ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 [2] 3  All   Go Down

Author Topic: Still trying to wrap my head around 3 phase 100 amp distro  (Read 1502 times)

Stephen Swaffer

  • Hero Member
  • *****
  • Online Online
  • Posts: 1847
Re: Still trying to wrap my head around 3 phase 100 amp distro
« Reply #10 on: September 13, 2017, 12:38:54 pm »

18 20 amp circuits is not a big deal-a lot of homes have 30-40 20+amp circuits on a 200 amp single phase.

As for incompetent electricians-I've actually seen just as bad or worse wire/fuse/disconnect/overload sizing and practice from design "engineers" that are building industrial stuff and have virtually the same understanding of loads as first year apprentices.

Looking at a runoff on a machine 2 weeks ago the engineer had spec'd a 40 amp service (using a 60 amp disconnect).  He had a total motor load of less than 10 amps and less than 2 amps control load.  Granted this was the safe way to err-but I've seen it many times the other way.  Usually people overlook the fact that you need to be sized at 125% for continuous load.

This may have been (and perhaps likely?) been built by a panel building shop or something similar by someone who has never done any building wiring and the sole qualification might have been telling the resident head hunter "I know how to wire stuff".
Logged
Steve Swaffer

Jonathan Johnson

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2624
  • Southwest Washington (state, not DC)
Re: Still trying to wrap my head around 3 phase 100 amp distro
« Reply #11 on: September 13, 2017, 12:46:52 pm »

Looking at the naked picture... I see lots of black going from the neutral bar, and from the breakers (hot) -- I don't *THINK* I see wiring going to the grounding point on each receptacle.

Anyone else?

-Ray

Reminds me of the time my brother rebuilt an old WWII surplus Willy's Jeep. He had to replace all the wiring. He got a big roll of yellow wire. Every wire on the thing is now yellow.

I sincerely hope the ground and neutral are not bonded. Can't tell from the picture.

The label indicates that this is purpose built assembly by a UL-listed panel shop, possibly even as a special order item directly from Siemens. I would consider that an assurance of safety and quality and code compliance, providing the other end of the supply cord is connected in a code-compliant manner.
« Last Edit: September 13, 2017, 12:58:08 pm by Jonathan Johnson »
Logged
Stop confusing the issue with facts and logic!

Jonathan Johnson

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2624
  • Southwest Washington (state, not DC)
Re: Still trying to wrap my head around 3 phase 100 amp distro
« Reply #12 on: September 13, 2017, 01:00:13 pm »

Also note that NEC2017 520.53 requires portable stage switchboards to be listed, and while this bare panel may be listed, the assembly as constructed certainly is not.

The labeling indicates that this is a listed "exhibition hall temporary wiring device." It appears to be a purpose-built assembly by Siemens, and not a "bare panel" that has been field-modified. It was probably a custom build.
Logged
Stop confusing the issue with facts and logic!

Jerome Malsack

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1150
Re: Still trying to wrap my head around 3 phase 100 amp distro
« Reply #13 on: September 13, 2017, 01:37:14 pm »

If custom built by Seimans or other than why the lack of the color code wire not being used.  White for the common. 
Logged

Scott Holtzman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4036
  • Ghost AV - Avon Lake, OH
    • Ghost Audio Visual Systems, LLC
Re: Still trying to wrap my head around 3 phase 100 amp distro
« Reply #14 on: September 13, 2017, 02:06:12 pm »

If custom built by Seimans or other than why the lack of the color code wire not being used.  White for the common.

Was it bare bones from Siemens? 

I do a lot of conventions in my other vocation and I can tell you a company that makes PSAV look like angels is Event Source.  The convention floor powering is shocking (pun intended).

Logged
Scott AKA "Skyking" Holtzman
River Delta Audio is now:

Ghost Audio Visual Solutions, LLC
Cleveland OH
www.ghostav.rocks

David Buckley

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 529
Re: Still trying to wrap my head around 3 phase 100 amp distro
« Reply #15 on: September 13, 2017, 04:41:27 pm »

If custom built by Seimans or other than why the lack of the color code wire not being used.  White for the common. 

