Strand Century Dimmy

[STEVETERRY]

yes the 10th dimmer is working and I know it was the breaker but I did go through all the cards and cleaned them up
I do have one card that when I plugged it in a good channel it was dim like the light was only getting half the power
one thing that I don't understand is the breaker was overheated but it did not trip and the fuse was not blown, the fuses are 50 rated and the breakers are 20 amp rated
these breakers are able to be taken apart, on the back there are 4 holes covered in some kind of glue and under the glue there are screws and the contact was pitted and over heated, I cleaned them up nice and smooth on both pieces and it works for now, I cant trust it for safety purposes because it looks like it never tripped so I'm looking everywhere for new breakers, but anyways I only have 3 channels to go and its not the cards, I think that's going to be wiring in the back with all the wire nuts
From the beginning I would find a problem then another would show its ugly head then another and another the further down I went more problems showed up but I see a light at the end of the tunnel and I don't think its a train it might be one of our Century cans with a 500 watt bulb

In general, molded-case circuit breakers in 15A or 20A ratings are not suitable for disassembly and internal cleaning of contacts. If the breakers in question are the Heinemann 0911 series, they are notorious for contact failures. I suggesting locating replacement breakers as soon as possible.

ST

 

[FMEng]

There are a few companies out there that refurbish, test, and sell obsolete breaker types. I have purchased a few breakers that way, for 1950s buildings, that would have otherwise been unobtainable.

 

[Scott S]

here are some pictures of card that seems to be at half power and a breaker

 

[STEVETERRY]

here are some pictures of card that seems to be at half power and a breaker

That breaker is the beast I previously mentioned.

ST

 

[Scott S]

In general, molded-case circuit breakers in 15A or 20A ratings are not suitable for disassembly and internal cleaning of contacts. If the breakers in question are the Heinemann 0911 series, they are notorious for contact failures. I suggesting locating replacement breakers as soon as possible.

ST

Is there a different breaker that can be used

 

[jhochb]

First I thank you for allowing me in to your group
I'm wondering if anybody can help me with some technical problems
I'm the facility manager at a school in Detroit the building is over 100 years old and we have a sizable stage with lighting and when I first started to work here they had only about 5 lights that work and now our school has been open for the past couple months I have been picking away at this lighting system
First we have a Leprecon 612 DMX with 6 LED lights and they work good with no problems and our stage is large and just 6 of these is not quite enough.
Second like I said before there was only 5 analog lights that worked off this older Strand Century system and after working on wiring, bulbs, plugs I now have 26 analog lights, We have 2 Strand Century Dimmy boxes with 6 channels each and I have been able to get 3 channels in each box working but for the life of me I can not find any type of schematic for these Strand Dimmy boxes, I do believe these are from the mid 80's, there are no serial numbers or model numbers on these boxes, I can post pictures here if needed but I'm looking for any type of help.
The only information I have found on this system I will attach
Any help would be grateful
help me OB1 your my only hope

Good Morning

When SCRs & Triacs fail they short circuit to full on.
If the circuit wouldn't turn on look at the control side or The chips that drive the power device ( SCR, Triac )

Analog Systems are relatively simple. Most of the components can still be found & hopefully the chips are in sockets making swapping chips easy

 

[derekleffew]

When SCRs & Triacs fail they short circuit to full on.

Always? You've never seen one fail "open"?

 

[RonHebbard]

Always? You've never seen one fail "open"?

@derekleffew & @jhochb I've seen several fail open; they may have initially shorted. The end result was definitely open and quite spectacularly so in a sparkling blaze of glory. (TRIAC's & SCR's blow to protect fuses)
Toodleoo!
Ron Hebbard

 

[microstar]

SCR dimmers have two SCR's. If one of them fails open, you would get only half brightness. I seem to remember this actually happening once or twice.
Guessing the same condition could happen with a TRIAC, but it would be an internal failure since there is only one in the circuit.

 

[JD]

I see two pulse transformers on those pictures of the board. Only one would be needed for a Triac, so it is safe to say these are back-to-back SCR dimmers. As the firing cards are plug-in, the next stage in diagnostics would be to swap a working card for one on a non-working channel. If the problem moves with the card then the issue is with the card. Since they are all discrete parts, repairs should be straight forth.

 

[microstar]

I see two pulse transformers on those pictures of the board. Only one would be needed for a Triac, so it is safe to say these are back-to-back SCR dimmers. As the firing cards are plug-in, the next stage in diagnostics would be to swap a working card for one on a non-working channel. If the problem moves with the card then the issue is with the card. Since they are all discrete parts, repairs should be straight forth.

I guess @Scott S did say he had a card that when he plugged it into a GOOD channel the lights only came on dim, so the problem is in the card and not the SCR's.

 

[Scott S]

I guess @Scott S did say he had a card that when he plugged it into a GOOD channel the lights only came on dim, so the problem is in the card and not the SCR's.

