You can use a 20 amp circuit breaker with 12/2 Romex as 12/2 wire is rated for 20 amps.

Can 12 2 wire handle 25 amps?

Usually, a 25 amp breaker requires 10 AWG (6 mm 2 ) copper wire. But sometimes 12 AWG (4mm 2 ) wire is also used based on the conductor materials, types of loads, and temperature. However, it is not preferred to use 12-gauge wire for more than 20 amps current by most electricians.

Can 12 gauge wire handle 50 amps?

50 AMP Wire Size – For a maximum of 50 amps, you’ll need a wire gauge of 6. Fifty amp breakers are most often used to power many different appliances. However, a kitchen oven can alone require 50 amps. Many electric dryers also require a 50 amp breaker.

Can you use 12 2 wire 240V?

Amazon.com: Preguntas y respuestas de los clientes Yes, it is possible to carry a 2000w 240V load on a 12/2 NM-B cable like this one. No, it will not pass an electrical inspection. The breaker must protect the wire, and if someone comes along and adds load to your heater circuit they could easily overheat the 12/2 and the 40A breaker would just let it fry as long as it Yes, it is possible to carry a 2000w 240V load on a 12/2 NM-B cable like this one.

1. No, it will not pass an electrical inspection.
2. The breaker must protect the wire, and if someone comes along and adds load to your heater circuit they could easily overheat the 12/2 and the 40A breaker would just let it fry as long as it never pulls 40 amps.
3. Neither #12 nor #10 is good for 40 amps – both would overhead on a 35A load.

You can drop down the breaker to a 240V 20A circuit breaker and both the cable and the load would be protected. It still would not pass inspection because of the improper color coding of this 12/2 cable. If the next owner of your home calls an electrician to rewire the house, he will think that your wall heater is 120V because standard household color coding is : black = +120 volts (Bus A) white = 0 volts (neutral wire) red =-120V bare = equipment ground (no current flow in during normal operation) That is why people are advising you to use 12/3 or 14/3 cable – 3-conductor Romex-type cables have a red jacketed wire in the bundle which is the proper color to use alongside the black cable for the two “hot” wires in a 240-volt circuit.

This NM-B cable has an insulation rating of 600V, so it can tolerate 240V operation. I have used 12/2 to feed a 240V circuit – I fed the cable from a 240V 20A circuit breaker and used a red felt-tip permanent marker to color the white wire. This still would not pass an electrical inspection but it addresses the safety issues associated with serving your heater with 12/2 cable as long as the wire remains dry.

I don’t know the National Electrical Code well enough to say whether or not a black electrical tape on the white wire would pass an electrical inspection – that is also a obvious signal that the white wire is not a neutral wire. The calculations of 8.3 amperes drawn by your 2000-watt heater are correct.

Using a 15A 240V breaker instead of 20A would introduce no further safety issues. Please do not use 12/2 to serve this load unless you mark the circuit as 240V in a can’t-miss-it fashion, or the next person who tries to work on your wiring may assume that the white wire had 0 volts on it when it actually has 240 volts relative to the black wire – you may forget about it yourself and hurt yourself or your property sometime in the future.

Misidentified wire is a cruel wiring mistake to leave behind. Happy wiring! Yes, it is possible to carry a 2000w 240V load on a 12/2 NM-B cable like this one. No, it will not pass an electrical inspection. The breaker must protect the wire, and if someone comes along and adds load to your heater circuit they could easily overheat the 12/2 and the 40A breaker would just let it fry as long as it never pulls 40 amps.

1. Neither #12 nor #10 is good for 40 amps – both would overhead on a 35A load.
2. You can drop down the breaker to a 240V 20A circuit breaker and both the cable and the load would be protected.
3. It still would not pass inspection because of the improper color coding of this 12/2 cable.
4. If the next owner of your home calls an electrician to rewire the house, he will think that your wall heater is 120V because standard household color coding is : black = +120 volts (Bus A) white = 0 volts (neutral wire) red =-120V bare = equipment ground (no current flow in during normal operation) That is why people are advising you to use 12/3 or 14/3 cable – 3-conductor Romex-type cables have a red jacketed wire in the bundle which is the proper color to use alongside the black cable for the two “hot” wires in a 240-volt circuit.

