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What are two black wires attached to a single breaker lug called?
This condition is commonly known as a "Double Tap", and is only permitted if the breaker specifically allows it. Some Square D breakers and possibly other manufacturers allow terminating two wires under the screw, and if the breaker allows it, it will be identified as such on the label.
If your specific breakers do not allow two wires terminating under one screw, you will need to install another appropriately sized breaker for that circuit, assuming your panel has the space available for the additional breaker.
As always, if you are in doubt about what to do, the best advice is to call a licensed electrician. Before you do any work yourself on electrical circuits, equipment or appliances, always use a test meter to ensure the circuit is, in fact, de-energized.
IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.
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If it was two wires under one screw on a single-pole breaker, that would not be proper, and most probably against electrical code. If it was two wires, each under th…eir own screw on a double-pole breaker, then that would be a 220 volt circuit; each wire going to its own "leg" of the breaker panel.
Sounds very strange and that the electric code isn't being met. If it is main box a ground rod can be driven into earth and a wire grounded between box and ground rod. However…, you should have an electrician investigate what is going on since this box is a safety hazard.
I believe it is, as long as the wires are the same size i.e. 2 12/2s or 2 14/2s.
Overcurrent devices cannot be doubled up for higher voltages. You need breaker designed for 220V. While you are technically correct, you need the 220V breaker because it is de…signed so that you always get 220V from the two phases (as opposed to 0V from one phase) and so both "breakers," so to speak, always trip together. Don't just use two 110V breakers you have lying around, it is not safe. The approved method is to obtain a 2 pole breaker of the right amperage to run your 240 volt appliance. Also approved but not used as much is a common tie bar that incorporates the two breaker toggle handles into one. The reason for this is safety, if just one breaker trips there will still be 120 volts to ground on the un- tripped breaker. Anyone working on the appliance thinking that the power was off could get a severe shock. This holds true also with switches to turn off 240 volt loads, don't just use a single pole (SPST) switch which just shuts off one leg, use a double pole single throw (DPST) switch which isolates the load completely.
Look at the faceplate. There should be a 75˚C or 60˚C rating bsed on the temperature rating of the terminals. You have to use the lowest rating shown, ie, if you use 90˚C c…able with a 75˚C termination, you have to derate the cable ampacity to a 75˚C. An example is look at 310.15(B)(16) in the 2011 NEC. 500kcmil cable is good for 430A in this table at 90˚C, if you had to derate to 75˚C, you loose 50 Amps and derate to 380A.
Positive and Negative Terminals.
The rule of thumb for a single phase 240 volt motor is 7 amps per HP. The code book only includes up to 10 HP motors. So 7 x 15 = 105 amps. Motor conductors have to be rated… at 125% of the full load amps. 105 x 125% = 131 amps. A #1 copper wire with an insulation factor of 90 degrees C is rated at 140 amps. The breaker for a motor load should be 250 % of the full load amperage. 105 x 250% = 263 amps. The next biggest size breaker up from 200 amps is 300 amps which will work and still be within the electrical code standards. It is for this exact reason that larger size motors are usually three phase and require higher working voltages to reduce the wire size and breaker sizes.
black wire is hot wire .And the white is the common or white is ground. Depends on what your talking about in an outlet or car battery. In a outlet the ground wire …is green or bare copper. neutral is red and hot is black (I remember it by hot can kill you so black is death) if I am not mistaken. As for a car battery i think it's the opposite red is hot and black is neutral.
With a 2 wire + ground sized to the amperage that the load requires. From one lug on the breaker to the load, then from the second wire on the load back to the other lug on th…e breaker. Be sure to connect the ground at both ends, at the panel under the ground strip and at the load end under the ground screw. IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB SAFELY AND COMPETENTLY REFER THIS WORK TO QUALIFIED PROFESSIONALS. If you do this work yourself, always turn off the power at the breaker box/fuse panel BEFORE you attempt to do any work AND always use a meter or voltage indicator to insure the circuit is, in fact, de-energized.
question does not contain enough information to be answered. If you mean the wires on a device, it means it does not matter how it is connected. If you mean wires supplying p…ower, something is wrong or they are so old the white has become so dirty you cannot see it.
