Main Beam of a Residential House

Status
Not open for further replies.

bencelest

Member
Location
California
I made another calculation which I based it on a book I bought at Home Depot "Stanley Complete Wiring" since I have not receive the 2005 NEC book I ordered here. Please make a comment.
I called the AC guy who will install the duct but will not install the unit. He gave me the cna of the 2 units. The HO will make buyer install them in the future.
House elect calculation
1. Multiply square footage x 3 watts
2. Add 1500 watts for each kitchen small appliances circuit and laundry room ckts
3. Add the wattage for all appliances that are on their own ckts i.e. electric dryer, water heater, range , AC (Check the nameplates and remember that watts =volts x amps)
4. Add the 3 numbers up
Figure the first 10,000 watts at 100% and the remaining watts at 40 %.
5. Add the wattage of either the heating unit or the central AC whichever is greater
6. Divide this figure by 230.

1. 4,200 sq ftx 3 12600 watts
2. 2 appliance load + laundry
3 x 1500 4500 watts


3. Water heater 5500 watts
Dishwashers 1200 watts
Dryer 5500 watts
Garb disposal 1200 watts
Range 8000 watts
Wall mounted oven 3000 watts?
Hot tub 8000 watts?
----------------
32400 watts
-----------------------
49500 watts

4. First 10,000 at 100% 10000 watts
Remaining 39500 at 40% 15800watts
---------------------
Subtotal 25800 watts

5. Central air 13892 watts
4 ton 26.2a x 230=6026 watts
5 ton 34.2 x 230 = 7866 watts
-------------------------
Total 39692watts

6. Total divide by 230 172.6 amps

So, is my calculation within the limit of a 200 amp service?
Please respond.
 
Last edited:

bencelest

Member
Location
California
Bob:
Sorry I did not notice riight away your alternate calculation.

"Consider using the alternate method of 220.82 and Example D2(b) in Appendix D.

Everything but the A/C, including making the water heater 4500 VA, comes to 46,100 VA.

Use 100% of the first 10,000 VA + 40% of the balance:
10,000 + 0.4 x 36,100 = 24,440 VA
Add A/C load = 14,000
Total is now 38440 VA

Amps = 38440/240 = 143.8 Amps ==> 160.2Amps

Well within 200 amp service."

I changed the value of the AC units since I got the ACTUAL amp load value from the A/C unit installer.
 

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
Did the AC installer also include the air handler amps in those numbers (the air handlers are separate inside units from the outside AC compressors)? You also need to multiply those amp values by 240 and not 230. 120 and 240 are the standard numbers to use when doing calculations for both multiplication and division.

When using this alternate calculation method, you have to use the nameplace values from the range and not the table value. Did that 8000W value come from the table or is that the actual nameplate value? I'd use 12000 since many ranges are this size or more. If that was just a cooktop and not a range, then 8KW is reasonable.

If you have to add more amps for the range and air handlers, I think you're going to be close to 200A. For a house this large, I'd go with a larger service so he not 10A away from his limit.
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
Do you have gas?

Do you have gas?

I was looking over your post and I see there is a wine room, is there a small A C unit in there? maybe 20a 120v split system in a house that size.
I noticed that the GC is letting the buyer put in the AC units later ,does that mean there is natural gas for heating? if so is the water heater gas? or the Dryer? That would buy back a few watts off the calcs.
In California you need to be aware of the title 24 impact on lighting, If your plans were submitted after 10-16-2005 the city is going to inforce compliance to that.
 

bencelest

Member
Location
California
ACRW:
Yes, I am in California.
I thank you for pointing these things to me. I talked to the HO and he said I believe that the range will be electric but the central heat will be on gas.
I will suggest that range, water heater and dryer will be on gas to save electricity and of course main panel.
The HO I believe is new to building new houses for he asked my opinion as to the size of canned lights to be installed. It is around 90.
I will be so much grateful if you can tell me some more regarding
Title 24. You can email me or post it here.

(Moderator’s Note: Edited to remove email address. If you wish to send an email message to this person, then first send a Private Message via this Forum, and ask for the email address.)

The HO told me that he was planning to build similar houses 2 a year and insinuated that I will be his electrician.
Thanks

Mark: Thanks for those important info. I need all the help I can get. I will recalculate as such.
Thanks again.
 
Last edited by a moderator:

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
I sent you a message through the forum messages.check the upper right side of the screen to see "private messages"
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
california title 24

california title 24

the place to find the cal title 24 is on the state web site. Also look at the industrial relations dept. section ''labor code 3099.2 (3)(b) and 3099(c) if you need to hire help in the future.

