Control/Dimming CD80SV Power Module Retrofit

[jfarrow]

Hey ya'll;

I've got a CD80SV rack in our black box (circa 1995) that I need some help with.

We just purchased 25 LED wash lights. As a result I'd like to retrofit a few of our Dual 2.4kw dimmer cards to be non-dim constant voltage. I've taken a look and it seems simple enough to just bypass the SCR and choke and go direct from breaker to output pin; but I'm not sure if I need to modify or close any of the low voltage control circuitry. Has anyone got the answer or access to the schematic for the constant voltage power module as it applies to CD80SV Dimmer Module (part # 72314)

Thanks

 

[Footer]

You can just completely bypass it and don't even worry about the power cube/choke. Just be sure you are just bypassing that and the breaker is still in the loop. Because you are asking, I assume you are capable of safely doing this job. Strand did make CD-80 non-dim and relay modules, I would suggest you go this route if this is a permanent fix.

 

[derekleffew]

See this thread, particularly this post.

 

[phenry]

See this thread[/URL], particularly this post[/URL].

I agree with Footer and Abby, while it is possible to alter modules, it is not advisable. It can be dangerous if done wrong and will make the venue liable for any damage or death to equipment or persons. The UL listing will be voided as well as the warranty, but it is unlikely that it was still under warranty anyway. What you need is a 72302 dual constant module.

 

[jfarrow]

Thanks everyone for the quick reply.

All work will be inspected by a licensed electrician.

 

[STEVETERRY]

Hey ya'll;

I've got a CD80SV rack in our black box (circa 1995) that I need some help with.

We just purchased 25 LED wash lights. As a result I'd like to retrofit a few of our Dual 2.4kw dimmer cards to be non-dim constant voltage. I've taken a look and it seems simple enough to just bypass the SCR and choke and go direct from breaker to output pin; but I'm not sure if I need to modify or close any of the low voltage control circuitry. Has anyone got the answer or access to the schematic for the constant voltage power module as it applies to CD80SV Dimmer Module (part # 72314)

Thanks

You have a much bigger issue here. If the rack is permanently installed, the electrical system feeding it underwent a fault current analysis based on the original Short Circuit Current Rating (SCCR) of the rack. By modifying the rack or bypassing chokes (which are one of the primary contributors to the SCCR), you could create an unsafe condition. You need to determine what the SCCR of the rack is when a "breaker only" module is installed (get this from the manufacturer), and verify that that SCCR rating coordinates with the available fault current on your feeder. This must be done by a licensed electrical engineer.

Plus, what Abby said in the post Derek pointed out. Do not modify it yourself.

ST

 

[JD]

Funny thing about dimmers, that choke. We think of it as only an inductor, but at its heart it is a long length of #14 or #12 (or larger, depending on dimmer rating) enameled copper wire. In other words, a resistor. As such, it greatly reduces the potential current flowing in a dead short condition. There is also an interesting math trick that also acts to limit current via a choke as the load resistance drops (or at least until the core hits saturation.) Both characteristics also increase the survivability of the SCR/TRIAC/SSR when a short occurs.

 

[jhochb]

CD80SV CC modules needed

Good Morning All

I have a venue that wants to put some ETC LED S4 on 3 of their stage electrics.
Issue is, they have a Strand CD80SV rack.
Does anyone know where I can get 6 CD80 dual constant circuit 2.4K modules SL # 72302?
Or maybe the dual contactor mod SL# 72385 / 6 type "Z"

Thanks

 

[tyler.martin]

Re: CD80SV CC modules needed

Ive been looking for some as well. Strand was unsure if they had any...

 

[jhochb]

Re: CD80SV CC modules needed

Good Morning Tyler

Strand doesn't have the metalwork anymore. They told me they can't make them.
Johnson Systems may be working on something & Century can convert the dual 20's. Either 1 or both chanels.
My job is still in the quote stage so I can wait a bit.

 

[TimMiller]

Re: CD80SV CC modules needed

You can have a dimmer repair tech make the modules cc modules. They pull out the ssr and choke and run a wire directly from the breaker to the load side pin on the module.

 

[DavidNorth]

Re: CD80SV CC modules needed

You can have a dimmer repair tech make the modules cc modules. They pull out the ssr and choke and run a wire directly from the breaker to the load side pin on the module.

Exercise some caution here. The choke helps to manage the SCCR rating of the module by providing a partial inrush resistance [in rough terms] to a large short circuit current draw and helping to protect the rest of the power feed. IE, a large enough short could damage components in the module or cause a main feed to trip. Likely? Not really, but then no one really expects a large, low-resistance short-circuit until it happens. You really should put a large, and appropriately class-rated fuse in the module to replace the choke.

