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

(1/6) > >>

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