My house breaker box have only breakers which seat only 1 wire. No seat for a load neutral. Can I still install a GFCI Breaker?

Question

My house breaker box have only breakers which seat only 1 wire. No seat for a load neutral. Literally one screw on the breaker. There are neutrals on the bar and everything works no problem. I want to protect my circuits with GFCI breakers but they have 2 seats, 1 for the load hot and one for the load neutral, but my box has no load neutrals going into the breakers. Can someone tell me if I can just plug the hot into a GFCI breaker and plug the pig-tail into the bar, and leave the neutral seat on the GFCI breaker empty? And if so, will I still get GFCI protection in this way?

Lastly, why were boxes/homes wired this way? What are the advantages and disadvantages to this type of box? (where every breaker has just a seat for hot and there's no neutrals running around and the only neutrals seem to go directly into the bar?)

Answer 1

For "reasons", the US electrical system normally only has breakers on hot and not neutral. That is why hot goes to breakers while neutral goes to a bar. That is also one of the reasons keeping neutrals matching their hot wires is so important - an overloaded mismatched neutral won't trip a breaker.

GFCI breakers need to monitor neutral in order to detect ground faults. That is why GFCI breakers have a neutral connection as well as the traditional hot connection. If you don't connect the neutral to a GFCI breaker then even a small load will register as a ground fault. The result is that when you install a GFCI breaker to replace a regular breaker you move the neutral wire from the bar to the breaker, resulting in the configuration you've seen elsewhere but not (yet) in your panel.

Most breakers will have a one-to-one match between hot and neutral - i.e., one white (or gray, but far more commonly white) neutral wire for each colored (most commonly black, but can be red or blue or any other color except green, white or gray) hot wire. However, there are some legitimate exceptions:

• MultiWire Branch Circuits (MWBC) - These will have two hots and one neutral. The two hots need to be on opposite legs (i.e., the voltage from hot to hot will be ~ 240V while the voltage from each hot to neutral will be ~ 120V) and breakered so that they are turned On/Off together. An MWBC provides two 120V circuits that share a neutral.
• 240V circuits with Neutral - These will have two hots and one neutral, similar to MWBC. These are used typically for ovens & dryers which need 120V power for controls/lights and 240V for heat.
• 240V circuits without Neutral - These will have two hots and no neutral. These are used typically for water heaters and similar large loads that need lots of power but don't have any 120V components.

The end result is that the number of neutral wires will typically be a little lower than the number of hot wires.

In a main panel (but not a subpanel) you can also legitimately have ground wires (green or bare) connected to the neutral bar. It is debatable whether that is "good" or not, but it is legal as the ground & neutral are bonded together in the main panel.

Finding the matching neutral for each hot can be tricky. With cables it is usually not too hard as everything in a single cable has to be part of the same circuit. But with conduit it can get tricky as multiple circuits can share a single conduit.

Answer 2

If you want to change a circuit from current-overload protection to GFCI protection, you must trace and locate the neutral wire for that circuit and remove it from the neutral bar. The neutral wire for a circuit is the one that enters the service box through the same opening as the hot wire for that circuit.

Having removed the circuit's neutral wire from the neutral bar, connect it to the neutral seat on the breaker.

Connect the circuit's hot wire to the hot seat on the breaker, and connect the breaker pigtail to the neutral bar. Your ground wire is probably already in place and may be left undisturbed.

Answer 3

Your description is a little hard to follow. It's possible your BOX is a "Plug On Neutral" design, so the GFCI or AFCI breakers attach to the neutral bar when you attach them, and the hot and neutral wires to the circuit would attach to the breaker. (No pigtail wire to neutral.) If it's the older style box, the breaker for that box would have a pigtail white wire connected to the neutral bus, to feed the circuit's neutral.

RE why use plug on neutral- there's fewer wires running around in the box, so it's less crowded, it's easier to see what goes where, and it's easier to work in the box. It also saves time.

Plain (not GFCI, AFCI) breakers only attach the hot to the breaker. If you have no GFCI/AFCI breakers then only one wire is to be expected. DO you already have AFCI/GFCI breakers? They're relatively recent.

As another commenter noted, the GFCI compares the current going out to the current coming back through the neutral, so they HAVE to be attached to the GFCI breaker.

A picture would help, or Google the serial # on your panel box to see if it's "Plug On Neutral"?

A last question is why GFCI and not AFCI, or are you retrofitting spaces which really SHOULD have GFCI like basements, kitchens and bathrooms? Be careful running GFCI to appliances like a freezer, because the start up current may trip the GFCI. Newer GFCI designs have supposedly fixed that problem.