WARNING: None of what I have told you to do is covered under the UL or ETL listings for the product. Modification of the product and a failure sometime later with put all liability on the facility and the person doing to modification.

It's a shame someone hasn't yet made a listed module for the tons of these racks that are out there.

One more very important point...there is a real and distinct advantage to using relay modules to power LED fixtures. You make a large investment per LED fixture and you want it to last a long time. A relay module allows you to shut off power to the fixture thereby reducing time on the power supply and allowing it to run for much more time down the road. Protect your investment in LEDs....use relays.

Have fun,
David

 

[MNicolai]

Re: CD80SV CC modules needed

It's a shame someone hasn't yet made a listed module for the tons of these racks that are out there.

Yeah. Somebody should.

If only there was a company who was in the business of making modules you can put into dimmer racks...

 

[TimMiller]

Re: CD80SV CC modules needed

I understand the reason for the choke when using an scr/ssr but it can be removed when using just a breaker to power a feed.

 

[DavidNorth]

Re: CD80SV CC modules needed

I understand the reason for the choke when using an scr/ssr but it can be removed when using just a breaker to power a feed.

Yes, you can remove it, but the technical reason behind my earlier statement still stands. The choke does more than merely create a voltage drop when faced with a sudden change in current [risetime for a forward-phase control dimmer]. The secondary benefit to having a choke in series is a creating a less than sudden current draw through the breaker, bus bars and feed thereby provding another series point of dimmer component, rack and feed protection in the case of a short circuit.

Can you get by with remodeling or modifying your dimmer modules. Probably, but I, for one, do not wish to be in the responsibility chain for any problems arising from information given in this forum. Note that any product modification, especially when it comes to power-handling products, does assume some responsibility and liability.

David

 

[jhochb]

Re: CD80SV CC modules needed

Good Morning David

Thanks for your input.
This is why I've been looking for orphans.
I an move a wire like the best of them
I'd like to use Relay mods if I could find them but finding CC's are looking slim.

__/)_

 

[derekleffew]

Re: CD80SV CC modules needed

Good luck in your search, Jack. We'll keep an eye out for you.

Every time the topic arises, the end is the same:

... As an ETCP Certified Entertainment Electrician, and a factory authorized field service technician for various manufacturers, I want to emphatically state that an end user should *NEVER* modify a dimmer rack in this manner. The liability and risk of injury or death is too great.

Modifying the dimmer rack can void the dimmer rack warranty, voids UL (or ETL, or whomever), and likely makes you, your venue, and your employers/supervisors responsible for any and all damage this may cause if something fails. You risk, at the least, damage to the dimmer rack and connected devices, and at most, loss of life.

I implore you, if you need power that can't come from a dimmer...install a relay module if you're able to / your rack has that option, or have a licensed electrician help you come up with a safe and viable solution. ...

In order to prevent further discussion of modifying dimmers, this thread is closed. Anyone able to help Jack can contact him via jhochb.

 

[kesowul]

CD80 Non-Dim

I am looking for information from anyone who has used or is using a Strand CD80 rack. We have recently received stock of some ETC LED fixtures and I want to purchase a few Non-Dim modules for use with these new fixtures. I am much more familiar with ETC gear, and want to make sure I am looking at the correct part. From what I've found so far, I would be looking for Strand Part# 72384 or 72386 for the 2.4k module. The latter being a fully Non-Dim module and the former being either a dimmer or switched to be a Non-Dim (please correct me if that is incorrect). I'm also having a tough time trying to find these online. I know it's a legacy product, but I know there has got to be a bunch of these out there. Anyone know of a supplier who still sells old Strand equipment? Thanks!

 

[jhochb]

Re: CD80 Non-Dim

Good Morning


I started a thread like this Months ago. I think it was in classifieds.
There are people out there who can modify an old dimmer mod and certify it
I can do the mod but I don’t want the liability.
I think Strand is now selling a non-dim module for some of the CD-80 racks depending on its age

 

[Calc]

Re: CD80 Non-Dim

Both the dimmers you mention are dual-channel. #72386 has both channels as non-dim. #72382 has the first channel dims, the second is non-dim. #72384 has the first channel is non-dim, the second dims.

If you only need one channel to be non-dim, figure out if you want it to be even or odd. If it's even, go with 72382. If it's odd, 72384. If you need both to be non-dim, 72386.