I thought I would share the results of one of our tests that caught counterfeit product that was not only fake, but constructed so that it would perform at only 50% of its rating.
The part in question is a FOTEK SSR-25DA which is a 25A AC Solid State Relay.
As with any new product, before we offered them up for sale we tested our first shipment of these relays that came in the door. These types of relays often need to be mounted to a heat sink under higher power loads, but during our testing this one was getting hotter quicker than expected for the 1300W (50%) load that we had it under, so something didn’t seem quite right and we decided to investigate further.
Looking on the internet, it quickly became obvious that there have been a lot of complaints about these parts failing. Since the manufacturer FOTEK is considered to be a good quality manufacturer overall, the common conjecture is that the failing parts are counterfeit and therefore presumably of inferior construction.
One of the modules was dissected to see what we really had and the physical construction was found to actually be quite reasonable and unlikely to be a quality/performance issue.
What we were surprised to find is that the Triac used in the device is part number BTA-12-1000B. This device is spec’d to handle a maximum of 12A RMS on-state current which is far short of the 25A that the relay is rated at.
That change from the part that is presumably in the original relay would appear to have been done as a way to produce less expensive relays since the 12A triac is approximately 1/3 the cost of the 25A parts.
If you are in possession of some of these parts and wondering what you may have, there appears to be a couple of possible ‘tells’ to determine if they are genuine and able to handle the rated power.
- The label inset in the molding has a rounded corner in the lower right corner of the real parts and are square on the fake parts. Note that on the parts that we received, the label is cut to make it look rounded, but the plastic itself is not rounded. This is probably the best ‘tell’ overall from what I have been able to determine of whether a part is real or not.
- Real parts are labeled ‘Taiwan Made’. Many of the fake parts do not have that marking at all which flags them as fake, but others like the ones we received are marked slightly differently with ‘Made in Taiwan’. Mfrs may change this type of thing on their end, so this may or may not be a good flag to rely on.
- The text “Rated: 25A max.” is usually or perhaps always missing on fakes.
- The top horizontal line that goes across the AC pins is thicker than the bottom horizontal line that goes across the Input pins on most fakes. They are the same thickness on the real parts.
There are other items that may be tip-offs as well such as the sloppiness of the print around the LED, flat vs textured appearance of the label stock etc.
Here is a link to a UL notice released several years ago about fraudulent use of the UL logo that calls out some of the signs of fakes that were identified at that time. UL Link
Below are a pic of a genuine relay with some key items to watch for. Below that is the label from the parts that we received. You can click to enlarge the pics.
Looking at these relays for sale on the internet, it appears that the vast majority are fakes from what I can determine.
If you do have some of the fake parts, it is impossible to say if they all have the same shortcoming regarding the underspec’d part, but it is probably likely. Assuming construction is similar to what we found, it appears that as long as they are derated down to be within their 12A limit and have good heat sinking at higher power levels over maybe 6- 7A, they should probably perform OK. Ours ran comfortably at 5A and were starting to get pretty hot up around 8A with no heat sinking.
If you have any further info on this topic or corrections to the information I have found and provided, please feel free to share.
Hi. I must confess that during the past few years I have bought a few dozens of those fake “Fotek” relays and used them in noncritical applications switching 1.5-2kW 230VAC loads (approx. 6-9A).
At first they were not so bad – SSR-25DA was found to contain a 20A TRIAC, 2 years later it had a 16A TRIAC, then 12A.
OK, guessing where this was heading I upped the game and tried ordering SSR-40DA 🙂
The first batch had a BTA16-600, (16A 600V TRIAC), the next year it also was down to 12A.
The PCB-design inside some of them is also unbelievably bad with no respect for proper insulation clearance between input and output.
Today I got some SSR-60DA relays, split one open and found a single BTA04-800 inside, yes it is a 4A TRIAC – a whole 6.67% of the rated capacity!!
Great info Thor, thanks for sharing.
I think there are probably quite a few people who take the same approach and figure they will be OK if they just derate the module by 50% or so. As you have clearly shown, even that may not be a safe assumption unless you sacrifice one out of every order to see what is it that you actually received. With something like the SSR-60DA, those are virtually useless.
In the same order, I had also received some SSR-40DD DC relays. They also appeared to be counterfeit and came from the same supplier, but I could not find any performance issue with them during testing and they were built with 80NF70 MOSFETs which should be up to the job to meet the full spec.
So, where do we get the REAL version?
Hi, I received a SSR-25 DA with a jst24a-600bw triac. Is that ok for a 10A load?
The JST24A-600bw is a 25A / 600V part so that part meets the original relay spec and should be quite happy at 10A assuming the rest of the construction is reasonable.
I also received some SSR-40 DA DC relays. They appeared to be counterfeit, took apart and triac shows BTA16-1000 as the label says SSR-40 DA, this is the 3 burnout in 4 months.
Thank Ken for this article! Also Thanks to all those who commented!
This cautioned me to test the SSRs before using them. I am worried as I have just ordered SSR-100DA online. Hope it passes my loading test.
Note that the counterfeit pictured in this story actually is branded “FQTEK”, not “FOTEK”. Many of the more recent knock-offs share this Fotek-look-alike strategy. The ones I bought off of Amazon last week are branded “FWIER”, but looks almost like Fotek’s logo. I didn’t notice this until I had stared at the device for 1/2 hour. Needless to say, this ‘SSR-25DA’ marked device has a 12A triac inside and no zero-crossing circuitry. The device label doesn’t claim that it’s a 25A device anywhere. But the Amazon seller did in the product listing.
I should note that the knock-offs now have a beveled lower-right label just like the genuine device. But the knock-offs I’ve seen lately have two distinguishing characteristics:
1. The label has a red brand that looks like Fotek, but has very slight differences that turn the O into a Q, K into an R, etc.
2. They do not have the a current rating (e.g., 25A) on the label. They are marked with a part # like SSR-25DA that you would expect to be the current rating.
So look for devices that actually have a current rating printed on them. And if it’s too cheap to be a real 25A device, it probably isn’t.
I wrote Amazon to notify them of this deceptive, dangerous cheap knock-off device being sold, including photos of the insides showing the triac’s part number and a data sheet showing that it’s a 12A device. You would think that Amazon would take it down. But no, it’s still for sale at https://www.amazon.com/gp/product/B07PPGFKFL/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 . DO NOT BUY.
I bought “Fotek” ssr-25 DA several year ago to power 1.5 kW water boiler. Recently it’s got out of order. So I torn it down and found bta12. I soldered bta16 instead and it worked out. Now i’m trying to figure out what’s to blame: overheat or bad circuitry of the unit. It has a small heatsink from pentium3 cpu