Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums > AC Power and Grounding
Venue with NEMA 10-50R side stage
Douglas Cyr:
--- Quote from: Scott Holtzman on January 09, 2022, 11:32:14 PM ---
The amp is setup for single leg service even at 230v so you are out of luck. CPC 45 A AMP connector is on the back. Please refer to page 5 section 4:3 for these details. The wiring is H-N-G. If it was a four wire connector at the venue you could accomodate this. Don't even consider a bootleg ground.
Please also not downstream protection requirement from the manual "With K6, K8, K10 and K20 a sectioning breaker between the mains connections and the amplifier must be installed inside the rack cabinet. Suggested device is 32A/250VAC, C or D curve, 10kA."
The venue doesn't have any other high current connections? I usually go hunting in the kitchen. If not you will have to get a generator.
--- End quote ---
Thanks for this insight, I may have to look in the kitchen. I didn't notice the section in the manual about the rqckmount circuit breaker, where would I look to find one like they specify?
Chris Hindle:
--- Quote from: Douglas Cyr on January 09, 2022, 11:15:42 PM ---Also, the wiring diagrams I saw online showed their should be 245-250v between the phases rather than 208v I measured.
--- End quote ---
Douglas, you're seeing 2 legs of a 3-phase system.
220/240 is NOT possible without transformers.
Chris.
Tim McCulloch:
A lot to unpack here...
First, Steve White's observations: spot on, if Douglas is measuring 208V he's seeing 2 legs from a 3 phase service. The 10-50 is listed for 125-250V operation which means this has no EGC. I wasn't aware it was permissible in new work, but every jurisdiction can be different (or there was no permit and no inspection).
Second, Douglas, your question of a separate ground shows you payed attention to what each wire does. Code says all wiring must be enclosed so Code says no. I have seen what you are asking, done in locales where permitting and inspections are lax. That should not be considered an endorsement, but an observation.
Finally, if none of your equipment requires 240V to operate the whole 208V from 3 phase is kind of a moot issue, other than being aware of it. The primary issue here is the connector and wiring lacks the equipment safety ground. It should be changed to a NEMA 5-50. The venue and other users will resist because they have "Kludge Kords" built and changing all that is where the expenses really are.
Helge A Bentsen:
ASSuming you can make a legal connection, my experience with Powersoft is that they run on anything.
My K20 run fine on 2 hot legs (230V between legs) or hot-neutral (230V between hot-neutral).
Douglas Cyr:
--- Quote from: Helge A Bentsen on January 10, 2022, 03:50:03 AM ---ASSuming you can make a legal connection, my experience with Powersoft is that they run on anything.
My K20 run fine on 2 hot legs (230V between legs) or hot-neutral (230V between hot-neutral).
--- End quote ---
Interesting, and is there such a thing as +phase and - phase? Does it matter which phase goes to which terminal and is there a way to test that with a multimeter?
Also in this image:
https://bit.ly/3JQm1wt
What is going on what that ground wire running to the receptacle? What would that be connected to?
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