# SSR relays not flipping **URL:** \ **Category:** Motors, Mechanics, Power and CNC\ **Created:** [September 11, 2020, 8:18pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169 "2020-09-11T20:18:25Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![LeandroAR](https://avatars.discourse-cdn.com/v4/letter/l/f07891/32.png) [@LeandroAR](https://forum.arduino.cc/u/LeandroAR)\ **Post date:** [September 11, 2020, 8:18pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/1 "2020-09-11T20:18:25Z")
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! ---
**Author:** ![anon91032956](https://avatars.discourse-cdn.com/v4/letter/a/9fc29f/32.png) [@anon91032956](https://forum.arduino.cc/u/anon91032956)\ **Post date:** [September 11, 2020, 8:22pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/2 "2020-09-11T20:22:51Z")
Could the SSR be burnt or faulty? ---
**Author:** ![LeandroAR](https://avatars.discourse-cdn.com/v4/letter/l/f07891/32.png) [@LeandroAR](https://forum.arduino.cc/u/LeandroAR)\ **Post date:** [September 11, 2020, 8:25pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/3 "2020-09-11T20:25:03Z")
> apylypenko: > 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? ---
**Author:** ![Wawa](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wawa/32/1211303_2.png) [@Wawa](https://forum.arduino.cc/u/Wawa)\ **Post date:** [September 11, 2020, 9:41pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/4 "2020-09-11T21:41:23Z")
Not sure what you're doing, but an SSR has a minimum holding current. Leo.. ---
**Author:** ![LeandroAR](https://avatars.discourse-cdn.com/v4/letter/l/f07891/32.png) [@LeandroAR](https://forum.arduino.cc/u/LeandroAR)\ **Post date:** [September 11, 2020, 10:07pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/5 "2020-09-11T22:07:30Z")
> Wawa: > 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. ---
**Author:** ![Wawa](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wawa/32/1211303_2.png) [@Wawa](https://forum.arduino.cc/u/Wawa)\ **Post date:** [September 11, 2020, 10:11pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/6 "2020-09-11T22:11:20Z")
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.. ---
**Author:** ![LeandroAR](https://avatars.discourse-cdn.com/v4/letter/l/f07891/32.png) [@LeandroAR](https://forum.arduino.cc/u/LeandroAR)\ **Post date:** [September 11, 2020, 10:19pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/7 "2020-09-11T22:19:56Z")
> 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.. 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. ---
**Author:** ![Wawa](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wawa/32/1211303_2.png) [@Wawa](https://forum.arduino.cc/u/Wawa)\ **Post date:** [September 11, 2020, 10:52pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/8 "2020-09-11T22:52:02Z")
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.. ---
**Author:** ![Ballscrewbob](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ballscrewbob/32/950458_2.png) [@Ballscrewbob](https://forum.arduino.cc/u/Ballscrewbob)\ **Post date:** [September 15, 2020, 8:36pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/9 "2020-09-15T20:36:30Z")
@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. ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [September 16, 2020, 11:34am UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/10 "2020-09-16T11:34:42Z")
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... 🙂 ---
**Author:** ![Wawa](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wawa/32/1211303_2.png) [@Wawa](https://forum.arduino.cc/u/Wawa)\ **Post date:** [September 16, 2020, 8:42pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/11 "2020-09-16T20:42:25Z")
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.. ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [September 16, 2020, 9:48pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/12 "2020-09-16T21:48:36Z")
Hi, What is the load you are switching? Can you post a picture, link to the SSR module you have please? Thanks.. Tom.. 🙂 ---
**Author:** ![LeandroAR](https://avatars.discourse-cdn.com/v4/letter/l/f07891/32.png) [@LeandroAR](https://forum.arduino.cc/u/LeandroAR)\ **Post date:** [September 16, 2020, 11:46pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/13 "2020-09-16T23:46:33Z")
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. ```cpp 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](https://europe1.discourse-cdn.com/arduino/original/4X/6/4/1/6410269d4ca8ccfa717cac5902b2521044fe2c0c.jpeg) ![relay.jpg](https://europe1.discourse-cdn.com/arduino/original/4X/6/4/1/6410269d4ca8ccfa717cac5902b2521044fe2c0c.jpeg) ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [September 17, 2020, 12:02am UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/14 "2020-09-17T00:02:56Z")
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... 🙂 ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [September 17, 2020, 2:48am UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/15 "2020-09-17T02:48:06Z")
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 ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [September 17, 2020, 3:34am UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/16 "2020-09-17T03:34:20Z")
Hi, ```cpp 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... 🙂 ---
**Author:** ![LeandroAR](https://avatars.discourse-cdn.com/v4/letter/l/f07891/32.png) [@LeandroAR](https://forum.arduino.cc/u/LeandroAR)\ **Post date:** [September 17, 2020, 11:35am UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/17 "2020-09-17T11:35:32Z")
> 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? ---
**Author:** ![LeandroAR](https://avatars.discourse-cdn.com/v4/letter/l/f07891/32.png) [@LeandroAR](https://forum.arduino.cc/u/LeandroAR)\ **Post date:** [September 17, 2020, 11:40am UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/18 "2020-09-17T11:40:33Z")
> 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... ---
**Author:** ![CrossRoads](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/crossroads/32/214033_2.png) [@CrossRoads](https://forum.arduino.cc/u/CrossRoads)\ **Post date:** [September 17, 2020, 12:04pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/19 "2020-09-17T12:04:20Z")
Are these the SSRs on the board? > **[en-g3mc.pdf](https://omronfs.omron.com/en_US/ecb/products/pdf/en-g3mc.pdf)** > > 437.73 KB Can you read the full part number on yours? ---
**Author:** ![LeandroAR](https://avatars.discourse-cdn.com/v4/letter/l/f07891/32.png) [@LeandroAR](https://forum.arduino.cc/u/LeandroAR)\ **Post date:** [September 17, 2020, 12:15pm UTC](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169/20 "2020-09-17T12:15:31Z")
> CrossRoads: > 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. ![relay.jpg](https://europe1.discourse-cdn.com/arduino/original/4X/0/1/8/0187772ad90b939969d4a3bcdb4c6d8e71d2a47c.jpeg) ![relay.jpg](https://europe1.discourse-cdn.com/arduino/original/4X/0/1/8/0187772ad90b939969d4a3bcdb4c6d8e71d2a47c.jpeg) [Next page](https://forum.arduino.cc/t/ssr-relays-not-flipping/674169.md?page=2)