That is correct, i have 1 card that i put in a couple working channels and the lights worked but dim, that is the picture of the card

 

[Paulene Thyratrol]

First I thank you for allowing me in to your group
I'm wondering if anybody can help me with some technical problems
I'm the facility manager at a school in Detroit the building is over 100 years old and we have a sizable stage with lighting and when I first started to work here they had only about 5 lights that work and now our school has been open for the past couple months I have been picking away at this lighting system
First we have a Leprecon 612 DMX with 6 LED lights and they work good with no problems and our stage is large and just 6 of these is not quite enough.
Second like I said before there was only 5 analog lights that worked off this older Strand Century system and after working on wiring, bulbs, plugs I now have 26 analog lights, We have 2 Strand Century Dimmy boxes with 6 channels each and I have been able to get 3 channels in each box working but for the life of me I can not find any type of schematic for these Strand Dimmy boxes, I do believe these are from the mid 80's, there are no serial numbers or model numbers on these boxes, I can post pictures here if needed but I'm looking for any type of help.
The only information I have found on this system I will attach
Any help would be grateful
help me OB1 your my only hope

The firing circuit in the Dimmy is pretty much the same as the Edkotron. It is a gutless wonder that was the workhorse analog dimmer circuit that American Century Strand used right up until the CD80. Are the dimmers dead, or do they have a low output? If dead, check the incoming control signals, check to see if the dimmer module is receiving 120v line voltage via the protective device (is the circuit breaker bad?). Use your eyes and look for burnt, disconnected line, load wires. Can you swap good dimmer modules and bad ones to confirm if the problems are the dimmers or the positions? You need to do a bit of "triage" to pinpoint where the troubles actually are before you start tearing things apart and replacing parts. Please remember that these troubleshooting suggestions are from someone (me) who was in field service for 20 years. They require you to work with 120/240v line voltage. PLEASE BE EXTREMELY CAREFUL! If you aren't completely comfortable working on live equipment, Don't attempt these tests. In a building as old as yours, in an industrial city, look out for a grounded B phase!

 

[Scott S]

The firing circuit in the Dimmy is pretty much the same as the Edkotron. It is a gutless wonder that was the workhorse analog dimmer circuit that American Century Strand used right up until the CD80. Are the dimmers dead, or do they have a low output? If dead, check the incoming control signals, check to see if the dimmer module is receiving 120v line voltage via the protective device (is the circuit breaker bad?). Use your eyes and look for burnt, disconnected line, load wires. Can you swap good dimmer modules and bad ones to confirm if the problems are the dimmers or the positions? You need to do a bit of "triage" to pinpoint where the troubles actually are before you start tearing things apart and replacing parts. Please remember that these troubleshooting suggestions are from someone (me) who was in field service for 20 years. They require you to work with 120/240v line voltage. PLEASE BE EXTREMELY CAREFUL! If you aren't completely comfortable working on live equipment, Don't attempt these tests. In a building as old as yours, in an industrial city, look out for a grounded B phase!

Thanks for the info, I am comfortable working with these voltages
I started a month ago with only 3 channels total working out of 12 each box being 6 channels, at this point there has been bad wires, cut wires, dirty contacts on cards and now i have only 3 channels that don't work, I still have to check those breakers and I have 1 card that is dim when I plug it in a working channel, that's were I'm at at this point, these boxes are not easy to get to and work on them they are about 12 ft. in the air sitting on a 2 ft. ledge and only a ladder to stand on and checking wires etc.
I listening to everybody here and getting a better feel for what I need to do without a diagram, all the wires coming from the control board are all new and plugs replaced and all pinouts correct from board to dimmers etc. only 3 channels not working and I think I have done pretty good not knowing a thing about this and just using common sense, I'm learning more every time you guys post a reply or a comment and I thank all of you because there is NO information out there about any of this
the school has worked with only 3 channels with a couple light on each channel plus 6 LED's lights and now I got them 26 lights on 9 channels with 6 LED's, I have cleaned all 26 cans by taking them apart and cleaning the lens and reflectors etc. and there are at least 8 more 750 watt cans that need bulbs and cleaning and if I get these other channels working that's where those cans will go
Once again thanks to everybody for any information that you have posted because it helps.

 

[Mac Hosehead]

I see two pulse transformers on those pictures of the board.

The black cube is the pulse transformer and connects to the triac gate. One of the bigger transformers is for the power supply and connects to the line. Another one is for feedback and connects to the output. I don't remember exactly what the last one did but I think it was for control signal conditioning when using half-wave DC.

 

[STEVETERRY]

The black cube is the pulse transformer and connects to the triac gate. One of the bigger transformers is for the power supply and connects to the line. Another one is for feedback and connects to the output. I don't remember exactly what the last one did but I think it was for control signal conditioning when using half-wave DC.

100% correct--one of those transformers is actually an inductor in an L-C integrating circuit used to integrate the output of a 60Hz half-wave crossfader in the console.

Dimmy is a triac dimmer where the pulse transformer only has a primary and a single secondary feeding the gate of the triac.

ST

 

[Radio]

ok here are some pictures of our equipment and I have found my mistake
the control board I'm using for the halogen lights is a TTI Galaxy

If the Leprecon 612 is a functional board, check its outputs. If it has both Sinch-Jones and DMX outputs, it can drive both at the same time. So you can easily have a dedicated six channels of analog for your conventional dimmers and the other six for your LEDs without going through the soft-patch.