Power Distros

[jeffsw6]

Of course the OPD supplying that MWBC will be equipped with handle ties or other common-trip provision, correct? What happens if you want to power down only one of the circuits (such as for a hard reset)?

The trade-off for conserving copper, while meeting the handle-tie/common trip requirement for MWBCs, is not being able to cycle only one of the two phase legs by using the circuit breakers. I can easily live with this limitation given the low-caliber work I am doing.

If your 120/240V distro is powered by two legs of a 120/208Y system, is an over-sized neutral not required?

Not in my case, since these are LED fixtures, not ordinary dimmers. With dimmer loads, certainly the neutral of MWBCs must often be over-sized; and the code provides some guidelines in this area.

 

[rochem]

Can someone clarify the meaning of Hot Pocket vs. Convenience Outlet?

Hey, click those links in your post!

While we're talking terminology, what would the proper term be for Non-Dimmed power that was switchable (on-off only) via DMX from the lighting console? I'm mainly referring to a Non-Dim module in a Sensor+ rack (NOT a regular dimmer set to Non-Dim). I've heard the term Relay for this, but is that correct?

Sometimes a mover will have an error that can be cleared by a hard reset. If two movers are on the same circuit and you need to reset one of them the other one looses power as well. Also by twofering you back yourself into a corner should a circuit on the multi go bad or you need to add another fixture to that location and you have already used all your spares.

I think some people misinterpreted what I was trying to ask before, so I'll clarify: given the choice, would you choose to put your ML power on a DMX controlled Non-Dim power source (NOT a dimmer set to Non-Dim), or is it more common to just have it on constant power so the only way to turn it off is via the circuit breakers? In the case of needing a hard power reset, would you ever want to kill Mover power by turning the Mover Power channel on the board off, or would you just walk to the actual dimmer rack and cycle the circuit breaker? This would have the result that every night when you powered off the board (if you did so - that's a different discussion), your Mover Power would also turn off. Do you usually stop the flow of power to your movers when you go home for the night (from the source, since adjusting the physical switch on each fixture is usually impractical), or is lamping down usually enough?

Thanks!

 

[Pie4Weebl]

While we're talking terminology, what would the proper term be for Non-Dimmed power that was switchable (on-off only) via DMX from the lighting console? I'm mainly referring to a Non-Dim module in a Sensor+ rack (NOT a regular dimmer set to Non-Dim). I've heard the term Relay for this, but is that correct?

Both terms are acceptable, though "non-dim module" is pretty ETC specific. For a standalone product, you will be able to find "DMX relays".

 

[gafftapegreenia]

There are two reasons why I think most people wouldn't use a rack of DMX relays to control power:

1) It's a new piece of equipment to be trucked, to fail, to need repairs, and overall cost money. Where is the benefit of adding another point of failure in the chain just to allow one to remotely switch the circuit that powers a ML on and off when most modern ML's can have their power up/down sequences initiated remotely?

2) Just like on most follow spots, most ML's have fans. When one uses the board to send a DMX signal that tells the ML to lamp down, the fan will continue to run for quite a while to cool the fixture. If one where to just kill the power outright, they risk doing heat damage to the unit by preventing the fans to complete the cooling cycle. (The same is true with projectors)

 

[mstaylor]

I think some people misinterpreted what I was trying to ask before, so I'll clarify: given the choice, would you choose to put your ML power on a DMX controlled Non-Dim power source (NOT a dimmer set to Non-Dim), or is it more common to just have it on constant power so the only way to turn it off is via the circuit breakers? In the case of needing a hard power reset, would you ever want to kill Mover power by turning the Mover Power channel on the board off, or would you just walk to the actual dimmer rack and cycle the circuit breaker?

While possible to tie MLs to DMX nondims there is no advantage. If you need to restrike then you can do it from the board, if you need to a hard restart then do it at the breaker.

 

[derekleffew]

Both terms are acceptable, though "non-dim module" is pretty ETC specific. For a standalone product, you will be able to find "DMX relays".

I'd argue that "non-dim module" is not manufacturer-specific at all, unlike R20 (Relay Module) and CC20 (Constant Current). As for DMX Relay, there's Doug Fleenor Design -.

...what would the proper term be for Non-Dimmed power that was switchable (on-off only) via DMX from the lighting console? ...

"DMX-controlled, switched power." Not to be confused with the "swtiched" setting of a dimmer on the CEM.

...given the choice, would you choose to put your ML power on a DMX controlled Non-Dim power source (NOT a dimmer set to Non-Dim), or is it more common to just have it on constant power so the only way to turn it off is via the circuit breakers? ...

I think the answer largely depends on whether it's a touring or permanent installation. For tours, the ML PD is just a bunch of dumb breakers. If something needs to be reset, the LBO says on com, "Hey, dimmer b!tch, reset light#XXX." For a permanent installation, ML power can be provided by an ETC SmartSwitch, or similar by other manufacturers. I don't know of anyone making a touring version. Even when using DMX-controlled relays, it still may be more expedient for the LBO to tell someone backstage to do it rather than look up the correct number and park the offending channel/dimmer/address/output, then wait the appropriate time, then unpark, etc.

As for removing power to MLs overnight, see the threads Control/Dimming Non-Permanent Shutdown Procedures - View Poll Results and http://www.controlbooth.com/forums/lighting-electrics/11584-shutting-down.html .

 

[soundlight]

As a note, on Leprecon racks, there is a row of "NDs" or "Non-Dims" in the patch panel that are breaker-controlled outlets much like the described hot-pockets. 4 patch points per ND, as with any dimmer patch in the rack. There are 6 NDs in all of the Lep racks that I test at work (24s, 36s, and 48s - most are VX series, I think), and as for outlets on the back, I think that there's 2 convenience circuits with breakers on the back and then there're the X-outlets, which are six patchable outlets - mix of stagepin and edison connectors.

So Non-Dim isn't exactly something that I'd use to exclusively refer to the ETC R20 module - in fact, I've always called it a Relay module, and always heard it referred to as such.

As for switching ML power from the rack, as was mentioned by Derek: For a touring situation, why do it - more of a chance of it getting messed up. Use an ML Distro. For an installation or just for a theatre that switches out modules in the rack for ML power depending on the show, yeah the ability to switch off MLs from the console is nice. Back in college when we powered movers from the dimmer rack, I would have a power up macro that would power (park) on all of the appropriate circuits, home all of the movers (Ibeams need to be told twice), and run everything to limits. There was also a power down macro that doused the lamps and then waited before powering everything down.