If you ran a wire between two 110V breakers, then you've created a phase to phase dead short. You could arc you entire panel. Sounds like you don't know what you're doing in a…n electrical panel. Get a qualified electrician to install a 220V breaker before you start a fire or get hurt!
This will depend upon the current draw of the ACs as well as the size of the circuit. My guess, based upon what 240V units tend to draw, is that you probably won't be able to,… especially if the circuit is only 15 Amps. With a 20 Amp, you MIGHT be able to. You will have to check the nameplates on each unit to find what the current draw is and ADD THEM TOGETHER. And remember that AC units should be considered a continuous load. This is when a load may run for three hours or longer. Here, you must "derate " the circuit by 80%. So a 15 Amp circuit should only have a load of 12 Amps; while a 20 Amp should have a load of only 16 Amps. My best "guesstimate" is that they will need their own circuit.
What is the wiring gauge breaker size and type single vs Double pole requirements for wiring in a 240v single phase 15amp 60HZ compressor motor?
You will need a two pole breaker for the 240 volt. Recommended wire size would be a #12 copper wire RW90 C connected to a two pole 30 amp breaker. As always, if y…ou are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed. Before you do any work yourself, on electrical circuits, equipment or appliances, always use a test meter to ensure the circuit is, in fact, de-energized. IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB SAFELY AND COMPETENTLY REFER THIS WORK TO QUALIFIED PROFESSIONALS.
My new table saw has a cord with three wires total red black and green can you run two wire BX from the breaker panel and if so do you just consider the black and white as hot and no neutral?
Sounds as though your saw is a 220 volt saw. If so then yes if you run a 2 conductor BX cable you will employ the black and white conductors in the cable as the two "hot" cond…uctors. So just wire black to black, and red to white. However, you should be running a 3 conductor cable to provide a ground to your saw.
I would like to take a 220 volt 3 wire black white and bare and connect it to a sub panel or two separate 110 circuits for a workshop The 220 is powered by 2 20 amp breakers connected?
Answer for USA, Canada and countries running a 60 Hertz supply service. i personally would use a 2 pole 20 amp breaker since its a safety issue since 1 hot would be live if a… unqualified person would work on that circuit later and not knowing better! code violation also The above answer missed the point completely. The black, white and bare ground wires are not considered to be a three wire cable. In cable sets the bare ground wire is not counted, as it is not a current carrying conductor. To achieve what you want to do the wire must be a three wire cable with a black, red, white and bare ground. To do what you want on a two wire means that the neutral wire for the two separate circuits must use the bare ground wire. This is against what the electrical code requires, as all current caring conductors must be insulated. A sub panel requires three insulated conductors for its operation. Install a new three wire cable to feed the sub panel. Before you do any work yourself, on electrical circuits, equipment or appliances, always use a test meter to ensure the circuit is, in fact, de-energized IF YOU ARE NOT REALLY SURE YOU CAN DO THIS JOB SAFELY AND COMPETENTLY REFER THIS WORK TO QUALIFIED PROFESSIONALS.
Your question presumes that each connected wire would be a separate circuit. They are not. However, you may place as many as 2 wires on a breaker, provided they are the same… size and both either stranded or solid. Do not mix solid and stranded or different size conductors as this makes it likely that one wire will not be as tight as the other. It is better practice, and in some local jurisdictions is required, to put only one wire on the breaker, run it to a junction box outside the panel, and branch from there. It eliminates confusion and the look of poor workmanship inside the panel, and it meets the requirements of the jurisdictions that do not allow you to do otherwise. The Canadian electrical code only allows one wire to be connected under the breaker's screw termination. The reasoning for this is that the installer can keep track of the exact amount of devices on the circuit and what section of the home the circuit services. A good reason to keep the breaker to one circuit is when trouble shooting the circuit, two circuits are not disconnected when the breaker is shut off.