Some random thoughts
I'm sorta of facing a similar decision about distributed or collected (
dimmer rack) for a new complex going in, in the next few years.
In my mind, I don't see enough advantages to recommend
IGBT over
SCR, the
IGBT does not allow "
Non-Dim"
power to a ML, so the advantage of "
Plug and
Play" is not (in my mind) a reality and a Sensor handles a
mirror ball motor or
gobo rotator just fine, and can at least have dual circuits swapped to
relay, which you cannot do with
IGBT raceways.
IGBT has theoretical advantages in terms of dead short protection, but from a user that has tripped breakers maybe 6 times, on a 300
dimmer Sensor
system in 4 years, I don't see any big advantage.
One advantage to
IGBT I see, is in a scenario we are facing with 3
FOH catwalks that probably would work well with 32 x 1.2kw dimmers (96 total) across 40 feet or so, all fixtures on individual dimmers @ 1.2kw. The cost savings in wiring "may" be actual,. though ST brings up a very valid
point that the labor to install
circuit panels for 32x20 amp, 3 pole breakers, as
power distro to
IGBT raceways, might eat up the savings in copper.
And you still need dedicated
power for the ML's of the future.
As other have pointed out, there are many ML's wanting 208v, though I question as to the application of the larger and brighter ML's that need 208, being needed in smaller spaces. You still need "some" 208 around, so best plan for it, but I have a question - are the fixtures needing 208, using 208 only beceause they are brighter ?, or is the feature set of the larger fixtures what people are after ?.
The
ETC SmartSwitch
system, "seems" like a good way to go, but as I discovered, they do not have internal
circuit breakers, so you are back to the labor issue of installing and wiring up separate
breaker panels alongside the SmartSwitch panel(s), so at what
point is it cheaper to simply make the dedicated
power circuits needing
DMX control into a Sensor rack with relays. Sensor is very, very easy to
wire up. (Edit: - SmartSwitch does allow for 2 pole circuits, which Sensor does not).
The
IGBT systems, as well as standard raceways that offer built in
Ethernet or
DMX, have to pay close attention to providing for separation within the enclosure of the lo-vo section with the 120v. Combing Lo and Hi
voltage in raceways, while seemingly desirable, forces you to think about the robustness of the data cable running/
bundled alongside the 120v multi. This is less an issue when the
raceway isn't flying - catwalks,
etc... where you can specify off-the-shelf
Cat5 receptacle panels somewhere convenient to the devices needing data. You still need to do some thinking about data to moving positions that use
Soca for dimmed
distro, or that are getting dedicated
power. Many questions in my mind as to how to do this well.
I'm currently toying with the idea of not overloading on racked dimmers, especially at positions that will see occasional use, but simply putting in a lot of dedicated
power off Sensor relays, as well as lots of local data ports, then buying a whole bunch of BakPaks or
Leprecon 4 way
dimmer packs. Then the circuits can be ML
power, OR
power to a
dimmer pack for conventionals. An example is a series of 19
balcony rail positions that can handle 3-4 conventionals, OR maybe 1-2 ML's, ea. Rather then put in 4 circuits @ 2.4kw dimmed, I'll install 2 @ 2.4kw as
relay. Thus I have ML
power for easily 4 fixtures @ up to 700
watt lamp types, OR a
Leprecon 4 pack that can run on 2 circuits and provide for 4 x 900w dimmed circuits. Do I need 208v ML fixtures here, probably not.
In any event, I wish
ETC still made the old
LMI quad 1.2kw dimming rack that had (if memory serves) 192x1.2 dimmers in a rack. Put that in a Sensor and I'd spec. it in a minute. Trouble I see is a re-design would be required to fit 192 lugs for branch circuits, not to mention more space needed for the chokes. Or maybe a cheap Sinewave @ 1.2kw ?.
Steve B.