What does ND mean regarding a plug on a pipe?

Techatom

Member
Hello,

There are plugs on the electrics pipes that are labeled ND, while all the other plugs are gvien a number. What does ND mean and how do I get access to the power through our dimmers. I believe this is an old Colortran wiring system, now controlelled by a new ETC dimmer panel. The dimmer panel can see all the "numbered" plugs, but not he ND plusgs.

Thanks.
 
If the ND plugs also have a number, there is likely some kind of button panel somewhere that will switch them on and off
 
Thanks.

I plugged a light into one of the ND circuits but nothing happened. So, it might be that this circuit is just dangling at both ends, unconnected from power.

This wiring goes back to the 1970s before LED and movable lights. At that time, how and why would there be a circuit not connected to a dimmer? Would it have been connected to a relay, on or off? Out of over a hundred dimmered circuits, about 16 or so are labeled ND, several on each pipe.
 
So when the newer dimmer system was installed these were not terminated... So where did the installer leave them Hmmm an interesting question. Was there any install drawings.
 
Also, they were all connected back in the day to an older board which was replaced by a modern board.
@Techatom Back in the 1970's non-dims were popular for items requiring on and off but no ability to dim. Things such as fans, strobe lights, fog machines, old style mechanical (motor driven) chasers, motion wheels, color wheels, neon signs, fluorescent lights, work lights. Anything and everything that required normal line voltage on and off with absolutely no ability to be dimmed. In the era, non dims were powered at least three ways:
- Breakers only; you had to physically go to the breakers and manually turn them on or off.
- Mercury wetted (and other types of) mechanical relays capable of being controlled remotely by low voltage control from latching switches on your lighting board.
- Small mechanical relays rated to switch 20 amp 120 volt loads via two normally open momentary low voltage push buttons; one for on and the other for off.
Google MAY be able to find General Electric relays from the era, they were designed to be inserted through a trade-size 3/4" conduit knockout and click into place with integral spring clips on their exteriors. When inserted through a knockout from within an electrical box the 120 volt wiring remained in the enclosure and the low voltage wiring remained out side the 120 volt enclosure. GE RR7 is the part number coming to mind. GE intended them for remotely switching lights in commercial installations keeping the relays near the power sources and running appreciably smaller / lighter low voltage control wiring over distances. One theatre in London, Ontario used the little GE relays to switch all lighting throughout their entire two venue facility with local switches throughout the structure and duplicate master panels in the box office manager's and stage door guard's offices where the remote indicators alerted them to activities throughout the building and also allowed them to turn any / all lights on or off. The guard would switch on a few lights around the building for his hourly walks and switch them off again upon his return. The box office manager could switch off all public areas at days end. A theatre I was with in Hamilton, Ontario used the GE RR7's for work light control. GE made one or two sizes of breaker panels with 120 / 208 volt sections down the centre and low voltage wiring down both sides. Vertical metal barriers ran the full height of the panels with knockouts for the RR7 relays to snap into. GE sold so many that they were economical to purchase and install. During my electrical apprenticeship, while I was still living at home, I installed six of the GE RR7 relays in my bedroom permitting me to control two circuits of receptacles plus all lighting in the room from beside my bedroom door, seated at my desk or from the comfort of my bed. Yes, I'll admit to being a little weird, even in my teens.
EDIT 1: To add link to images and info; https://www.google.com/search?source=hp&ei=ouUPXaKREIXttQaJpr2ACw&q=images+ge+rr7+rellay&oq=images+ge+rr7+rellay&gs_l=psy-ab.3..33i160l2.2801.30848..32143...1.0..0.97.1591.21......0....1..gws-wiz.....0..0i131j0j0i10j0i22i30j33i22i29i30..11:1j12:14j13:0.Kheqta2bGiw
EDIT 2: Corrected the inadvertent misspelling of "the" as "they".
EDIT 3: Added motion wheels, color wheels, large electric heaters for dry ice foggers plus Pani projectors.
@Dionysus Steve; do you recall your Grand and McMannus venues having at least two dozen of the GE RR7's and their associated momentary buttons and low voltage pilot indicators?
Toodleoo!
Ron Hebbard
 
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I suppose it could mean "no dimmer" as in we didn't connect it to a dimmer when we upgraded the system, and it's a wire that leads nowhere useful at present. Maybe they didn't think they needed as many dimmers, or didn't have money to buy them, or sufficient electrical infrastructure to power them all, or physical space for them, or something. If the old system was patched while the new is dimmer per circuit, I could easily see any of these being a constraint during the update.
 
I'd be pretty sure there were Non-Dimmed circuits and may have likely used a GE relay like the RR7 (or 2, 3, or 5 - later 9s). Strand used them routinely. I have designed non-dimmed circuits into every project for over 35 years.

I'd guess the replacement was designed by someone who did not understand theatre, an electrical engineer or electrical contractor, did not include in estimate, so just left them in reused. Really short sided considering the whole world of automated lighting and LED which has evolved.
 
Thank you all. There are enough connected dimmered circuits to do the job, but some day I will trace the lines back to see where they are. I don't think there are very many extra dimmers to "re-connect" them.

As a thought exercies, since we do not have LEDs or movers, what would you all use these circuits for? I would need to install the RR7 relays, supply power, and figure out a way to activate them, and if I could, what would I use them for? What are we missing?
 
Thank you all. There are enough connected dimmered circuits to do the job, but some day I will trace the lines back to see where they are. I don't think there are very many extra dimmers to "re-connect" them.

