Film-Tech Forum ARCHIVE: Dimmer choices

This is topic Dimmer choices in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Brad Miller (Member # 2) on 11-25-2002, 09:47 AM:

What is the general consensus for a 3 step dimmer recommendation? I have been very pleased with Lindsey/Fairbanks dimmers, but they do not have a manual override on the box itself. Ash/Stevenson dimmers are also quite reliable and do have an override.

What are your thoughts for the best bang for the buck? I am only interested in 3 step dimmers and NOT digital dimmers. Please note whether there are manual override buttons for UP/MID/DOWN on the box.

Posted by Steve Guttag (Member # 268) on 11-25-2002, 11:32 AM:

For the most part, I'm pleased with the Kelmar dimmers in their LCS line. They have many models to accommodate the features you value as important. They also have a no-frills model in the "Architectual" line that does not buttons on the box.

Steve

Posted by Anthony Hopland (Member # 336) on 11-25-2002, 11:38 AM:

Manual controls are (or was) an option from LFI. It adds cost but if you need them it is nice to have it come that way from the factory.

Posted by Gordon McLeod (Member # 33) on 11-25-2002, 04:00 PM:

Bang for the buck the Ash dimmer is the best deal and has the best noise filtering out there

Posted by Daryl C. W. O'Shea (Member # 1303) on 11-25-2002, 04:07 PM:

I've never had a problem with Ash Stevenson archetectual or stage dimmers. The oldest ones I've used, from 1988, still work perfectly. They've never given me a reason to look for others.

Posted by Rick Long (Member # 213) on 11-25-2002, 04:52 PM:

We have used Ash-Stevenson dimmers for years with virtually no problems. I like the ability to adjust the up / down speeds as well as, of course, the three individual level settings.

Posted by Ken Layton (Member # 133) on 11-25-2002, 05:47 PM:

I agree with the Kelmar LCS series. Very easy to install, reliable, simple, and has manual buttons, too.

Posted by Don Sneed (Member # 955) on 11-25-2002, 06:10 PM:

I like the Strong & Christie dimmers, easy to install, has good control on both, same problem with all dimmers the triac goes out from time to time but easy to repair...as for noise...I have not had any in any of these two dimmers even when a dimmer is near the sound rack....

Posted by Mark Gulbrandsen (Member # 72) on 11-25-2002, 06:15 PM:

I also vote for the Kelmar dimmers. Have literally put in hundreds of the 2 Channel DeLuxe model and never had to go back to fix one of them. The Stan Ash dimmers are ok but do not have the high build quality of the Kelmars. My second choice would be the Strong/Eprad dimmers. They too are pretty much bullett proof.
Mark @ CLACO

Posted by Gordon McLeod (Member # 33) on 11-25-2002, 08:13 PM:

Come on mark the Ash is a better built dimmer than Kelmar any day better design and better rated components

Posted by Mark Gulbrandsen (Member # 72) on 11-25-2002, 08:16 PM:

Sorry Gord, but the Kelmars have been the least problem dimmer I've ever worked with. Build quality is actually much better as is the cabinet quality. In Boise there were quite a few Stan Ash problems to work out.
Mark

Posted by Scott Norwood (Member # 30) on 11-25-2002, 09:16 PM:

Brad needs a Ward-Leonard resistance board. One (sort of) local theatre has had one for 76 years without a failure, which I think is a pretty good reliability record. I bet it can even be controlled with the CA21 and some custom hardware! [Smile]

Posted by Steve Kraus (Member # 476) on 11-25-2002, 09:33 PM:

No no, a motor-driven variac. No RFI.

Posted by Kenneth Wuepper (Member # 1174) on 11-25-2002, 09:35 PM:

I have found the Frank Adam "Major System" board to be excellent for reliability as well as providing an excellent source of heat back stage.

Frank Adam Electric board in the Temple Theatre, Saginaw MI. This board still works 100% and when a power surge took out the solid state dimming system, this old board ran the whole stage show. The settings are limited only to the operator's ability to pull the levers that operate the resistance pancakes. New in 1927 Still goin'.

