Electrical Plan: What Have I Missed??

Discussion in 'Home Theater Projects' started by Chip_Slattery, Jun 22, 2003.

  1. Chip_Slattery

    Chip_Slattery Stunt Coordinator

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    Electrician will be coming this week to wire the HT so I thought I'd post my plan here to try and get some feedback on things I may have missed. My HT is in a completely new addition so while the walls are open I'd like to try and cover as many bases as possible.

    (NOTE: I've posted a diagram here for reference)

    Here's what I'm planning:

    1. 60A subpanel in equipment room - will be a 125A 24-space panel wired to handle the full load but fed from a 60A breaker. All lighting and outlets not dedicated to A/V equipment will be on same phase & leg. (though I'm not sure how critical this is in a subpanel application, I have the room so what the heck...)
    2. Two 20A dedicated quad outlets in equipment room
    3. 20A dedicated quad outlet in lobby area (mini-fridge, popcorn machine, etc.)
    4. Dedicated 20A ceiling outlet at projector location
    5. Two 20A outlets (dedicated circuit) on both side walls behind proscenium (in case of future powered subs)
    6. 15A ceiling receptacle behind proscenium wall (future motorized drapes)
    7. Two 15A floor receptacles on riser (motorized recliners)
    8. Three 15A receptacles in face of riser (motorized recliners & convenience)
    9. Seagull 600W 12v magnetic transformer in equipment room (LV rope lighting)
    10. Nine 4" recessed cans in theater area (3x3 grid) & three cans in lobby
    11. Five wall sconces - two along each side wall and one on rear wall.
    12. Recesseed wall step lights for riser steps
    13. Various 15A convenience outlets to meet code requirements.

    Lobby cans will be controlled by Lutron Maestro dimmer near the entrance to the lobby.

    All lighting in the theater itself will be controlled via a six zone Grafik Eye. (model

    GRX-3106) Grafik eye will be wired according to the "DE two-box method".

    Zones setup as follows:

    Zone 1 - Front two wall sconces
    Zone 2 - Rear three wall sconces
    Zone 3 - Front six recessed cans
    Zone 4 - Rear three recessed cans
    Zone 5 - Step lights
    Zone 6 - LV transformer in equipment room

    So, what have I missed?

    Obviously I haven't touched on the low voltage A/V wiring. I'll leave that to another post once the main electrical work is complete.

    All comments and/or suggestions are welcome.
     
  2. Wayne A. Pflughaupt

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    Hi Chip,

    A few things come to mind:
    • The 20A circuit for the projector will require a 20A outlet, since it will be the only outlet on the circuit (Item 4). Of course, your electrician should know this.
    • Make sure you run signal cable for the future subs (Item 5).
    • Since the subs pull a lot of power, put them on a separate circuit from the other electronics. This will help insure that the electronics get a more stable power supply (i.e., less voltage/amperage fluctuation).
    • You might want to re-think having only one phase for this panel. When possible, it’s preferable to keep the audio equipment on one phase, and all that motorized equipment, light dimmers, etc. on another.
    Regards,
    Wayne A. Pflughaupt
     
  3. Chip_Slattery

    Chip_Slattery Stunt Coordinator

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    Wayne,

    Thanks for the suggestions.

    1. I wasn't aware that having only one receptacle on a 20A circuit mandated that it be a 20A receptacle. I knew you could run 15A receptacles on a 20A breaker...

    2. I will actually have two subs in those locations from the get-go, but they won't be powered. (Dual SVS 20-39CS+)

    3. The outlets in the sub location will be on their own circuit.

    4. I should have been more specific regarding the leg/phase information. I will be putting all electrical outlets (that aren't otherwise dedicated to equipment) as well as lighting on the same leg/phase.

    I'll modify my original post to make it a little clearer for others.

    Thanks for the info!
     
  4. Dave Milne

    Dave Milne Supporting Actor

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    Chip,
    Looks like you're going to have a great theater. A couple of items:

    1) It's not clear if any doors open to exterior. If so, I believe code requires an outside light and switch just inside the door.

    2) Most codes these days require AC-powered smoke detectors on a separate dedicated circuit. You'll need to plan for this.

    3) I didn't see what you were planning for HVAC. With a room this elaborate, I would imagine you would want dedicated HVAC equipment. Don't underestimate the heat load generated by a bunch of equipment and viewers. At the very least, you'll want to consider ventilation to keep the theater from getting stuffy. With 7 people in an soundtight (read: airtight) room, it won't take long.

    4) That seems like a very long throw for the CRT projector [​IMG]
     
  5. Chip_Slattery

    Chip_Slattery Stunt Coordinator

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    Dave,

    Thanks for the comments.

    1. The door that is inside the theater itself (lower left on diagram) opens to the exterior and there will be a light outside that door with a switch just inside. That exterior light switch will actually be part of a 2-gang switch box since by code I also need an interior light accessable from just inside the doorway. The second switch will be tied to a switched outlet along the same wall as the door, thus meeting the code requirement. I left these items off the plan since I figured most folks here wouldn't really care about the minutia of my wiring. Good catch!

    2. I'll have to look at the smoke detector requirements. I actually completely forgot about this and my electrician didn't mention it. Even if it isn't required it's certainly a good idea.

    3. I have another plan dedicated to the HVAC layout. I will be installing a completely independant forced hot air system (furnace/condenser) for the theater. This will allow me to run A/C year-round, independant of the main house system. In addition to the normal supply/return runs I'm planning on dedicated returns at the projector location and in the equipment room, each with thermostatically controlled exhaust fans. This should help to exhaust any excess heat. I think between the dedicated system and extra care in the design to reduce heat build-up I'll be in good shape.

    4. No CRT for me... [​IMG] I'll spend my time watching movies, not tweaking, thank-you-very-much! (a little joke...let's not go there)
     
  6. MikeWh

    MikeWh Second Unit

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    Chip,

    You might want to spec out all the items you may put in the lobby area. A smaller popcorn machine (4-oz) and a mini-fridge might be ok... A larger machine might start to push the circuit. Paragon's 8-oz machine is rated at 12 amps. I can't seem to find specs on the compact fridges I know of.

    Sorry to go OT here, but have you finished the exterior yet?? I'm dying to see siding up! [​IMG] Also, could you take a picture just like "ext_roof3.jpg", but taken from a position a little more to the right.... so we can see a little more of how the room blends with the rest of the house?
     
  7. Chip_Slattery

    Chip_Slattery Stunt Coordinator

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    Mike,

    When I was originally speccing(sp??) out the lobby equipment I found that most 6oz. popcorn poppers were around 1200W (10A). I had a hard time getting much energy info on run-of-the-mill undercounter refrigerators, so I took a look at a few commercial units in the 6.0 Cu.Ft. range to get general numbers, and it looks like they operate at around 1.2-1.5A, with start-up in the 5-7A range.

    Given these numbers I may just have two seperate 20A circuits run to the lobby, rather than a quad outlet on one circuit. Won't be much money and I'll know I'll (probably) never max it out.

    Other than building a landing & stairs for the secondary egress doorway, fixing the sprinkler system and re-landscaping the yard the exterior is pretty much done. If it stops raining for more than five minutes around here [​IMG] I'll try to get out and get some more pictures posted!
     
  8. Don Marsh

    Don Marsh Extra

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    I don't have anything constructive to add other than to say i think you have a fantastic looking design, and i can't wait to see our theater when it's finished. I've bookmarked it so i can check back on it!
     

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