Dear Sirs, Mr. Art Pini, a contributing author at DigiKey, has an interesting article in the Digikey Library entitled “How to Apply Hybrid AC Surge Protection Devices for Improved Surge Protection”.
How could I contact Mr. Pini to know the component values for 230V rms AC mains?
Thanks a lot in advance for the help.
Hello enrico.borsetti - welcome to the Tech Forum community! I am sorry, we are not able to share the contact information from our contributing authors. Check out DigiKey’s IsoMov Hybrid Surge Protectors from Bourns that the author refers to in his article. Take a look at the datasheet for the many options that are available.
Hello Jenny, I will take a look as you suggested, thank you.
Hi enrico.borsetti,
Here are the recommended IsoMOV parts for 230 Vac:
* ISOM3-230-B-L2 V-clamp <= 620V, Energy <= 105 Joules
* ISOM5-230-B-L2 V-clamp <= 620V, Energy <= 188 Joules
For higher energy handling, at the expense of slightly higher max V-clamp, you might also consider this:
* ISOM8-250-B-L2 V-clamp <= 675V, Energy <= 313 Joules
Comparison link
Correction, after further review, see my post further down for correct recommendations. IEC/UL62368-1 requires components rated for at least 1.25x maximum supply voltage for safety reasons.
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Dear David, thanks a lot for recommending the MOV’s.
What GDT model do you suggest me to buy?
Cheers,
Enrico
Hi enrico.borsetti,
That’s the beauty of the IsoMOV products – they contain both an MOV and a GDT within the same component, so you don’t have to buy separate parts, and they are matched to work well together.
See the datasheet and product highlight for more details.
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So, the schematic by Mr. Art Pini (here with parts for USA AC Mains) has to be reduced to 3 IsoMOV’s and the GDT’s has to be removed, right?
Hi enrico.borsetti,
I stand corrected on my previous answer. A more detailed reading of the original source work from Bourns instructs that for IEC/UL62368-1 compliance, the MCOV (Maximum Continuous Operating Voltage) of the IsoMOV should be at least 1.25 x the highest expected normal operating voltage. Therefore, if your “normal” voltage could be as high as 240Vac (which I believe is the case in a “230Vac” system), the IsoMOV should be rated for at least 300V.
Therefore, these are the recommended Line-to-Neutral IsoMOVs to consider:
- ISOM3-300-B-L2 V-clamp <= 800V, Energy <= 137 Joules
- ISOM3-320-B-L2 V-clamp <= 875V, Energy <= 144 Joules
- ISOM5-300-B-L2 V-clamp <= 800V, Energy <= 242 Joules
- ISOM5-320-B-L2 V-clamp <= 875V, Energy <= 258 Joules
- ISOM8-300-B-L2 V-clamp <= 800V, Energy <= 367 Joules
- ISOM8-320-B-L2 V-clamp <= 875V, Energy <= 388 Joules
Regarding the GDT to be used between Line and Protected Earth and Neutral and Protected Earth, the required voltage is of a higher value than Bourns currently offers in the combined IsoMOV package, so they suggest using individual GDT and MOV’s for that part of the circuit.
For the circuit you show above, they recommend GDT-1 and GDT-2 be rated for 3kV or more, and MOV-1 and MOV-2 should be rated for the same 300Vac as the IsoMOV parts. So for the GDT, the 2095-300-BLF looks like a valid option. For the MOV, here is a selection of 300Vac options to check out.
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Fantastic!
Thank You Very Much for your detailed information and precious help.
Kindest Regards,
Enrico Borsetti