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Modification of Old Electrical Work
Electrical and building codes have changed over time and new methods proscribed for safety. Converting the old to the new leads to lots of questions.
4,592 Questions
Can you use a 40 amp breaker to feed a sub panel?
Yes, you can use a 40 amp breaker to feed a sub panel. The wire from the 40 amp breaker must be #8 or larger. If you intend to use the full 40 amps a larger conductor must be used. Conductors can only be loaded to 80% capacity in continuous load conditions. A #8 wire is rated at 45 amps x 80% = 36 amps. The suggested size would be a #6 rated at 65 amps x 80% = 52 amps.
Can you run a 20 amp machine on a 15 amp plug?
A 15 amp receptacle is protected by a 15 amp breaker. The 15 amp breaker will trip on any current over 15 amps. So if the 20 amp machine draws a full 20 amps, then the answer is no. Due to some operations of machines they will not draw the full nameplate amperage until they reach a certain point in there cycling. The machine may run at the start but when it reaches that point it could trip the breaker. If the machine is not hardwired but plugged in, you could not run a 20 amp machine on a 15 amp receptacle, due to the different pin configurations on the plug cap.
Are junction boxes used to wire exposed portions of a basement?
Any splice or termination to a device has to be done in a junction box. Wire splices are the critical and most likely point in a circuit where a fault can occur. The purpose of the junction box is to suppress the fault to to the confines of the box. This usually is enough protection to cause any fires that may be started from the electrical fault from spreading to other surrounding combustible surfaces.
How do you determine the white and black wire if they are not marked?
Turn the mains switch OFF. In a "earthed neutral" system, the neutral will be earthed. With the mains off, neither wire should display voltage, and one of them should be grounded. That one is the neutral.
Be careful - electricity is dangerous.
In the above answer, third sentence both wires will read to ground as the hot wire will read to ground through the load.
The hot wire is the live supply, the load is the wire going to the appliance, so I assume you are talking about wires at a switch, if so, it doesn't matter; when they are closed (touching) the light will be on, when they are open (not touching) the light will be off. DANGER don't touch any potentially live wires until the circuit has been isolated and proven to be dead.
How do you switch a 3 pronged plug to a 4 pronged outlet?
3 wire plugs are old and outdated. Way back in the old days they didn't ground equipment so plugs didn't have a ground. (Remember the old 2 wire 110V outlets on houses built before the 50s?) A few people got killed so they decided to add a safety wire. It took them longer to catch on with heavy appliances, but eventually they did. That is what the fourth pin is for. Since many homes still have the 3 wire plug it is allowed in older homes. New homes must use the new 4 wire plug.
Changing your 4 wire cord to a 3 wire cord is the same as plugging a 3 wire 120V appliance into one of those 3 prong to two prong adapters they sell. Your appliance works now, but is ungrounded.
Don't listen to anyone who says to replace the new up-to-code plug with an older plug. That is the same as replacing your 3 prong 120V outlets with old two prong outlets! Ignore anyone who tells you to do so, they think they know a lot more than they actually do. Buy a new cord. It is cheap and safer.
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Although configuration of the plugs are not universal, NEMA has a huge listing of plugs and receptacles. Once you know which one you need, all you have to do is rewire it. Your old range didn't have have ground (bare or green wire, which only carries current in a fault situation). The new one you have purchased does. Although you do not have to hook this wire up for the range to operate, there is a severe risk of electrical hazard. The best advice anyone can give you is that you must run a new power cable to the range's location, one that includes a ground wire. This is a lot of work, but it has to be done for the installation to be safe.
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[Note: don't do this! See the first answer to this question!]
This may or may not be allowed by the electric wiring code operating in your town or location - it is best to check with the appropriate electrical safety officer in your locality before you do any of this: Change the cord on the new range to a three wire cord. Buy a new three wire cord for the receptacle configuration that you have. Remove the four wire cord from rhe range, taking note where and how the wires are attached, especially the white wire and the bare or green wire. Attach the red and black hot wires to their respective terminals. Attach the white neutral wire to its terminal and use a ground jumper (bare copper wire #10 gauge) to attach the frame of the range back to where the white wire is attached.
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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.
What does open hot mean when you test an electrical outlet?
"Open hot" means that there is no power coming to the outlet's hot wire, which carries electricity. This could be due to a tripped circuit breaker, a damaged wire, or a faulty outlet. It is important to address this issue promptly to avoid electrical hazards.
Can you wire wall outlets with 14 3?
Answer for USA, Canada and countries running a 60 Hz supply service.
