POCO tranformer load

[SSDriver]

Here's is the transformer on my block. Best i can tell its feeding 8 to 10 houses. I have a few questions.

I would love to see the spec sheet on this transformer but not sure what manufacturer goes by HO.

At 50Kva 1 phase thats 208A on the secondary at 240 volts. I know a bunch of neighbors have EV chargers ect. Average house is 2000-3000 sq ft. How is this operating during summer with all ACs on ect. Is this possibly 3 phase with some funky taps to get 240/120 and split up to send out 1 phase to each huuse.

Also the primary is

HV 16340GRDY/9430

So what is the actual primary voltage and what does the GRDY stand for? Which of the two voltages do you think they're operating at?

 

[don_resqcapt19]

Most likely fed line to neutral from the 16.3kV grounded wye system. If the distribution system would be a 9.4kV delta, then it would be fed line to line from that system. In either case the primary winding sees 9.4kV.

This is a single phase transformer, not 3 phase. One primary winding and a center tapped secondary winding.
Feeding 8 to 12 dwelling units from a 50 kVA transformer is common. My transformer is a pole mount 50 kVA and feeds 10 houses, most of shich have 200 amp services. The utility knows that the real world loads are substantiantially less that what is required by the Article 220 calculations, and installs their systems based on what the KNOW the loads really are.

However, this could be an issue as there are more and more EVs installed and being charged at the peak load times. Utilities in many areas offer off peal pricing to encourage changing the EV when the loads are expected to be lower. Some are looking to have control of when you charge, how much current you can draw for the charging, and some are even looking to the use of bi-directional charging systems where the utility can pull power out of your EV to support the grid.

 

[kwired]

Most likely fed line to neutral from the 16.3kV grounded wye system. If the distribution system would be a 9.4kV delta, then it would be fed line to line from that system. In either case the primary winding sees 9.4kV.

This one likely only has one insulated terminal though (on the primary) and must be connected between ungrounded to grounded conductor of that 16.3/9.4kV system.

 

[kwired]

POCO's often will factor in how much overloading and for how long a transformer or even their distribution conductors can handle, and how long of a "cool down" period is needed before that peak can happen again.

Summertime yes the AC is likely a majority of the load throughout the day, but the AC itself is probably less than the rating of that transformer. Most the other loads are not as long term and it can get by with a little overload as long as not for too long at a time.

If in a place where there is significant heating loading happening - you to have to consider the transformer is in a low ambient during the worst heating demands.

 

[electrofelon]

Here's is the transformer on my block. Best i can tell its feeding 8 to 10 houses. I have a few questions.

I would love to see the spec sheet on this transformer but not sure what manufacturer goes by HO.

At 50Kva 1 phase thats 208A on the secondary at 240 volts. I know a bunch of neighbors have EV chargers ect. Average house is 2000-3000 sq ft. How is this operating during summer with all ACs on ect. Is this possibly 3 phase with some funky taps to get 240/120 and split up to send out 1 phase to each huuse.

Also the primary is

HV 16340GRDY/9430

So what is the actual primary voltage and what does the GRDY stand for? Which of the two voltages do you think they're operating at?

View attachment 2563485
View attachment 2563486

See this document for an explanation of the various transformer voltage designations. Note you are 1(d) in the document. Its 99% likely the primary neutral connects to the tank, so only one HV bushing.