The solid state system is a Strong Mantrix. [eyes]

Posted by Mark Gulbrandsen (Member # 72) on 11-25-2002, 09:58 PM:

Kenneth,
Part of my last job was as a Strand service technician(Colortran also) [Eek!]

. The Mantrix board is now obsolete, something which Strand is famous for doing quickly. You should see the computerized board that replaced it [bs]

. They are still trying to get it to work right after nearly two years. When you call Strand technical support you might be lucky to get the one person that really knows how it should work, but mainly you end up with voice mail or getting someone that hasn't a clue about anything to do with it [Confused]

. With the older CD80 series dimmer racks they rarely will be able to supply a part [Frown]

. Other companies are doing well making computer retrofits that are reliable to replace the aging, sometimes troublesome computers in these racks [Cool]

.

While the lighting community needs these computer based lighting systems to pull off really large complicated shows the average smallish theatre should stick with something more old fashioned. They will experience far fewer problems if they do [Smile]

.
Mark

Posted by Oscar Neundorfer (Member # 458) on 11-26-2002, 07:37 AM:

Brad,

SMART makes a line of dimmers rated at 3 kW each. They are available for console mount, in wall mount packages, and with manual override buttons in the wall mount packages. They are 3 stage with an emergency instant full capability. Also, they are UL listed.

Panastereo also makes a line of 3 stage dimmers which have either contact closure control (for automation connections) or RS-232 control capability if you need that kind of thing.

Posted by Gordon McLeod (Member # 33) on 11-26-2002, 07:46 PM:

Mark what are those issues with the ash dimmer. I have installed thousands of them with out any grief other than the odd triac killed by a contractors short circuit
They also have a very good curve unlike the kelmar

Posted by Daryl Lund (Member # 356) on 12-01-2002, 01:04 AM:

Check with paul. some of his friends go to Home Base or lowes and sometimes ACE Hardware

Posted by Mark Gulbrandsen (Member # 72) on 12-01-2002, 10:26 AM:

Gord, have had a number of PCB card failures with them. Also the cabinet which is just thin sheet metal leaves someting to be desired. I know they are good dimmers but the construction could be a bit better.
Mark @ CLACO

Posted by Gordon McLeod (Member # 33) on 12-01-2002, 04:28 PM:

Onely had 2 pcb failures booth where there was a open neutral on the feed. The cabinets are not thing metal but standard CSA spec steel back plate and alimunium U shaped cover. The shape and material of the cover is designed to specific limit physical noise from magnetic coupling of the torroid choke that could make it noisy. This was develeped for a museum we were doing way back when

Posted by Paul G. Thompson (Member # 655) on 12-01-2002, 08:23 PM:

The only thing that troubles me with the Kelmar dimmers are that if some doofus changes a light bulb with the dimmer powered up and the light bulb or its socket accidently shorts out, there goes the Triac! I have seen that happen twice in the last three months or so.

Whether or not other brands of dimmers can be easily damaged in the same way, I really don't know, but:

...never let the janitor change a damn light bulb! [Mad]

Posted by Gordon McLeod (Member # 33) on 12-01-2002, 10:10 PM:

Most lower capacity dimmers still use triacs and they are usually destroyed by a dead short instantly. In fact the fuse blowing or the breaker tripping is usually what causes the damage as the collapsing field in the filter choke causes a massive dv/dt that exceeds the rating of the dimmer
starting usually around 3.6K and up a SSR block is used that is two discrete SCR's and they are less suseptable to dv/dt related faults

Posted by Mark Gulbrandsen (Member # 72) on 12-01-2002, 11:00 PM:

Pretty much the same thing happens with a Solid State relay as does with the triac. Have seen this happen on Strand, Colortran, and ETC systems many times. The main thing in the first place is to prevent any dufuss's from entering your site........ [Smile]

Mark