1,000 Volts

J

jmellc

Senior Member
Location
Durham, NC
Occupation
Facility Maintenance Tech. Licensed Electrician
I just renewed my license a few minutes ago. I see I am now qualified for $60,000 project value and 1,000 volts max. I hadn't heard about voltage increase. All my previous licenses have been 600 volts. Project value has been 60K last few years. I think my first ones were either 40K or 50K. I can't see myself working 1,000 volts. I don't recall for sure ever having worked 600. Possibly in the 70's working as someone's helper, assisting with a transformer. Not live for sure. I worked a fair amount of 480 in commercial and industrial buildings. 480 is the most I work nowadays, but 208/120 most common, and 277v lighting. Our buildings don't have any 600 or 1,000 volt equipment. Our main transformers with incoming line voltage are all serviced by the POCO. I think 13,200 is incoming.

How many of you work with 600 or 1,000 on any regular basis? What type of equipment?
 
My first big boy electrician job was in a textile plant that had a 600 volt ungrounded delta 2000 amp service. It actually ran at about 575 volts. I have since worked on some old 600 volt delta one as recently as a couple months ago. I have had training for medium voltage work, but the most I have ever touched personally was 4160 in a large industrial setting. I did run some conduit for 12470 but never touched the conductors..
 
The code has been replacing the "over 600 volts" with "over 1000 volts" the past couple of cycles. I think the process is complete in the 2023 code.
 
I could never understand places that put project value limitations on licensing, permits, etc.?

One could easily have say $75-100k in something that is rather simple for the electrician when it comes drawing a one line diagram of what is going on.Like maybe a high power pumping station but most of the equipment is the pump itself, and maybe an already listed control panel and all you need to do as the EC is bring service to it and a circuit out to the pump and connect a few incidental items.

Yet that big mansion down the road maybe is a $50,000 wiring job but is a lot more complex when it comes to what was field installed, or how much time/effort it actually takes for the inspector to do the inspection on it compared to the pumping station.
 
The license must be based on a NEC definition of 'low voltage' vs medium voltage or high voltage?
In 2017 the NEC changed many if not all references from '600V' to '1000V'.
So a system with a nominal voltage over 1000V is 'medium voltage'.
The Public Input No. 2854-NFPA 70-2014 stated in part:
going to higher operating voltages reduces I2R losses and with transformer impedance changes can reduce AFC levels which increases safety for workers by reducing the incident energy levels.
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I have been told by a old lineman that kVA per kVA 600 is actually safer than 480, he said he'd prefer to use the high voltage cutouts over throwing a 480V main breaker any day, I am not an expert on incident energy levels I'd be curious what others think.
Its a interesting trend to see 1000Y/577V systems I am not sure how the incident energy levels compare kVA per kVA I have yet to see one in person.
 
I often use 480V VFD's in our control panels, and their DC bus sits somewhere around 700VDC or so, depending on incoming line voltage and regen status of the motor. So I do work on panels with over 600V.

Technically, the 600V MTW wire that we use is over-dutied if used to connect a brake resistor for a 480V drive. That said, the peak voltage on 480VAC is right there at 700V so I don't think anyone worries too much. It's not like we're hooking up brake resistors with 2kV PV wire.


SceneryDriver
 
tortuga said:
The license must be based on a NEC definition of 'low voltage' vs medium voltage or high voltage?
In 2017 the NEC changed many if not all references from '600V' to '1000V'.
So a system with a nominal voltage over 1000V is 'medium voltage'.
The Public Input No. 2854-NFPA 70-2014 stated in part:

I have been told by a old lineman that kVA per kVA 600 is actually safer than 480, he said he'd prefer to use the high voltage cutouts over throwing a 480V main breaker any day, I am not an expert on incident energy levels I'd be curious what others think.
Its a interesting trend to see 1000Y/577V systems I am not sure how the incident energy levels compare kVA per kVA I have yet to see one in person.
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I have two linemen in my family that say the same thing. Both hate 480V. Their reasoning is that 480V sustains an arc better than any voltage above it or below it.
 
kwired said:
I could never understand places that put project value limitations on licensing, permits, etc.?

One could easily have say $75-100k in something that is rather simple for the electrician when it comes drawing a one line diagram of what is going on.Like maybe a high power pumping station but most of the equipment is the pump itself, and maybe an already listed control panel and all you need to do as the EC is bring service to it and a circuit out to the pump and connect a few incidental items.

Yet that big mansion down the road maybe is a $50,000 wiring job but is a lot more complex when it comes to what was field installed, or how much time/effort it actually takes for the inspector to do the inspection on it compared to the pumping station.
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Dollar limit would have knocked me out of several nice jobs. Most of which I had no idea what the final total would be.

Bill in $50,000 increments? Each being a new job?
 
ptonsparky said:
Dollar limit would have knocked me out of several nice jobs. Most of which I had no idea what the final total would be.

Bill in $50,000 increments? Each being a new job?
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In NC that's not allowed
 
I did some work in an old mill in Providence RI that had an ungrounded 600V service. When we finally upgraded the service I set up an SDS
at 600 volts corner grounded to refeed the old elevator.

690 is a fairly common voltage in other parts of the world, but not the US.