The web site is www.bsc.ca.gov then look for title 24 2005 california energy code. what you need starts on page 72 of the code.

In a nut shell it goes like this ,1) all exterior lights must be high efficacy or on a motion sensor, 2) 50% of kitchen lighting wattage must be high efficacy "this is determand by max. lamp size allowed in fixture" this includes the lamps in the hood and the nook area, 3)bathrooms, laundry, garage, and utility room lights high efficacy, Low efficacy lights may be installed in these areas but need to be switched seperatly from high efficacy lights and controlled by a manual-on auto-off occupancy sensor.all other lighting can be either high or low efficacy as long as low efficacy is controlled by a dimmer or manual-on auto-off occupancy sensor.
This is a real change from the past when all we needed was the first switch to control a fluorecent in the kitchen and bath.The manual-on sensors are selling for about $50 bucks each.$$$$$$$$$$$$$
 

bencelest

Member
Location
California
Yes, it is drawn in the electrical drawing that jots down where to put high efficacy lightings.
I've wondered what that means. I thought I would just go to Home Depot and ask or look for high efficacy lights stamped on their boxes but can you help me on this as well?
The highest wattage that I can see on a 6" or 5" can lights are 75 watts. Will this classified as HE lights? Or I am on the wrong track?
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
Your on the wrong track.High efficacy is fluorescent with elecronic balast,there are others but for our purpose this is what you are looking for.Home Depot was selling a 6" fluorescent that takes a 26watt lamp. You would be better off going to a lighting store to get a good recess fluorescent. Most of them will have a hand out with the new code summary. And they should be more then happy to explain the code to you. Halo and elco are making lights that will fit this requirement. Also the recess lights need to be "air tight" and IC rated if in contact with insulation.
 

bencelest

Member
Location
California
Wow!!! Thanks Dan. You just save my a$$$$ big time. You just don't know how much.
And thanks to this forum. You guys are helping me so much I cann't say in words how grateful I am.

Benny
 
Last edited:

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
acrwc10 said:
In a nut shell it goes like this ,1) all exterior lights must be high efficacy or on a motion sensor, ...

Does this code really use the words "efficacy"? If so, I think they are using the wrong term. Efficacy means effectiveness, whereas efficiency means they make a lot of light for a little power. To me, incandescant lights are not all that efficient, but are about the most effective choice (good color, instant on, can be dimmed easily, easy to focus). Fluorescents are very efficient but I don't like their poor efficacy (buzzing ballasts, you don't get full brightness instantly, their color temps and CRI are OK now but not the best, dimming is real expensive).

I think this code should use the words high efficiency instead of high efficacy, if that is what they really mean.
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
its not a spelling test its a ''efficacy test''

its not a spelling test its a ''efficacy test''

suemarkp said:
Does this code really use the words "efficacy"? If so, I think they are using the wrong term. Efficacy means effectiveness, whereas efficiency means they make a lot of light for a little power. To me, incandescant lights are not all that efficient, but are about the most effective choice (good color, instant on, can be dimmed easily, easy to focus). Fluorescents are very efficient but I don't like their poor efficacy (buzzing ballasts, you don't get full brightness instantly, their color temps and CRI are OK now but not the best, dimming is real expensive).

I think this code should use the words high efficiency instead of high efficacy, if that is what they really mean.


Yes they used the word "Efficacy" it made me double check myself, double check myself.
don't forget who our govenor is "Arnold" something or other.It may have been his choice of wording.
If you go through the title 24 it uses the word efficient elsewhere in the code,like high efficient heater. But us 'lectrishin' can't spell no good anyways.
 

bencelest

Member
Location
California
"Does this code really use the words "efficacy"? If so, I think they are using the wrong term. Efficacy means effectiveness, whereas efficiency means they make a lot of light for a little power. To me, incandescant lights are not all that efficient, but are about the most effective choice (good color, instant on, can be dimmed easily, easy to focus). Fluorescents are very efficient but I don't like their poor efficacy (buzzing ballasts, you don't get full brightness instantly, their color temps and CRI are OK now but not the best, dimming is real expensive).

I think this code should use the words high efficiency instead of high efficacy, if that is what they really mean. "





acrwc10 said:
.....don't forget who our govenor is "Arnold" something or other.It may have been his choice of wording.
If you go through the title 24 it uses the word efficient elsewhere in the code,like high efficient heater. But us 'lectrishin' can't spell no good anyways.

