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Using Arduino => Motors, Mechanics, Power and CNC => Topic started by: LeandroAR on Sep 11, 2020, 10:18 pm

Title: SSR relays not flipping
Post by: LeandroAR on Sep 11, 2020, 10:18 pm
Hi All,

I'm currently developing a home automation demo with:
- Arduino Mega 256
- Multiplexer PCF8574
- 8-SSR board (2A max)

Wiring and coding are fine, once I'm able to make an EMR (regular relay) close and open. But I can't make the SSR close. The led on the SSR turns on, but the conductivity test on the AC screws runs at 682 (I get 0 using EMR).

I tested the SSR with and without load (127VAC), same result. I tried running the control signal from 5VDC to 17VDC, nothing.

I'm going nuts! What am I missing here??? Any assistance is mostly appreciated!
Title: Re: SSR relays not flipping
Post by: apylypenko on Sep 11, 2020, 10:22 pm
Could the SSR be burnt or faulty?
Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 11, 2020, 10:25 pm
Could the SSR be burnt or faulty?
I tested it with 11 8-SSR-bank. I bought them from the same place, but 11 faulty?
Title: Re: SSR relays not flipping
Post by: Wawa on Sep 11, 2020, 11:41 pm
Not sure what you're doing, but an SSR has a minimum holding current.
Leo..

Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 12, 2020, 12:07 am
Not sure what you're doing, but an SSR has a minimum holding current.
Leo..
Hi Wawa, does this mean it won't work like EMRs? I'm simply replacing regular relays (EMR) by SSRs.
Title: Re: SSR relays not flipping
Post by: Wawa on Sep 12, 2020, 12:11 am
European Metal Recycling?

Working voltage of a 3GMB-202P must be between 75V and 264V AC, and current between 0.1A and 2A.
See datasheet.
Leo..
Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 12, 2020, 12:19 am
European Metal Recycling?

Working voltage of a 3GMB-202P must be between 75V and 264V AC, and current between 0.1A and 2A.
See datasheet.
Leo..
Sorry, EMR is electromagnetic relay, the "click" relay. I tested the SSR with 127V and current surely between this range. It just doesn't work. When I replace it with a regular relay, it works, same conditions.
Title: Re: SSR relays not flipping
Post by: Wawa on Sep 12, 2020, 12:52 am
For proper help you need to follow the forum posting guidelines.
We need to see a diagram (not Fritzing), links, code (inside code tags), etc.
Leo..
Title: Re: SSR relays not flipping
Post by: ballscrewbob on Sep 15, 2020, 10:36 pm
@LeandroAR

Could you take a few moments to Learn How To Use The Forum (https://forum.arduino.cc/index.php?topic=148850.0).
Other general help and troubleshooting advice can be found here. (https://forum.arduino.cc/index.php?topic=52113.0)
It will help you get the best out of the forum in the future.




Title: Re: SSR relays not flipping
Post by: TomGeorge on Sep 16, 2020, 01:34 pm
Hi,
European Metal Recycling?

Working voltage of a 3GMB-202P must be between 75V and 264V AC, and current between 0.1A and 2A.
See datasheet.
Leo..
Where did this bit of info come from?  3GMB-202P ? ? ? ? ? ?
Tom... :)
Title: Re: SSR relays not flipping
Post by: Wawa on Sep 16, 2020, 10:42 pm
I don't know any other 8-relay SSR board (https://www.amazon.com/SMAKN%C2%AE-Level-trigger-8-channel-Module/dp/B00UR5Z4I6) than the ones with 2Amp Omron 3GMB-202P relay modules.
Leo..
Title: Re: SSR relays not flipping
Post by: TomGeorge on Sep 16, 2020, 11:48 pm
Hi,
What is the load you are switching?
Can you post a picture, link to the SSR module you have please?

Thanks.. Tom.. :)
Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 17, 2020, 01:46 am
Folks,

Apologies for the delay, I was trying to use Eagle to draw the diagram, without much success...

The relay bank is a 3GMB-202P, but it must be a cheap copy, not sure. Follows its image.

And here's the code, pretty straight forward. VDC, GND and pin 30 are connected correctly, believe me!

I'm switching a very low load, 0.2A.

Code: [Select]

int ssrControlPin = 30;
void setup() {                
 // initialize the digital pin as an output.
 pinMode(ssrControlPin, OUTPUT);    
 digitalWrite(ssrControlPin, LOW); // set the SSR on
}

void loop() {}



(https://forum.arduino.cc/index.php?action=dlattach;topic=704678.0;attach=382046)
Title: Re: SSR relays not flipping
Post by: TomGeorge on Sep 17, 2020, 02:02 am
Hi,
The SSR is zero-crossing switching, not sure if  200mA is enough.
Have you got a lamp to try?
What is the load, resistive, capacitive, inductive?

Tom... :)
Title: Re: SSR relays not flipping
Post by: Paul_KD7HB on Sep 17, 2020, 04:48 am
Your relays come with one of three possible input voltages. Look on the case for the input voltage of your devices. Can be 5 volts, 12 volts or 24 volts. All have the identical mfg. number, according to the data sheet.

Paul
Title: Re: SSR relays not flipping
Post by: TomGeorge on Sep 17, 2020, 05:34 am
Hi,

Code: [Select]
int ssrControlPin = 30;
void setup() {                
 // initialize the digital pin as an output.
 pinMode(ssrControlPin, OUTPUT);    
 digitalWrite(ssrControlPin, LOW); // set the SSR on
}

void loop() {}

Does setting output LOW supposed to activate the SSR?

Forget Eagle, use pen/paper and photograph your drawn circuit.

Tom... :)
Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 17, 2020, 01:35 pm
Hi,
The SSR is zero-crossing switching, not sure if  200mA is enough.
Have you got a lamp to try?
What is the load, resistive, capacitive, inductive?

Tom... :)
Tom, I'm flipping a 25W led panel lamp. I tried LOW and HIGH, but only the LOW makes the led on the SSR to light up. I have also tried 4x 25W led panel lamps (100W, almost 1A), nothing happens.

Are you saying on a 2A capable relay, I need a current larger than 10% of its capacity to flip it?
Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 17, 2020, 01:40 pm
Your relays come with one of three possible input voltages. Look on the case for the input voltage of your devices. Can be 5 volts, 12 volts or 24 volts. All have the identical mfg. number, according to the data sheet.

Paul
Paul, I tried with 5V and 17V (both with reliable external power sources capable of 5A), nothing does the trick...
Title: Re: SSR relays not flipping
Post by: CrossRoads on Sep 17, 2020, 02:04 pm
Are these the SSRs on the board?
https://omronfs.omron.com/en_US/ecb/products/pdf/en-g3mc.pdf (https://omronfs.omron.com/en_US/ecb/products/pdf/en-g3mc.pdf)
Can you read the full part number on yours?
Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 17, 2020, 02:15 pm
Are these the SSRs on the board?
https://omronfs.omron.com/en_US/ecb/products/pdf/en-g3mc.pdf (https://omronfs.omron.com/en_US/ecb/products/pdf/en-g3mc.pdf)
Can you read the full part number on yours?
It's G3MB-202P.

(https://forum.arduino.cc/index.php?action=dlattach;topic=704678.0;attach=382101)
Title: Re: SSR relays not flipping
Post by: CrossRoads on Sep 17, 2020, 02:33 pm
"I tried running the control signal from 5VDC to 17VDC, nothing."

These are 5V parts,  I wonder if you damaged something?
I see what looks like buffer circuits, or could just be LED indicator circiuts near the left side of the board.
Have you tried tracing those out to see what they do? Or does the board source have any info on those?

Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 17, 2020, 02:46 pm
"I tried running the control signal from 5VDC to 17VDC, nothing."

These are 5V parts,  I wonder if you damaged something?
I see what looks like buffer circuits, or could just be LED indicator circiuts near the left side of the board.
Have you tried tracing those out to see what they do? Or does the board source have any info on those?


I applied 17VDC to one board only. All other 10 are intact. Specs say input voltage ranges 5-24VDC, so I assume no damage is done.

I didn't trace any of the components in the circuit path. I found a diagram on it.

(https://forum.arduino.cc/index.php?action=dlattach;topic=704678.0;attach=382103)
Title: Re: SSR relays not flipping
Post by: Wawa on Sep 17, 2020, 02:58 pm
but the conductivity test on the AC screws runs at 682 (I get 0 using EMR).
What does that mean (682).
An SSR, like any other transistor, never fully conducts.

I'm flipping a 25W led panel lamp.
I tried LOW and HIGH, but only the LOW makes the led on the SSR to light up.
So the problem is on the AC side.
Time to see a real picture.
Leo..
Title: Re: SSR relays not flipping
Post by: CrossRoads on Sep 17, 2020, 03:07 pm
CH1 goes to an Arduino pin, 5V is where you connected the 5 to 17V, and Gnd is connected to Arduino Gnd?

PNP transistor, CH1 has to be Low to turn it on to allow current flow into Pin 3 (and the indicator LED) to turn the device on.
R2 will not left much base current flow, on the order of 0.5mA, so the transistor won't turn on hard, Vbe will be high, the diode D1 drops some of the 5V before the transistor.

Can you measure Pin 3 of the SSR to Gnd when CH1 is low and tell us what you see?
Measure the 5V pin also.

Transistor spec

https://www.digikey.com/product-detail/en/micro-commercial-co/MMSS8550-L-TP/MMSS8550-L-TPMSCT-ND/2827205 (https://www.digikey.com/product-detail/en/micro-commercial-co/MMSS8550-L-TP/MMSS8550-L-TPMSCT-ND/2827205)
Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 17, 2020, 04:33 pm
CH1 goes to an Arduino pin, 5V is where you connected the 5 to 17V, and Gnd is connected to Arduino Gnd?
SSR CH1 goes to Arduino pin
SSR 5V goes to 5V bus (I removed the 17V from the wiring)
SSR GND goes to GND bus

PNP transistor, CH1 has to be Low to turn it on to allow current flow into Pin 3 (and the indicator LED) to turn the device on.
R2 will not left much base current flow, on the order of 0.5mA, so the transistor won't turn on hard, Vbe will be high, the diode D1 drops some of the 5V before the transistor.

Can you measure Pin 3 of the SSR to Gnd when CH1 is low and tell us what you see?
Measure the 5V pin also.

Transistor spec

https://www.digikey.com/product-detail/en/micro-commercial-co/MMSS8550-L-TP/MMSS8550-L-TPMSCT-ND/2827205 (https://www.digikey.com/product-detail/en/micro-commercial-co/MMSS8550-L-TP/MMSS8550-L-TPMSCT-ND/2827205)
SSR pin 3 (CH1) to GND (when low) = 0 (full conductivity)
SSR pin 3 (CH1) to GND (when high) = 1 (no conductivity)
5V (on any pin) to GND (on any pin)= 4.99V measure
SSR AC side, port 1, conductivity between screw 1 and screw 2 when low, measures 657.
SSR AC side, port 1, conductivity between screw 1 and screw 2 when high, measures 1.
Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 17, 2020, 04:38 pm
I also removed the arduino from the wiring and left it like this:

SSR CH1 goes to GND bus
SSR 5V goes to 5V bus
SSR GND goes to GND bus

Even with this, the measures are the same.

(https://forum.arduino.cc/index.php?action=dlattach;topic=704678.0;attach=382111)
Title: Re: SSR relays not flipping
Post by: Wawa on Sep 17, 2020, 11:15 pm
SSR AC side, port 1, conductivity between screw 1 and screw 2 when low, measures 657.
SSR AC side, port 1, conductivity between screw 1 and screw 2 when high, measures 1.
Are you saying you 're trying to measure the AC side of an SSR with a DMM (ohm meter)?
Can't do that. It's not a contact, but some sort of transistor/diode volt-drop.
An SSR always has some remaining voltage across a "closed contact".
And it needs it's load interrupted (AC) to release.

This thread is getting weird.
What else are you trying to do, apart from switching a mains AC lightbulb.
Does a common incandescent light work? And the LED light not?
Leo..

Edit: I only see two wires connected to your relay board.
It needs a minimum of three. (5volt/GND/IN)
Title: Re: SSR relays not flipping
Post by: dougp on Sep 18, 2020, 12:35 am
Edit: I only see two wires connected to your relay board.
It needs a minimum of three. (5volt/GND/IN)
Hard to see but if you look closely there are a RED and BRN wire at the upper end.



(https://forum.arduino.cc/index.php?action=dlattach;topic=704678.0;attach=382143)

Edit: I like this new auto-image-include feature!
Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 18, 2020, 01:30 am
Are you saying you 're trying to measure the AC side of an SSR with a DMM (ohm meter)?
Can't do that. It's not a contact, but some sort of transistor/diode volt-drop.
An SSR always has some remaining voltage across a "closed contact".
And it needs it's load interrupted (AC) to release.
Hmm, yes, I was. I thought it acted like a regular relay (EMR).


This thread is getting weird.
What else are you trying to do, apart from switching a mains AC lightbulb.
Does a common incandescent light work? And the LED light not?
Leo..
Nothing but switching AC lights. I never tested it with an incandescent bulb, I don't even have one. Does this mean this SSR cannot be used to switch LED bulbs?

Edit: I only see two wires connected to your relay board.
It needs a minimum of three. (5volt/GND/IN)
There are 3 wires, red = 5VDC, brown = GND, blue = CH1 to GND
Title: Re: SSR relays not flipping
Post by: WattsThat on Sep 19, 2020, 07:04 pm
As Wawa mentioned, you will not get a zero resistance across an SSR when it is on. More importantly, you're not measuring resistance on that meter setting, you're measuring voltage drop as the "diode" test function being used does not measure resistance.

The reading of 682 on the meter diode setting would indicate the SSR is switching on, that's the voltage drop across the triac, 682 millivolts is what you'd see for a typical silicon device.

You stated you where trying to switch 25 watt led's on and off but you never stated what their rated voltage was. If they are not rated at 100-240 vac, you cannot switch them with that SSR.

Nothing is adding up here. Have you actually trying switching a proper load on and off with the SSR?

PS: I have no idea how you're making the measurement that displays the 682 as the black meter probe is nowhere to be seen. Just another mystery that may never be answered.
Title: Re: SSR relays not flipping
Post by: LeandroAR on Sep 20, 2020, 09:15 pm
As Wawa mentioned, you will not get a zero resistance across an SSR when it is on. More importantly, you're not measuring resistance on that meter setting, you're measuring voltage drop as the "diode" test function being used does not measure resistance.

The reading of 682 on the meter diode setting would indicate the SSR is switching on, that's the voltage drop across the triac, 682 millivolts is what you'd see for a typical silicon device.

You stated you where trying to switch 25 watt led's on and off but you never stated what their rated voltage was. If they are not rated at 100-240 vac, you cannot switch them with that SSR.

Nothing is adding up here. Have you actually trying switching a proper load on and off with the SSR?
Everything I'm trying to switch is 127V. I tried 127V LEDs between 5W to 100W. I had EMRs (regular relays) working in my design, then I replaced them with SSRs, but it just won't work.


PS: I have no idea how you're making the measurement that displays the 682 as the black meter probe is nowhere to be seen. Just another mystery that may never be answered.
The measure I'm making is conductivity. In the selected meter switch, if I touch the 2 poles, I get 0. If they are apart, I get 1 (infinite). 682 is somewhere between 0 an infinite.


(https://forum.arduino.cc/index.php?action=dlattach;topic=704678.0;attach=382539)

(https://forum.arduino.cc/index.php?action=dlattach;topic=704678.0;attach=382541)
Title: Re: SSR relays not flipping
Post by: WattsThat on Sep 20, 2020, 09:57 pm
I suspect as a non-native English speaker you are confusing "conductivity" with  "continuity" which are two very different things.

You are not measuring continuity and you are not measuring resistance.

You are using the "diode test" function of the meter. It is a voltage drop test. Google "DMM diode test".

There are several possibilities for why the ssr's do not work.

1. They are defective.
2. They are are incompatible with the led loads
3. They are off spec devices and don't work at lower voltages

Test them with a 50 to 100 watt incandescent lamp and you might have some answers.

Or, you could just abandon the idea and return to using electromagnetic relays.