Asked in Home ElectricityModification of Old Electrical WorkElectrical WiringThe Difference Between
Modification of Old Electrical Work
The Difference Between
How do you wire a 220V 30A 3prong receptacle?
Can you replace a 50A receptacle with a 30A 3-prong receptacle and keep the existing dedicated 20A pair of breakers?
No. The receptacle, wiring, and breaker ratings should all be matched properly. Replacing the 50A receptacle with a 30A receptacle isn't a problem, since the wire should be rated at least 50A. But a 30A receptacle should be protected with a 30A double pole breaker. The breaker only costs about $8.00, so why wouldn't you change it given you don't have to change the wire which would actually be expensive or time consuming? The fact that you mention a 50A receptacle protected by a 20A existing breaker isn't normal either. I would check to make sure the wiring is actually rated for 50A and that someone didn't just throw a 50A receptacle onto a 20A circuit. (This means your wiring should be at least #8AWG THHN Copper wire.) If you protected a 30A receptacle with a 20A breaker, the load might trip the breaker often, considering the appliance requiring a 30A receptacle probably requires about 30A. If you do not understand the work well enough to accomplish it yourself properly and safely, don't try it. Consult a professional electrician, as they are proficient enough to do it properly and safely. When working on electrical circuits and equipment, make sure to de-energize the circuit you will be working on. Then test the circuit with a definitive means to make sure it is off (multimeter with metal tipped leads, voltage tester with metal tipped leads, etc., not a non-contact tester, which is non-definitive.)
What is the US equivalent of European 4x2.5 sq mm HO7RN-F and could US 10 2 be substituted for the European cable to hardwire a 240V 27A appliance?
If you want an American plug to power a 30A 220V device look at a dryer outlet. It will have an extra neutral conductor, but it is standard. Otherwise, you can go with a 220V 30A TwistLok plug. All the home centers [I've been to] carry these plugs. 10ga wire is heavy enough for 30A runs under 75ft, though for a 27A appliance you should consider a 40A breaker with 8ga wire.
Can you make an extension cord that would have a NEMA l5-30p 30a 125v plug on one end and a NEMA l14-30r 30a 125v receptacle on the other end to connect a generator parallel kit to a transfer switch?
Can a 240V 30A outlet be converted to 240V 15A?
An existing outlet can be converted by replacing the 30A circuit breakers or fuses in the circuit breaker or fuse box with 15A breakers or fuses. The 30A outlet should also be replaced by a 15A outlet. This is all that is required if the wire from the supply to the outlet is 10, 12, or 14 guage. The existing wire should be 10 guage wire to handle the 30A and there will be no problem in the same wire providing the 15A.
Asked in New Electrical Work
Can you safely change a 20 amp breaker to 30 amps?
No, this is not a recommended procedure. The breakers main job is to protect the wire that is connected to it. A 20A breaker will have a #12 wire (rated 20A) connected to it. A 30A breaker will have a #10 wire (rated 30A) connected to it. As you can see if you use a 30A breaker on a #12 wire you could overload the wire by 10 amps. I have seen an incident where the insulation has melted off of an overloaded wire, the wire short out and a fire start before the bigger size breaker tripped. DON'T DO IT.
Can you connect a dryer with a 30A cord and receptacle to a line that has a 50A circuit breaker?
Yes and no. You can't put a 30A outlet on a 50A breaker as it will be a fire hazard. You can put a 50A outlet on it safely. Then you can plug the 30A load into it, but this is unwise and can be dangerous if you don't put fuses in your pigtail adapter. The best solution: Go ahead and install your 30A outlet but replace the 50A breaker with a 30A breaker. This is the safest and cleanest solution.
Can 110V circuit with 2 wire size of 10 and a ground be converted to 220V after changing the outlet and breaker?
What happens when a 20amp device connects to a 30amp receptacle and the power supply fails - will it trip the breaker?
Assuming you are referring to the power supply failing in your 20A device, it could cause the 30A breaker protecting the receptacle to trip. It depends on the mode of failure. It is easy to imagine a condition where a short in the power supply could cause a current in excess of 30A to flow to the device and trip the breaker.
In wiring for 220v can one use 2 15a breakers instead of a ganged 30a breaker?
Asked in Home Electricity, Electrical Wiring
Can you use two separate 120 volt circuits to make 240 volt power and run 30 amps through the circuit they are both wired with 12-2 wire?