Things only can happen in Californiaeyy.......
Thanks for the laugh.

I've been reading the examples on Chapter 9 -Tables and Examples for Load Calculations and I come up with different result. I'll post as soon as I am able.

I just talked to the HO and I convinced him to change the Hot water heater, dryer and the range to gas.
But now he wants to add floor heating at some parts of the house and possibly a swimming pool.
 
Last edited:

bencelest

Member
Location
California
Regarding the swimming pool, I was reading Article 680 but it does not say anything about the size of the motor etc.... size of wire, guidance of installing the motors and associated equipments, is there any body who can help me on this?
I know it depends on what size pool but what I like is just the average size pool a home owner usually order so I have an idea what is ahead. FLAmps, volts, HP? Heating water(?) .
I also did some research here and here's what I found " Quote:
Originally Posted by ronbannon
I was hoping to get some feed back on this senario.
I have a pool with a swim up bar, it is in a residance on one end of the pool they put on a bar with the bar area in the pool there is a dishwasher and a refridge in that area they are on gfi but well with in 10 feet of water line acctually 5 foot from edge of water. also below the water line. There is also a fan and a few lights above that area. In 680 it talks about outlets not closer than 10 feet and lights need to be 12 feet above water line so I falled the installation. also keep in mind that this is not an existing pool or structure.
Now I would not like to be the one down in the bar area with wet feet and do dishes or go into fridge. Just trying to get some feed back from others in the field.


You saved some drunken nut from killing himself.What EC would even have wired this ?"

I am not sure if we have a rep in my area because it is always cool here. I am not sure if I have seen one installed even in the high class neighborhood except in public places such as the YMCA or private clubs.

What about the floor heating? Is there anybody had the experience installing them?
Appreciate any help on this please.
 
Last edited:

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
My 16x36 pool has a 3/4 HP circulation/filter pump. This is 6 amps at 240V. You may want to plan 10A in case the pool installer convinces him that bigger is better. Some pools also have built in spa's. These have either air blowers, or pumps that move a lot of water that suck in air in the pipes. My spa pump is 2HP, or 11A at 240V. Pool lights can also be rather large. A normal incandescent pool light can be 250 to 500 watts each. There could also be separate pumps for cleaning.

Heating the pool can be done with gas or a heat pump. I have a heat pump on mine and its MCA is 35 amps. Which is better depends on utility costs, and I don't know the cost per therm of gas or the KW-Hr rate for electricity in your area. A pool heat pump is hard to beat on cost, but they are of limited BTU capability (about 130 KBTU is the largest you can buy), and many don't have defrost so they can't be used below about 50 degrees F. A pool heat pump can also be a pool cooler, so if it gets real hot in this area and they want the pool cooled down, go with the heat pump.

This customer sounds like he doesn't know what he wants, but is able to buy a lot of things. I'd definitely install a larger service now than what you think he needs. I'd go with at least a 300A service based on your previous posts of equipment, as that should provide a lot of growth room.
 

bencelest

Member
Location
California
Thanks Mark for your nice effort describing your pool. That helps me a lot visualizing what I have to do.
This HO thinks a lot to spend his money. The last house we renovated , when we upgrade the kitchen he made the exhaust fan ducts dropped close to the stove on an island kitchen, and made all the countertops made of marbles , he made me install lot of canned lights, and installed bathroom fans in all bathrooms. He installed all kinds of gadgets in the master bathroom shower, spa, jacuzzi, and sauna. He even bought two 60" plasma TV's installed in the guest room and living room, made all floors hardwood even in thebathrooms. He tore down a very nice looking redwood patio and replaced it with almost the same redwood materials. He also bought all kinds of expensive furnitures for the bedroom and living room. And .......put the house up for sale after some gardener landscaped the whole lot.
But who cares. As long as he is paying good..........
In this new house he's already made changes in the plan. Who knows what comes next.
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
The pool contractor will most likely do all thier own electrical work related to the pool.Usally they want a 60amp 240volt circuit for there pool panel.It will not draw that much though. just two pumps normally.In Monterey it will be a gas heater. If the floor heat is in the bathroom tile it will most likely be a deticated 20a 120v circuit,"Nu-Heat" brand is common in our area.All of them I have done the draw is about 1200 watts. And I still think 200 amp is more then addiquit.I would not fight putting in a larger service if thats what the customer wanted though, I like money as much as the next guy.
 
Status
Not open for further replies.
Top