Help identify a Zener?

[alwalker]

alwalker you mentioned installing the 990LM surge protection modules in Reply#58 So you are still getting obstacle sensors zapped by lightning?
Apparently the 990LM surge protector was replaced by Chamberlain CLSS1. Not sure what if any changes were made, looks the same.

I would stand by the one weakness I saw with the obstacle sensors' mounting bolt. As a ground to the garage door and rails, it can arc to the PC board/IR LED from the center hole. Very little spacings on the bad PCB design, your pic in Reply 54 shows the bolt passing through really close to the IR LED leads and that silly pour on the board. I'd expect an arc would zap there.
So I would try mount the sensors with a plastic bolt, or on wood- something to electrically isolate them from the door metal rails.

That IR LED looks good, hope it aligns with the lens right.
With the module housing, I use a laser pointer to sorta align the sensors, instead of eyeballing it. They are not that finicky.

The lightning damage did still happen with the 990LM surge protector in place. I do intend to try isolating with a nylon bolt and wingnut. I just have to wait for it and the IR led to be released from US Customs. I think they must be holding my package hostage--they've had it since July 29. Good idea with the laser pointer. I have my cat's laser toy that I'll have to try that with.

[redwire]

alwalker you mentioned installing the 990LM surge protection modules in Reply#58 So you are still getting obstacle sensors zapped by lightning?
Apparently the 990LM surge protector was replaced by Chamberlain CLSS1. Not sure what if any changes were made, looks the same.

I would stand by the one weakness I saw with the obstacle sensors' mounting bolt. As a ground to the garage door and rails, it can arc to the PC board/IR LED from the center hole. Very little spacings on the bad PCB design, your pic in Reply 54 shows the bolt passing through really close to the IR LED leads and that silly pour on the board. I'd expect an arc would zap there.
So I would try mount the sensors with a plastic bolt, or on wood- something to electrically isolate them from the door metal rails.

That IR LED looks good, hope it aligns with the lens right.
With the module housing, I use a laser pointer to sorta align the sensors, instead of eyeballing it. They are not that finicky.

[alwalker]

From what I can tell the Rx is 950nm and you'd lose 20% sensitivity at 900 or 1,000nm. So 940nm will work OK.
But, there are wide angle (IR remote control) and narrow angle (light curtain or obstacle sensor) IR LED's.
I think it's originally a narrow angle one, you can see the LED die/cup is at about the middle or further back. It might even be special if the end is fat?
The eBay ad one is closer to the end (die cup) so I think it's a wider angle IR LED, like for IR remote controls.

With the big lens it makes a narrow beam. As long as the fit and alignment (white holder post #9) are kept the same, give it a try.


For the lightning zaps, I think all you could do is move the obstacle senors off of the metal rail, put them on some wood so it cannot arc to them. Or change to a plastic mounting bolt.

I ordered some TSAL6200 diodes from AliExpress. If the diode is true to the specs it should do ok. I also have some nylon bolts coming to see if isolating the mounting will stop my lightning damage issue. It may take a year or two before I know if that resolved the issue. I'll try to remember to post an update on how that works out.

[redwire]

From what I can tell the Rx is 950nm and you'd lose 20% sensitivity at 900 or 1,000nm. So 940nm will work OK.
But, there are wide angle (IR remote control) and narrow angle (light curtain or obstacle sensor) IR LED's.
I think it's originally a narrow angle one, you can see the LED die/cup is at about the middle or further back. It might even be special if the end is fat?
The eBay ad one is closer to the end (die cup) so I think it's a wider angle IR LED, like for IR remote controls.

With the big lens it makes a narrow beam. As long as the fit and alignment (white holder post #9) are kept the same, give it a try.


For the lightning zaps, I think all you could do is move the obstacle senors off of the metal rail, put them on some wood so it cannot arc to them. Or change to a plastic mounting bolt.

[alwalker]

Made it all the way through 2024 without a lightning strike taking out the 14LG479-2C emitter board. Not so lucky this year though. I have another emitter board fried with the almost daily thunderstorms we've been getting this summer in NC. What would be a good replacement for D103--it is dead shorted. The 5mm 940nm led's I see on Ebay perhaps?

https://www.ebay.com/itm/37637395887...3ABFBM1Lfw6YVm

[alwalker]

Re: Help identify a Zener?