This NM-B cable has an insulation rating of 600V, so it can tolerate 240V operation. I have used 12/2 to feed a 240V circuit – I fed the cable from a 240V 20A circuit breaker and used a red felt-tip permanent marker to color the white wire. This still would not pass an electrical inspection but it addresses the safety issues associated with serving your heater with 12/2 cable as long as the wire remains dry.

I don’t know the National Electrical Code well enough to say whether or not a black electrical tape on the white wire would pass an electrical inspection – that is also a obvious signal that the white wire is not a neutral wire. The calculations of 8.3 amperes drawn by your 2000-watt heater are correct.

Using a 15A 240V breaker instead of 20A would introduce no further safety issues. Please do not use 12/2 to serve this load unless you mark the circuit as 240V in a can’t-miss-it fashion, or the next person who tries to work on your wiring may assume that the white wire had 0 volts on it when it actually has 240 volts relative to the black wire – you may forget about it yourself and hurt yourself or your property sometime in the future.

Can you put a 30 amp breaker on 12 2 wire?

What is the Recommended Size Wire for 30 Amp Breaker? The National Electrical Code (NEC) recommends that you use a 12 gauge wire for all general purpose circuits, including those running to outlets and switches.

What is the max voltage for 12 2 wire?

Voltage rating – 600 volts.

What is the max amp for 12g wire?

‘Twelve-gauge wire is good for 20 amps, 10-gauge wire is good for 30 amps, 8-gauge is good for 40 amps, and 6-gauge is good for 55 amps,’ and ‘The circuit breaker or fuse is always sized to protect the conductor.’

How many amps is 12 2 good for?

You can use a 20 amp circuit breaker with 12/2 Romex as 12/2 wire is rated for 20 amps.

What gauge wire for 40 amp 220v?

The recommended size wire for a 40 amp breaker is 8 AWG. This is the American Wire Gauge, and it is the standard that is used in the United States for determining wire size.8 gauge wire is rated for 40 amps, and it can safely handle up to 50 amps. This 40 amp wire size can safely handle most needs.

What size wire do I need for a 20 amp circuit?

A 20-amp circuit, protected by a 20-amp breaker or fuse, must be served by 12-gauge or 10-gauge wire.

When would you use 12 2 2 wire?

The 12-2-2 NM cable (and 14-2-2 NM) was designed for specific uses.It is not an everyday use cable. It can be used (and in certain applications is required) for specific 3-way and 4-way lighting circuits. It can be used for ceiling fans or bathroom fans with light kits and night lights incorporated into them.

Can you run 220v with 12 2 wire?

Perhaps you mean 12/2 wire to be used with 220 Volts power supply.so, yes you can. size of conducting wire is independent of the voltage with which it has to be used. Higher the voltage, more is the thickness of the insulation.

Can I use 12 2 wire for everything?

Yes, it’s fine. Many people routinely upgrade to 12/2 as it also give you the option of upgrading to 20 amps on your power circuits, now that 20 amp outlets are getting quite common. Ignore references to needing 12/3 – 12/2 already has a bare wire for the ground.

Can you put a 40 amp breaker on 12 2 wire?

No by code a 40 amp breaker requires 8 gauge wire, and 240 Volt will require 3 conductors so 8/3 wire 12/2 is only approved for a 20 amp and smaller 110/120 volt breaker.

What gauge wire for 30 amp 220v?

In short, the perfect wire size for most 30 amp services is the #8 AWG wire with 50A ampacity. This is the common size wire for 30 amps 240 volt service, 30 amp 220 volt service, and so on.

What happens if wire gauge is too big?

Why Does Wire Size Matter? – Circuit breakers are sized according to the wire gauge of the circuit. Since a breaker is designed to interrupt current flow before the conductor is damaged, using too small a wire gauge can result in an overload. The breaker will allow too much current to flow and won’t trip even if the wire is compromised.

What is 12 2 used for?

Cable and Wire Basics – Most house wires—the wires that run from the service panel through walls and to electrical boxes—are solid-core, meaning they’re made of a single, solid strand. Light fixtures and some switches have leads—wires made of many strands of thin wire, which are more flexible.

