Results 1 to 6 of 6

Thread: Theatre Entertainment Panel Ratings

  1. #1
    Join Date
    Jan 2018
    Location
    Atlantic Beach, Duval, Florida
    Posts
    2

    Theatre Entertainment Panel Ratings

    I am the tech director at a community theatre . We have conventional fixtures hooked to shoebox dimmers that are powered by the a 240V 200 Amp electric panel.

    My first question is how many Amps can be drawn from the electric panel on each leg? Does each leg supply 200 Amps or 100 amps from the box on the branch lighting circuits? This electric panel only supplies 120 Volt, 20 Amp lighting circuits. It seems to me that the total Amperage from the panel should be 400 Amps and that theoretically the neutral would have 0 Amps on it with a properly balanced load.

    It is my understanding that in the code it allows for 100% maximum usage of the Amperage in the panel if it is used for entertainment and less than three hours use at a time. Is this correct?

    It is my understanding that a 20 Amp branch can carry the full load if used under three hours (supplying a shoebox dimmer). Further, I thought that in the entertainment section of the code, it states you can use a conventional 15A plug to connect the shoebox dimmer to the 20 Amp branch circuit instead of a 20 Amp plug. Is this correct?

  2. #2
    Join Date
    Feb 2003
    Location
    Massachusetts
    Posts
    120
    Keep in mind that most shoebox dimmers (ADJ, DMX4, etc) have severely underrated components - 6A triacs, a 10A switch, and some with a 16AWG cordset. Unless you are using Leprecons, I wouldn't load them to more than 575W per channel, and only 3 of the 4 channels on at a time. As for the 20A circuits, as long as they have 2 or more receptacles (ie. one or more duplex), they can take 15A plugs (with a 15A or less load, of course...)
    .

  3. #3
    Join Date
    Apr 2009
    Location
    Williamsburg, VA
    Posts
    5,438
    Welcome. Answers in red.


    Quote Originally Posted by barefootbryan2335 View Post
    I am the tech director at a community theatre . We have conventional fixtures hooked to shoebox dimmers that are powered by the a 240V 200 Amp electric panel.

    My first question is how many Amps can be drawn from the electric panel on each leg? Does each leg supply 200 Amps or 100 amps from the box on the branch lighting circuits? 200AThis electric panel only supplies 120 Volt, 20 Amp lighting circuits. It seems to me that the total Amperage from the panel should be 400 Amps and that theoretically the neutral would have 0 Amps on it with a properly balanced load. Yes, a perfectly balanced split phase 240V panel will have 0 amps on the neutral.

    It is my understanding that in the code it allows for 100% maximum usage of the Amperage in the panel if it is used for entertainment and less than three hours use at a time. Is this correct? Yes

    It is my understanding that a 20 Amp branch can carry the full load if used under three hours (supplying a shoebox dimmer). Yes. Further, I thought that in the entertainment section of the code, huh? it states you can use a conventional 15A plug to connect the shoebox dimmer to the 20 Amp branch circuit instead of a 20 Amp plug. Is this correct?Yes, you can use a 5-15 plug on a 6-15 receptacle
    No idea what "entertainment section of the code" is. Any non-heating load that runs less than three hours is non-continuous. Typically lighting loads are continuous; if so, you can only load the branch circuits to 80% of their breaker rating.
    Electricians do it until it Hertz!

  4. #4
    Join Date
    Dec 2012
    Location
    Placerville, CA, USA
    Posts
    19,285
    Quote Originally Posted by barefootbryan2335 View Post
    I am the tech director at a community theatre . We have conventional fixtures hooked to shoebox dimmers that are powered by the a 240V 200 Amp electric panel.

    My first question is how many Amps can be drawn from the electric panel on each leg? Does each leg supply 200 Amps or 100 amps from the box on the branch lighting circuits? This electric panel only supplies 120 Volt, 20 Amp lighting circuits. It seems to me that the total Amperage from the panel should be 400 Amps and that theoretically the neutral would have 0 Amps on it with a properly balanced load.

    ...
    ...
    It is a 200A panel, which means that it can equally well supply 200A of 240V, line to line, load OR two sets of 120V line to neutral loads each adding up to 200A. As you note, in either case the neutral current is zero. The worst case neutral current would be if for some reason only the 120V loads connected to one of the lines is active. The neutral current in that case would be equal to the line current on that line.

  5. #5
    Join Date
    Dec 2010
    Posts
    1,389
    If the dimmers have harmonic content, the neutral current might not be zero.
    The more they overthink the plumbing, the easier it is to stop up the drain

  6. #6
    Join Date
    Oct 2007
    Location
    New Jersey
    Posts
    5,846
    Quote Originally Posted by JFletcher View Post
    Welcome. Answers in red.




    No idea what "entertainment section of the code" is. Any non-heating load that runs less than three hours is non-continuous. Typically lighting loads are continuous; if so, you can only load the branch circuits to 80% of their breaker rating.
    Section 520: Theaters, Audience Areas of Motion Picture and Television Studios, Performance Areas, and Similar Locations.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •