SSR-40DA Solid State Relay DC to AC (Input 3-32V DC Output 24-380V AC) with Heat Sink, 40A

This is the second unit I purchased due to the first one burning out... but it was totally my fault. I looked at the power rating and my application was way under the upper amperage limit so I thought I could forgo the heat sink. WRONG! I fried the first one. I ordered a second and put it in a larger enclosure and included the heat sink this time. It's been working perfectly ever since. I use the switch to turn on a dust collection system for one of my CNC routers. The switching signal is taken of the spindle control of the CNC's control box. Works great!

Exactly as advertised. Shipped fast enough, packaged well enough and works fine.I used this to run my well pump using a 110V trigger from an electronic pressure switch unit. I wanted to use this to power the well pump as it will be more bullet proof on the amperage running the well pump, though the well pump is only at 4.5 amps. If you have a heavy amp draw you might consider adding a little computer fan to the heat sink and make it more bullet proof to heat. Good little unit, good price and very handy.

Basically that's it. Got it to replace a unit on our pre-treat machine and it seems to work flawlessly.

Nice ssr. Relays do go bad; I have two old ones neither was working so I had to buy a new one. I like this one because of the red led when the circuit is working and the load is applied. My old ones didn’t have that and I had to use a volt meter to figure out what was going on. Not hard to do but one more thing.

Quick answer avoid, pick a different brand.On my 3D printer I needed to replace the Solid State Relay that controls the hot-bed. I selected this brand as a close match for the original (different brand but with the exception of the sticker it looks identical). The original was a 40 amp so I replaced with a 40 amp, original was not on a heat-sink so I reinstalled identical to the orig. The replacement died within 1 hour of installation. Replaced it with 80A and a 40A fuse... same problem, Replaced again, with provided huge heat-sink, replaced the load (hot bed), 3 down. Replaced it with different brand, works fine, does not need the heat-sink. Glad they were inexpensive... this was an time-consuming problem. If you are switching any current at all pick a different brand.

I have the DC to DC version of this and when I wired it up, it incorrectly allowed current flow even with nothing connected to the input. I thought it was defective but before giving up I tried reversing the load and the supply wires and now it works perfectly.In particular, the diagram uses the SSR-60DD as an example:1) It shows an AC supply voltage but the device is DC-to-DC2) It shows supply voltage on terminal 1 and load voltage on terminal 2. That is backwards and those should be reversed.I can't yet speak to the longevity of the product since I've only been using it for 1 day.

It works according expected

Need this to prevent the current from my solar panel and the temperature drop to 0Cdegress. Works very well.

Wired into my RV to use a on/off switch for power legs on 5th wheel front end. keyed switch works but out put has 12V going through it all the time. Removing and returning. Other review says these unit s have a a high rate of failure so I guess I should have bought local for $50 as obviously you get what you pay for.