Control/Dimming - Portable Dimming Racks

[chawalang]

I am recently doing alot of more event work but have a question about patching portable dimmer racks. As in an installation theatre I have the understanding of what a soft patch and a hard patch is. What I'm trying to get clarification on is what am I looking at when Im looking at the back of a portable dimmer rack when it comes to the hard patch. I understand that there are soca plugs for the fan outs that are run where ever you need them but per each grouping of cables to the hard patch, what is the general knowledge I should know for hard patching everything. I guess the difference between hard patching fixtures with two fers etc, in a theatre to doing the patching on the back of the dimmer rack. I just need a good understanding so I can go about doing the hard patch myself

[derekleffew]

For nomenclature, see Patch, Types of (Lighting) .

Other random points:

A rolling rack's individual receptacle s (stagepin, Edison, or TwistLock) will always be direct, i.e., plugging to the one labeled "1" will always assign to dimmer #1.

If the rack contains less than 48 dimmers, the multipin (Socapex) outlets will be direct also, and will be labeled as "1-6, 7-12," etc. If you don't use all six circuits on a multi, you've "wasted" that dimmer. But you can still use the individual receptacles. Since these are wired in parallel with the multi-cable outputs, care must be taken not to use or overload a dimmer already in use.¹

If the rack has 48, 72, or 96 dimmers, the multipin outlets are usually assignable via the pin patch. The way to tell is that the outlets will be labeled with a letter (A, B, CC, DD). Most often a rack will have twice as many multipin circuit as dimmers (a 48-way rack will have 16 Socapex outlets (A-P); a 96-way rack will have 32 (after the first 26, double letters are used (A-Z, AA, BB...FF).²

If using more than one rack, a prefix of R1, R2, and so on is used so there isn't more than one "Multi A," for example. R3B or [R3]B would be the second multi on the third rack.
If the DMX address of the rack is not 001, the rack's dimmer numbers will be off. Thus the second dimmer on R2 may be labeled 2 on the rack but will be DMX address 50 on the console (assuming Rack#1 is a 48-way).

¹Some racks have only Socapex outs. In order to access an individual dimmer with these, a break-out is required at the rack. The male end of the multi-cable may have a break-in as well. This practice can quickly dissolve into an ugly mess of spaghetti at the back of the racks.

²Most dimmer racks' pin-patch have four holes per dimmer (there's only one hole/pole/pin as only the "hot" is patched; the neutrals are all bussed together), allowing four circuits to be patched to one dimmer. But some racks have only two holes, which can cause issues if three or more fixtures need to be in the same dimmer. One will need a two-fer on the pipe somewhere.

This document: http://www.etcconnect.com/docs/docs_...pec_Sht_vD.pdf , shows the various options available when specifying a modern touring dimmer rack.
See this one for a dimmer pack: http://www.etcconnect.com/docs/docs_...pec_Sht_vF.pdf .

Note the difference between dimmer rack and dimmer pack.

[JCarroll]

If the rack contains less than 48 dimmers, the multipin (Socapex) outlets will be direct also, and will be labeled as "1-6, 7-12," etc. If you don't use all six circuits on a multi, you've "wasted" that dimmer. But you can still use the individual receptacles. Since these are wired in parallel with the multi-cable outputs, care must be taken not to use or overload a dimmer already in use.¹

Not always...
The Leprecon packs I use quite often have 12 channels, and 4 patchable socapex outlets.

[cbrandt]

One thing that can help, aside from GOOD labeling, as outlined by derekleffew, is to seperate the patch into smaller parts. You have the circuits that all run out to the lights, and are generally labelled with the rack and letter of input. You have the patch bay in the dimmer rack, with dimmer numbers, and you have the dmx addresses of those dimmers. On a straight forward touring rack, your dimmers and circuits will be well labeled, and pretty straight forward.

I generally (as the master electrician/lead tech/backup programmer/project manager) hand the road ld a patch sheet of fixtures and dmx addresses. It really isn't his problem what the hard patch or the circuiting is, as long as he has what he needs.

Am I the only one out there who really wishes we could all agree never to use 120k again? Beautiful light, but I hate hanging and patching those things...