How does GFCI Protection work?

I've been reading a lot of professional blogs about GFCI protection and was a little disturbed so much was either confusing or wrong, so let me clarify what exactly a GFCI protection (outlet or breaker) does. 

Much like the astrological sign Libra, GFCI's are constantly looking for balance.  But balance where you may ask?  The balance in this case is between the current flowing through the hot wire and the neutral.  In a well functioning outlet the current flowing from one is the same as the current flowing into the other.  So long as this balance is maintained the tiny coils inside maintain equivalent pressure and the outlet or breaker continues to work. 

Now lets take an example of a person with wet hands who inadvertently comes into contact with a live conductor.  Current then flows from hot, through the person to a ground path such as a sink or the ground and flows back to the electrical panel.  The circuit is completed by the human being instead of by the neutral wire.  This causes an imbalance in the current flowing out of the hot, because part of the current is now flowing through the person and never returns to neutral.  Because it takes very little current to stop a heart (~ 10 mA) only a tiny bit of imbalance is needed to trip.  For instance, Class A GFCI units trip at around 5mA. 

Incidentally, 5 milliamps is 3,000 times less than the current needed to trip a common breaker, at 15 Amps.  So you can see why a breaker isn't up to the task of shock protection. 

What about 2-pole GFCI breakers? 

With the 2023 National Electric Code (NEC) many homeowners are starting to see GFCI breakers for the dryer and electric range when present.  The same principle applies but it's a little more complicated.  With 2 pole devices there's 2 hots and a neutral.  Depending on the feature current may flow in a range of combinations.  For instance, control circuits and lights are 120V but the heating element is 220V.  

The 220V circuits would flow from one hot to the other (black to red) but the 120V circuits would flow from one hot (black) to the neutral (white). So long as the GFCI breaker "sees" all of the current in and coming out all is good.  As soon as there's an accounting error however they will trip. 

The need to account for 100% of the current flow is why GFCI breakers always require the neutral to be plugged into the breaker as opposed to directly to the neutral bar.

Breaker vs. Outlet

A breaker with GFCI features and outlet with GFCI serve the same function and may be used interchangeably.  The difference is convenience, cost and size.  For instance the NEC now requires clothes washers to be GFCI protected.  In my case, I can't really get to the outlet.  It's behind a stacked washer and dryer and resetting the outlet would require movers.  Instead I use a GFCI breaker.  Should the outlet trip I can reset it from the panel.  The same is true for my microwave and disposal.  I could use either option but the breaker is much more convenient. 

Generally the NEC leaves it up to the installer to pick between a GFCI outlet or breaker except when the outlet is not accessible, then the breaker is actually required.  Part of the reasoning is that the breaker panel itself must be readily accessible, including for tenants. 

The outlet is cheaper but larger and bulkier.  The kitchen counter, bathrooms and outside outlets are all easily accessible so best served by an outlet but the NEC does not mandate one solution or the other.  Technically I could put in nothing but GFCI breakers and the code requirements would be satisfied.

Surge Protection

Most GFCI outlets do not incorporate much surge protection at all.  A basic MOV to protect the delicate GFCI circuits is included but you really should not think of these outlets as surge protection devices.  Same for the breakers. 

Some writers online have used the term "ground surge" to describe what causes a GFCI device to trip and this causes many readers to assume this makes a GFCI outlet a surge protector.  I wouldn't call 5 mA of current a surge, but in any event no, a GFCI outlet is not also a surge protected outlet. 

Ground Wire

Incidentally, a ground wire is NOT required for GFCI outlets to work.  As you read above, the only monitoring is of the hot and neutral.  There's no monitoring or circuitry present to the ground wire.  For this reason a GFCI outlet may be used to retrofit an outlet when no ground is present.

LG Microwave Counter Light Upgrade

To my great surprise in late 2024 LG microwaves are shipping with very old-school halogen bulbs for their counter lights.  In addition to not having clocks that run even when the power is out, this seems very low tech for a company who is trying to show itself off as a high tech corporate giant. 

If you bought a Frigidaire you'd get a modern LED strip with fabulous light output.  

Sadly, I did not.  I bought an LG and I love to change things.  You can now benefit from my regrets

Upgrading the LG Counter Light Output

My model is the one with the giant door, the MVEL2137F but I imagine these steps apply to a number of other 2024 models as well. 

So, you need for this exercise: 

• Phillips head screwdriver
• G8 / 50W equivalent, dimmable LED light bulb 
• Our surprise guest, aluminum foil duct tape! 

The steps are so obvious I'm not going to list them.  There's one Phillips screw and one light bulb.  Replace the old bulb with the LED bulb with one major hack.  

Before you put the bulb in take a look at the inside of the light bar.  Notice how dark most of it is?  You need to cover the dark areas with aluminum foil duct tape which will turn the light absorbing chamber into a light reflecting chamber!  You don't have to cover every millimeter, just 50-75% of it, so if you see areas which look like ventilation and you are afraid of taping over them leave them alone.  The key part is to convert the inside from mostly black to mostly reflective, giving you significantly more light from your LED bulb onto your stove.  Try especially hard to get the area right behind the bulb. 

For safety, don't do the tape hack without also replacing the bulb.  The reason is heat.  The original bulb gets very hot (and wastes energy) when on, which could affect the adhesive in the tape but the replacement bulb you'll put in will stay cool to the touch, and put out more light than you had originally.

You are welcome. 

LG Dishwasher and Night Dry

I don't know why but the appliance features for LG are often completely inscrutable.  The Night Dry feature for dishwashers is too.  Here's the simple answer: 

Night Dry is an effective and economic but slow, cheap way to dry your dishes, presumably overnight, hence the name.  Night Dry foregoes heated drying methods in favor of a few hours of fan-only drying.

Essentially it uses no heat, just a fan to circulate dry air, which is far cheaper than the heated drying methods. It's also plastic safe!  If you are like me, you don't mind air drying if that means your plastic food lids can be safely washed.  Night Dry will save you the trouble if you are willing to wait for it, and if you routinely wash your dishes before going to bed, why not? 

Of course, if you still find you have spots consider a rinse aid like Finish Jet Dry.

LG's Worst Microwave: MVEL2137F

 

 

LG makes many good microwaves, but this particular model should be avoided.  It's as good a cooking tool as the others with one major design feature that sets it apart: The door.  For style, the door is the entire width of the microwave, 30".  However the cooking chamber is the same as the other models.  

Why is this a problem?  Because you need a bicycle helmet to operate it.  OK, we are being a little silly but honestly the door comes out 6 3/4" more than a normal door, and as a result you are constantly having to step out of it's attack radius, and are left in an uncomfortable position, far to the right or far in front of it while putting dishes in and out.  In addition, most of us normally open the microwave with our left hand, and insert food items with our right.  In this microwave you can't.  The handle is all the way on the right, behind the door,  so you feel like you are juggling.  Here are all the steps you now need to do: 

1. Put your food down.  
2. Step to the right, 
3. Open door with the right
   
4. Push fully open with the left while stepping to the left
5. Step forward, 
6. Insert food.  
7. Step back
8. Push closed with left hand while stepping to the right. 
   

Every day use is just a little more frustrating than it needs to be, and there's a very easy solution: Get the other model.

In addition, the door hinges have extra stress and start to wear faster because of the additional weight and angle of the door. 

Unless you need a kitchen to look good in Southern Living or your listing on Zillow get an LG with a normal door like the MVEL2125F.  Practically the same feature set, looks great, less dangerous door that is much easier to operate: