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wospital

Relay switch 2x1,5kw - Lights not turning off.

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Hello,

 

At my home i installed a

HCL

10x dubble relay switchs

2 motion detectors

1 smoke sensor

6 wallplugs

 

I have a problem with 2 of the relay switches that are doing strange thing.

 

Some times it happens that when i put the lights on 1 of those switches that i can’t turn it of anymore.

Then if you look at the dubbel relay switch 1 side turns off and 1 side not

 

I need to push 10 times the on/off switch on the wall to turn the lights off.

Verry fustrating.

 

I already changed the dubbel relay switches to new one , no solution same problem…

 

Does anyone have an idee to solve this.

 Thx 

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  • that doesn't look like my problem... i got 10 led lights behind it from 9 watt and i can enable those lights from 2 points with push buttens

    most of the time it works perfectly and then suddenly out of nothing i can't shutdown/disable those lights anymore...

    really strange ....... i can draw i electrical schema if you like.

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    With 10 LED lights, this may very well be your problem, but it doesn't have to be. Have you checked the topic in post #7 "Switch 2x1,5kW stuck (welded) because of 20W LED driver" too? Next time it's stuck in the "on" position (meaning: you switched it off, the GUI displays "off" but the light is still on), please gently tap the module with the back of a screwdriver. If it helps, this is a "stuck" or "welded" contact.

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  • that is strange .... because if you take the sum of the led lights it is 90watt in total. and normaly the the double relay switch can power 1500 watt on both sides

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    that is strange .... because if you take the sum of the led lights it is 90watt in total. and normaly the the double relay switch can power 1500 watt on both sides

    Please read my other topic, it's explained why that happens.

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    Don't want to sound harsh so I'll summarize: 1500 W is for "resistive" loads. Like halogen, or tungsten. An LED is "capacitive" and can draw large inrush currents, that cause the contacts to stick. More info here:

    Please login or register to see this link.

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  • no prob .

    how can i solve this Capacitive load .

    do i need to place something in between.

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    Sorry for the delay, I've had a busy week. First, I'd make certain that it is indeed a "stuck relay". See my post #4. Since you've had the same issue with a different Fibaro module, this is very likely your problem, but you never know. There are different ways of solving this, depending on a number of factors.

    - Adding a second relay type "din mount" and screw terminals. This is something you can do yourself if you know how to work safely with mains voltage. The trouble is the size of the relay. It's much bigger than a module. The "in" has to connect to the "out" of the FGS and the contact of the relay connects to your light circuit. But where do you put the relay? A dropped ceiling might work...

    - Adding a second relay with PCB terminals. This relay is much smaller, about the size of a Fibaro module. But that's probably still not small enough to fit in the same space as the Fibaro Relay. You need to solder wires and you'd want to use heat shrink tubing. So this is definitely not for everyone. You need the tools and the skills.

    - Putting a passive component called an "NTC" of a certain specification in series with the load. It's a kind of resistor, disc shaped roughly 10-15 mm diameter and a few mm thick. But... this is even more difficult to use than the relay(s). You need to solder wires to this component and make sure it does not touch anything. In fact, it should have about 1 cm of air around it to function properly. If you get it right, it's the smallest possible solution. It's also very reliable. This is the solution I'm using, but I am an Electrical Engineer and I have the tools.

    - Replace the load. I can't guarantee success, but I've established 2 years ago that some no-brand LED make these relay stick, because they can cause a high inrush current. When I tested a few OSRAM and Philips bulbs, I saw a much reduced inrush current (one fifth ff the current of the "bad ones"). So I expect these to be OK. Unfortunately, there are so many brands & models and it changes all so fast that I cannot recommend a certain type. Maybe another forum member can help you with this... I say this for completeness.

    - And finally, maybe something stupid... If you don't really need a double relay... try the "single" 3 kW version. It's not guaranteed to work, but it does come with a bigger relay.

    If you tell me what's possible for you, I can help you with the details.

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  • hello already thanks for your help.

     

    i like to try the ntc ---- but how can i know the specifications that i need ( i am handy so i am trying it , i also have a special solder machine so i can solder verry small things ...  don it before with my xbox

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    /emoticons/default_icon_razz.gif" alt=":-P" /> )

    and i got some space where i put the fibaro double relay switch so no prob...

     

    what i already did is from the the 9 led lamps i toke out 3 - so 6 left with 9watt eatch ... no i got less problems with the stuck relay ... but like you set it is possible that the led lights are crap ...

    i already orderd 10 philips brand lights ...

    and i also orderd a 3kw fibaro switch to test this out...

     

    and i am going to update this post.

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    You can buy a suitable NTC thermistor (B57237S0220) here:

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    This thermistor can withstand a continuous power of 600 Watt, something you won't get with LED. But I select this high value to avoid destruction of the device if you forget it is in the wall and overload it. this might happen, for example, when you change the bulbs to halogen. To be really safe, and do things by the book, you must add a glass fuse of 2 AT in series. From the same supplier I'd recommend:

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    And:

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    To make sure the NTC does not touch anything, I have tried different methods. First, I was lucky to have floodlights, with enough space near the terminals. The leads of the NTC are stiff enough to keep it in place. For a second project, I took a 2 cm piece of PVC tubing 2 cm diameter, and glued the thermistor in it (with holt melt glue, which may seem like an odd choice but it works).

    For testing: I've build this device (post #19):

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  • hello

     

    the solution with the NTC need to be in serial with the Led lamps ? to reduce the power on curend flow

     

    a college fond this

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    this is the same only expensive to ship.

     

    to day i am going to an electronica shop here in Belgium to get the NTC

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    hello

     

    the solution with the NTC need to be in serial with the Led lamps ? to reduce the power on curend flow

     

    a college fond this

    Please login or register to see this link.

    this is the same only expensive to ship.

     

    to day i am going to an electronica shop here in Belgium to get the NTC

     

     

    Please share your expirience and what kind of NTC are you using? One more question is, what we can use where the use of the relay controlling those LED lights is more often/frequent? Can you use another small PCB relay on 220VAC instead?

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  • this week will i receive the NTC and the Osram led lights and the 3KW fibaro relay switch

    i am goin to test it over here and will give me conclusions wat wil work for the best .....

     

    i already think baying new Led lamp from philips of Osram of a brand kwality wil help a lot ....

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    What I do not understand at all is that happens sometimes an not permanently. That makes no sense to me. If the load is too much then always and not sometimes.

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  • at my home it's the same... sometime it happens and most of the time it works.

     

    but i know that it depends on the product led you use ... i almost know it for sure. 99%

    i can't wait to change the 12 led lamps that i have with the Osram leds

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    Well ... I doubt it a little. Sorry for that.

    I use the same LEDs in restroom (3), living room (6), dining room (4), canopy (6), bathroom (4), shower (2), study (8)

    I have probs in restroom, canopy, study, living room. Never in the rest.

    So I can not even say it is the number of LEDs.

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  • what brand do you have from the led lights.

    it also posible that in those groups of led there is 1 led that has some bad electronica in it...

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    For the technical minded: explanation of the "welding" and an attempt to explain why certain loads cause this, sometimes...

    Mains voltage is AC. It has an amplitude that changes from 0 to 324 Volt in 5 milliseconds. It's a sine wave, so it does that again with a minus sign (- 324 Volt) after another 10 milliseconds. The cycle repeats 50 timers per second. When you switch on the light at 0, the capacitors in the LED charge with the rising voltage. That is "slow" compared with switching on at the peak. We say that ramping up has a low change of voltage per time, often represented by "dv/dt". A capacitor is essentially a dead short until it has charged. Switching on from 0 to 324 Volt in 0 seconds mathematically gives an infinute "dv/dt". So switching on the light at the peak gives a current that is only limited by the circuit resistance... That is: the copper wire in your house and to the distribution transformer, plus contact resistances everywhere, plus the resistance of the components in the lamp. If everything is very low, then you probably get around 1/2 Ohm so Ohm's law says the peak current is 324/0,5 = about 600 Ampere. It would really surprise me if you could get such a low resistance, in my house a dead short generates "only" 300 Ampere (I've measured the resistance. I have not shorted the supply...). A more realistic resistance would be "a few ohms" so let's take a nice figure of 3 Ohms. That is still 100 A. As a rule of thumb, relays get a difficult time when you get above 10 x rated current = 80 A (for a double relay). These numbers are all indicative. There is at least +/- 20 % of uncertainty in all of that. And measuring this current is difficult. It can't be done with a multimeter.

    In a typical LED there are 2 capacitor types (so to spike), that contribute to the effect. The first capacitor, the main capacitor, holds the DC charge to make the supply work. The second capacitor is an EMI suppressor. Switching mode power supplies generate radio frequency noise. Anyone still listens to AM or shortwave radio? Then you'll know what I mean. To avoid turning the wires into antennas some circuitry is across the terminals of the lamp. Both types contribute to the inrush current effect. The amount of Watt and the design dictate the effect of the main capacitor. The number of lamps determines the current drawn by the EMI filter. To give an example: I have ONE type of LED, a 20 Watt floodlight, that would weld my relay contacts once every fourteen days. It doesn't do that because I have an NTC in series. The current drawn by the primary capacitor and the EMI filter is just to big. I don't have this situation, but I think the relays will have a difficult time if you have between 10 and 20 bulbs, even if the wattage is very low, because you get the sum of 10 - 20 EMI filters. BTW to get in the "safe zone" of the relay, I would limit the inrush current to the relay to 5 times its rated current (around 40 A for a double relay). So what you need is "a few ohms" in series with your load. I repeat: resistance IN SERIES, not in parallel! You want to INCREASE the total resistance, and lower the current.

    This explains to me the randomness of the "welding". It depends on: How close you are switching on to the peak of the sine wave, the circuit resistance, the sum of the capacitive load(s). Not all LED lamps are equal, so you can't say "but it is only 20 Watt"!

    Side note: if you have worked with dimmers or solid state relays, you may have noticed that they mention "zero-crossover switching" and "leading/trailing edge switching". This is related to the subject of unrush current. ZCS aims to switch on when the sine wave is near zero. With a capacitive load, this will be the most "gentle" way to do it. The FGD-212 auto calibration detects this and chooses the parameters to ramp up the voltage. But even this technology has its limits. I can't find the topic at the moment, but someone noted that with plus-minus 10 LEDs the FGD-212 would sometimes detect over-current at switch-on, and protect itself. These lamps were probably of a "high inrush current" type, but that is speculation! Because a double relay can't detect this situation, I bet this particular load is a fair candidate to make it stick... I'm not sure what to prefer... a stuck relay or a dimmer that doesn't turn on...

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    What I do not understand at all is that happens sometimes an not permanently. That makes no sense to me. If the load is too much then always and not sometimes.

    The load depends on the "instantaneous" voltage. It's not about the load, and not about the 230 V. It is the exact voltage at the moment of switch-on. So right now it is maybe minus 50 Volt. Next time it is + 100 V. And statistically, a few % of all switch attempts, the voltage is above 300. Depending on the nature of the load, that causes a different current. For full explanation, see previous post.

     

    at my home it's the same... sometime it happens and most of the time it works.

     

    but i know that it depends on the product led you use ... i almost know it for sure. 99%

    i can't wait to change the 12 led lamps that i have with the Osram leds

    Yes, different designs have different inrush current. It's not on the box, it's not in the datasheet. Power supply manufacturers, like "Mean well", do publish this data! I have a 30 Watt supply and it says: "Inrush current: 60 A".

     

    Well ... I doubt it a little. Sorry for that.

    I use the same LEDs in restroom (3), living room (6), dining room (4), canopy (6), bathroom (4), shower (2), study (8)

    I have probs in restroom, canopy, study, living room. Never in the rest.

    So I can not even say it is the number of LEDs.

    If you add up the effect of randomness (due to the random switch on), you still have "better" or "worse" performance that is unexplained?

    Statistically, the more you switch a light circuit, the more you get the impression it causes trouble. But I think if you count success/failure you still get the same result for the same bulbs on the same circuit (e.g. 100 to 1).

    If you find the time to read my previous post, would it be possible to give me your thoughts on why your circuits behave differently?

     

    what brand do you have from the led lights.

    it also posible that in those groups of led there is 1 led that has some bad electronica in it...

    I've got a crate full of bulbs. Some people collect stamps, I collect... Never mind

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    /emoticons/default_icon_smile.gif" alt=":-)" />

    I have a crate full of bulbs and I cannot recommend any of them because they are no longer manufactured. It changes so fast. And I am only an end-user, I can only buy 1, not 10 of the same type, just to see if the relays stick. Hint to all resellers: please give us some data.

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    /emoticons/default_icon_wink.gif" alt=";-)" />

    If you mean "bad electronica" then you mean cheap design? Skimped on components? Possible... If you mean: "defective" then I doubt that. I'm thinking of a self healing input capacitor, that could cause a temporary short. I have to look into this, it's a good question.

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