Yes. this is a type of connection that is used to wire a split receptacle usually in the kitchen for counter plugs. Look on the back of the receptacle at the gold coloured screws, there is a tie bar that connects the screws together pry this bar out by wiggling it back and forth until it breaks. Connect the red wire to the top screw, the black wire to the bottom gold screw and the white wire to the silver coloured screw. If this connection is made without removing the tie bar, the breaker will trip, as you are putting 240 volts across the receptacle's top and bottom outlet causing a short circuit.
Three wire circuits are also used to feed individual rooms fed directly from the distribution panel. The black and the white wire are used for all of the receptacles in the room. From the same cable the red and white are used for the lighting circuit in the room. The white wire being common to both circuits.
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.
What wire size do you need for a 3phase 80amp 60hz 220v load amp 68?
A #4 copper conductor with an insulation factor of 75 or 90 degrees C is rated at 85 amps. This size wire will also be the same for a load amperage of 68 amps as the next wire size smaller #6 is only rated at 65 amps.
If you are taking the power from the existing light outside you have to be aware that when that outside light is switched off then the sensor light will not work. Your best choice should be power the sensor light from an un-switched source. This could be an existing receptacle outlet in a nearby location. Check your sensor configuration to see if the device has the function to be locked on and off by interrupting the voltage supply to it. If it does then a switch in its circuit is mandatory to make this function work. If this function is not included in the device then just connect it as the instructions explain and the fixture will come on when it senses movement and go off after a timed interval.
Yes, when you plug the air conditioner in to an ordinary house receptacle this is the configuration that exists. Just make sure that additional loads on that same circuit are not any more that 7.5 amps or the circuit breaker will trip. For air conditioners it is best to have a dedicated circuit right back to the distribution panel. This means that there can be only one appliance, the air conditioner, on that specific circuit.
How do you wire one light two switches?
This is what is known as three way switching in the trade. See related link below for wiring diagram. believe it's like this
(this circuit would work but it may be done differently by licensed electricians - I'm an engineering student, not an electrician
L------------o ------- o-------------L
.-o-------------------------Light-------------------------o-.
N------------o / ------- \ o-------------N
a single pole double throw switch at each end of the light terminals, either the light is connected to two different rails and will shine, or connected to two rails of the same potential and wont shine
Can you use a 30 amp breaker for a stove?
The breaker commonly used for ranges is a 40 amp. This size is used to cover the total wattage of the range. If for some reason all of the top elements and the oven were in use at the same time then the amperage drawn would be just under the trip setting of the breaker. If this same scenario were played out on the range with a 30 amp breaker supplying the power it would trip the breaker.
What size wire should I use for a 50' 30 amp 240 volt line?
For the short distance of 50 feet no voltage drop calculations are needed.
A #10 copper conductor with a insulation factor of 60, 75 or 90 degrees C is rated at 30 amps respectively. This conductor can legally be loaded to 80% capacity. This allows 30 x .8 = 24 amps. If the device draws more that 24 amps then go to the next wire size which is a #8. A #8 copper conductor with an insulation factor of 75 and 90 degrees C is rated at 45 amps respectively. This legally allows 45 x .8 = 36 amps to flow on the wire. Of course with this size wire only 30 amps will be allow to flow before the breaker will trip.
How many amps are in 1700 watts on a 110 receptacle?
The formula you are looking for is I = W/E. Amps = Watts/Volts.
What size electrical wire is required for 20 amp breaker 275 feet away?
Would probably go with 10 gauge since 12 would do normally, a 275' length is a long run. Voltage drop would be a concern, especially if the load of the device had a high start up demand. Air conditioner, refrigeration unit, air compressor, etc.
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To answer this question correctly a voltage must be given, since sizing the wire is all about voltage drop over a distance.
How far can you run 250 mcm wire rated for 90 c for 200 amp service?
For a 200 amp service, a 250 MCM wire rated for 90°C can typically be run up to around 200-250 feet before exceeding voltage drop limits set by the National Electrical Code (NEC). However, it is recommended to consult with a licensed electrician to determine the exact length based on factors such as ambient temperature, conductor insulation, and specific installation conditions.
How do you change a 4 prong cord to a 3 prong cord on dryer?
I needed that answer years ago and was told that the two outer wires are the hot leads and can be interchanged on the two outer lugs on the machine, the center wire is your neutral and needs to be attached to the center lug( the neutral lug on the machine is almost always silver, the hots are brass color) it's really simple once you know,outer to outer, center wire to center lug.
Can you use a 30 amp time delay fuse instead of a 30 amp inverse time circuit breaker?
