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Joined: Jan 2005
Posts: 7
Junior Member
Presently in NEC section 230.95 and 240.13 there is a requirement to have ground fault protection on 1000+ amp mains for; service disconnects, and building or structure main disconnecting means, respectively. The section in 240.13 first appeared in the 1990 code. I know that the section in 230.95 was in the code as far back as 1981. Does anyone know in what NEC version the section in 230.95 first appeared?

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Joined: Oct 2000
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Broom Pusher and
The oldest NEC version I have "Readilly Accessible" at this time is 1981, and it says about the same thing for Section 230-95 as the 1999 NEC does.
BTW, Section 240-13 does not exist in the '81 NEC - the last entry is 240-12

I have the 1968 City of Los Angeles Electrical Code "Readilly Accessible" - it is based on some version of the NEC, which one is of mystery at this time!
(errata per ammendments is quite ambiguous!).
Anyhow, it does not mention GFPE for Main Service of the infamous 480Y/277 system.

I have seen GFPE Mains on Buildings that date back to mid 1970's, which use the 4 wire Wye service.
Not very many of these services/systems were used at or above 1000 Amps.
The more commonly used 480 VAC 3Ø 3 Wire Ungrounded Delta service/system is found within these 1970's era Structures.

My Father did mention to me that when he did the Playboy Mansion "Remodel" (more like major T.I.!!!), the new Service consisted of a 2500 Amp 480Y/277 VAC 3Ø 4 Wire system - derived from the LADWP's Transformer (4800 VAC Primary x 480Y/277 Secondary) - and the new service had GF Protection.
This was back in 1972 or so.

On a side note, it seems to me that the service size pre-dating the 1981 NEC, may have been 1200 Amps and up.
Is this possible, or am I just looney?


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
Joined: Jan 2003
Posts: 4,391
Scott why the heck would a residence be fed at 480Y/277?

Other than some HVAC what can that voltage be used for?

When we build hotels we usually will have a 208Y/120 service @ 3000 to 4000 amps.


By the way, how long did that job take? [Linked Image]

Bob Badger
Construction & Maintenance Electrician
Joined: Oct 2004
Posts: 806

I somehow don't think the Playboy mansion would be considered as just a "residence" by any stretch, lol. [Linked Image]

Stupid should be painful.
Joined: Oct 2000
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Broom Pusher and
Hello Bob,

"mxslick" nailed it!

Considering that darn Mansion in "Residential" sense, is akin to considering the "Spruce Goose" as a small Fishing Boat!

They throw some RAGING PARTIES, and I mean frikken ragers!
They normally overload the Primary Circuit's Breaker during such ragers, resulting in darkness and mad neighbors.

To avoid the "Inconvenience" of power loss during previously mentioned off-hook parties, they (the Mansion personnel) have installed 2 separate back-up gennys!
One is a "Small Unit" - 250 KW rating,
The other is a "Modest" 750 KW rating.
Both are Diesel Prime Movers
(8V92 and 12V92 may be the types, not sure... need to ask the guys/girls up there about the Prime Movers' CU­³ displacement + make/model #)

The place is just really cool!
The "Remodel" took a few years overall, and upto just recently when a good friend of ours retired as Site Engineer, there was always something to do there every few months.

They feed you, give you as many Pepsi Colas as you can drink, and help move materials + etc. - even the Security Staff treats you great!
(now if you were not supposed to be there, that's another story! The LAPD would be the "Housekeeping Staff" dealt with in this alternate scenario!).

One of the most memorable things for me was seeing an Emu, poking her head over the Service Entrance Gate, while we were "On The Comm" with Security for entrance.
It was so funny - just a big old Bird's head and part of a neck, through the top part of the fence - totally staring at us.
She followed us while we drove in, all the way to the parking area - then poked her head in the passenger side window.
That was her way of saying "Hello"!
She was a real Sweetheart.

As to the GFPE deal, I asked Pops today when he remembers the first of such NEC articles.
Seems like early 1970's for him, as there was a large Industrial T.I. in Garden Grove he was involved with at this time, and was like the first GFPE he had seen and dealt with.
He was used to the "Commonly Used" 480 VAC Ungrounded Deltas.

I can still remember this job well! (I was between 8 and 9 years old at the time)
It was a HUGE Tilt-Up!
Seemed like it went on forever!
Big, beautiful Machinery inside it!!!
<enter Tim Taylor "grunts" here>

Ahhh, those were the days!
End of reminiscing


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

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