My relay doesn't switch off when it gets hot

Other Hardware General Electronics
1

Hi guys,

I am using arduino for my experimental setup and I need it to work for quite a long time (e.g. continuously for months). To control a water bath device which uses AC power supply I used a 5V relay board to connect and disconnect phase when it is needed. But after 5 days I noticed about a problem with the relay board. I just found that it does not switch off the device probably because the related channel is considerably hot.

With reseting the arduino everything works fine again but I cannot know when it will happen again, so reseting the arduino could not be a perfect solution.

So any idea for troubleshooting?

Thanks!

2

Could be something needs to be changed in your code.

3

Hi guys,

I am using arduino for my experimental setup and I need it to work for quite a long time (e.g. continuously for months). To control a water bath device which uses AC power supply I used a 5V relay board to connect and disconnect phase when it is needed. But after 5 days I noticed about a problem with the relay board. I just found that it does not switch off the device probably because the related channel is considerably hot.

With reseting the arduino everything works fine again but I cannot know when it will happen again, so reseting the arduino could not be a perfect solution.

So any idea for troubleshooting?

Thanks!

4

Maybe you need to change something in your code.

5

Hey Shannon, I don't think that is the case for me, because it worked totally fine for like 4 days and this problem is something new.
After several switching on and off (which says that the code is fine), I saw that the LED of the related channel is off but the device is still working which says something is wrong inside the relay channel.

6

Well, if you have the wrong 'type' assigned to a variable it may take 4 days to raise its ugly head.

Do you think we might need more information to be able to help you.

Show us a good schematic of your circuit.
Show us a good image of your wiring.

Always show us your ‘current’ compete sketch.
Use CTRL T to format the sketch.
Please use code tags.
Use the </> icon in the posting menu.

[code] Paste sketch here. [/code]
7

Relays get warm after a while. I would be more worried about the relay contacts of those sugarcube relays.
What sort of heater are we talking about (voltage/current/wattage).
Maybe you should use a SSR (solid state relay).
Leo..

8

Post your code. Don't trust your assumptions. And stop spamming.

9

Your relay contacts could be welded shut, but this would not explain why the relay coil is warm/hot.

However, if the contacts welded, their resistance could be high enough that heat may be generated.

10

@hosseinzr, please do not cross-post. Threads merged.

11

Change relay, it is taking to much current if the coil is hot, show the relay.
Before resetting Arduino, when relay is hot check voltage on it.

12

hosseinzr:
I saw that the LED of the related channel is off but the device is still working which says something is wrong inside the relay channel.

Put LED in parallel to relay coil

13

ted:
Put LED in parallel to relay coil

With a series dropping resistor.

14

Sorry about that, I tried to delete the second one but I couldn't

15

hosseinzr:
With reseting the arduino everything works fine again but I cannot know when it will happen again, so reseting the arduino could not be a perfect solution.

Show details of that relay. Eg..... ratings, specs etc.

Could replace that relay, and see what happens with the new relay..... such as ...see if the new one operates normally for more than 4 days.

16

If the indicator LED is off and the load is still powered, I would think the contacts are welded, pull the wire off the In terminal and see if the load turns off. What kind of load, AC, DC, volts, amps?

17

ted:
Put LED in parallel to relay coil

Would you please provide a sketch for this?
I checked that specific relay channel with another item, but it does not switch it on even when its LED is on. I assume this channel is out of order.

I double checked the code, it works fine, but I can post it if required.

The relay is this one:
https://www.amazon.ca/dp/B06XCKQ1M9/ref=sspa_dk_detail_3?psc=1

18

outsider:
If the indicator LED is off and the load is still powered, I would think the contacts are welded, pull the wire off the In terminal and see if the load turns off. What kind of load, AC, DC, volts, amps?

The device is 120V AC 12A which is above relay board safe range. What can I do to avert the problem for the a new channel?

19

hosseinzr:
The device is 120V AC 12A which is above relay board safe range. What can I do to avert the problem for the a new channel?

Solid state relay is called for.

Paul

20

Thanks Paul!