AFCI Woes

jwelectric · Oct 1, 2005

Re: AFCI Woes

Originally posted by sparky_magoo:
De-rating isn't an issue. I ran #8's for the 20 amp. ckt.s The pipe is almost 120' long.

The house hasn't been rocked yet and the plumbers aren't done.

Since the owner told me to use multi-wire ckt.s, perhaps he is plannig on using two pole AFCI breakers.

edited to correct spelling.

I don?t understand why the use of #8 for a 120 foot pull even if there was a maximum load of twenty amps on the circuit.

Replace the #8 with #12 and have room to spare.

Some one has money to burn. Spending this kind of money to wire a house the help can?t be getting much pay.

I know that I have heard it all now.

sparky_magoo · Oct 2, 2005

Re: AFCI Woes

This is a T&M job. The owner of my shop wants the large wire to overcome voltage drop. There will be about fifty feet of romex in addition to the conduit.

It is also questionable wether running branch ckt.s in PVC under the slab is worth the expense. Perhaps the owner is over charging his clients. He has a good reputation with custom builders around here. We are so busy, we aren't acceting any new clients.

sparky_magoo · Oct 2, 2005

Re: AFCI Woes

Do the math. 120" of 8 AWG with a 16 amp load is a 2.5% drop. Fifty feet of 12 AWG adds another 2.7% drop. This means at full load, I am over the recomended 5% drop. Our customers are willing to pay extra for what they percieve to be quality work.

jwelectric · Oct 2, 2005

Re: AFCI Woes

Will all of these circuits have a 16 amp load on them at all times? We are talking about the general purpose circuits, right? The smoke alarm, a couple of lights and maybe a TV?

I can?t see the bath having that load on it for any length of time. What will it have on it most of the time? A couple of lights and an exhaust fan?

160 feet of underground, how many square feet of house is this?

still

sparky_magoo · Oct 2, 2005

Re: AFCI Woes

The house 4600 sq. feet. It is shaped like a "L". It is long and skinny. Your right that it is unlikely there will be much of a load on these ckt.s. The owner expects me plan plan the VD calc.s
on general purpose branch ckt.s at full load. We even test all of the receptacles for voltage drop with an Ideal shuretest.

The first job I did for him was a hotel. The foreman got slammed because some of the rooms far from the panels had greater than 5% drop. I learned from that experience to run over size wire to keep the guy who signs my check every week off my back.

macmikeman · Oct 2, 2005

Re: AFCI Woes

Me, I would have stuck a sub panel or two on this house, and used a big enough feeder to overcome the distance. Maybe I read too fast again, but what size conduit did you run?. Maybe you could pull out all them #8 wires and send a subfeeder thru this pipe if you continued it to a subpanel.

macmikeman · Oct 2, 2005

Re: AFCI Woes

Ok, let me correct the last post I did before somebody else does. There is no "subfeeder" in the code anymore, only "feeders". So pull some "feeders" thru the pipe. It is hard to break some old verbal habits, but I have seen the light, er.. luminaire.

jimwalker · Oct 2, 2005

Re: AFCI Woes

You need to either repull the wire or run some romex before it gets covered.Hard to charge
T and M for goof like this.Figure out what cheap way out is and go do it

How big of a load will a master bedroom have ? Maybe 10 amps max and thats unlikely.

[ October 02, 2005, 01:45 AM: Message edited by: jimwalker ]

George Stolz · Oct 2, 2005

Re: AFCI Woes

Originally posted by sparky_magoo:
I learned from that experience to run over size wire to keep the guy who signs my check every week off my back.

It's above and beyond code, so that being the case, the man with the checkbook is right.

Even if he is crazier than a ****house rat.

sparky_magoo · Oct 2, 2005

Re: AFCI Woes

I have a subpanel in the middle of the house. It is nearly full. It's a 3/4" PVC conduit. I didn't lay put the job. Remember that guy was fired. I agree a second subpanel is called for. I was shot down when I asked for one. The forty position main is nearly full as well. The second sub would have freed up space in the main. I would have rather blown off the under-slab conduit and spent some of the savings on another sub. I also have supanels in the Cabana (guest house) and garage.

I personally believe the under-slab conduit and over-sized wire to be sales tools to convince customers we make superior installations.

I think pulling multi-wire ckt.s to the bedrooms is stupid if it requires the use of $200 ckt. breakers.

al hildenbrand · Oct 2, 2005

Re: AFCI Woes

Jim Walker wrote:

Hard to charge
T and M for goof like this.

Where's the goof?

Sparky_magoo wrote:

This is a T&M job. The owner of my shop wants the large wire to overcome voltage drop.

Think about it. The client is paying for better than minimum (a lot better). . .5% VD at 80% circuit capacity at the most distant outlet and the job already is T&M!

The cost of the double pole AFCI, even at full MSRP of $348 for a BR220AFIT, is not going to break that bank nor queer the deal, I just bet!

iwire · Oct 2, 2005

Re: AFCI Woes

Originally posted by al hildenbrand:
The cost of the double pole AFCI, even at full MSRP of $348 for a BR220AFIT, is not going to break that bank nor queer the deal, I just bet!

Al you must have deep pockets.

It seems to me $300+ for a residential breaker is outrageous, we can buy a 'contractor pack' that includes panel, meter socket and 20 breakers for less than the one two pole AFCI.