I think Liftmaster/Chamberlain made a design mistake so the sensors are susceptible to lightning damage. The sensor mounting bolt arcs to the PC board and kills them. I think this is because the mounting bolt/bracket is grounded to the garage door rails yet the opener electronics is grounded to mains ground.
It seems suspect the sensor PC board has traces around the mounting bolt- when you actually want lots of clearance instead.

This might be why the 990LM did not work- lightning zap happens at the sensor mounting bolt and the lightning protection module is a mile away, it's over at the opener. I wonder if adding a thick ground wire to the door rails would help, but to what? The pad? or Mains ground? It's hard to know if the rails/door are the antenna for the discharge, or the lighting surge comes in on mains.

I would think the mains ground. I wish I had an easy way to install an extra ground rod near the basement opener. That one is furthest from the electric entrance panel. BTW--I did check the condition of the ground rod and wiring at the meter. No problem there. I do suspect since the opener I have had the most lightning problems with is the furthest from my electric panel and that ground rod another ground rod directly attached to the rails might do the trick. I wish I could do it easily in the basement without tearing up the concrete floor to add a ground rod. It's doubtful the wife would approve

[redwire]

Re: Help identify a Zener?

For the Liftmaster 990LM possible bill-of-materials:

where				Qty		Description				mfgr		p/n		Mouser		Digi-Key
								
								
Sensors				2		TVS DIODE 1,500W 33.3VWM 69.7VC DO-201	ST		1.5KE39A	511-1.5KE39A	497-6607-1-ND
								
								
Neutral-GND			1							Original	GNR14D431K				
						MOV 275VAC 6kA Disc 14mm 		Bourns		MOV-14D431K	652-MOV-14D431K		118-MOV-14D431K-ND
						MOV 275VAC 6kA Disc 14mm 		TDK Epcos	B72214S0271K101	871-B72214S271K101	495-1412-ND								

Line-Neutral and Line-GND	2				need thermal fuse	Original	GNR20D431K				
						MOV 275VAC 10kA Disc 20mm Thermally Protected	Littelfuse	TMOV20RP275E		576-TMOV20RP275E		F4042-ND
						MOV 275VAC 10kA Disc 20mm Thermally Protected	Eaton		MOVTP20V275N		504-MOVTP20V275N 		283-MOVTP20V275N-ND
													
								
Sensors ground			1		Original	GNR14D201K				
						MOV 130VAC 6kA Disc 14mm		TDK Epcos	B72214S2131K101		871-B72214S2131K101 		495-1436-ND
						MOV 130VAC 4.5kA Disc 14mm		Bourns		MOV-14D201K		652-MOV-14D201K 		MOV-14D201K-ND
						MOV 130VAC 6kA Disc 14mm		Panasonic	ERZ-V14D201		no stock			P7217-ND

[redwire]

Re: Help identify a Zener?

I think Liftmaster/Chamberlain made a design mistake so the sensors are susceptible to lightning damage. The sensor mounting bolt arcs to the PC board and kills them. I think this is because the mounting bolt/bracket is grounded to the garage door rails yet the opener electronics is grounded to mains ground.
It seems suspect the sensor PC board has traces around the mounting bolt- when you actually want lots of clearance instead.

This might be why the 990LM did not work- lightning zap happens at the sensor mounting bolt and the lightning protection module is a mile away, it's over at the opener. I wonder if adding a thick ground wire to the door rails would help, but to what? The pad? or Mains ground? It's hard to know if the rails/door are the antenna for the discharge, or the lighting surge comes in on mains.

[sam_sam_sam]

Re: Help identify a Zener?

Not sure where the part number is not working? The 990LM schematic is just a picture. I could post a bill-of-materials if you are making one.

If I lived in Florida or Texas I would definitely have lightning protector on the garage door opener.

