74
votes
Accepted
What is a tandem breaker (aka duplex, cheater, twin, double-stuff, etc.)?
It starts with spaces in the panel
A service panel has a basic unit I call a space. That's apparent when you look at the "knockouts" on the cover.
Electrical power in North America delivers split-...
68
votes
Can I use 220 V outlets on a 15 ampere breaker and wire it up as 110 V?
Send it back right now
You bought it off Amazon Marketplace, the world's biggest junk shop. A step down from eBay, even, because this garbage hides amongst legitimate products. Here. See what you ...
37
votes
Why would replacing this 240 V outlet with a 120 V outlet trip my breaker?
You can't do that! Don't switch any wires. That a 240 volt outlet, a 120 Volt line to each of the two brass screws and a ground on the old outlet. You plugged a 120 Volt appliance into a 120 Volt ...
- 86.2k
37
votes
Will installing European outlet in US change frequency to 50Hz?
TL;DR A different receptacle will not change voltage, frequency or anything about the electricity. It just changes the physical configuration.
But there are devices to change voltage and/or frequency. ...
32
votes
Accepted
Can I safely plug a 15A 100V appliance into a 20A 250V wall outlet?
No. That is a NEMA 6-20 receptacle. Your NEMA 5-15 appliance is specifically designed to not plug into it.
Because it would destroy the appliance if you did.
That is why the system of plugs works ...
32
votes
Will installing European outlet in US change frequency to 50Hz?
No they do not convert the frequency.
- 1,844
28
votes
240 V outlet is not delivering 240 V
I bet if you go to your service panel, you're going to find a completely full service panel, and a unique creature we call a "double-stuff breaker". Quite likely the landlord does his own electrical ...
26
votes
Why would replacing this 240 V outlet with a 120 V outlet trip my breaker?
This could have easily been done correctly if you had done the research beforehand that you are doing now... as things are, you have created a 120V socket that is supplying 240V... it did fry your ...
25
votes
Accepted
Do travel voltage transformers really not have grounding?
All this stuff is cheap Cheese junk
You describe a genre of travel transformers, not just a specific one... but who's kidding who? The "genre" you're talking about is "the infinite ...
25
votes
Will installing European outlet in US change frequency to 50Hz?
No, sockets don't change frequency. Changing frequency requires very complex electronics comparable to a VFD (Variable Frequency Drive). Basically a DC power supply coupled to a DC/AC inverter. The ...
20
votes
Accepted
What are the advantages of running a power tool on 240 V vs 120 V?
As alread mentioned by others, Half the current, which makes 1/4 the resistive losses (if the wire was the same size, which it probably won't be.)
The more subtle follow-on effect is that what ...
- 226k
18
votes
Should I run 240v for any supported appliances?
There's no need to do this for computers/networking gear/...
While the switching power supplies used in IT equipment are slightly more efficient when running on 240V vs when they are running on 120V, ...
- 86k
17
votes
Can I use 220 V outlets on a 15 ampere breaker and wire it up as 110 V?
Send it back and get something that's listed for the job
While what you have is indeed a 120V outlet (the outlet configuration governs, not some text in a manual somewhere), this outlet is not usable ...
- 86k
17
votes
What are the advantages of running a power tool on 240 V vs 120 V?
IMHO it's always better to run at 240v than 120 if possible. For one thing you can run smaller, less expensive wire and get the same amount of power.
Next, even if you keep the same wire size for 120v ...
- 23.3k
17
votes
How can I power both sides of breaker box with two 120 volt battery backups?
Assuming that the two battery backups are not designed to be synchronized, the problem is that the two together will not produce true 240 volts: this requires that the two generators run at exactly ...
- 13.6k
16
votes
Should I run 240v for any supported appliances?
For ordinary residential usage, there is generally no need (in the US and other 120/240 areas) for 240V except for:
HVAC
Electric Dryers
Electric Water Heaters
Electric Car Chargers
Electric Ovens ...
14
votes
Does running a dryer on 120 V drive up electricity costs?
Not an immediate danger, but quite a few problems
According to the spec sheet, this dryer is rated for 240V, 30A. Running it on "120V outlet" in the US normally means either 15A or 20A. ...
14
votes
Do travel voltage transformers really not have grounding?
TL/DR: there is no way this abomination is certified to any of the usual standards like UL. If a device that requires Earth is plugged into that, it won't be safe. If they ignore such basic safety ...
- 10.5k
13
votes
240 V outlet is not delivering 240 V
One possibility is that the two hots, labelled X and Y, are on the same line or leg of the service.
The 240V electrical service typical in the US is a three wire Edison circuit, with two of the ...
- 25.3k
13
votes
Accepted
Can you use a 2 pole 2-slot wide breaker to provide 240V?
Oh boy...whoever did that work really botched it up good
You need to call whoever rearranged those breakers back and tell them to fix their messed-up work on their dime, or better yet, pay someone ...
- 86k
12
votes
Can I use 220 V outlets on a 15 ampere breaker and wire it up as 110 V?
This is a 220V outlet (note horizontal "live" slot on the right):
And this is a 110V outlet (vertical "live" slot):
Pictures valid in USA.
Look at these two outlets. I recently grabbed a 110 ...
- 4,563
12
votes
Accepted
Electrical service sizing mix up in Mexico
Why 30A service?
Because of provisioning. They are not able to provision 50A service at this time at this location. That is probably due to transformer or pole-line wire capacity in the ...
12
votes
How wasteful is a voltage transformer?
The bigger problem is the transformer is going to set you back about $100, so it spectacularly fails to make sense for a $40 humidifier.
Dollar for dollar, if you're coming to North America, you ...
12
votes
In a multiwire branch circuit, can the two hots be connected to the same phase?
Yes, this does sound like a problem. Assuming your panel is like most, the breakers are on the same phase and you have two problems:
No Common Shutoff
MWBC is required to have common maintenance ...
12
votes
Can I safely plug a 15A 100V appliance into a 20A 250V wall outlet?
At the moment NO.
You have three choices:
sell that device and purchase one that is rated 230V.
get a 230 to 110 transformer.
replace that supply and socket with one of 110V.
Which of these is ...
- 28.7k
12
votes
Can you use a 2 pole 2-slot wide breaker to provide 240V?
Allow me to color in ThreePhaseEel's superb answer.
First, you need to understand how panel busing works. Check that link for the basics, however, the tandem/quadplex concept does not apply to GE -- ...
12
votes
What are the advantages of running a power tool on 240 V vs 120 V?
You get around the 1500 watt limit. 120V plug-in appliances won't get UL approved if they take more than 1500 watts (or 1800 watts in rare cases). In fact drawing more than 1800 watts will trip a ...
11
votes
Accepted
Why would a 120v circuit work without a neutral?
It's using the earth as a return path
You really don't want to do that. Dirt doesn't conduct electricity very well.
Your neutral is bonded to ground in your main panel. The power company's ...
11
votes
Accepted
Why does my electric oven present the option of 40A and 50A breakers?
There are a few different issues here:
120 vs. 240
A typical oven for installation in a system like the US (split 120/240) will use 240V for the heating elements (i.e., needs 2 hot wires) and 120V ...
Only top scored, non community-wiki answers of a minimum length are eligible