How many have ringed delta?

[bobbo]

I know detroit. Anywhere else?

[reppy007]

I know detroit. Anywhere else?

Ive never heard of ringed delta...I may not understand even if you explain,but lets give it a try.Explain please.

[bobbo]

Ive never heard of ringed delta...I may not understand even if you explain,but lets give it a try.Explain please.

If wire goes down its hot. No outages anywhere. Circuit is ringed and the cans are paralleled. You have to isolate the primary on both sides and the secondary both sides to deeneegize. Sometimes you get lucky you have switches on one side and the secondary you will have a fuSed Johnny ball. You have fused can leads. They have open delta banks on different poles running the four wire. It's a great system if you are a customer. Detroit hands could tell you more.

[reppy007]

If wire goes down its hot. No outages anywhere. Circuit is ringed and the cans are paralleled. You have to isolate the primary on both sides and the secondary both sides to deeneegize. Sometimes you get lucky you have switches on one side and the secondary you will have a fuSed Johnny ball. You have fused can leads. They have open delta banks on different poles running the four wire. It's a great system if you are a customer. Detroit hands could tell you more.

Thank you,that was easy to understand,unusual but easy.Fused x-former leads.....now theres a thought.

[bobbo]

Thank you,that was easy to understand,unusual but easy.Fused x-former leads.....now theres a thought.

detroit line work : seperates real lineman from all the posers. Your brain has to work all the time! It's a great system, hot all the time. You can't fake it in detroit!

[tramp67]

Detroit has a great system for reliability. Its basically an overhead network system, transformers are paralleled and the secondaries of each transformer are fused with tattletale indicators, making it easy to spot a blown fuse. If a transformer fails, fuses on both the primary and secondary sides isolate it. I enjoy working on this system, you just need to understand it and pay attention. Being a true delta primary in a lot of the system, "the first ground is free", thus the system staying energized even with primary laying on the ground. Typical of any ungrounded delta system, with the exception that they tend to not have a normal open point on their loop systems, so no outages occur with any one failure on the system. Helps keep you from needing to go into "bad" neighborhoods after dark and minimizes outages.

[reppy007]

It does sound like a good system,but why is it only in the Detroit area?Anyway,good info about the delta system.And good to know that something is working well in the Motor-City.

[tramp67]

Good question, I don't know why other utilities don't have similar overhead construction. Its a good system for heavily populated areas, minimizing any outages on the system. Maybe liability? Having worked on a lot of different systems, I often wonder why utilities don't exchange information and ideas more. There's a lot of great ideas out there, but it seems like every utility feels they need to come up with their own unique ideas, good or bad.
Another interesting question, are there any other utilities besides CL&P (Connecticut Light & Power) that is going backwards, in lowering their primary voltage, building new subs and heavier lines, extra feeders to accommodate the lower voltage?

[Orgnizdlbr]

We have overhead network here in Jersey in some of our larger towns. Secondaries are fused with what we call flag fuses.

uG network tied through secondary network protectors, 4 kv and 12 kv primary with 208 sec. On UG.

240 v secondaries on OH.

[reppy007]

Since you have secondary fuses on this system ,would that mean that if one sec.leg fell down it should blow a fuse or would it have to be two or more wires down?Ive never worked with fuses on any secondary side.You mentioned that if a transformer failed,both secondary and primary fuses would blow.....I understand the primary side blowing but how would a secondary side fuse blow if the fault was on the line side of that fuse?