breakers on a multi-wire circuit so that the only time both circuits go off is when the handles are moved to reset a tripped breaker or intentionally turned off. You will need to connect the #12’s to either a 2-pole 20 amp breaker or two 1-pole 20 amp breakers that are side by side and have a Tie-Bar connecting them. The above statements are expressed solely as my opinion and in all probability will conflict with someone else's. It sounds like the two breakers are attached to the same buss, so your only getting the 110 volt reading. Thanks, and the reason is that I don't get quite what I want with either of them, but that's ok. Will just go with the single pole option I think. suggestions. So total amperage available is what the ampacity of that size wire is, or the fuse at the transformer, whichever is less. We’ll take a closer look at the differences between each of these breakers and discuss when you should use one over the other. The two phases disconnects are tied together inside the breaker itself so that if one phase trips it kills power to both. One leg had power one didn't so it backfeed across the dead leg through the heater element. You say you want to use all 4 circuits concurrently, but for what use. And a 15 amp double breaker would be 7.5 amps on each leg. problems contact webmaster@doityourself.com. Single-pole breakers: Provide 120 volts, 15-20 amps and have one hot wire and one neutral wire. For instance, one circuit is basically taken up by all the fluorescent lights I have going. Breakers go bad, whether they are a Single pole or double pole. For some reason I've been finding a lot of 120V circuits fed from one pole of a two pole breaker. This is a double gang, where [COLOR="#0000FF"]the top switch - right side of pic by the date stamp - is for the pool light[/COLOR]. A 30 amp two pole breaker allows up to 30 amps per leg or phase to conduct in fact provided a "total" of 60 amps. A 2-pole breaker is normally used where you're hooking up a 240-volt service. Look in the panel cover - look at all 240v breakers - there should be only one wire to each side of any 240v breaker . Two-pole breakers control circuits for large appliances. That's basically a resistor so I had a voltage drop and now we get 46v feeding back across the dead leg to the building and the lights. The first, a single pole breaker and the second, a double pole breaker. It would also mean that an unbalanced overcurrent condition in say a subpanel would mean meltdown rather than trip. This can happen if you are using a Twin Breaker. Using a Two-Pole Breaker to Feed Split-Wired Receptacles with Break-off Tabs ... a multiwire branch circuit supplying more than one device or equipment on the same yoke shall be provided with a means to disconnect simultaneously all ungrounded conductors at the panelboard where the branch circuit originated. Click to see full answer Beside this, how does a double pole breaker work? wiring a G 73, have 2 wire with ground, L1 to white wire, L2 to black wire, copper to ground wire. One leg had power one didn't so it backfeed across the dead leg through the heater element. BREAKERS. Circuit breakers come in several styles, including the standard single-pole breakers that serve 120-volt household circuits and double-pole breakers that take up two slots in a breaker box and serve 240-volt appliances.A special kind of circuit breaker is the tandem breaker, which is designed to allow two 120-volt circuits to be fit into a single slot in the circuit breaker box. 2. Website operating Some makes of breaker have the single handle for a 2 pole and some have two handles with a tie, but will still trip both poles if the tie is removed because of the internal connection. Nothing to do with Ohm's law. Using a Two-Pole Breaker to Feed Split-Wired Receptacles with Break-off Tabs ... a multiwire branch circuit supplying more than one device or equipment on the same yoke shall be provided with a means to disconnect simultaneously all ungrounded conductors at the panelboard where the branch circuit originated. A circuit breaker controls one "hot" leg of a circuit. breaker with only one hot lead coming off of it. The way the breaker works is via "vector addition." What size wire or cable were you planing to use? I have never found myself looking for a four pole breaker. Does this mean that in theory as long the wires were a large enough gauge it could work? Copyright© I just learned something (again). We are considering the following two circuit breakers: Single Pole… I would have thought that the 240 breaker would not trip if one 120 volt circuit overloaded. More data. PIC #1 is the inside switch.