Could you please do that for me because I want to add this to my garage door openers because I have had lightning strike one of the opener more than once

One time it fried the door sensors another time the same thing and the controller board as well and the door switch controller as well I also think it damaged the motor as well in some way because it would run very warm also the up/down force adjustment we're screwed up as well

That time I just replaced the garage door opener because the replacement parts were almost as much as a new one

[sam_sam_sam]

Re: Help identify a Zener?

I have two Liftmaster garage door openers and they both now have the 990LM surge protectors wired into them. I was a little curious about the protection going to the safety sensor and opener switch so just to see the answer I would get I sent an email to Chamberlain/Liftmaster asking (1) why the 990LM was discontinued, (2) if they had a schematic of the 990LM itself available and (3) if it protected the logic board or if it actually protects the safety sensors. Here is the response I got:

Thank you for contacting Chamberlain Group Technical Support. We sincerely apologize for the delay in our reply. Please see below for a response to the inquiry you recently submitted on our website.

Hello, I will be happy to assist you. Unfortunately, we no longer have schematics for the 990LM surge protector. Details as far as why it was discontinued have not been given. The wiring to the safety sensors and to the motor was protected while using the surge protector.

After dismantling the 990LM we now have a very nice schematic courtesy of Redwire. I don't believe that Chamberlain does not have a schematic of the unit even though that is what I was told. I also do not believe that the 990LM protects the sensors--at all. Hopefully it will protect the logic board if a strike comes through the rails and wiring. I already knew that the surge protector does not protect the sensors since I experienced lightning damage to the sensor when the 990LM had already been installed. Sometimes it's just fun to ask questions of manufacturers when you already know the answers will be either irrelevant or incorrect.

This is unacceptable and unfortunate that this company has this attitude about there product and surge protector device which must have been discontinued because then that way they can make more money on replacement parts or the hole unit

[alwalker]

Re: Help identify a Zener?

I have two Liftmaster garage door openers and they both now have the 990LM surge protectors wired into them. I was a little curious about the protection going to the safety sensor and opener switch so just to see the answer I would get I sent an email to Chamberlain/Liftmaster asking (1) why the 990LM was discontinued, (2) if they had a schematic of the 990LM itself available and (3) if it protected the logic board or if it actually protects the safety sensors. Here is the response I got:

Thank you for contacting Chamberlain Group Technical Support. We sincerely apologize for the delay in our reply. Please see below for a response to the inquiry you recently submitted on our website.

Hello, I will be happy to assist you. Unfortunately, we no longer have schematics for the 990LM surge protector. Details as far as why it was discontinued have not been given. The wiring to the safety sensors and to the motor was protected while using the surge protector.

After dismantling the 990LM we now have a very nice schematic courtesy of Redwire. I don't believe that Chamberlain does not have a schematic of the unit even though that is what I was told. I also do not believe that the 990LM protects the sensors--at all. Hopefully it will protect the logic board if a strike comes through the rails and wiring. I already knew that the surge protector does not protect the sensors since I experienced lightning damage to the sensor when the 990LM had already been installed. Sometimes it's just fun to ask questions of manufacturers when you already know the answers will be either irrelevant or incorrect.

[sam_sam_sam]

Re: Help identify a Zener?

If I lived in Florida or Texas I would definitely have lightning protector on the garage door opener.

This is the reason I have been closely watching this post after you mentioned about how to maybe survive an indirect lightning strike directly getting hit with a lightning strike nothing is going to help this

[redwire]

Re: Help identify a Zener?

Not sure where the part number is not working? The 990LM schematic is just a picture. I could post a bill-of-materials if you are making one.

If I lived in Florida or Texas I would definitely have lightning protector on the garage door opener.

[sam_sam_sam]

Re: Help identify a Zener?

1.5KE39A.

The part number for the bottom circuit diagram is this

1.5KE39A when try to copy and paste the part number it drops the 1. and only show the 5KE39A
Just posting this in case someone tries to copy and paste the part number to find the date sheet

[redwire]

Re: Help identify a Zener?

I've never seen any, I think because it has a safety function i.e. the door sensors will stop a door opener if they go dead as well as when there's an object present so they'd have to transmit a blip quite often. Using a light beam takes a lot of power too. Big battery probably.