The thicker a wire, the lower its number; for instance, 12-gauge wire is thicker than 14-gauge. Cable refers to two or more wires encased in a protective sheathing. Cable packaging indicates the gauge and number of wires. For example, “12/2 WG” means two (black and white) 12-gauge wires plus a ground wire.

Nonmetallic (NM) cable, sometimes called Romex, has two or three insulated wires plus a bare ground wire all wrapped together in plastic sheathing. Many local codes permit NM cable inside walls or ceilings, and some codes allow for exposure in basements and garages.

Underground feed (UF) cable has wires wrapped in solid plastic for watertight protection. Use it for outdoor projects. Armored cable encases insulated wires in metal sheathing for added protection. BX (also called AC) has no ground wire, only a thin aluminum bonding wire unsuitable as a ground; the metal sheathing provides the path for grounding.

Metal-clad (MC) has a green-insulated ground wire, Some local codes require armored cable or conduit wherever wiring is exposed.

Can I use 12 2 wire in my house?

You could wire all 120 Volt branch circuits in a residence with #12 AWG Cu wire, provided there are no appliances or machinery that require circuits larger than 20 Amps or are excessively long where Voltage drop would be an issue.

How many watts can 12 2 wire carry?

2 AWG Wire Wattage Chart + How Many Amps Can A 2 AWG Wire Handle?

What is 12g wire used for?

Choosing Electrical Wire Size – You may determine the gauge based on the helpful pointers below assigned according to Wire Use- Rated Ampacity:

• 18-gauge are used for low-voltage lighting and lamp cords in 10 amps
• 16-gauge are used for light-duty extension cords supporting 13 amps
• 14-gauge are usedfor light fixtures, lamps, lighting circuits with 15 amps
• 12-gauge are used in kitchen, bathroom, outdoor receptacles, and 120-volt air conditioners supporting 20 amps
• 10-gauge are used in electric clothes dryers, 240-volt window air conditioners, electric water heaters supporting 30 amps
• 6-gauge are used for cook tops and ranges carrying 40-50 amps
• 4-gauge are used for electric furnaces and large electric heaters protected at 60 amps

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Can you use 12g wire on 15 amp circuit?

Recommendation. Because it’s thinner and lighter, 14-gauge wire is easier to run than 12-gauge wire. However, 12-gauge wire is acceptable on both 15- and 20-amp circuits, so some electricians use it exclusively when wiring a house.

Can 12 AWG handle 20 amps?

12 Gauge Wire Ampacity: How Many Amps Can 12 Gauge Wire Safely Handle?

• 12 gauge wire is a very popular wire thickness used for speakers, extension cords, home, and car electric installations, and for all other applications where a wire must safely handle 10-20 Amps current.
• However, current carrying ability differs depending on the maximum allowed wire temperature, wire length, and similar.
• Updated: August 8, 2022.

Can 2.5 mm cable take 25 amps?

2.5mm wire for 4.2kW oven Hi, My electician has rewired the house and installed a 4.2kW oven (with a separate gas hob). The oven radial uses a 2.5mm wire with a 20 amp fuse, and the length of the wire from the consumer unit to the oven is about 4m. My builder has told me that the 2.5mm wire is unsafe, but my electrician insists it’s okay because the oven has no hob.

• Can anyone confirm whether the 2.5mm wire is safe and compliant with the regulations?,
• Thanks all, much appreciated.
• Best Answer Builder normally equals BODGER! they are some of the biggest cowboys going and should not be touching or even commenting on electrical matters, as 99% of them are not electrically competent and have not undergone formal electrical training or hold relevant qualifications.

Where as most Part P registered electricians do. A 4200 watt (4.2Kw) oven at 230volts (4200 divided by 230 ) = 18.26 amps. A 2.5mm cable is capable of supplying around 23-25 amps depending on the method of installation, so is fine, safe and compliant on a 20amp circuit breaker.

Its very clear that the builder is not an electrician and probably knows little or nothing about circuit design and calculating circuit current. If he did then he could have done this quick calculation and realised it was perfectly compliant with BS7671:2008.2014-04-10T10:00:02+01:00 Answered 10th Apr 2014 Liked by the question poster Hello, A quick calculation for your problem: A 4.2kw oven =4200w 4200/240=17.5amps A 2.5mm short length of cable without diversity applied for insulation etc is capable of 24amps Therefore your 2.5mm cable over the short distance IS SUITABLE for the capacity of the oven.

