Kw hours usage

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JDB3

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San Antonio, Texas
Help please.
Trying to figure the size of service needed for a small church building. A "mechanical engineer" designed & wired (I was told) it originally. From the grounded (neutral) wire going up the pole riser to the power company's transformer & everything there after looks wrong to me. 3 phase service.
I could not open the lock on the disconnect to look inside of it, to verify size of any of the conductors. Looks like he then ran some multi-wire copper cable (2 runs, direct burial) in rocky ground & then cane up and went into 2" PVC (inches deep) into the 3 phase indoor panel. Triple parallel (perhaps #6) onto the panel lugs.
The structure is perhaps 2,000 square feet. It was cold, rainy, windy day when I was there, did not spend much time there.
Contacted the power company & they could just tell me that the past billing was 760 Kw hours usage for that billing period.

Approximately 150 foot run from disconnect @ road to building.
What size service would you'll recommend? {Because cost is a big factor here}

As always, thanks.
 
How'd he manage to get 2 runs of direct burial cable to turn into triple #6 on a 3? panel...?!?!?!?

What is the disconnect rating?

What is the panel rating?

Need more info.

Have you considered doing a load calculation? That's what ultimately determines the minimum size service is required.
 
You can't use watt hours to size a service. The only number that you can get from the utility that would help you size the service would be the demand.
 
As stated in the opening post, I could not unlock the disconnect to verify the size of the conductors, nor the size of the over-current protection (if there is such inside the disconnect). The multi-wire cable is just that, with more than 5 conductors in each cable (he used various colors on each phase of the panel)

It has been a while since I did a church 3 phase load calculation, I am in the process of doing that now.


Unfortunately there is not a demand meter at this site.
 
JDB3 said:
What size service would you'll recommend? {Because cost is a big factor here}

As always, thanks.
Click to expand...

It cost what it cost. You cannot let cost get in the way of a NEC safe compliant installation. As far as service size, do a Article 220 load calculation.
 
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Problem with small churches is you often have heavy demand for only a few hours of the week and then it sits nearly idle the rest of the week.

You can say you had 760 kWhrs on a month, but you likely had 95%+ just on Sunday mornings, maybe for some period on Saturday's and maybe a couple hours on one other day - often youth programs occur at least one day during the week for a couple hours or so. But you can't divide that out over the whole month and have any idea just how hard it is loaded when it is loaded because the idle time is usually so much greater that it throws the average way off of what is needed when heavy load is present.

Heating and air conditioning people have similar difficulties with small churches - you can run a cooling load calc and determine a unit to cool that building, but if you have a few hundred bodies in there it adds to the heat gain, and you can maybe get away with some under sizing if time of occupancy is never over an hour or so, but once you have that special situation with a long time of occupancy - it gets too hot in there and the AC will never keep up. Some small churches don't have a separate sanctuary and fellowship hall like was traditional in past - then if you have a service followed by social event - time of occupancy does accumulate for heating and cooling purposes, over the separate function rooms of the past.
 
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