Any experiences with the EA-EL 9000 DT series electronic loads?

[hhg2]

When searching around for electronic loads, I keep finding the EA-EL 9000 series from Elektro-Automatik https://elektroautomatik.com/shop/en/products/programmable-dc-electronic-loads-br-conventional-and-regenerative/series-el-9000-dt-br-conventional-electronic-loads-br-400w-up-to-1200w/

I can't for the life of me find any meaningful reviews of any electronic loads from this or neighboring series (or, really anything from the entire manufacturer).

Do anyone know anything about the quality of these electronic loads or how they relate to other similar products from e.g. B&K Precision 8600 series? Or do anyone have any tests or personal experiences to share?

Cheers

[nctnico]

I have looked at these loads before but the problem is that they can't run at their rated load power. There is always a catch.

Last time I went looking for a DC load, I ended up with a Korad KEL2000 series. I've also been very insterested in the B&K Precision 8550 series (Tonghui rebadges) but couldn't get one to try for a decent price.

[hhg2]

Very interesting, thanks! I've got tons of questions now

Do you mean like for example the EA-EL 9080-45 DT 600W, rated to 0...80V/0...45A, would stop working at e.g. 60V, 30A or 500W? Did you see it in the datasheet or did you try it out? How large were the discrepancies? Would you know anything about the quality until the too early cutoff, like does it operate correctly until the earlier failure?

[nctnico]

Very interesting, thanks! I've got tons of questions now

Do you mean like for example the EA-EL 9080-45 DT 600W, rated to 0...80V/0...45A, would stop working at e.g. 60V, 30A or 500W? Did you see it in the datasheet or did you try it out? How large were the discrepancies? Would you know anything about the quality until the too early cutoff, like does it operate correctly until the earlier failure?

I have never tested any of the EA DC loads because the specs are incomplete. For me it stops there. Voltage & current readback specifications are very minimalistic. If you look at the datasheet you'll see a note saying power rating is derated from 25 degrees. But no derating graph or anything. So no idea what to expect.

For the specific model you refer to, note that dissipating 600W in such a small case is challenging to say the least.

[Martin72]

Hi,

If you look at the datasheet you'll see a note saying power rating is derated from 25 degrees. But no derating graph or anything. So no idea what to expect.

They are listed in the manual. Here is an example(pic)..
Otherwise, it's relatively simple: 80V maximum, 45A maximum, 600W maximum, meaning that only one of the three can be maxed out.
Add to that the temperature-related derating.
We have various DC power supplies from EA. I fell for it once, but never again in the sense of looking more closely at what you need from them.

Edit:  Manual
https://elektroautomatik.com/shop/media/pdf/b4/6f/91/33210501_EN.pdf

[nctnico]

That is the power rating versus current / voltage graph. That makes sense; every DC load has that. But the temperature derating graph is completely missing so there is no way to know what the actual continuous power is that the DC load can handle at maximum operating temperature.

[Martin72]

As I said, an example: the temperature derating comes right after that...

[nctnico]

As I said, an example: the temperature derating comes right after that...

No, that is only time limited peak power. Right next to it, it says derating will continue with rising ambient power. But no info what the actual continuous rated power is.

[Martin72]

You're right, in the section on thermal de-rating it says that steady power refers to an ambient temperature of 40°C or below...
...but nowhere does it mention what power this refers to.
Not very clever.

[evac]

No, that is only time limited peak power. Right next to it, it says derating will continue with rising ambient power. But no info what the actual continuous rated power is.

They seem to specify that as "steady power" but even that is confusing because in the temperature derating section they state "[...] down to the steady power which is rated for the typical ambient temperature of 40°C" but in the tech specs on page 10 this "steady power" is specified at 25°C.

However looking at the EL 9080-60 DT specs I'm not sure I would trust it could dissipate 900W of "steady power" with such a small form factor...

[electr_peter]

Specs are incomplete w.r.t. to max continuous load capability. Probably load transistors are capable of more power disipation safely (relaying on thermal inertia), but are limited by heatsink and fan rating. Does this load have fan at max speed all the time (i.e. over-cooling to have some thermal inertia in reserve)?

[Brad O]

I can't for the life of me find any meaningful reviews of any electronic loads from this or neighboring series (or, really anything from the entire manufacturer).

EA is owned by Tektronix now which might be one contributing factor here. A lot of content for the 9000 series has been removed over the years as EA shifted focus to the 10000 series, because it was misleading for the 10000 series or just appeared outdated.

EA's technical support team is very responsive if you have questions though, and they might have supplemental spec information for continuous loading on the 9000, I'm not sure. I have used a 9000 T load before without issue, but that was just for basic testing. The quality is very good and they're hand-built in Germany.

[Martin72]

I can confirm that. The last thing we purchased there was three DC power supplies, each with 30 kW/0-750 V.
We installed them in a 19" tower and connected them all in parallel, so that we now have a mobile, compact 90 kW power supply.

[Martin72]

I contacted EA because I was interested in understanding how the performance works.
Using the example of the 600W load mentioned above:
The 600W is the short-term peak value that can be drawn for 150...210 seconds without the derating kicking in.
It can therefore be achieved for a short period of time, e.g. for dynamic tests.
The actual continuous power is 500W.
This is as long as the external ambient temperature does not exceed 40°C. If it does, the power is reduced again to prevent overheating.