diy solar

diy solar

How good of an electrician are you?

Ya got it,

Question 4
Its 120/240 delta high leg

black L1 120 to ground
red L2 120 to ground
orange L3 165-180 to ground......the stinger leg, a non standard voltage

Question 5
Its 480/277 volt wye three phase
all three voltages are non standard but cant use the same color so tan, brown, orange will say 480/277 three phase

A lot of electricians think orange means three phase, but it does not, it is a ”non standard voltage”

480/277 is a non standard voltage (to ground) so orange is used there
120/240 delta hi leg L3 is a non standard voltage (165-180) so orange wire there

Like you noted many electricians do not know what the three dedicated colors are so they misapply orange to where it should not be used.

There is a very good reason for the code.

I do lots of industrial so i learn these tricks. It helps to know what you are dealing with at a glance.
 
Yup, so, it can be several things, but in a blk/red/org combo, it is usually, 120/240 wye combo split phase, and 3Phase… usually, BK L1, RD L2, OR is high leg, 3rd phase… which would be 277 to N IT GETS COMPLICATED AND THE PANEL WILL HAVE 2 phases that get 120V to N, but the OR will be 277 … always be wary when there is an orange in the bundle…
You got just a bit of this wrong


120/208 is wye three phase, all legs are 120 volts to ground....so black, red, blue

On 120/240 Delta hi-leg

L1 is 120 to ground
L2 is 120 to ground
L3 is varying voltage approx 165-180 volts...not 277 volts

on 480/277 WYE three phase all three legs are “non standard voltage” thus, tan, brown, orange (277 to ground)

and yes always be wary of that orange wire, the voltage is not declared but it will be a “non standard voltage”

After i pooped out on EMI/RFI in the communications division of GE I transferred into power systems so i did a lot of feild analysis in GE turboshaft generators which are widely used as backup power in mission critical applications.
Did mostly 2 mw to 8 mw units both jet-A and natural gas in N+1 arrays. So a bunch of big power experience before I retired from corporate bulls##t

unlike parallel inverters which is almost always one master and one or more slaves on a N+1 system no single one is the master, first one to respond is master and and the others are slaved to the master. If you need 6 generators at a minimum then you have 7 in the N+1 net so anyone can fail and another will come on line. These were used to power hospitals in a 100% no fail 24/7/365 situation
 
Last edited:
Yup, it is always fun when I find a delta setup in a home.
Industrial, its all over the place, depending on distribution transformers, but on residences customers ALWAYS want me to feed with all the breakers, and cannot understand why I can't
 
I have seen many shops where some unqualified person has gone into the panel and used the only space available and installed a breaker to feed a 120 volt item...on the “stinger leg” ....the magic smoke is released from the unsuspecting device.

I always attach a custom label which clearly points out the “stinger leg” when i do three phase delta hi-leg panels, I had them designed and printed on vinyl. And wrap orange tape on every “stinger leg” feed wire, both in and out from the panel.....still i get fools that say it will work.....its only 120....
 
I was good at electrical work from an early age. When I was about 15, my father taught me how to use a soldering iron. I immediately got good at fixing CD players for my friends. Later, I moved on to fixing custom headphones, and the whole college came to me for help. Of course, I would have liked to do better at it. To pass a Master Electrician exam, you must be 22 years old. And when I was about 26 years old, I decided to take that exam after all, and an electric car repair company hired me. But my dream job now is to work for Tesla. Thank you for these questions, I enjoyed taking them, but I don't see the point in impressing you with the answers. Please, tell me how I can get closer to Tesla? Where should I apply?
 
Last edited:
5. 277/480 3Phase L1,L2,L3, N, Ground
I would have just cut to the chase and given OP this and then gone on to explain that the neutral should be gray and not white, so that a lesser qualified electrician might not mistake that lighting circuit for 120vac. If you've ever been hit with 277vac you'd be a true believer if you survived. Most jurisdictions require the neutral on their 277/480 systems to be gray.
Lesson over.
 
