The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!


2017 NEC and Related
2017 NEC
Now Available!

Recent Posts
Parking lot pole light swap....
by gfretwell
Yesterday at 08:46 PM
International Wire Colour Codes
by Tjia1981
10/23/16 12:08 PM
Son of Sparky
by HotLine1
10/20/16 07:43 PM
Speaking of Plugmold ...
by gfretwell
10/17/16 02:37 PM
Broken battery charger? Check for cobwebs!
by gfretwell
10/17/16 02:30 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 14
HotLine1 7
ghost307 7
renosteinke 6
Potseal 4
Who's Online
1 registered (gfretwell), 321 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#166100 - 07/12/07 04:49 PM Service calculation
jem Offline
New Member

Registered: 04/30/07
Posts: 8
Loc: nc
Single family home with mother-in-law apartment, 200 amp service, all electric except for gas heat. Customer wants to install a 50 amp hot tub. Using 220.83(A) to determine if service is of sufficient capacity since no HVAC is being added. Should the existing HVAC load and new hot tub load be added to 220.83(A)(1)through(A)(4)before taking first 8kVA of load at 100% and the remainder at 40%.

2014 / 2011 NEC & Related Books and Study Guides
#166140 - 07/13/07 07:25 PM Re: Service calculation [Re: jem]
HotLine1 Offline


Registered: 04/03/02
Posts: 6792
Loc: Brick, NJ USA
My read is to do the calcs on the EXISTING items, then add the hot tub.

One may also consider installing an amp recorder to 'see' the real world numbers to have actual (real) load.


PS: Welcome to ECN


ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals