Solid state relay for dump load heating

DIY
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1

I have a small off-grid system in an alpine hut with 1 solar panel 380 Wp, 2 x 240 Ah 12 V batteries and an EasySolar 24/1600/40. Now I would like to use the solar power when the battery is full to heat a small room.

I was thinking of controlling a 24 V electric heater with a SolidSwitch 104 via the virtual load output of the MPPT. However, the SolidSwitch 104 can only switch 4 A, which means I can’t utilise the full surplus power.

Does anyone have a tip for a suitable solid state relay that can switch at least 16 A at 24 V?

Thanks in advance for any help.

2

An SSR of that load rating will be expensive. I would recommend an electromechanical power relay or contactor.

If you are hell bent on SSR, you will find something at Digikey. They have excellent product filters.

3

Agree, i looked into DC SSR’s and came to the co conclusion they are not suitable / cheap ones ain’t anyway.
Old school relays are cheap & reliable.

4

RS Components have plenty that would meet your needs. Would have to be paired with a suitable heatsink.

5

To be able to switch DC, you absolutely need a DC SSR … a normal relay would probably burn through the arc.

e.g. SSR-40DD solid state relay DC to DC at Ama…n :wink:

1 Like
6

I think that’s what I got from Amazon but the version that switches AC. I think it’s 40D or something. The thing I liked about it is that it has a heat sink built-in and can be mounted on a DIN rail.

7

Thanks to everyone for the good advice. I will now buy a solid state relay, just not from Am* or eB*, because there are often fakes sold there. I don’t want my system to go up in smoke :fire:.