Enough power?

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Utility customer

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Kingston ny
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Home owner
Howdy. New user Ryan from kingston, NY here. I have a question. The transformer that serves my residence and 11 others on my street is 15 kva. Is this adequate enough? I have been having Power quality issues. The power co installed a meggar mr-4 meter recorder to monitor the situation. F and S For flicker and swell has been recorded. Other neighbors also have light flicker and such. Our Eletronic issues are: t3 modem timeouts. Packet loss. Errors. We’ve had premature electronics fail. Fridge motherboard, etc. Please let me know your thoughts. Our end of line service pole also does not have a copper ground. The utility co. Says there are no issues. Thanks in advance for helping us.
https://forums.mikeholt.com/x-apple-data-detectors://1/0

Additional info moved from another thread (now locked) was added below. I am allowing this thread even though I doubt the OP is an electrician (not in profile) because he is not indicating that he will be doing anything himself, he is just asking for opinions.
Click to expand...

does the megger mr-4 recorder measure both external and internal power surges or swell. I am having issues with electronics burning out prematurely and other weird things like smoke detectors going off for no reason. any thoughts. Could Extertal power issues in the neighborhood caused this. Or an under powered transformer
 
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Jraef

Jraef

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San Francisco Bay Area, CA, USA
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Electrical Engineer
15kVA at 240V single phase is good for 62.5A under normal NEC operating conditions. But utilities are not bound by those rules, they can basically do what they want with their transformer; it's their loss (notwithstanding your anger) if it catches on fire... So it would not be unusual for them to consider that adequate for a 100A service, knowing that it will rarely be required to deliver that much.

But for 11 residences? That would be way to far over the line IMHO, even for a utility. How do you know it is only 15kVA, and how are you certain it is feeding all 11 residences?

As to your meter recorder, there is no such concept as "internal and external power surges" unless you are generating your own energy at your house. It will record swells, dips and spike of at least 1/2 cycle duration. About the only thing that could happen on your side are transients caused by large loads switching on and off, as in larger than anything found in a typical residence. Someone in the neighborhood trying to run a home machinists shop and/or a large air compressor is one possibility. But generally, it's hard for a residential user to create line distrubances unless there is something else wrong, such as a poorly connected neutral somewhere. That's something that a licensed professional electrician could check for you.
 
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hillbilly1

Senior Member
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North Georgia mountains
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Owner/electrical contractor
A lot of houses on one small transformer seems to be pretty common up north. Eleven is a little excessive, usually they will do four to five. My cousin in Ohio had a five hp air compressor in his garage, and it would strobe his neighbors lights when running! Must be an old neighborhood. Back then the loads were very small, no A/C, no large loads. Now you have A/C units, large refrigerators, etc. The exsisting drops are usually small, and ran long distances, whoever lived the furthest away had really sucky power. With internal and external sags and surges, the meter is looking for amps vs volts. If the amps drop along with the volts, its usually an external problem. ( line side of the recorder) If the amps rise as the volts drop, its usually internal (load side of the recorder)
 
mbrooke

mbrooke

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Location
United States
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1) Residential homes are not continuous loads. Instead power draw takes place in short peaks and long troughs. As such utilities will take advantage of the thermal inertia present in all oil filled transformers loading them to 200-300% of their nameplate rating for short period of time typically lasting about 1 hour. The oil will absorb the extra heat from the core/coils and then gradually cool during none peak hours.

2) If the peak takes place during winter, the continuous rating of the pig goes up as well as their ability to tolerate overload in duration.

3) If the transformer does overheat slightly, it will not immediately fail. Utilities on top of number one and number two can further choose to over-drive the unit such that it fails in 30 years instead of 100 years. There are economics sometimes found in sizing to a life cycle.

4) Most homes can get away with a 20 to 60 amp service. Few homes will ever pull anywhere close to their disconnect rating.
 
mbrooke

mbrooke

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Location
United States
Occupation
Technician
Of course, that is not to say the 120/240 secondary or the transformer itself could not have become under sized over the years. Homes that previously had no AC or large loads could have all filled up with them over the year not being known to the POCO.
 
mbrooke

mbrooke

Batteries Included
Location
United States
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Technician
Utility customer said:
Howdy. New user Ryan from kingston, NY here. I have a question. The transformer that serves my residence and 11 others on my street is 15 kva. Is this adequate enough? I have been having Power quality issues. The power co installed a meggar mr-4 meter recorder to monitor the situation. F and S For flicker and swell has been recorded. Other neighbors also have light flicker and such. Our Eletronic issues are: t3 modem timeouts. Packet loss. Errors. We’ve had premature electronics fail. Fridge motherboard, etc. Please let me know your thoughts. Our end of line service pole also does not have a copper ground. The utility co. Says there are no issues. Thanks in advance for helping us.
https://forums.mikeholt.com/x-apple-data-detectors://1/0



does the megger mr-4 recorder measure both external and internal power surges or swell. I am having issues with electronics burning out prematurely and other weird things like smoke detectors going off for no reason. any thoughts. Could Extertal power issues in the neighborhood caused this. Or an under powered transformer
Click to expand...


Can you post pictures of the setup? The pole pig and the run underneath it going for several spans?
 
U

Utility customer

Member
Location
Kingston ny
Occupation
Home owner
hillbilly1 said:
A lot of houses on one small transformer seems to be pretty common up north. Eleven is a little excessive, usually they will do four to five. My cousin in Ohio had a five hp air compressor in his garage, and it would strobe his neighbors lights when running! Must be an old neighborhood. Back then the loads were very small, no A/C, no large loads. Now you have A/C units, large refrigerators, etc. The exsisting drops are usually small, and ran long distances, whoever lived the furthest away had really sucky power. With internal and external sags and surges, the meter is looking for amps vs volts. If the amps drop along with the volts, its usually an external problem. ( line side of the recorder) If the amps rise as the volts drop, its usually internal (load side of the recorder)
Click to expand...
Neighbor has professional air compressor. Soon after. Megger mr-4 lights up like Christmas. Utility co days no issues found
 
kwired

kwired

Electron manager
Location
NE Nebraska
I have to agree with some others, if you indeed have 15 KVA and it supplies that many dwellings, it probably is overloaded at times and nearly everyone is starved for voltage when it is overloaded. At very least they all probably see a significant sag in voltage whenever someone's AC compressor starts or if anyone has other larger motors like the mentioned commercial air compressor.
 
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Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
If we have two on a 15kVA I will start looking at loading and usually change it to a 25.
Gas houses could be stacked four or five to a 15, but AC in even small houses limits you to about three max on a 15.
 
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