Maybe. Your house is supplied with two "phases" of 120v, and they're on separate wires with a neutral in between. For ease of explanation, we'll call one hot wire the X wire and the other hot wire the Y wire. It's 120v between X and neutral, and 120v between Y and neutral. But if you connect the X wire and the Y wire to your item and forget about the neutral, you get 220v. (This is how a water heater is connected.) If one 120v circuit is fed by the X wire and the other by the Y wire, and you use 10-2 wire (12-2 is for 20-amp service; you'll burn the house down running 30a through 12-gauge wire) and a 30-amp double-pole breaker, you'll have a perfectly good 30a 220v circuit. If both circuits are fed from X or both from Y, you won't get any voltage because there's no potential difference between the two hot lines.
Asked in Home Electricity
Where are the 2 hot 1 neutral and 1 grn placed on a 6-30 3 prong female plug?
What size wire do you use with a 30a breaker for house receptacle?
Use a 10 AWG wire when a circuit is to be driven by a 30 Amp breaker. As with all home electrical projects, make certain that you understand and follow all local codes regarding any modifications that you are performing. If you have any questions, contact a qualified electrician or competent handyman, depending on state regulations.
If you have a 240V dryer and installed 30A breakers on both sides of the line reads 120 and 120 how do you get 240 and you have a receptacle that reads 30A 125250 and still does not work?
you do NOT put two 110v breakers in. you put 1 two pole breaker in. the panel is designed to give you 220v off one side OR the other side if you use a 2 pole breaker on one side or the other side. If you look at both 120V lines on an oscilloscope you will notice that they are both 120V to the neutral, but they are 180 degrees out of phase. This means that when one hot is at +120V the other is at -120V. So between the two you have 240V. If you put your meter across both hots you should see 240V. If you do not see 240V across both hots you (or an unlicenced electrician) has wired the outlet without using a proper 220V breaker. You do not see 240V because the hots are in phase, to the voltage differential is 0V, not 240V. 220V breakers cannot do this, unless forcebly installed in the wrong type panel. More than likely someone tried to wire it with 110V breakers.
What are the NEC requirements if a laundry circuit is to be installed in a basement of a dwelling for a washing machine and the dryer will be connected to a 30A dryer receptacle?
== == The washing machine outlet should be ground fault protected on 12-2 wire. The 30 amp dryer circuit should be on 10-3 wire with a ground. <><><> Laundry receptacle outlet for washer, 12/2 with ground yes! GFCI required if receptacle is within 6 feet of sink or duplex receptacle rather than single receptacle [but a GFCI isn't a bad idea anyway... Dryer, 10/3 with ground and 4-wire outlet and cord set connection at dryer location! NO NEUTRAL BONDING LINK! 1) NEC requires a disconnecting means [plug and receptacle works] if equipment [dryer] is not within sight of the power source [in this case, if the panel is in the garage] 2) You were never allowed to use the ground wire to carry neutral current, so you need an insulated white or grey neutral [this means three wire] 3] You are not longer allowed to use the neutral jumper at the terminal in the dryer for a chassis ground [with certain limited exceptions - existing ungrounded three wire cable and new dryer] Ground wire goes to chassis. <><><> As always, if you 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.
Connecting a 30 amp device to a 20 amp receptacle does it violate NEC?
Asked in Home Electricity
Why the 3rd pin in a 3 pin electric plug is bigger in size than other two?
It is so there is no confusion about how it must be inserted and what type of outlet is required. Many plugs use different shapes and sizes to determine the amount of power available or the amount of power required. For instance, a 30Amp US plug is very different from a 15Amp US plug because you cannot allow consumers to plug a 30A device into a 15A outlet. Similarly, you cannot plug a 15A device into a 30A outlet because they're different, and they are different so that a 30A circuit breaker is not expected to protect a user of a 15A device, when something goes wrong. A "larger" prong on a plug is often used for the "neutral" wire, perhaps because the receptacle hole is larger and would be more dangerous if it were the hot wire.
What is the amp rating for a 3 wire?
The amperage rating of any wire or conductor is determined by its size or gauge. It has nothing to do with whether it is a two, three or four conductor wire. For example, in basic residential wiring, a 14 gauge wire is rated at 15 amps, a 12 gauge wire is rated at 20 amps, a # 10 is rated for 30A and so forth.