Of course any house that has a 120' pipe run is no tar paper shack.

al hildenbrand · Oct 2, 2005

Re: AFCI Woes

As you say, Bob, this is not a cheap house. From the clues in what Sparky_magoo has posted, I suspect that the person with the checkbook has a very different relationship to money than the one I have with my thread bare pockets.

BR120AF Manufacturer Suggested Retail Price $181
BR220AFIT (AFCI independent trip) MSRP $348
The difference of MSRPs is $167.!! That's less than the cost of the second BR120AF (assuming both branch circuits presently supplied by the multiwire circuit are required to have AFCI by 210.12(B))

I don't know about others on this forum, but I sure can't repull the homerun for negative $14.00.

Sparky,

From what you've written, I'm understanding that the home run in question is 120' 3/4" PVC with 3-#8 plus an EGC.

What guage is the EGC?
Are there other conductors in the 3/4" PVC?
If separate neutrals are run, will both branch circuits require AFCI, per 210.12(B)?

Edit typo - Al

[ October 02, 2005, 10:17 AM: Message edited by: al hildenbrand ]

iwire · Oct 2, 2005

Re: AFCI Woes

In that case I can not help but agree with you Al, I had no idea a single pole AFCI would be $181.

Truth be told I have never actual touched an AFCI breaker, I have seen them.

They are not yet required in the places I work.

No one really pays that much do they?

What is the price to an EC with a busy account at the supply house?

Bob

al hildenbrand · Oct 2, 2005

Re: AFCI Woes

Good question. I don't traffic in CH. I can get the CH120AF over the counter at the local building center for $39.

As an aside, curiously, the CH Online Catalog does not include the CH120AF. They do show the CH120AFGF (AFCI with GFCI) MSRP of $209.

jwelectric · Oct 2, 2005

Re: AFCI Woes

Sometimes my curiosity gets aroused and I do some stupid things. After reading about the #8 being pulled in a house for the voltage drop I had to see what my house had.

My wife, bless her heart, trying to get ready for church was about to call the insane asylum and have me committed.

We have 2250 square feet of living space and our house is 74 feet long. This morning I get up fix a pot of coffee and proceed to turn everything in the house on, every light including the table lamps to the highest wattage, TV, stereo, DVD, VCR, surround sound, I mean everything. Sitting here typing I just remembered I didn?t plug in the vacuum cleaner.

Using a Triplett 9015-A meter I checked every receptacle in the house except the kitchen and baths. The lowest voltage reading I got was 115.3. The 115.3 was on the living room circuit where we have never had everything on at once in the 10 years that we have lived here. At the panel with everything off except the master bedroom light I have 122.1 and 121.3 volts on the meter. This is a 5.5 percent voltage drop.

My home is wired with 14/2 with ground on all the general purpose circuits.
I fail to see why the #8 is being installed.

still

sparky_magoo · Oct 2, 2005

Re: AFCI Woes

In the 3/4 PVC, I have 3 AWG's and 4 10 AWG's. All conductors are THWN-2/THHN.

The other half of the CKT. in question is the bathroom GFI which doesn't require GFI protection. The two pole AFCI would be a waste of money.

This HO has very deep pockets. All of the fixtures are expensive. I talked him into installing recessed MR-16 halogen cans in each of the properties 19 exterior arches. It took me quite a bit of time to rope through all of the fire stops surrounding the arches. The house has a 100' hall down the long side of the "L", with a radiused ceiling. I installed the same MR-16 remodel cans into the very tight space above the arched ceiling. This also took a long time. The kitchen cabinets are being redrawn for the third time. We will be doing extensive 120 volt lanscape lighting. He now wants a 240 volt icemaker in the garage. I have never seen a 240 volt ice maker. He wants a central vac. in the the 550' sq. foot guest house. This means tearing out lathing to get the pipe from the garage to the GH. He has radiant floor heating, which I think is a waste. I could go on & on. These breakers won't break him. There is no way this house could have been a bid job.

BTW the appliance garage debate this house spawned recently just had the AG's deleted.

edited to correct spelling.

[ October 02, 2005, 12:56 PM: Message edited by: sparky_magoo ]

George Stolz · Oct 2, 2005

Re: AFCI Woes

Originally posted by sparky_magoo:
The other half of the CKT. in question is the bathroom GFI which doesn't require GFI protection. The two pole AFCI would be a waste of money.

You mean, "AFCI" protection, right?

sparky_magoo · Oct 2, 2005

Re: AFCI Woes

Your right. I meant AFCI. They have forced air heat as well. No AC. Not needed on CA's cool central coast.

al hildenbrand · Oct 2, 2005

Re: AFCI Woes

Sparky_magoo wrote:

The two pole AFCI would be a waste of money.

Compared to what? If your company is billing the double pole AFCI at $348 and the single pole AFCI at, say $100, could you really separate the master bed branch circuit from the bath for less than $248? What if the company is billing the single pole at the full MSRP of $181 and you have to fix this for T&M of $167? Could you do it?

Nothing prevents putting AFCI on circuits that don't require it. AFCI protection of the bath will work just fine (given the real world limitations of the implementation of the whole idea of AFCI embodied in the hardware the manufacturers have given us).

AFCI Woes

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