Lee Colortran ENR 96 rack issue

[Geoffrey L Bryan]

We have a Colortran ENR 96 dimmer rack at my church in the Los Angeles area (came from an attraction at Universal Studios) and we are having this problem: The control cards keep thinking there is no air flow, even though the fan is running just fine at full tilt and there is obvious air intake through the vent ports on the dimmer modules. The symptom is that periodically the lights will all flicker down to zero, then a few seconds later flicker back up to full brightness. The airflow lights on the control cards light up when this happens. There is no obstruction of the cabinet and the ambient temperature is not excessive where the cabinet is installed.

I am assuming there is some kind of vane or sensor inside the cabinet that measures air flow, and that it has dust buildup or something. Or maybe it is failing and needs replacement. Where would I look for that sensor? I am hoping not to have to pull all the dimmer and filler modules out to go hunting for this.

There doesn't seem to be any mechanism on the control cards themselves for measuring air flow, which is why I'm assuming there is something elsewhere in the cabinet.

All help gratefully accepted.

Geoff Bryan

 

[BillConnerFASTC]

You have it exactly correct - vane in airstream and dust/dirt collects on it and it sags. Needs to be pushed up by airflow. I think near top of rack but not sure.

 

[Mac Hosehead]

I am not aware of a vane in an ENR rack. There is an air-flow sensor in the control modules directly behind some small grill openings to allow for air to pass. The sensor is round and similar to what is used in a ETC Sensor Classic processor. The sensors can collect dust and not read the temperature correctly but can also be defective and need to be replaced.

In addition to the air-flow sensors, there is another sensing mechanism that can cause the symptoms that have been observed. There is a speed sensor in the main fan at the top. If the speed of the fan drops below a certain point then it will cause an air-flow situation that will shut down the rack or make lights flicker. If this fan ever needs to be replaced then it will need to be one that has this sensor built-in.

 

[Geoffrey L Bryan]

There is an air-flow sensor in the control modules directly behind some small grill openings to allow for air to pass. The sensor is round and similar to what is used in a ETC Sensor Classic processor. The sensors can collect dust and not read the temperature correctly but can also be defective and need to be replaced.

I saw small grill openings on the left side of the two controller cards, but at first glance wasn't sure there was any kind of sensor in there. Obviously I'll have to take another look!

I'm hoping we don't have to replace the fan up top because that looks like a pricey item.

Thanks to both you and @BillConnerFASTC for your responses. I'm more of an audio guy so the lighting controls are somewhat foreign territory for me.

GLB

 

[BillConnerFASTC]

I may be thinking D192, not ENR. Sorry.

 

[RonHebbard]

I saw small grill openings on the left side of the two controller cards, but at first glance wasn't sure there was any kind of sensor in there. Obviously I'll have to take another look!

I'm hoping we don't have to replace the fan up top because that looks like a pricey item.

Thanks to both you and @BillConnerFASTC for your responses. I'm more of an audio guy so the lighting controls are somewhat foreign territory for me.

GLB

@Geoffrey L Bryan @BillConnerFASTC @Mac Hosehead All of my time maintaining ENR's was with an adjoining bussed pair of 12 module / 24 dimmer racks installed in a newly constructed producing theatre for house and work lights in 1990.
I'll speak to three points.
1; The racks were initially installed with aluminum main busses which were upgraded to copper by Colortran within the system's first year of operation.
2; I too have never seen a vane style airflow sensor in an ENR rack.
3; The sensors I became familiar with were located behind two or three small ventilation slots in the front lower left corner of each rack. I always found the way the sensors worked interesting in that they employed a small heating coil to raise the temperature of an electronic sensor above a trip point and depended upon air-flow through the two or three small vents to keep the temperature sensor from reaching its trip point. Part of the theory was if you left any dimmers or blank modules out of the rack, air would enter via the larger opening and less air would flow past the sensor thus it would know if you tried to run the rack with any modules not fully inserted.
BOTTOM LINE: (On this point) Keep the two or three small ventilation slots in the lower left front corners of the racks open and free of dust. If the air-flow is tripping, stand a large fan directly in front of the two or three small ventilation slots and your system will likely work fine for days on end. [Ours did.]
When Colortran paid for a team of electrical contractors to tour North America replacing aluminum main busses with copper, in our case they also added the oft' mentioned Hall Effect sensors to the four fans, in the tops of our bussed twin racks.
From memory, Colortran footed the invoices for 17 service calls to our racks by their Eastern Canada servicing and commissioning contractor plus an overnight visit by a fellow from California who finally got to the root of our installation's main problem but that's a whole other matter involving the two control trays leaving the factory with different generations of software loaded on their two PROM's, E-PROM's or whatever their correct acronym is.
Once the magical Hall Effect sensors had been added, and we were still having over-temperature problems, I asked a visiting service tech' how long it took for the Hall Effect sensors to activate. The short answer was he didn't honestly know and had been told a variety of answers ranging from near instantaneously to minutes. I found Chris Mentis' test interesting, honest and informative. Chris stopped the fans, inserted a nutdriver or screwdriver into each of the four fans then we re-powered the racks and enjoyed a refreshing can of juice while we watched and waited for the Hall Effect sensors to complain about the four stalled fans. So far as either of us could tell, the Hall Effect sensors neither noticed nor minded that the fans were stalled. So long as we kept air flowing past the sensors in the front lower left corners the racks kept on working.
The team of crack specialists that Colortran sent across North America replacing aluminum busses with copper and adding Hall Effect sensors pinched a small gauge (approximately #22 copper) conductor behind one of the newly installed copper main busses resulting in the insulation melting off the light gauge wire and a small, smelly, fire which apparently burnt itself out with little damage other than a few scorch marks. At least the fans stopped when the wire fused thus I guess this was "feature".
I could go on and ON and ON about my love and lack of for Colortran's ENR racks. Electronic Noise Reduction.
No! Don't do it! Please don't wind me up, it's not good for my blood pressure.
EDIT: Inserted an inadvertently omitted word.
Toodleoo!
Ron Hebbard

 

[John Palmer]

Hi Geoff,
The sensor in the control module is a "SAF1005 100fpm".
It is soldered to the underside of the PCB in three spots with a resistor connected to one.
I HIGHLY recommend powering down dimmer racks before doing any service.
You could try using a vacuum to clean out any dust and dirt. If you remove the module after powering the rack down, you could try canned air as well. You DO NOT want to blow air into a powered dimmer rack.
If you want to get your rack serviced, I would recommend a call to Kinetic Lighting in Glendale.
If you need documentation, I have a wealth of information on the ENRs. You are welcome to come visit me in Cerritos and copy any of it that you might find useful.
Take care,
John

 

[Geoffrey L Bryan]

Just wanted to post an update on this issue.

Mark Knight (who invited inquiries about Colortran issues in an earlier post above) spent a fair amount of time with me on the phone to discuss what we were experiencing. He agreed that it was probably the SAF1005 air flow sensors as noted above by @John Palmer and @RonHebbard. He proposed a simple test: Block the ventilation grill on the front left of each control module, and see how long it takes for the yellow "air flow" warning light to come on. He stated that on a properly functioning unit, it should take 6 or 7 seconds. If it's more like 1 or 2 seconds, the sensor is failing.

Well, I tried the test last night and I could not even get to "one thousand and one" counting the time period. The yellow light would come on almost immediately on each control card. In fact, I would say that both cards were hovering on the edge of air flow shutdown -- the slightest interruption would trigger them.

So, we have ordered replacement sensors and hope to have the system working normally again soon.

Thanks again to everyone who responded.

Geoff

 

[Geoffrey L Bryan]

We ordered the new SAF1005 sensors on Tuesday from Knight Sound & Lighting, and they arrived today (Thursday). I installed them in the control cards, and the airflow shutdown issue is now completely a non-issue. Whereas before the system would shut down almost immediatly with any blockage of the control card vent grille, now is takes about 10 seconds for the airflow shutdown to occur.

Regrettably, a new issue has surfaced: The "Rack No." thumbwheel on one of the units is showing its age, and it has to be carefully positioned to avoid light flickering from bad switch contact continuity. Sheesh. I don't know whether it's worth replacing the thumbwheels, or whether it would be feasible to simply hardwire jumper wires to permanently select "0" (zero) since we will never need the capability to change this setting. Anyone ever deal with this issue?

GLB

 

[FMEng]

The switch might be resurrected by flooding it with DeoxIT D5 and exercising it. Follow the cleaning with DeoxIT G5 protectant.

Jumpering the appropriate contacts on the solder pads should work fine, too. You'd have to ohm out the switch while its working, or look up the specs if it marked well enough to identify it. My guess is that zero closes four contacts to the common, assuming it's a 0-9 selector.