As a thought exercies, since we do not have LEDs or movers, what would you all use these circuits for? I would need to install the RR7 relays, supply power, and figure out a way to activate them, and if I could, what would I use them for? What are we missing?
@Techatom A tone tracer would make tracing your errant wiring easier. "Fox and Hound" is the name of one of the originals but there are now several makes and models at affordable prices to choose from. Home Depot even carry an acceptable unit. If you have any friends in electrical / telco installation they likely have something you could borrow for a weekend. As to what to use non-dims for; I believe we've more than covered this further up this thread.
Toodleoo!
Ron Hebbard
 
Thank you all. There are enough connected dimmered circuits to do the job, but some day I will trace the lines back to see where they are. I don't think there are very many extra dimmers to "re-connect" them.

As a thought exercies, since we do not have LEDs or movers, what would you all use these circuits for? I would need to install the RR7 relays, supply power, and figure out a way to activate them, and if I could, what would I use them for? What are we missing?
I regulary use ND's for Black lights, Gobo Rotators, haze machines, running lights, as well as using them as a hot circuit while doing maintenance in a grid or in the wings when you need to do a lamp check. Many venues I work have work lights and fly gallery run lights on ND circuits. I'd hate to work in a theater that didn't have any ND circuits, where would you plug in your ghost light?
 
I regulary use ND's for Black lights, Gobo Rotators, haze machines, running lights, as well as using them as a hot circuit while doing maintenance in a grid or in the wings when you need to do a lamp check. Many venues I work have work lights and fly gallery run lights on ND circuits. I'd hate to work in a theater that didn't have any ND circuits, where would you plug in your ghost light?
@DeanBrady Or your DMX controlled coffee percolator from @jfleenor 's Dad.
I see you're in Alaska; you've probably got DMX controlled block and space heaters to power as well.
Toodleoo!
Ron Hebbard
 
@DeanBrady Or your DMX controlled coffee percolator from @jfleenor 's Dad.
I see you're in Alaska; you've probably got DMX controlled block and space heaters to power as well.
Toodleoo!
Ron Hebbard

These are the most important ND's up here in Alaska.

ND.jpg
 
I suspect the relay boxes still exist but the control panel went away. Start by snooping around your breaker panels. Make note of any out of the ordinary load labels. Any odd breakers in the patch bay?
My old place had the GE RR7 types for work lights and such along with a separate Strand panel for Non-Dims. Both were tucked away in some convenient space that was not the dimmer room.

The RR7 relay boxes often have an external 24vac transformer attached . But if the box is big it may be internal.

Question for anybody...Any easy way to integrate DMX with a GE latching relay like the RR7?
 
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I suspect the relay boxes still exist but the control panel went away. Start by snooping around your breaker panels. Make note of any out of the ordinary load labels. Any odd breakers in the patch bay?
My old place had the GE RR7 types for work lights and such along with a separate Strand panel for Non-Dims. Both were tucked away in some convenient space that was not the dimmer room.

The RR7 relay boxes often have an external 24vac transformer attached . But if the box is big it may be internal.

Question for anybody...Any easy way to integrate DMX with a GE latching relay like the RR7?
@venuetech Check Shaun Johnson's (Johnson Controls) site for DMX operated (air gap) relays and use Shaun's relay's to operate your RR7's. I wouldn't use any of the small, low current, solid state outputs to operate the GE's, I'd be worried inductive spikes from the RR series relays would fry most small solid state outputs. I'll do a little Googling for a series of plug-in solid state industrial control modules which existed in he 1990/s and were designed to tolerate inductive loads. The line I'm recalling were made by a US relay manufacturer and were available in four, color-coded, models:
- Low voltage AC control for line voltage AC loads.
- Low voltage AC control for substantial DC loads.
- Low voltage DC control for line voltage AC loads.
- Low voltage DC control for substantial DC loads.
Don't ask me the colors of the four modules; as I recall they were bullet proof when it came to dealing with transients and spikes from inductive loads.
I used a row of 24 of the modules to build out dry closures from some manner of solid state building control system for a project in Las Vegas in 1999. I put Gray Interface onto the useful plug-replaceable modules. If I find them, and if they're still being manufactured, I'll let you know. Now that I'm thinking about it, I used another dozen or so to build out a dancing fountain system to operate solenoid operated pneumatic and solenoid operated water valves in a casino's lobby in Windsor, Ontario. We'd ordered a few spare modules but never had a module fail.
Toodleoo!
Ron Hebbard
 
Today there are many products that eould be easier the the GE relays. I would look at ETC Foundry panels or if a lot, Echo.

In my systems, they were built into an aux bay that looked like a dimmer rack. Good chance demo of previous dimmers included demoeing the non-dimmed relays. Probably nobody planning or doing the work understoidvthe difference,
 
I think that would be called a Courtesy Outlet, or is it Hot Pocket? @derekleffew tried to explain it once but I didn't quite understand.
It’s so you can plug your engine block heater in when you are at work and it’s 40 below zero ( Fahrenheit or Celsius ) outside. Otherwise you go out and try to start your car every two hours. To reduce auto emissions you plug in at +20F other wise the EPA tries to tell entire community’s to stop driving, and stop heating the house with wood. Till the wind comes up and blows some fresh air in. But that could be two weeks away.
All our outlets are on the docks here in the North Pacific, and we just have to put up with Gail force winds in the winter.
 
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