Square D QO120DF SP 20 Amp 120 VOLT Combination Arc Fault & GFCI Breaker

Bought one on Ebay for my boats QO panel.
QO GFCI work fine with my setup which includes a gen and an MSW inverter.
The price of $26 was real good for this combination AFCI and GFCI.

Is there any interest in having AFCI breakers on a boat?
I also wonder how it will work with my MSW inverter waveform.

I currently use a Hubbell GFCI outlet to protect all my outlets. Plan is to use the QO120DF on that branch circuit. I can use the GFCI outlet elsewhere.

I might get another one for the Cruisair heat pump, would that be worth doing?

Right now have all outlets GFCI by Hubbell and the kitchen - galley on another branch Square-D GFCI breaker in the QO panel.

This is a new design AFCI, so should have been improved.
Claim is AFCI has saved lives and prevented fires from arcing wiring from loose connections and abraded wires, so why not also on a boat, which IMO, would be more likely to have wiring faults.

For example in your home, basically now everywhere they are required.
electrical - Where *shouldn't* I use GFCI/AFCI? - Home Improvement Stack Exchange

National Electrical Code 2014 requires ground-fault protection for personnel in dwelling units for all 120 volt, single phase, 15 and 20 ampere receptacles installed in the following locations:

Bathrooms.
Garages
Accessory buildings with floors at or below grade that are not intended as habitable rooms.
Outdoors, except where receptacles on dedicated circuits are not readily accessible, and are used to supply snow-melting, deicing, or pipeline and vessel heating equipment.
Crawl spaces
Unfinished basements, unless the receptacle is on a dedicated circuit and used to supply a burglar alarm.
Kitchens where the receptacles serve coutertop surfaces.
Where a receptacle is within 6 ft. (1.8m) of sinks in other than kitchens.
Boathouses
Where receptacles are installed within 6 ft. (1.8m) of the outside edge of bathtub and shower stalls.
Laundry areas


Arc-fault protection is required in dwelling units for all 120 volt, single phase, 15 and 20 ampere branch circuits supplying outlets and devices installed in:

Kitchens
Family rooms
Dining rooms
Living rooms
Parlors
Libraries
Dens
Bedrooms
Sunrooms
Recreation rooms
Closets
Hallways
Laundry areas
and all similar rooms and areas
I don't know where you shouldn't install them,

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I installed two of these into my panel.
And they work no nuisance trip yet.
One is for Cruisair heat pump.
One is for all my outlets, except kitchen-galley-fridge which run hither and thither all over the boat about 11 outlets. I have the galley-microwave on a separate panel GFCI breaker, simply I had bought one for that circuit couple years ago.

I managed to finally thermal trip them at 27 amps after a time of 2 minutes.
I ran a portable heater, a variable power drill, a circular saw, a heat gun, two vacuum cleaners all simultaneously and individually and AFCI-GFCI breaker did not trip or nuisance trip on shore power.

My next test is to use the MSW inverter and the gen and broadcast VHF to verify if they work the same. I have read VHF signals have tripped AFCI breakers on forums.

I honestly think the Square-D breakers are one of the better ones for AFCI after reading comments by others on forums about how their GE and CH AFCI breakers will nuisance trip on running a vacuum or universal motor.

I am keeping my fridge on a normal non AFCI-GFCI breaker.

This leaves my princess oven, 12 gallon water heater, fridge, two hardwired cabin heaters no GFCI-AFCI.

The MSW inverter works fine with those AFCI and GFCI breakers.
They continue to revise the working standards on the AFCI-GFCI combo breaker, hopefully for the good since you read on forums of people removing them after they get their house inspected. I could not make mine nuisance trip off.

sdowney717 said:

For example in your home, basically now everywhere they are required.
electrical - Where *shouldn't* I use GFCI/AFCI? - Home Improvement Stack Exchange

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These are only required on new construction and major renovations or additions so you don't have to make a run to the home center to upgrade today.

Of course, there's nothing preventing you from installing the latest safety equipment in your home or boat.

My niece bought a new home a few years ago and the refrigerator was plugged into a GFCI protected receptacle. Not a great feature, it cost her some food.

WesK said:

These are only required on new construction and major renovations or additions so you don't have to make a run to the home center to upgrade today.

Of course, there's nothing preventing you from installing the latest safety equipment in your home or boat.

My niece bought a new home a few years ago and the refrigerator was plugged into a GFCI protected receptacle. Not a great feature, it cost her some food.

Click to expand...

I decided to do this for safety reasons, and definitely kept fridge off a GFCI-AFCI.

A few years ago, I had some rain get into my Cruisair heat pump's electric potential relay-capacitor box on the unit. I reached down and was checking the water temperature and outflow with my hand.
I got a massive tingling shock. And this had been leaking current into the salt water for a few weeks by way of the water stream.
I dried it out and drilled a 3/8 inch drain hole through the box and through the base, plus sealed the edges of the hole so no rusting. No more problem. So I always wanted to put a GFCI on the thing since then. It is working great with the Square-D AFCI GFCI breaker, no tripping.

The electric box is supposed to drain by way of the front edge where cover intersects the relay-capacitor box, but it was holding water back and somehow rain dripped in there, maybe a big storm.

Update, it's all good, no nuisance trips. Happy to say. Square-D makes good intelligent breakers.

Something to consider, this Square-D QO distribution panel is 47 years old, yet still in great condition, even being in a boat and still can take the latest intelligent breaker technology they make for today.

Consider also the box is rated for at least 125 amps, and it is just loafing at 60 amps, really only 30 amps per incoming line, which also in a boat you almost never would use that much power, so stressed to the max it never will be.

The only improvement I made was about 10 years ago, when I did some rewiring, I pulled the box and epoxy coated the outside, then painted the outside, not that anyone can see it and not that it needed that, I just wanted to do it, cause I like to fix up old things like new, if they are worth fixing, which I think it is since I can now have AFCI-GFCI breakers, which improves the safety of the system. And it did not cost me much to do that.