The 20amp fuse is the correct size fuse. But in doubt always consult your ovens manual on there MINIMUM specification for electrical conections. I hope this helps you. Leighton Haynes 2014-04-10T10:00:02+01:00 Answered 10th Apr 2014 Liked by the question poster You have not given the method of installation, they are as listed below.

• Your builder is only quoting from limited knowledge that generally cooker supplies are run in 6.0mm T+E and does not know how to calculate the requirements.
• It sounds like your electrician has taken the cable to its design limit if using method B or C which is acceptable.2.5mm T+E Installation method A (enclosed in conduit in a thermally insulating wall, etc) current carrying capacity 18.5A (max MCB 16A) Installation method B (enclosed in conduit on a wall or in trunking, etc) current carrying capacity 23.0A (max MCB 20.0A) Installation method C (clipped direct) current carrying capacity 27.0 (max MCB 20.0A) 2014-04-10T10:00:02+01:00 Answered 10th Apr 2014 Liked by the question poster Your electrician is right.

The cooker will pull a max of 18amps and the cable is rated at around 24amps and protected by 20amp fuse so your good to go : ) 2014-04-10T10:00:02+01:00 Answered 10th Apr 2014 Liked by the question poster hi 4200w divided by 230v = 18.26 amps from memory 2.5 t and e in normal conditions can carry apprx 27 amps so : cable is rated at 27amps fuse is rated at 20amps oven is rated at 18amps the numbers look fine to me, however there are other things to consider.i.e if the cable run travels through more than 400mm (depth) of thermal insulation the current carrying capacity of the cable has to be halved so the cable will become the weakest link in the chain.

Can 12 AWG wire handle 26 amps?

12 AWG wire can handle 25 amps of current but we use this wire as a 20 amp wire (more about this here). This is because we have to account for the 80% National Electric Code (NEC) requirement. This requirement states that any wire used in circuits should carry at most 80% of the total amperage.

Can 12 2 wire handle 15 amps?

12 gauge wire is the minimum for 20 amp circuits.14 gauge wire is the minimum for 15 amp circuits.

Can I run 12 2 on a 15 amp circuit?

It is perfect to use 12/2(or larger) on a 15 amp circuit. The code only states the minimum size gauge to use on a circuit.14 gauge is the minimum on 15 amps. You cannot add 20 amp breaker if any wire is smaller than 12 gauge, must all 12 gauge or larger. Most devices have a maximum gauge that will fit on it’s connection points. answered Mar 31, 2022 at 14:16 crip659 crip659 18.5k 1 gold badge 27 silver badges 50 bronze badges 2

Label it when done. Subsequent maintainers who see the mixed gauges need to know that you added 12/2 to an otherwise 14/2 circuit, and didn’t add 14/2 to a circuit that needs to be 12/2. Mar 31, 2022 at 14:19 In fact for very long runs, as to an outbuilding, voltage-drop rules may mandate 12-ga (or better) for a 15-Amp circuit; and I’ve often wired my outlet circuits with 12 ga out of an abundance of caution. It certainly is a bit harder to work with, though. Apr 1, 2022 at 20:20

So long as the breaker is 15A, because there is 14Ga wire on the circuit, you can use 12Ga (or 10, or 8, or whatever larger size you like, though it becomes inconvenient in practice) on the circuit as well.14Ga is a minimum size, and 15A is a maximum size if there is any 14Ga.12Ga is larger than minimum, and perfectly safe/acceptable. answered Mar 31, 2022 at 14:14 Ecnerwal Ecnerwal 172k 9 gold badges 208 silver badges 434 bronze badges 2

Label it when done. Subsequent maintainers who see the mixed gauges need to know that you added 12/2 to an otherwise 14/2 circuit, and didn’t add 14/2 to a circuit that needs to be 12/2. Mar 31, 2022 at 14:18 There’s no accounting for incompetent “future maintainers” – Competent ones see a 15A breaker and 12 joined to 14 and know that all is well here. The ONLY case where a “note” might be called for is if the 12Ga is connected to the breaker and 14Ga is not visible there. This is a connection between outlets that have 14Ga, so I don’t see any need for a “note.” It’s obvious. Mar 31, 2022 at 15:14

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