Fuses and circuit breakers are rated differently as applied to electrical loads. A motor load of 12 amps would require a fuse rating of 21 amps ( 12 X 1.75=21) or the next standard size of 25. A breaker for the same load of 12 amps would be a 30. (12 x 2.50=30) However if your circuit is number 10 copper wire and supplies 30 amp rated receptacles, you would be perfectly safe in using the fuses.
What size wire for 12vdc 30 amps?
For a 12VDC system with 30 amps, you would typically use a wire size of at least 8 AWG (American Wire Gauge) to ensure it can handle the current without overheating. It's always a good idea to consult a wire ampacity chart to select the appropriate wire size based on the length of the wire run and the specific conditions of your setup.
Why colors of wire is red black and green always?
Red wire is typically used for power supply, black wire for ground, and green wire for grounding in electrical wiring systems to maintain consistency and ensure safety. These colors help electricians quickly identify the function of each wire and follow standard practices. However, it is important to always verify the specific wiring codes and standards applicable to your location or project.
Will siemens breakers pass inspection on gould panel box?
As long as the breakers are made to fit the box, there shouldn't be a problem.
you can only use breakers listed for the panel, there should be a label on the panel door. It will list all of the breakers approved for use in that panel. If you don't see the breaker by manufacturer name listed, then it should not be used. Lots of brands will interchange, but they have to be listed to be approved.
Can you plug in a 125 volt 30 amp plug in a 120 volt 30 amp outlet?
No, it is not recommended to plug a 125 volt 30 amp plug into a 120 volt 30 amp outlet. The voltage difference may cause damage to the equipment and pose a safety hazard. It is important to use the correct voltage outlets for your devices.
How many 20 amp circuits can you run on a 50 amp service?
In the United States, there isn't a hard limit on how many 20 amp circuits that can be run on a 50 amp supply. This is because in most cases, especially in homes, we don't load most circuits with more than an amp or 2, even when they are protected by a 20 amp breaker. From a practical perspective you probably have a limited number of slots for breakers in your service or supply panel.
First let's consider the existing wiring in the wall box: A Red wire can be the first "Hot Leg" of a 240 volt supply.
A Black wire can be the second "Hot Leg" of a 240 volt supply or the "Hot" wire of a 120 Volt supply.
A white wire is normally the "Neutral" wire. It is common to both hot legs on a 240 Volt supply.
A Green wire (or bare wire with no insulation) is normally the local "Ground " wire. However, if, and ONLY if, there was an on/off switch for a 120 Volt lighting fixture installed onto that wall box before, it is possible that the red and black wires in this situation are:
a) the "hot" feed wire coming from the mains breaker panel to the switch and
b) the "switched hot" wire going to the lighting fixture.
BE VERY CAREFUL TO BE SURE HOW TO DO ANY OF WHAT FOLLOWS SAFELY BEFORE YOU TRY TO TEST ANYTHING WHICH MAY BE A HOT OR LIVE WIRE: Only someone who knows how to use a test lamp or voltmeter safely would be able to confirm whether the red wire in the wall box is a) and the black wire is b), or if they were actually wired the other way round meaning the black wire in the wall box is a) and the red wire is b).
If that is the case,
AND YOU ARE ABSOLUTELY CERTAIN THERE IS NO 240 VOLTS MAINS SUPPLY INVOLVED IN THIS JOB,
then all that is needed is to do the following: BE SURE TO SWITCH OFF THE MAINS SUPPLY AT THE MAIN BREAKER PANEL.
TEST THAT NO WIRING IN THE WALL BOX IS LIVE USING A PROPER TEST LAMP OR VOLTMETER.
Then connect one of the black wires on the dimmer to the red wire in the wall box and the other black wire on the dimmer to the black wire in the wall box - using proper insulated connectors of course.
The green wire on the dimmer must be connected to the existing Ground wire, a green or bare wire in the wall box. If there isn't an existing Ground wire then you must fit one or have an electrician fit one for you because the dimmer may be unsafe to use without it! After you have checked that all the screws holding the wires in the various terminals in the insulated connectors and the wall box are tight, screw the dimmer to the wall box using its fixing screws. You can then switch on the mains supply at the main breaker panel and check that the dimmer operates to dim the lamp in the lighting fixture. Please refer to the Related Questions shown below for more information, expecially the requirement to check whether what you want to do - to install a new dimmer - will comply with the wiring code in your locality. (Town/state/country). 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 an electrician's test meter having metal-tipped probes
(not a simple proximity voltage indicator)
to insure the circuit is, in fact, de-energized.
Can you put 20 amps on a 20 amp breaker or do you still use 80 percent?
If the load is continuous you need to observe 80% rule. A 20 Amp breaker will handle short term loads that exceed 16 Amps. Think about it as a heat issue where continuous higher current will heat up components to unacceptable levels.
