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:
Photo album: https://imgur.com/a/QJPjxAD
Hello,
I have an event coming up at venue with a NEMA 10-50R receptacle side stage installed right underneath a breaker panel running into a 50 amp breaker. I need a high current/voltage outlet to power a Powersoft K20 DSP for the four subs I'll be using - it is an EDM DJ event so the subs will be pushed very hard, here are Powersoft's current draw specs:
Idle 115 V: 91 W – 1.3 A 230 V: 88 W – 1.17 A
1/8 of max output power @ 4 Ω 115 V: 1650 W – 15.8 A 230 V: 1625 W – 7.9 A
1/4 of max output power @ 4 Ω 115 V: 3250 W – 29.3 A 230 V: 3250 W – 14.7 A
The question: Is there a safe way to create an adapter to use this receptacle? I've metered it and it appears to be wired correctly (~120v neutral to each phase, 208v between phases):
https://imgur.com/Hejm8Ux
I think it won't work because the amp wants a ground, neutral, and a hot, while the receptacle has a neutral and two hots, but the venue owner says bands/sound people use this outlet all the time and that's why it was installed. My amp originally came with a single phase L6-20P plug.
Please take a look at the photo album and let me know what you guys think, I don't want to do anything dangerous for people or equipment but am curious if it's possible to make an adapter that will work here, my only other options here are 15/20 amp 120v receptacles.
Photo album: https://imgur.com/a/QJPjxAD
Steve-White:
What I would do and what I would advise on a forum could be two different things.
That style of device and circuit is intended for use on 208V equipment only as it has a ground and no neutral. However, they are used for domestic appliances such as clothes dryers and ranges that have 110V lamps in them. However, that is in a residential setup on 240V.
I don't believe that to be a legit setup for stage gear. Maybe some of the other guys know more about that style plug on a 208V system. To be legit it would probably need to be a 4-wire setup with separate ground and neutral.
There could be liability connecting to that - again, let's see what the other guys think about it.
Douglas Cyr:
--- Quote from: Steve-White on January 09, 2022, 10:54:20 PM ---What I would do and what I would advise on a forum could be two different things.
That style of device and circuit is intended for use on 208V equipment only as it has a ground and no neutral. However, they are used for domestic appliances such as clothes dryers and ranges that have 110V lamps in them. However, that is in a residential setup on 240V.
I don't believe that to be a legit setup for stage gear. Maybe some of the other guys know more about that style plug on a 208V system. To be legit it would probably need to be a 4-wire setup with separate ground and neutral.
There could be liability connecting to that - again, let's see what the other guys think about it.
--- End quote ---
Hypothetically speaking, would I be able to make an adapter that taps the neutral and a hot leg with a clamp lead running to the exposed ground wire above the receptacle and would I still get the 50a current rating? I know this is sketchy but I'm just curious for education purposes.
Douglas Cyr:
--- Quote from: Douglas Cyr on January 09, 2022, 10:59:36 PM ---Hypothetically speaking, would I be able to make an adapter that taps the neutral and a hot leg with a clamp lead running to the exposed ground wire above the receptacle and would I still get the 50a current rating? I know this is sketchy but I'm just curious for education purposes.
--- End quote ---
Also, the wiring diagrams I saw online showed their should be 245-250v between the phases rather than 208v I measured.
Scott Holtzman:
--- 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 ---
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.
Navigation
[0] Message Index
[#] Next page
Go to full version