Jeff Remas

Will do Mike, thanks.

Blair, you are fast and you are good. Have Mike give you a prize!

You are inspecting a 20 year old home that is not considered to be unusually tight construction. The family has recently finished the basment and has framed around the utility area creating a separate, nice size utility/mechanical room of 12'x12' with 8' ceilings. The room has an energy rating and is sealed. All combustion air comes from within the room. In the room is an electric hot water heater and a gas fired hot water boiler for the hot water baseboard. The boiler has a 60,000 BTU input rating and a 52,000 BTU output rating. Is there enough combustion air in the room?

I have never seen one like that before. As far as the wiremold, I had a customer back in the late 80's who wanted wiremold under the cabinets to which I obliged but I had to install a GFCI breaker. He had a plug every 6" that was mounted directly under the cabinets against the backsplash so you never had any receptacles seen on the custom tile backsplash.

Quality builders will install it that way but there is no requirement that I am aware of. Call it a water heater and yes there is one required. Check with the local enforcement agency to see if they have any codes that would require it.

Remove the blower door and see if the problem still occurs. This way you will know if it really is the duct size / obstruction causing the problem or something else.

Without the mud/plaster ring, the box is undersized and would have to be bumped up to the 2-1/8" depth.

Jim, 1st of all I screwed up and posted 14/4 by accident. It should read 14/3. Sorry about that. 2nd item, let us just assume the metal mud ring is missing and that is one of the reasons there is no cover. The person could not figure out how to secure the devices to the box. Seen that too.

Yes in bedrooms and since there needs to be hard wired smoke detectors then they too must be on the AFCI breaker. Lighting and outlets for bedrooms do not have to be on the same circuit but most of the time they are. Typically there is 1 AFCI breaker (combination type) per bedroom and one of those also feeds the smokes.

Alright, 54+ views and only one taker. Probably because it is beyond the scope of a HI and no one feels the need to reply other than one person. Jim K I am sure is kicked back waiting to see what happens next since I am also sure he knows the answer. The answer from Carson2006 is correct. Anyone learn anything yet?

Any other takers?

*This is a box fill calculation question only and nothing else* While inspecting the unfinished basement for a client you come across a 4" square x 1-1/2" metal box that is fed with one 14/4 NM cable and one 12/2 NM cable. The box has one duplex receptacle and one single pole switch. As you are noting the missing cover for your report you look inside and easily see that the equipment grounds are attached to the box with a ground screw and properly attached to the devices. The NM cables are secured with a single cable clamp. The client states "There sure are a lot of wires in there." and this gets you wondering if the box fill is compliant with the NEC. Is it?

A, B & D are ALL correct.

OK, remove the word HOT from Hot Water Heater. Any other answers besides Richard?

Is the dropped ceiling there as a rated fire assembly requirement?

During your morning inspection you read the data plate on a 50gallon electric hot water heater. The data plate states 240v and 4500W per element (2- 1 upper & 1 lower) All terminals rated at 75 degrees. What size circuit is required? A) 10awg NM with 30A breaker B) 10awg NM with 25A breaker C) 12awg MC with 25A breaker D) 10awg MC with 30A breaker

Don't snort it or mail it to a politian whatever you do.

That's correct. Of course, the cables in the picture don't pass through wood framing that's fire or draft stopped. But I take your hint so I'll revise my statement: The NEC allows NM cable to be bundled with no restrictions for 24" unless they're fire or draft stopped. After that, you can still bundle, but you need to apply a derating factor. Read all about it in 310.15(B) and 334.80. - Jim Katen, Oregon Jim, I actually was not hinting anything, just following the severe thread drift in progress........[^]

I prefer to see multi-wire circuits fed from double pole breakers. If they are part of the generator panel then the should still be hooked up to a double pole breaker or you need to make sure that they are fed from separate phases as stated in the above post.

NM cable must be derated whenever 2 or more NM cables containing 2 or more current carrying conductors are bundled together and pass through wood framing that is draft or fire stopped using any type of sealant, even foam. You must derate each conductor by using Table 310.15(B)(2)(a) It does not matter if they are bundled for less than 24". The derating still applies as long as they are in firestop/draftstop material. I believe this started in the 05 code.

I don't understand what you are trying to explain. I think more detailed information will be needed.

Not the breaker? Not the transformer? You are saying that a fused disconnect is making the noise? If so then change the fuses as one of them may be defective or the wrong type. I am glad Jim addressed the "two phase" issue.

30kW should not even come close to 400A on a 240vac system, if that what this is. It will be closer to 125A. First thing is that you need to do an amp draw to see just how many amps you are drawing. The other systems in this setup may be adding to the total draw and the 400A breaker can be at or near its maximum, therefore arcing and causing the buzz sound. There can be a bad connection at the breaker. This type is probably a bolt in style. The breaker can be bad. Either way, someone qualified needs to evaluate the situation to determine what is wrong. There is something wrong.

Panel boxes are still allowed in closets. You are correct because the question was about a closet, not a "Clothes Closet"