Residential calculation

Status
Not open for further replies.

2Broke2Sleep

Senior Member
Location
Florida
Mike holts website has a free spreadsheet for download for residential calculations. I haven't used it in a while so I couldn't tell you what limitations it has (no optional calc, auto-derate of neutral, no commercial consideration), but it's great to check your answers to when doing the calcs by hand.
 

2Broke2Sleep

Senior Member
Location
Florida
Big advantage to the optional calc is the range demand factors are bypassed. Easier calculation with some less attention to detail required. Mike holt videos teach both of them great, but you'll still have to read through the codebook to get a good grasp on them. Don't let table 220.55 intimidate you like it did me, it is actually pretty simple. Don't confuse branch circuits with service/feeder calculations. They are both contained in the footnotes of the table.

The 'standard' calc is pretty much as simple as:
1) Outside building dimensions x occupancy VA table 220.12
2) Required laundry room receptacle (1500VA) 220.52
3)Small appliance branch circuits (2 x 1500VA) 220.52
4) Air conditioning or Heating load (larger of the two) 220.60
5) Appliances 220.53
6) Cooking appliances (Table 220.55)

220.42 calc done after considering all of the above, and you can find your required size there. A thorough write-up would take a while to do, so the easiest way is to stick your nose in the book.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Have Mike Holt written any book about plumbing?

------------------------------
]Plumber San Jose


I hope not--LOL

No he has not- he is an electrician, inspector etc who made a business from his electrical knowledge. He is not plumber. :D
 
Last edited by a moderator:

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
As stated in another thread,
Plumbers get paid for what they can do.
Electrical Engineers get paid for what they know.
Electricians get paid.

Sent from my XT1585 using Tapatalk
 
Status
Not open for further replies.
Top