Duplex Service Load Calculation

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Waynes

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I have created a excel spread sheet to perform service load calculations for standard dwellings and for duplex standard calculations. I have been trying to do one for the duplex "Service Load" calculation and was told what I had was wrong.
Can someone assist me in correcting the formulas that iuse to do the calculations? I really would appreciate the help.

Thanks!
 
Waynes said:
I have created a excel spread sheet to perform service load calculations for standard dwellings and for duplex standard calculations. I have been trying to do one for the duplex "Service Load" calculation and was told what I had was wrong.
Can someone assist me in correcting the formulas that iuse to do the calculations? I really would appreciate the help.

Thanks!
Click to expand...

Sure, can we see them?

Welcome to the Forum.
 
Has the person who told you that your method was wrong given you any details as to what was wrong?

Just flying blind here, but I can mention a common error that is made on multiple dwelling unit calculations. Part of the problem is distinguishing the "service" to the entire building from the "feeder" to any single dwelling unit. There are demand factors that you can apply to any dwelling unit. If you are just calculating the feeder to one unit, you use the set of demand factors. But if you are calculating the service to the entire building, you get to take credit for the fact that there are two or more of every item of equipment.

For example, in a single unit you might have three items for which the demand factor of Table 220.56 can be applied. If you are calculating the feeder to that unit, you get to use a 90% demand factor for the load associated with those items. But if you are calculating the service for the duplex, then there are a total of six items of such equipment. Therefore, you get to use a 65% demand factor.
 
Good Circuit Tracer?

Good Circuit Tracer?

I need to find a good instrument for tracing some circuits in a building that has had wire and cables strung all over the place in the last 35 years.

The building has a 3-phase supply that supplied a lot of electric space heating when it was built in the early 70's. Much of that has been abandoned and replaced with an oil-fired system. There are sub-panels all over and an assortment of wire in EMT, conduit, and NM cables run everywhere you can imagine.

The problem is to determine where the wires all go and the 3-phase circuitry seems to befuddle ordinary circuit tracers.

Any suggestions on what might be suitable equipment for running down which cables are powered by which breakers, and for detecting which cables may be abandoned and not connected to anything?
 
The Amprobe 2005 I just bought can be used on circuits up to 600v I believe. I haven't used it on the job yet, just around my house.:grin: From what I can tell, it seems to trace very well.
 
Either provide the sheet or describe your calculations. Plus, tell us what the other person specifically said was wrong.

Charlie took the initiative and jumped in with a problem speculation. Does his post describe the problem you think you have?

We need details, please.
 
Sorry, but I cannot read that file. My system does not recognize a "RAR" file, and I don't have the time to download the software that would allow me to use it.
 
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