4 Channel Relay Stops Working with components


I am having a problem that keeps recurring when I am trying to use a SEEED Grove 4channel spdt relay. Initial testing of the unit was positive. However after I have added the components to the relay it stops working. If I disconnect all parts from the relay and try initial testing again, I get nothing. I have the devices wired up to NC. This is also the second relay that has had this issue.

Can someone please help me with this. I feel that this might be a wiring issue.

/* Robert Lloyd Ploense
 * Testing Relay with components installed
 * Please refer do wiring diagram.

//For SEEED Studio SPDT 4 Channel Relay
#include <multi_channel_relay.h>
Multi_Channel_Relay relay;

void setup() 
  // put your setup code here, to run once:
  // Set I2C address and start relay


void loop() 
  // put your main code here, to run repeatedly:

Find the information on the relay here.

Writing Diagram should be attached to this post.

wiring diagram.png

I can't really make out your wiring diagram there/not sure what I'm looking at but, I would guess if they're no longer working you have either cooked your coil with too high a voltage, or burned your contacts with too high a load across them.

Have you tried pulling them out and just testing straight DC voltage from a source on the coils (battery or something - not an I/O pin). Listen for click or test for continuity if they're silent.

This is the OP's diagram
wiring diagram.png

I too am having trouble understanding this.

However after I have added the components to the relay it stops working.

What components are these then?

I'm pretty sure the OP is referring to the load devices, when saying "the components". Which could mean many things from interference to power problems, inductive kickback, the list goes on and on. So although "o3 o3 and "pump" exactly are, apart from apparently being 24V devices too, a lot more should be said about exactly what components they are. So is that ozone there, the O3? and a pump of some sort? Can we have some kind of link to that equipment?

Also, how much current does your full device load draw, and what is the power supply?

This diagram is implying the Arduino is being powered by 12 V.

That is a very bad idea and particularly likely to cause failure. The Arduino should be powered by the same 5 V regulated supply you use to power the relay module.

Can you post a picture of your project please, so we can see your component layout?

What is your DC Supply?
What are your loads you connect to the relays and what are their data/specs?

Do you have a DMM?

Thanks.. Tom... :slight_smile:

If the Nano is only driving the opto side of the relays , then powering from 12v is within its Manufacturers spec and won’t overheat its regulator .

Ops relay assembly;

Tom... :slight_smile:

Too bad, no galvanic isolation to be had ... they went all out on the pcb's relay coil to contact isolation (drillout paths) and labeling though.


I have the devices wired up to NC.

I think the contacts are welded shut. Easily done when using NC while controlling a DC load (lower contact rating). Tapping the relays lightly with the handle of a screwdriver has been known to free up lightly welded relay contacts.