Single Wire Utility Transformers?

mtnelect

HVAC & Electrical Contractor
Location
Southern California
Occupation
Contractor, C10 & C20 - Semi Retired
I just found out. While I was driving home from the market, I was listening on the radio. A homeowner in Compton was turned down on a claim from the DWP. When we had extreme weather a few months ago, a transformer on a pole in his backyard came loose and fell on his car. He was told by the emergency crew to file a claim. So, he filed a claim with the DWP. He was turned down, because it was caused by nature. In the government code they are exempted.
 

garbo

Senior Member
So, put a amp probe around your water service. Where did that come from ?
Just was curious. Can remember one of my brilliant shop teachers telling us that a New York city bridge had hundreds of amps following thru it so use my regular size amprobes to measure current flow inside of several houses that I replaced the service. Used my dad's 600 amp clamp on meter to measure current on steel gas lines.Then I clamped on two of my amprobes & a buddies amprobes to measure the current on both energy wires and the grounded conductor on single phase 120/240 volt services. The measurements never exactly added up. If one energized line on a 3 wire Edison system was drawing 30 amps and the other line 20 amps then the grounded conductor ( neutral ) should only be drawing 30-20 = 10 amps but would get maybe 9.6 amps. Then took measurements on copper water service & steel gas pipe and found current flow on both of them. I received steady readings when I had motor loads off so I would turn off breakers for refrigerator & heater and turn on every incandescent lamp on. This teacher never stopped challenging us.
 

kwired

Electron manager
Location
NE Nebraska
I just found out. While I was driving home from the market, I was listening on the radio. A homeowner in Compton was turned down on a claim from the DWP. When we had extreme weather a few months ago, a transformer on a pole in his backyard came loose and fell on his car. He was told by the emergency crew to file a claim. So, he filed a claim with the DWP. He was turned down, because it was caused by nature. In the government code they are exempted.
If you can prove that gross negligence was responsible for what happened you may still have a case.
 

mtnelect

HVAC & Electrical Contractor
Location
Southern California
Occupation
Contractor, C10 & C20 - Semi Retired
In my area, attorney's charge $350.00 an hour with a $1,000.00 retainer. You will have an experience of your life, that you will never forget !
 

kwired

Electron manager
Location
NE Nebraska
In my area, attorney's charge $350.00 an hour with a $1,000.00 retainer. You will have an experience of your life, that you will never forget !
If your car is fully insured, you submit a claim to your insurance and hopefully their attorneys get involved if necessary. Should only cost you your deductible worst case. Of course insurance is good at finding ways not to pay a claim sometimes as well, then you might need your own attorney.
 

retirede

Senior Member
Location
Illinois
And the cheaper the insurance the more likely it is that they will find a way to deny your claim. It's cheap for a reason.

A saw a sign in the service department of a car dealer stating that they won’t give out a loaner vehicle to people with certain insurance carriers. I don’t recall all of the companies, but Progressive was one.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
If your car is fully insured, you submit a claim to your insurance and hopefully their attorneys get involved if necessary. Should only cost you your deductible worst case. Of course insurance is good at finding ways not to pay a claim sometimes as well, then you might need your own attorney.
Insurance companies are good at only paying things that are actually insured. A lot of people have insurance that they have no clue what is actually covered until they want to file a claim and then find out what they are trying to claim isn't covered. Then they blame the insurance company. It's not the insurance company's fault that you bought insurance that doesn't cover what you think it covers.

For instance, very few homeowners policies cover black mold, but for some reason homeowners think it ought to.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Consulting Electrical Engineer - Photovoltaic Systems
Insurance companies are good at only paying things that are actually insured. A lot of people have insurance that they have no clue what is actually covered until they want to file a claim and then find out what they are trying to claim isn't covered. Then they blame the insurance company. It's not the insurance company's fault that you bought insurance that doesn't cover what you think it covers.