I would have just cut to the chase and given OP this and then gone on to explain that the neutral should be gray and not white, so that a lesser qualified electrician might not mistake that lighting circuit for 120vac. If you've ever been hit with 277vac you'd be a true believer if you survived. Most jurisdictions require the neutral on their 277/480 systems to be gray.
Lesson over.
...and I've been retired 13 years.
Edit. 277/480 systems are most commonly used in commercial lighting settings that also include 120/240vac circuits for general with a white neutral conductor. Also as a side note when talking about that grounded conductor (neutral), it's only a neutral conductor when at the main Neutral bus between there and ground. How "neutral' of a conductor it really is, will depend on how well you have balanced the loads.
Beyond that, any 120vac or 277vac branch circuit has one fused hot and one common current carrying conductor to ground. It carries the full current of any device powered from it. That's why when you look at the term screws on a 120volt receptacle the silver screw is labeled "com" not "neut"
 
Last edited:
Ya got it,

Question 4
Its 120/240 delta high leg

black L1 120 to ground
red L2 120 to ground
orange L3 165-180 to ground......the stinger leg, a non standard voltage

Question 5
Its 480/277 volt wye three phase
all three voltages are non standard but cant use the same color so tan, brown, orange will say 480/277 three phase

A lot of electricians think orange means three phase, but it does not, it is a ”non standard voltage”

480/277 is a non standard voltage (to ground) so orange is used there
120/240 delta hi leg L3 is a non standard voltage (165-180) so orange wire there

Like you noted many electricians do not know what the three dedicated colors are so they misapply orange to where it should not be used.

There is a very good reason for the code.

I do lots of industrial so i learn these tricks. It helps to know what you are dealing with at a glance.
Your value is wrong, if it's a delta 3 phase with a center tap on one set of windings that high leg will read roughly 208V the other 2 to ground 120V
 
I'm not an expert electrician, but I've been reading a lot on it lately about the bastard leg, and another good thing to note just for reference is that NEC changed which leg you label it in 2008...

"A change to the 2008 NEC now allows the high leg of a four-wire three-phase delta service to be labeled as the C phase instead of the B phase. This change was made because utilities usually require the high leg to be the C phase in the metering equipment."

But Orange is supposed to be the color on the high-leg to help the electrician identify it... Of course any good electrician always confirms with a voltmeter before ever plugging any device into the circuit and frying it. :geek:
 
"A change to the 2008 NEC now allows the high leg of a four-wire three-phase delta service to be labeled as the C phase instead of the B phase. This change was made because utilities usually require the high leg to be the C phase in the metering equipment."
That change was made so that the NEC is in agreement with the NESC.......the National Electrical Safety Code,,,,,what...???

That is the code set of the power grid, the nuclear power plants, hydro dams, power distribution grids, the whole network which is the same for all makes of power stations.....It is the highest code set universally used throughout the whole power grid coast to coast....unlike the NEC, CEC etc. , which can change on the city boundaries, it is universal
 
Not sure where you're reading about using black-red-blue-brown-orange-yellow as colors to ID ungrounded conductors. Granted it's what we use in the field, but the 2020 NEC only calls out 3 specific colors for AC under 600volts. White and gray for your grounded conductors and green for your grounding conductor. Sec 210.5 does call for DC positive to be red and DC negative to be black.
 
It's not written anywhere. It's just common practice.
Only Orange, for non standard voltage.
 
That change was made so that the NEC is in agreement with the NESC.......the National Electrical Safety Code,,,,,what...???

That is the code set of the power grid, the nuclear power plants, hydro dams, power distribution grids, the whole network which is the same for all makes of power stations.....It is the highest code set universally used throughout the whole power grid coast to coast....unlike the NEC, CEC etc. , which can change on the city boundaries, it is universal
That's interesting, I spent much of my career in those settings. In real world many times the fact that a utility ignores nec standard isn't because they have a higher standard of installation. It's so they can put it in however they see fit. I finished my apprenticeship at now defunct S.O.N.G.S. 2&3 and went on to cover the spectrum of other types of fueled powerhouses in 30 years of construction and maintenance and I can tell you first hand that the NESC has no more teeth "coast to coast" than the NEC does state to state or city to city.

I was terminating the interconnects in some 15kv switchgear in a powerhouse I won't name and the young eager EE for the turbine deck walked up behind me and asked "what are you doing?" to which I replied "electrical work". He says "what kind of electrical work?" I says "interconnects". He says "what are interconnects?" I stop what I'm doing, put down my tools and look down that long line of 15kv switchgear and says "really? Go back to your trailer and do some studying on those prints" This is the guy who would be enforcing NESC but since he never built anything he depends on me to tell him what's right and proper, not the other way around.
 
Oddly enough in the Midwest Commonwealth Edison still wants the high leg on the middle phase. You happen to know the section of the code that mentions the orange color requirement?
https://www.comed.com/SiteCollectionDocuments/service_and_meter_requirements.pdf (Page 115)

General Notes section here has some info (first 2 bullet points):



And on this page they are claiming NEC 2011 reference to the orange wire color requirement being on 110.15, but 230.56 also indicates such identification must be made anywhere when the neutral conductor is present: .
 
Back
Top