we are adding a 200 amp (second)service to a 80 x 24 wooden structured outbuilding on an acreage up here in canada.It is in a residential area and the tx supply 5 houses,all being acreages.The shop is being used as a mechanic/welding hitch shop and most of the other residences that are fed from the tx are running a lot of power as well.Is there any risk of blowing the fuses on the hydro tx with all these hi powered businesses and farms running off it?it looks as though one has a 400 a service
i didn't think about asking the utility at the time of application and permitting but now i wonder.....
what are hydros tx's usually rated at?
if they do have to upgrade who gets the bill?
any info would be great.......thanks guys

 

There is always a risk. I would not worry about it. The POCO will make whatever adjustments are required to their lines.

 

anybody know what they are rated at?

 

I am no expert but I do know they are all different. I have seen some small ones that feed only one house in remote areas. The standard one I see is about the size of a large garbage can supplying 10 houses. I have no idea what the ratings are.

 

I work for a utility, but I'm a little confused on your post. By tx do you mean the transformer. If so, does hydro tx just refer to the utility?

 

yes tx means transformer....i think it may be oil fillled and it supplies 5 houses that are all operational farms

 

Sorry about the confusion.....just don't see that particular abreviation down here.
Transformers are rated in KVA or Kilo volt amps. Standard sizes are 5, 10, 15, 25, 37.5, 50, 75 and up. A 50 KVA transformer at 240 volts would have a continuous full load current rating of 208 amps (50 KVA is 50,000 VA divided by 240).
This is it's continuous rating that it can provide without undue deterioration to it's components. It can supply considerably more current than 208, but for progressively shorter periods of time due to heating.

The utility will put up one large transformer to serve several houses because they count on diversity. Your water heater may not be necessarily running while your neighbors AC is on and vice-versa. The problem arises when you have some situation when everybody is on at the same time. I don't know about Canada, but when it hits 104 degrees here in Texas, the AC units never stop running and your diversity goes out the window. That's when you run the risk of blowing a fuse. At our Co-op, we fuse the transformers for 100% overload.

The other problem you might incur is flicker or dimming from your neighbors. In other words, your lights dim when their AC comes on, and their lights flicker everytime your welder strikes an arc.

You'll just have to see what happens. If the transformer turns out to be too small, the utility should upgrade to the correct size at their expense. At least that's what we would do. Good luck!

 

thanks wfo,that is exactly what i wanted to know