XHHW conductors are rated 1000V, which might come in handy for some sort of step up step down where you didn't want to go to medium voltage for some reason. Of course you'd have to order custom transformers because that's an odd voltage. Or you could use 2KV PV wire (that what I do at my house, long run), but again would require custom transformers unless you just go run it at 2400.

But basically, it's mostly a no man's land between 600 and 2400, except for PV.
 
infinity said:
You have not seen the work done by unlicensed hacks around here. Although licensing may have it's shortcomings it does provide benefits.
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I work both in Seattle which is very regulated and upstate NY which has no licensing except for within the larger cities. I actually don't notice any difference in the overall average quality of work. I know some people say they see a difference, I guess our experience and mileage varies.
 
infinity said:
You have not seen the work done by unlicensed hacks around here. Although licensing may have it's shortcomings it does provide benefits.
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I'm not against licensing. I'm just against people pretending like it's primary purpose is public safety. That is a secondary and maybe even a tertiary effect. It is primarily to collect revenue from people ambitious enough to generate revenue.
 
ptonsparky said:
Dollar limit would have knocked me out of several nice jobs. Most of which I had no idea what the final total would be.

Bill in $50,000 increments? Each being a new job?
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As Hv&Lv says, that won't work in NC.

Excerpt from NC Title 21 NCAC 18B

4) Project Value Limitation. In determining the value of a given electrical contracting project, the total known or reasonable estimated costs of all electrical wiring materials, equipment, fixtures, devices, and installation must be included in arriving at this value, regardless of who furnishes all or part of same, and regardless of the form or type of contract or subcontract involved. if the total cost of the wiring, materials, etc., including that furnished by others, plus the total cost of the installation involved, will be more than sixty thousand dollars ($60,000) but not more than one hundred fifty thousand dollars ($150,000), then only an electrical contractor holding either an intermediate or unlimited license will be eligible to submit a proposal or engage in the project.

a) if the total cost of the wiring, materials, etc., including that furnished by others, plus the total cost of the installation involved, will be more than sixty thousand dollars ($60,000), then only an electrical contractor holding either an intermediate or unlimited license will be eligible to submit a proposal or engage in the project.
b) if the total cost of the wiring, materials, etc., including that furnished by others, plus the total cost of the installation involved, will exceed one hundred fifty thousand dollars ($150,000), then only an electrical contractor holding an unlimited license will be eligible to submit a proposal or engage in the project.

If a given electrical contracting project is subdivided into two or more contracts or subcontracts for any reason, then the total value of the combined contracts or subcontracts which may be awarded to or accepted by any one licensee of the Board must be within the total project value in accordance with this Rule.
The Board’s staff shall make a determination of what constitutes a project in any given situation, and any party at interest shall have the right to appeal any staff determination to the Board for a final binding decision.
History Note: Authority G.S. 87-42; 87-43; Eff. October 1, 1988; Amended Eff. September 1, 2014; January 1, 2008; February 1, 1996; February 1, 1990.
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tortuga said:
What was the two phase job? that sounds interesting
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It was right up the street from our shop

"
Cheney Bigelow Wire Works in World War Two
1842-1974 - Springfield, MA
1974-1979 Weaverville, NC

This page added 9-11-2022.

The Cheney Bigelow Wire Works made wire cloth and Fourdiner wire for the paper industry for 137 years at 417 Liberty Street in Springfield, MA. In May 1962, the company was purchased by National Standard Company of Niles, MI. In 1972, the company built a second factory in Weaverville, NC and in 1974 the Springfield, MA plant was closed when the company headquarters moved to Weaverville, NC. In 1979, Mount Vernon Mills of Greenville, NC purchased the Weaverville plant and the Cheney Bigelow name disappeared.

armynavy-Eflag-42w-1.jpg

The Cheney Bigelow Wire Works won the Army-Navy "E" Award three times during World War Two.
The company was notified April 3, 1944 of its first award. The presentation of the award was made on April 26, 1944.​

Cheney Bigelow World War Two Products: Approximately 40,000 M9A1 rocket launchers (bazookas), artillery shell boosters.
There were four types of 2.36 inch diameter anti-tank rocket launchers built in World War Two. The General Electric plant in Bridgeport, CT exclusively built three of the four types. These were the M1, M1A1, and M9. For the last and most advanced type the rocket launchers, the M9A1, the Cheney Bigelow Wire Works was contracted and produced approximately 40,000 of these weapons between September 1944 and May 1945. The 40,000 unit production was 14.4% of the M9A1s produced and 8.2% of all types made.

Based on the contract amount shown in Table 1, each Cheney Bigelow-built M9A1 cost $46.57.

When the contract was terminated on May 17, 1945, the company had to let 250 workers go."

I started in June of 1973 working at an oil company right down the street. We sold them fuel oil (#6 oil I think). They closed the plant in 1974 and moved south so I only went their once or twice.

We worked on a couple of large oil burners there. The motors were two phase. I think we changed a motor starter. All I remember was my boss telling me. "the middle leg stays in the middle with no overload and the two outside legs have the overloads" I know they have two phase 3 wire and two phase 4 wire. I don't know which this building had. I was real green on electrical at that time and was barely an oil burner technician

​
 
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