Which circuit breakers should I purchase: Standard, AFCI, GFCI, Dual Function (AFCI/GFCI)

Question

I understand the need to have GFCI outlets in areas such as the kitchen and bathrooms, but when I was upgrading my electrical panel, I saw there are multiple options for circuit breakers.

The electrical panel I am interested in purchasing is the Leviton LP420-MB. It does not come with any circuit breakers (other than the main breaker), but I noticed that the options are:

• Standard
• AFCI
• GFCI
• Dual Function (AFCI/GFCI)

Of course, these can also be purchased as 'smart' options which integrate with WiFi and the My Leviton app. My location is in the Metro Detroit area in Michigan, so I don't think I need to purchase AFCI/GFCI breakers in terms of code. Aside from code standards, I'm not sure which ones to get.

---

Some more information. I recently purchased my home and have been renovating the home. The renovations pretty much include a complete rewire, installing new switches and outlets and even running new home runs as I am not only upgrading my electrical panel, but moving the panel to a new location and not using the old panel as a junction.

Answer 1

I understand the need to have GFCI outlets

Code doesn't require GFCI outlets anywhere. It's just the only format that people are familiar with.

Every GFCI device can protect a downline part of the circuit, giving it the same GFCI protection. This is the ONLY appropriate use of the "Load" terminals on a GFCI device. Many people use "Load" because they have 2 more wires to attach and don't know where else to put them. They end up accidentally protecting parts of their circuit, which causes frustration when that goes dead later. Don't use Load by accident, only as part of a plan to protect the downline.

AFCI in Michigan

My location is in the Metro Detroit area in Michigan, so I don't think I need to purchase AFCI

I'm not a Code lawyer in Michigan, but I believe Michigan adopted the NEC 2005 requirement for AFCI protection in bedrooms, but deleted the NEC 2014 requirement for AFCI protection frickin' everywhere. So bedrooms, yes. However they probably did retain the requirement that the AFCI protection protect the entire circuit, so it probably needs to be a breaker. (unless the run to the first receptacle is in metal conduit, and then it can be there).

GFCI in Michigan

/GFCI breakers in terms of code. Aside from code standards, I'm not sure which ones to get.

GFCI protects humans from electrocution by detecting current that doesn't follow the normal path. GFCI protection can be provided anywhere, but providing it at the breaker protects the wiring to the sockets, switches or devices... so it can be useful. Also for 240V devices a GFCI breaker is the only way to provide that protection.

AFCI uses digital signal processing to detect the "sound" of arcing (hook up speakers with the amplifier turned on, and you'll hear that exact sound!) Arcing is very bad, as it creates a great deal of heat which can ignite fires. It was originally required to protect electric blankets (whose wires take a beating in the washer/dryer) and cords of bedroom appliances that get pinched between furniture and walls. Michigan stops it there.

However in the rest of the country, AFCI was found to be very good at detecting wiring faults in junction boxes and in-wall wiring. So the requirement was rolled out on many circuits.

Other than what is required, you can choose it if you find it valuable for safety.

Generally merely replacing a panel does not create any new obligations for AFCI/GFCI.

Answer 2

It is great you are upgrading!

You should only purchase what is mandated by your local jurisdiction.

Anything more or less would be opinion even considering the National Electric Code or NFPA70.

My jurisdiction doesn’t require all the electronic breakers because of problems, so you should find out what is required then decide.

Answer 3

GFCI and AFCI cover different aspects of safety. GFCI/AFCI together, of course, covers both.

• GFCI - Ground Fault Circuit Interrupter

GFCI watches hot and neutral (or with a double breaker, both hots and neutral) for an imbalance. Any imbalance must be going somewhere that it shouldn't, which could be through a person, which can be dangerous and even fatal.

GFCI can be as part of a circuit breaker to protect an entire circuit. It can also be at a receptacle to protect either that receptacle or that receptacle and everything after it in the circuit. It can also be provide GFCI protection only, without a receptacle, to protect everything after it in a circuit. Each method has advantages and disadvantages. Generally speaking, the electrical code does not care where you put it as long as key locations are protected. Historically GFCI has been needed for kitchens and bathrooms, but has been gradually expanded to additional areas such as outdoor receptacles, laundry rooms, garages, etc. GFCI is almost always least expensive when added as a receptacle replacement rather than a breaker replacement.

• AFCI - Arc Fault Circuit Interrupter

AFCI watches for the telltale signs of an arc. An arc is generally an indication of faulty wiring or appliances. Unfortunately, AFCI is very susceptible (compared to GFCI) to false alarms (nuisance trips with no actual problem causing them), so generally it is not added except where required by code. For example, GFCI is definitely, in my opinion (and my electrician's opinion), for bathrooms even when you are not changing anything else, while code generally requires it only for new circuits. On the other hand, AFCI, while ironically most useful for old wiring (because old wiring is more likely to have worn out insulation and other lurking problems), is generally only added for new circuits as required by code.

Because AFCI protects the wiring itself (from rodents gnawing insulation, loose connections to receptacles, etc.), it provides the most protection when installed as a AFCI/circuit breaker or installed very close to the panel. So on a new panel that generally means AFCI/circuit breaker.

Michigan is currently using the 2017 NEC. So any requirements for new circuits are based on the 2017 NEC, plus any local amendments. As I understand it, the 2017 NEC requires GFCI or AFCI in a lot of rooms. So that is your starting point for any new circuits. For any existing circuits, generally speaking you do not need to add AFCI or GFCI if you are not adding any new receptacles - i.e., if you simply replace existing receptacles (for grounding or aesthetics or just because they wore out) then you are OK but for anything new check to see if you need AFCI or GFCI.

A panel replacement with no real circuit changes may or may not require adding GFCI and/or AFCI for existing circuits. That depends on your jurisdiction and, possibly, on the inspector.