Control/Dimming Help! Need Info on "Rat Pac" 10x1.2K dimmer

[NolaTek]

Greeting from NOLA,

I'm having some very frustrating experiences with a 10x1.2K mobile dimmer pack known only to me as a "Rat Pack". I've run into it a lot recently on film sets and would like to get a few solutions in my bag of tricks for the problems I'm having. A few specs: I dont know make or model number (kicking myself for not grabbing it last night) however I do know that it has a 100A Bates input connector with 10 channels of 1.2K output in the form of female edison connectors. The dimmer contains 4 sets of internal dip switches that control the behavior of each channel. It contains no fan, but has an entire side wall dedicated to a heat sink. So

Here's the low down:


I've had 2 separate unfortunate experiences with these little guys.

1. The first was on what I'm told was a "brand new unit". The dimmer would not accept my control once addressed properly. It did not recognize any input I gave it, but showed a positive indicator light for DMX being present. We shut the dimmer down and cracked it open to check the dip switches. All were in the appropriate positions to opearte the box in its default 10 channel mode. For kicks, I cycled every dip switch and closed the unit back up. Once we powered back up it had no issues and performed properly the rest of the evening. First time jitters I figured.

2. My problems continued 4 days later when I was back on set with the rat packs. A 2nd pack was working properly until about 6 hours into the day when it began to flash its dmx indicator light on and off randomly and sent my lights flashing. Other dimmer packs passing through this pack behaved just fine throughout this ordeal. I bypassed this pack in favor of a few 2k variac dimmers. AT the end of the day I noticed that the pack was passing voltage still, without any control signal coming through it. I opened it up as I did before and found dip switches in the proper alignment once again.

Has anyone had experiences with these or similarly designed dimmer packs in the past? I'd like to find out if I have 2 bum units on a grip truck or if the entire line is worthless. Thanks in advance!

 

[Edrick]

Nevermind just saw the spec sheet

 

[hobbsies]

Are these being used outside? Are they on for most of the time? Are they exposed to the sun? Its possible they're overheating. Could also be a dmx issue. When I run into these kinds of problems I find rebooting the system fixes the problem most of the time. Turn everything off on the board, kill the main switch, kill the board, and turn off any other devices you have in the dmx chain (movers, etc), then turn it all back on starting with the board.

 

[JohnD]

re: Help! Need Info on "Rat Pac" 10x1.2K dimmer

Here is the link:
Rat Pac

 

[NolaTek]

re: Help! Need Info on "Rat Pac" 10x1.2K dimmer

Here is the link:
Rat Pac

you sir, are a scholar and a gentleman, thanks for the info.

 

[NolaTek]

re: Help! Need Info on "Rat Pac" 10x1.2K dimmer

Strictly inside: problem number 1 occurred in an air conditioned hotel. Problem number 2 also occurred inside sans A/C however. I agree with you that this sounds like an overheating issue. The lack of fans and reliance on a heat sink seems suspect to me. Even at 1.2K it doesn't seem like adequate cooling could occur this way. As for the control system, I'm using someone else's Hog PC and single universe dmx widget so an issue on that end is totally possible. Also, it's been strictly conventional (only dimmers) in the dmx chain this far. Strand CD 80s and Sensor racks are the only other thing in the chain, so I doubt feedback is the problem. I'll take a look at the link that JohnD posted and see if any troubleshooting exists there. If not, I'll just demand more Sensor racks

 

[derekleffew]

The PDFs on the site cited are just glossy cut sheets. For some reason I was expecting at least a User Manual. I didn't watch any of the videos, but would be concerned about the lack of advertisement of Listed, by NRTL.

... The lack of fans and reliance on a heat sink seems suspect to me. Even at 1.2K it doesn't seem like adequate cooling could occur this way. ...

According to ratpack_10ch.pdf,

• Super quiet thermo controlled "Whisper Fan" Technology, designed to work right on the set without the noise.

Perhaps you have an older model that doesn't have the fancy, hi-tech fancy fan?

... AT the end of the day I noticed that the pack was passing voltage still, without any control signal coming through it. I opened it up as I did before and found dip switches in the proper alignment once again. ...

Did the problem fix itself, or is it still doing it? Was it all ten channels on the pack or just a few? If a dimmer outputs full voltage (with a load of at least 50W; see JD's post below) with no control signal, chances are likely the SCR, SSR, or triac (for these I would suspect it uses triacs) has failed gated closed. A Dimmer, Phase Control can fail either open (no voltage) or closed (full voltage), but closed happens much more often.

... If not, I'll just demand more Sensor racks

Yes. This. Always this. Other manufacturer's dimmers may perform adequately, but why take the chance?

-----

ETC folks: Any problems with wiring an SL1012A SmartPack to a 100A Bates plug, tying the two, or three, hots together? Would one need a double neutral? I see in the SmartPack Portable Setup Guide.pdf there's a "Single Phase Configuration (Europe)" using only three wires? Does this not work on other continents?

 

[JD]

AT the end of the day I noticed that the pack was passing voltage still, without any control signal coming through it.

Was this by meter or was there a lamp that did not go off? When metered, if a channel is not under load, voltage will always be present. This is normal as the firing circuit leaks voltage when there is no load. When metering, you should connect a 50 watt or bigger lamp to the channel.

Any problems with wiring an SL1012A SmartPack to a 100A Bates plug, tying the two, or three, hots together? Would one need a double neutral?

Triple would be more like it. Running HNG would require wiring capable of handling 120 amps.

The Ratpack is 10 channels so the draw is 100 amps. Connector ok. The ETC is 12 channels, 120 amps through a 100 amp connector?

Now I understand why the odd number of channels, they wanted to get away using the 100 amp connector!

 

[derekleffew]

... The Ratpack is 10 channels so the draw is 100 amps. Connector ok. The ETC is 12 channels, 120 amps through a 100 amp connector?

Okay, you got me there. But are we going to load every channel to 1200W? Wouldn't 12x 1000W lamps (=99.99999A @ 120V) be more realistic? NEC (with certain stipulations and exceptions) allows feeder to be sized to the load rather than nameplate rating.

-----
Two things I found interesting on the 24x1kW RatPac:

1. It uses "baby cams" (E1015, which STEVETERRY doesn't like)
2. It includes both genders of ground.

 

[STEVETERRY]

ETC folks: Any problems with wiring an SL1012A SmartPack to a 100A Bates plug, tying the two, or three, hots together? Would one need a double neutral? I see in the SmartPack Portable Setup Guide.pdf there's a "Single Phase Configuration (Europe)" using only three wires? Does this not work on other continents?

This would work with Smartpack, but the 100A feed and connector would need to be protected by a 100A overcurrent protective device.

One other comment--I know nothing about this product, but I am troubled by the apparent lack of a UL, ETL or other NRTL Listing. This would be a significant liability issue, IMHO.

ST