For instance, very few homeowners policies cover black mold, but for some reason homeowners think it ought to.
In the words of Tom Waits: The large print giveth and the small print taketh away.
 

retirede

Senior Member
Location
Illinois
Insurance companies are good at only paying things that are actually insured. A lot of people have insurance that they have no clue what is actually covered until they want to file a claim and then find out what they are trying to claim isn't covered. Then they blame the insurance company. It's not the insurance company's fault that you bought insurance that doesn't cover what you think it covers.

For instance, very few homeowners policies cover black mold, but for some reason homeowners think it ought to.

Policies here all require an extra rider for either earthquake or sewer/sump pump backup. Many aren’t aware and don’t have it. I have earthquake but not the sewer backup. But I made the decision.
 

garbo

Senior Member
I have posted this before, and everyone thinks this is BS. Except for me.
I think that only supplying one high voltage wire to step down very common 120/240 volt single phase transformers is dangerous. I live in a big city where even when the cheap lazy Ultility company has three phase right above their usually 75 KVA transformers they only run one high voltage wire to them. When I look at locations near me will often see at least 8' of old copper wire missing and nogoodnics even steal the aluminum wire leading to ground rod at bottom of poles. Often takes months before ground rod conductor is repaired. Far majority of these poles are surrounded by paved roads & concrete sidewalks so wonder in the winter if any of these ground rods would be lower then 250 Ohms. Started doing hundreds of service upgrades & replacements since helping my sparky dad back in the early 1960's. Measured my first copper water service pipe back in 1967 while attending a great Vo Tech school. For next 40 years took ampere readings on copper water pipe service & steel gas pipe. Al! had at least 0.08 amps. Some were over 1/4 amp. So the Ultility company that only has 4 wires on their distribution transformers and no direct connection for other side primary winding are creating to appears to me a dangerous situation. Side note. I have been in my house for 48 years and from the first year if we were away for a weekend we would have a faint smell of natural gas. Had the gas company come out and by the time they got there odor disappeared. Talked to a plumber and he thought it was partially to due with steel buried gas lines having current flow 24/7. Houses were only 10 years old before numerous neighbors had the same problem.About 5 years ago they finally drilled holes on sidewalks where the 6" gas main is buried and took gas measurements there, on lawn & inside every house on the block. Ended up digging up halve of the sidewalks and pulling a p!astic tube inside of leaking stee! gas lines over a couple of years. No longer have a gas smell after returning to a closed up house. Have to take an ampere reading on gas lines repair and several ground rod wires from distribution transformers.
 
. So the Ultility company that only has 4 wires on their distribution transformers and no direct connection for other side primary winding.
I think you are still not understanding the connections. There is indeed a direct connection on both conductors serving the transformer primary. The only difference is in an MGN one conductor is at or close to ground potential so it doesn't need to be highly insulated with a porcelain bushing.
 

ramsy

Roger Ruhle dba NoFixNoPay
Location
LA basin, CA
Occupation
Service Electrician 2020 NEC
The fact we use grounded conductors as a normal current carrying conductor is what introduces the stray voltage issues.
on single phase 120/240 volt services. The measurements never exactly added up.
Electrodes are in parallel with service neutral, because of the main bonding point (MBJ).

Communication cables are in parallel with service neutral, because of the Demarcation point bonds.

250.6 (B) Alterations to Stop Objectionable Current. allow interrupting or moving some grounding bonds.

Appliance bonds to Comm.cables are considered temporarily in parallel during ground faults, and open-neutral conditions at the service.
 

mtnelect

HVAC & Electrical Contractor
Location
Southern California
Occupation
Contractor, C10 & C20 - Semi Retired
This attachment shows the connection from primary to secondary. Also see page 9, where a pole was taken of Electrical Engineers not associated with an utility.
 

Attachments

  • Multi Grounded Neutral #2 .pdf
    185 KB · Views: 14
Location
Lahaina, HAWAII
Occupation
Training consultant
Google SWER. (Single Wire Earth Return) and study the configuration drawings.
I have observed this in rural Canada, it’s also been used in Australia where loads may be many miles apart.

Don’t know how the earth ground is established at the feed end and at the load transformers.

Someone please train me.
 
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