# Lighting Ugrade: Go all in on LEDs or add dimmer circuits?

#### macsound

##### Well-Known Member
I agree, just because LEDs are becoming commonplace doesn't mean dimmer racks ara going anywhere.

I'd also add, just running the CAT5e isn't good enough. You want to make sure it's terminated and labeled.
If you're running 40 lines, you'll want the installer to terminate into a patchbay that's usable.
Lots of times they'll put these above a door in a locked cabinet or something stupid becauase it's convenient for them and out of reach for prodding fingers, but who wants a patch panel that requires a ladder and a key that they never gave you.
Also, electricians (high and low voltage) aren't always the type to ask questions. Give them a layout with what the areas are called so the labels are helpful and predictable. Been in many a building where no one knows where jacks 11-20 terminate and stage left and right are flipped.

edit: spelling

Last edited:

#### AAMorgan

##### Member
Is 330 feet still the maximum run for ethernet? Is that the TOTAL combined distance from point to point (console to switch to far-away box boom) or just individual cable length?

CAT5e or better cable is very cheap and will run DMX or network. This can be a good upgrade path. Swapping a DMX gateway for a switch lets you add more gateways/universes later.
So I think what I'm hearing is to run CAT5e cable all the way to the electrics (since you can transmit multiple universes over ethernet) and then break out to DMX (or straight network if the fixture accepts it) on the batten?

I recommend running cat5e or cat6 to each position(at least 2 lines - never know when you'll need a backup, and extra cable is way cheaper than the labor to do it again
2 lines in case one run goes bad? And the second line is there to simply switch over to? Or 2 lines that are both in use?

#### SteveB

##### Well-Known Member
Yes, 330 ft/100 meters is the usually max. length of Cat 5/6 between 2 devices.

Think about the run of Ethernet to an electric. Presumably you then place a node on the pipe. Are you ever going to have enough fixtures on a pipe that needs more then one universe on the pipe ?. How wide are your electrics and how many fixtures do you plan to put on the pipe ?. A 48 ft pipe can fit 32 LED non moving fixtures at 1.5’ spacing. A Lustre is 10 addresses, so I need 320 addresses on a pipe, maybe some extra if I’m running moving LED heads. very dependent on the inventory and use. I generally put the nodes on a side galley and run whatever DMX is needed. In my space it makes it easier to get to the nodes in case I need to access them.

#### RickR

##### Well-Known Member
I too think that gateways should not be on pipes unless you really need multiple universes. I prefer them on the grid/ceiling/floor where they are easily accessible. That also allows for larger gateways that are cheaper per port. Breaking up the wire runs is another benefit.

If your switch to switch distances exceed that 300' fiber-optic becomes part of the conversation. I see that in arena shows, but rarely in a house under 5000 seats.

#### SteveB

##### Well-Known Member
I too think that gateways should not be on pipes unless you really need multiple universes. I prefer them on the grid/ceiling/floor where they are easily accessible. That also allows for larger gateways that are cheaper per port. Breaking up the wire runs is another benefit.

If your switch to switch distances exceed that 300' fiber-optic becomes part of the conversation. I see that in arena shows, but rarely in a house under 5000 seats.

Agreed. It's generally cheaper to run something like a Pathway Octo on side of stage for overhead electrics, using 1 Ethernet jack in the process, then 4 - 2 port nodes, needing 4 Ethernet taps. You DO need local A.C. power though, where as a 2 port runs on POE.

#### AAMorgan

##### Member
When I added the Seladors, I *think* they were powered by dimmers that had been programmed to on/off either at the board or the rack.
Ha! After reviewing ETC's Selador manual I found the following, "You may use a circuit powered through an SCR dimmer, as long as the dimmer is set to unregulated non-dim (switched) operation." (Page 7, Selador Series User Manual.)
I'm pretty sure this is how I had originally installed them - and they worked! I wonder if ETC still stands by this? Either way, I plan to transfer them to switched or relay power.

Last edited:

#### SteveB

##### Well-Known Member
Ha! After reviewing ETC's Selador manual I found the following, "You may use a circuit powered through an SCR dimmer, as long as the dimmer is set to unregulated non-dim (switched) operation." (Page 7, Selador Series User Manual.)
I'm pretty sure this is how I had originally installed them - and they worked! I wonder if ETC still stands by this? Either way, I plan to transfer them to switched or relay power.

Yes, ETC stands by this as well as for the ColorSource line as I understand it. Note however that not all the manufactures of LED and movers recommend this, thus you might still need a relay for other fixtures.. Thus easiest to plan to use relays when you can.

#### Jay Ashworth

##### Well-Known Member
Is 330 feet still the maximum run for ethernet? Is that the TOTAL combined distance from point to point (console to switch to far-away box boom) or just individual cable length?

