I am using 3 "Fotek ssd" 25A solid state relays to control 3 10A 240V water pumps.
I am still in the testing phase and have not yet connected the pumps.
Relays are activated by 12VDC via a 2N2222 transistor driven by a Arduino.
The 240V output from each relay is connected to 3 15A power points to which the pumps will eventually be connected.
During testing I have been using 3 240VAC desk lamps plugged into the power points.
I lamp is a 240V 100W Quartz Halogen lamp and this operates flawlessly.
The other 2 lamps are the cheap multiple LED desk lamps which switch on and off without a problem,however when the relay turns off the lamps still glow weakly and one actually strobes
on and off.
Testing the outputs of these 2 relays shows that when turned off the Voltage drops to 40VAC and gradually steps up to 200VAC and continuously cycles between these voltages.
When I attach normal 240V 60W incandescent bulbs to these outputs the Voltage acts normally.
There probably is a snubber circuit inside those SSRs, which can power low current devices like LED bulbs.
Try a LED bulb AND a 60watt incandescent bulb, together.
I guess they now will be both off.
Why the 12volt supply and the 2N2222.
Most SSRs work from 3volt, and can be driven directly from a 5volt Arduino pin.
Leo..
Due to snubbers you should never assume the output of a mains relay is safe if the relay is "off" - an important point to note.
The only time mains equipment is safe to work on is if protected by a dual-gang(*) isolation switch which is off, or
much better unplugged. Isolation switches do not have snubbers and thus need to be rated for the arcing they
will see.
(*) both live and neutral must be switched to make a mains circuit safe. Unplugging is really the best way as
switches can develop faults occasionally.