SSR relays not flipping

@LeandroAR

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Hi,

Wawa: 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... :)

I don't know any other 8-relay SSR board than the ones with 2Amp Omron 3GMB-202P relay modules. Leo..

Hi, What is the load you are switching? Can you post a picture, link to the SSR module you have please?

Thanks.. Tom.. :)

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.

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

void loop() {}

relay.jpg

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... :)

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

Hi,

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... :)

TomGeorge: 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?

Paul_KD7HB: 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...

Are these the SSRs on the board? https://omronfs.omron.com/en_US/ecb/products/pdf/en-g3mc.pdf Can you read the full part number on yours?

CrossRoads:
Are these the SSRs on the board?
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.

"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?

CrossRoads:
“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.

132d6f651153424ab49d8455913d0207.png

LeandroAR: 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.

LeandroAR: 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..

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

CrossRoads: 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

CrossRoads: 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

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.

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.

LeandroAR: 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)

Wawa:
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.

Edit: I like this new auto-image-include feature!