It used to be the maximum end-device to end-device run, in the days of hubs, as it was constrained not only by the PHY capabilities, but by the speed of light in the collision domain.

Nowadays, it's *just* the PHY capabilities -- since switches regenerate the packets and all links are p2p -- and given good cable and 2 devices with really high quality PHYs, you might well go further than 330ft; I'm pretty sure I have at least half a dozen runs in my cohort that are close to 500ft and work fine.

[ In my IT day job, I'm responsible for close to 500 customer desktops across probably close to 200 customer sites ]

#### coolsvens

##### Active Member
To reiterate what others said. Dimmer Doubling only works on ETC Racks. While it is less popular these days, I know of many sites still running dimmer doubling and it's actually very popular on Broadway still. Dimmer Doubling is one of my favorite magic/physics tricks ever. For those that don't know much about the magic of dimmer doubling (and it really is magic), here is some info. The rack and the special two-fer needed basically split the sine-wave so the top half of the power goes to one light, and the bottom half of the sine-wave goes to the other light with individual control of each. This is also why they have to be run at 77v. And interestingly even though it's lower voltage and wattage, it's the same brightness.

Or look at the pretty picture:

#### RonHebbard

##### Well-Known Member
To reiterate what others said. Dimmer Doubling only works on ETC Racks. While it is less popular these days, I know of many sites still running dimmer doubling and it's actually very popular on Broadway still. Dimmer Doubling is one of my favorite magic/physics tricks ever. For those that don't know much about the magic of dimmer doubling (and it really is magic), here is some info. The rack and the special two-fer needed basically split the sine-wave so the top half of the power goes to one light, and the bottom half of the sine-wave goes to the other light with individual control of each. This is also why they have to be run at 77v. And interestingly even though it's lower voltage and wattage, it's the same brightness.

Or look at the pretty picture:
View attachment 21139
Half the peak to peak voltage / power equates to the same brightness BECAUSE the lamps are designed to operate at 77 volts rather than 115 or 120 VAC. Voltage / lamp-wise, this should be no more surprising than a 6 or 12 volt lamp being equally bright IF it's designed to operate on 6 or 12 volts. Often, low voltage lamps have an inherent optical advantage due to their shorter filaments being closer to a point source. Low voltage lamps are often more forgiving of vibration / rough handling due to their short length / high current filaments being constructed with a larger gauge / diameter wire.
@DELO72 Would you care to comment?

#### coolsvens

##### Active Member
@RonHebbard - Agreed. The intensity equivalence is actually explained a lot better in the link. The lamp actually had to be made different to produce the same brightness.
And some additional info in the original brochure about what's actually happening with the voltage inside the rack: https://files.mtstatic.com/site_120...52HpKeZusHU_&Key-Pair-Id=APKAJ5Y6AV4GI7A555NA

Question: Will the 550 watt, 77 volt HPL lamp provide the same light output in a Source Four as the 575 watt, 115 volt HPL lamp?
Yes. The filament of the 77 volt HPL lamp has slightly increased surface area, emitting more lumens per watt than the 115 volt lamp, so equivalent lumen output and equal performance can be achieved with 25 fewer watts.

#### Ben Stiegler

##### Well-Known Member
My main comment is that you should absolutely avoid using any network equipment that is under the control of the school's IT department for lighting control. Since it seems like you would be having an electrician come in for a lot of this work anyway I would plan on having that electrician run new DMX or ethernet.

#### microstar

##### Well-Known Member
In one temporary mobile school expansion with portables, our network run from the closest building was about 30' too far to the first portable. So we got the electrician to install a transformer in the portable and run 9v capable cable into a buried irrigation box where we enclosed a switch in 3 ziplock bags. Wasn't our first choice but thought it would only last one year. 10 years later, we never had to replace or service that \$40 Netgear switch.
Is this an example of thinking outside the box or thinking inside the box?

#### MNicolai

##### Well-Known Member
Fight Leukemia
Is this an example of thinking outside the box or thinking inside the box?

Sounds like the beginning of a Schrödinger's Switch joke. Whatever you do, don't look inside the box and all remains well to the best of anyone's knowledge.

#### hoosierman

##### Member
Late to this discussion... It would be interesting to hearing more from those working in road houses considering/performing upgrades from conventional dimming to a hybrid mix that also includes LEDs. We're currently working through all the steps required to retire an EDI Mark VII system for our theatrical and house lighting. Opening one door opens up ten more that we have to walk through.

#### TimMc

##### Well-Known Member
If one door closes before another door opens... You're probably in prison.

Replies
7
Views
794
Replies
26
Views
2K
Replies
15
Views
745
Replies
27
Views
3K
Replies
20
Views
3K