I have a theory: white is the required neutral colour for installed wiring, but this piece of equipment is not "installed", it's effectively a plug-in appliance, and what it has is a construction technique common to control boards, whereby there is no colour coding but every wire is labelled.

This would be legit in my jurisdiction, but I don't know if it's legit in the USA.

Also - edited to add - the thing probably didn't arrive with the input cable attached, and thus the manufacturer has no knowledge of what the supply cable will be, it could be appropriate or inappropriate.
« Last Edit: September 13, 2017, 04:45:20 pm by David Buckley »
Logged

Stephen Swaffer

  • Hero Member
  • *****
  • Online Online
  • Posts: 1847
Re: Still trying to wrap my head around 3 phase 100 amp distro
« Reply #16 on: September 13, 2017, 05:02:08 pm »

Typically, in the US, industrial control panels use red for 120 VAC circuits-numbered to differntiate wires-becasue of numbering convention, #2 is almost always neutral and as well is almost always still white.

I would agree with the UL listing of the assembly.  I do think that viewing this as a "100 amp" distro might be an assumption.  The Siemens label looks like a typical panelboard label (even indicating required enclosure size) and the 100 Amp would me the maximum rating for that portion of the assembly-and likely the lowest rted panelboard they make.  The assembly rating would be the rating of the weak link-be that  the wiring or the connector.
Logged
Steve Swaffer

Jay Barracato

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1811
  • Solomons, MD
Re: Still trying to wrap my head around 3 phase 100 amp distro
« Reply #17 on: September 14, 2017, 06:50:44 am »

I think David is correct about the device not being provided with a cable on the original sale as the label gives the opening size for the feeder.

As it is currently offered for sale, with no main over current breaker, it appears to me the maximum draw is 120 amps, twice the rating of the cable.

Unfortunately, I can easily imagine this ending up in the campground of a festival with 36 rv's plugged in by extension cords.

Sent from my XT1254 using Tapatalk

Logged
Jay Barracato

TJ (Tom) Cornish

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 3845
  • St. Paul, MN
Re: Still trying to wrap my head around 3 phase 100 amp distro
« Reply #18 on: September 14, 2017, 08:32:32 am »

I think David is correct about the device not being provided with a cable on the original sale as the label gives the opening size for the feeder.

As it is currently offered for sale, with no main over current breaker, it appears to me the maximum draw is 120 amps, twice the rating of the cable.

Unfortunately, I can easily imagine this ending up in the campground of a festival with 36 rv's plugged in by extension cords.

Sent from my XT1254 using Tapatalk
18 circuits x 20A = 360A@120V, or 120A per leg theoretically, plus or minus the breaker tolerance and panel temperature.  How much power is likely to be drawn from this device could vary widely - if this is a lighting distro panel, it's possible that sustained loads could exceed 100A per leg fairly easily, and with 16-series camloks being used for supplies up to 400A, there are real-world scenarios where this thing could get VERY HOT.

It's possible that this was sold without a cable, but I am not aware of any multi-wire cable rated at 100A - #2 is the biggest SOOW cord sold, which is rated at 80A, and is no fun to work with.  I think the dimensions on the label are for an external cabinet for this panel - minimum of 23" H x 20" W.  Maybe I missed it, but I don't see a hole dimension for the feeder.

Tim Mc made a comment in another thread about "listing" not equaling "code compliant".  That seems to be coming into play here.
« Last Edit: September 14, 2017, 09:48:37 pm by TJ (Tom) Cornish »
Logged

Jay Barracato

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1811
  • Solomons, MD
Re: Still trying to wrap my head around 3 phase 100 amp distro
« Reply #19 on: September 14, 2017, 03:04:05 pm »

I think my old eyes read DP as OD and I took that as knockout size.

Sent from my XT1254 using Tapatalk

Logged
Jay Barracato
Pages: 1 [2] 3  All   Go Up
 


Page created in 0.187 seconds with 17 queries.