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Posted By: eswets commercial load calcs - 12/09/06 02:43 AM
I need to do a load calc for a new service on a restarant. I know commercial differs from res, but I cant find anything on the matter. Any info or a template to do the calcs would be great.
Thanks
eswets
Posted By: ITO Re: commercial load calcs - 12/11/06 08:03 PM
They are not to hard to build up in excel.
Posted By: ITO Re: commercial load calcs - 12/12/06 01:47 AM
Ok I got bored and made one for commercial kitchens. I just took my commercial calc-sheet and added item #7 for kitchen equipment.

Note:

STOP, if you don’t know excel, then don’t download this, and don’t read any further. Using an ITO excel calc page without first having a clue about excel will only get you in trouble so don’t do it. You have been warned.

Commercial Load Calc XLS Sheet

Only edit the yellow fields, if the answer is none, put a ZERO in it. I put plug numbers in to test the formulas, do NOT “delete” the contents of any cell, just right-click and “clear contents”.

1) Enter your square footage, if you don’t know what the lighting package specs are, but if you do you should use the actual as per 220-14 (D)

2)Number or general purpose receptacles.

3)Water heater, if its gas just put “0” and “clear the contents” for the VA value.

4)Again “0” it out if none, otherwise put the known values in.

5)Heat, there aint no way around it.

6)AHUs run with heat or AC so they get listed, and the rest is up to you.

7)READ 220.56 and only put “kitchen” equipment in. These will de-rate automatically but you must put a “zero” in if there is nothing or the de-rate formula will count it. Also if you need more rows, then “insert” them in-between 12 and 13 or you will mess up the formula.

8)Sign circuit…duh.

9)May not be required for a restaurant but I have seen some with a show window, and it was already on my calc-sheet. Just “zero” it out if you don’t want it.

10)You have to do it, so suck it up.

11)You don’t have to do it, but it’s a nice way to “bump” it if you need too.

12)The calc for amps at the end is for 3 phase only so be careful if you do a single phase service and edit the formula.

13)I converted this in about 15 minutes, so there make be a mistake…use at your own risk.

14)Comments and criticisms welcome.

(let me find a host for the xls file, brb)

[This message has been edited by ITO (edited 12-11-2006).]
Posted By: Obsaleet Re: commercial load calcs - 12/12/06 03:07 AM
Thanks ITO,
Itlooks like a nice set up I will check it out.

ob
Posted By: Amazingmg Re: commercial load calcs - 03/01/07 03:42 PM
I would like a copy of that spreadsheet if you could send it to me.

amazingmg@aol.com
Posted By: renosteinke Re: commercial load calcs - 03/01/07 04:19 PM
A new restaurant? Boy, does THAT bring back memories! I'd like to share a few pointers....

First of all, the load calc on the last place I did turned out to be optimistic. We had a number of problems, not the least of which was that the calcs put us over 320 amps, yet under 400.
Lesson #1: Push things with the PoCo. Better for them to up their metering before the place opens.

The next point is to look at the PoCo feed to the place. What else are those transformers feeding? Just because you're getting good voltage during construction does not mean there will not be voltage issues in the summer, when both the restaurant and the supermarket next door have their A/C running full blast!
In other words ... make sure the folks you are talking to at the PoCo actually considers that the new loads will overload the transformers.

Load calculations aside, be prepared to run a lot more circuits than you think you will need. For example, a coffee / soda station is likely to need at least 5 separate circuits. The ice machine, and the ice cream maker, are likely to require two circuits apiece.

Then there is the matter of the Ansul system. Again, you are likely to have a dozen circuits on the Ansul system. It might be easiest if you have a separate panel for these circuits. Think it over.

I know, I've gone well beyond simple load calculations. The place I did still likes me, though .. which is more than some of the other trades involved can say!
Posted By: NJ_WVUGrad Re: commercial load calcs - 03/02/07 02:38 AM
One of Renos statements raises an interesting point that I remember running into

Many POCO's in NJ try to push using a 320A rated meter pan when we submit a load letter for 400A...it keeps them from having to install CT's and the associated cabinet.

Because of this we really had to double and triple check our load calcs to put us over 320A.

Has anyone else run into this issue?
Posted By: LK Re: commercial load calcs - 03/02/07 11:45 PM
"Many POCO's in NJ try to push using a 320A rated meter pan when we submit a load letter for 400A."

The 320A Meter Sockets are rated 400A max 320 is for continous loads only, when you submited your load calcs, did your continous loads exceed 320A?
Posted By: WhiteRook Re: commercial load calcs - 03/03/07 11:06 PM
Ito, I too would like to see this. The link says it is no longer available for download so could you send me a copy please
Posted By: ITO Re: commercial load calcs - 03/05/07 04:43 PM
Ok ok if I get some time I will upload the latest Rev of my Restaurant load calc sheet today.
Posted By: ITO Re: commercial load calcs - 03/05/07 05:11 PM
This is my revised spreadsheet; the first one I posted here took me about 15 minutes, while this one took a lot longer because I put the time in to do all the references and check the formulas. This spreadsheet is intended to be used WITH the code book and not in lieu of the code book. If something does not seem right, question it.

Once again, if you are not skilled in excel, don’t even bother down loading this.

Revised Kitchen Load Calc Worksheet

1) General Illumination- (1A) Just the minimum table value, and if you know specifically what fixtures are being used then use (1B) instead. Don’t use both.

2) Count them up and put them in.

3) Some restaurants have a show window.

4) Outside lights, remember that if there is even one outside like that a minimum 1200va circuit at 125% is required.

5) Sign circuit, one is required at minimum.

6) Water heater, if it is under 120gal it goes in at 125%

7) List all your known loads (not kitchen) and note which one is the biggest motor load for later.

8) List all your kitchen loads, and the factor from T-220.56 should automatically update. If you need more lines “insert” one in the middle, if you do it on the end it will bork the formula. Also make sure you fill in a quantity or the formula wont work.

9) Heat and AC, note RTU’s are in at zero because the heat is bigger, and AHUs run for heat and AC so they stay in.

10) Largest motor from 7 OR 8

11) Future is not required but I always put it in there for the times when the owner tells me he will be expanding later.

I am still refining this for a cleaner look but it seems to work for now.
Posted By: ITO Re: commercial load calcs - 03/07/07 02:53 AM
Well that was a show stopper...
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