[alwalker]

Re: Help identify a Zener?

I wonder if anyone makes a residential opener that uses wireless safety sensors and wireless door opener switch. That would pretty much eliminate almost all of my lightning strike issues. I wouldn't mind changing a battery or two once a year--people do that already with smoke detectors in their house.

[redwire]

Re: Help identify a Zener?

I see the mounting bolt, which is electrically connected to the mounting bracket and door rail and concrete floor, goes through the center and ends up close to the PC board. I did see one that arced through the seam in the housing to the bracket.
Strange the PC board traces around the hole go to internals. On the 14LG372 model it's to the IR transmitter LED so that gets zapped. As if Liftmaster knows something how to cause failure lol...

[alwalker]

Re: Help identify a Zener?

If you are running one of the 990LM and lightning still took out the sensor, then I would also suspect the electrical panel ground for the home. If can be an old ground rod or plate that might be not working due to corrosion or bad wiring. Or the ground is too dry etc. Just something to inspect I guess.

What I have seen happen is between the garage door opener and the door rails you get high voltage, it's high frequency too and an arc or zap happens between them. I think the sensor/wall switch wiring acts like an antenna or something and picks up the lightning. The potential difference is between the mains ground (outlet) and the door rails I think.

New openers are terrible as I've said, tiny DC brushed motor and gears, have to authenticate with the server at head office and be on your WiFi network all the time. The belt drive is bigger than a rubber band but not by much. Chamberlain has cheapened their openers and hardware dramatically to the point you toss them out in the garbage every few years. So keeping old ones running is actually saving a lot of money.

I believe it has to do with the rails and sensor wiring. Almost every time I have had damage to the sensors you can see a scorched area on the pc board that leads back to the screw which mounts the sensor board and sensor to the rail. You can see it in the picture I uploaded. I will check the electric panel ground but I don't think I'll find a problem there.

[redwire]

Re: Help identify a Zener?

If you are running one of the 990LM and lightning still took out the sensor, then I would also suspect the electrical panel ground for the home. If can be an old ground rod or plate that might be not working due to corrosion or bad wiring. Or the ground is too dry etc. Just something to inspect I guess.

What I have seen happen is between the garage door opener and the door rails you get high voltage, it's high frequency too and an arc or zap happens between them. I think the sensor/wall switch wiring acts like an antenna or something and picks up the lightning. The potential difference is between the mains ground (outlet) and the door rails I think.

New openers are terrible as I've said, tiny DC brushed motor and gears, have to authenticate with the server at head office and be on your WiFi network all the time. The belt drive is bigger than a rubber band but not by much. Chamberlain has cheapened their openers and hardware dramatically to the point you toss them out in the garbage every few years. So keeping old ones running is actually saving a lot of money.

[alwalker]

Re: Help identify a Zener?

I posted a reply today but it seems to have vanished so typing it in again from memory.

Thanks for the teardown pictures of Liftmaster 990LM.
I drew a schematic for the Liftmaster 990LM and think it's a decent design and would use it if I lived in an area with lots of lightning.
The non-flammable insulating tape around the MOV's helps their heat get to the thermal fuse and pop it if the MOV's heat up. This was the way in power strips too for many years. It might be the liability that made Liftmaster discontinue these? Or they just want to sell you a new opener.

I did not know you already have one of these modules with the green LED out. Not sure if the TCO fuse popped or the LED died. Take it apart, do an autopsy I guess. If the fuse went, it should not have any power to the opener.

Thanks for the drawing. I scrawled pretty much the same thing out for myself already but yours looks much better. I didn't want to post the one I did because it looked amateurish. Perhaps I phrased it in a misleading way but I did not have a 990LM with green light go out. The one I have still indicated it was protecting the AC line. I was just referring to the fact that the emitter sensor board had obviously been damaged by lightning and after looking at the lightning suppressor circuit it appeared to me that the mov m4 could have been damaged in that strike and it would not have affected whether or not the green led on the module was still lit up or not. I did take it apart and verified that all of the mov's still appeared to be undamaged. Thanks for the drawing. I wasn't sure about the diodes off of M4 and it makes perfect sense that they would be zener diodes.