Automated Fixtures Rainbow Colour Changer Problems

[KeithGinty]

Hello

Wondering if anybody can shed some light on a small problem im having with some Rainbow Scrollers.

The setup is as follows -
ETC Ion running 12 x Rainbow Pro 8 Scrollers on two PSU's.
The DMX runs to our XTBA buffer splitter where is goes to each PSU at either side of the Auditorium. There is also 6 x Robe 600 LED's and 6 x VL1000TS connected to the same buffer.
The problem is -
Randomly we all the scrollers will shutdown and we have get we get two LED's on the display. The PSU's say that they are still receiving mains and DMX but they need a hard reset to get them going.

Anybody got any suggestions?

Many Thanks
Keith

 

[techno89]

Just to help eliminate variables I would try plugging the PSU's DMX right into the board and seeing if the problem still exists. We can go from there.

 

[derekleffew]

...Randomly we all the scrollers will shutdown and we have get we get two LED's on the display. The PSU's say that they are still receiving mains and DMX but they need a hard reset to get them going. ...

Is it six scrollers on each PSU, and all 12 shutdown at the same time? Or are noticed at the same time? Does it happen when the scrolls are dormant as well as moving? I'd check the output power. Possibly a weak 24V output. Sounds more like a power issue than a control issue.

I'm not familiar with Rainbow scrollers, (very rare in the US), so this might not be applicable, but are you using a return line (returning the last scroller back to the PSU)?

As a band-aid solution, can you program a hard reset just before you need the scrollers while the lamps are dark?

Have you contacted the manufacturer? From Rainbow Colour Changers - FAQ, the closest description of your symptoms:

My scroller goes stagnant to desired position, showing[bloc] during staging.
Check the length of the XLR cables to the PSU. Have you used a “return cable”? Check the scroller for rolling resistance / mechanical problems/gelstring damage. In doubt, measure power consumption and report to service. Also check the motorcabeling and the motorpack itself.

 

[KeithGinty]

Thanks for your reply

Yes it's six scrollers per PSU, and yes I do have a return cable.
I think they all shut down at the same time, if not very close to each other.

We have now replaced the 2 PSU's with 4 PSU's and are running 3 scrollers on each, seem to have sorted the problem.

I am in communications with Rainbow service department now, it's slow as they only have one english speaking engineer.

Will keep you informed!

 

[dramatech]

Thanks for your reply

Yes it's six scrollers per PSU, and yes I do have a return cable.
I think they all shut down at the same time, if not very close to each other.

We have now replaced the 2 PSU's with 4 PSU's and are running 3 scrollers on each, seem to have sorted the problem.

This would be a very strong suggestion that the PSUs were not able to supply the needed current. If these are single scroll scrollers, they should draw approximately 600 milliamps, when in full movement. That means that a PSU should be providing 3.6 amps for six scrollers. I would generally suggest at least 4 amps just to be safe. As Scrollers require 24 volts DC, and the fact that DC voltage will decrease considerably with the resistance of the wire, long runs of undersizied cable, especially for the first and last cable from the PSU to the scroller daisychain could make the voltage drop. One way to test this, would be to have all of the scrollers on the chain go from the first frame to the last. If they shut down, then try moving just one scroller on the chain again from front to rear of the gelstring. If it doesn't shut down, then the peek start up current of all the scrollers together is dropping voltage because of the combined scroller draw and the resistance of the wire.
I would think that the PSUs should have a large enough capacity, if they were sold with the scrollers. I would check cable runs. If they are long see if there is any way of putting the PSU closer to the scrollers. Check the cables for broken wires at the solder point of the connector. If a few strands are broken, then the remaining strands will create a high resistance, being forced to carry more current. Also, good scroller cable should be 14 gauge for the connections on pins 1 and 4. I personally run 18 gauge cable on some 40 scrollers with no trouble, but that doesn't mean that it will work under long runs or underrated PSUs.

I am in communications with Rainbow service department now, it's slow as they only have one english speaking engineer.

I have several of the the very early Rainbow scrollers. They were originated by a company named Camelont in Sweden. Then a German company took over all of the marketing of the brand. I am not sure if they are still manufactured in Sweden and marketed in Germany, but if so and Camelont will talk to you, there are many more Swedes that speak excellent English than Germans.


The best way to solve any problem of that nature, is to experiment with different connection combinations. Mark the cables with a temporary number and make notes about what works and what doesn't noting cables, scrollers and PSUs by a number. Then start removing or moving components. Once patterns occur of failures and successes, you can find the problem.

Tom Johnson