Hello,
Welcome to the DigiKey tech forum. This looks like a varistor to me. It’s function is circuit protection from high voltage spikes. Plenty of damage but any chance you can try decipher the part markings, we would need that to try match a possible alternate or if you have a schematic, that may list the part description.
1 Like
I havent been able to decipher the markings. Its from a milwaukee m12 m18 charger. Cat. No. 48-59-1812. I will try to find a schematic.
This is what I found. It came with a varistor 10N271, which I’d like to replace. But I found some instructions saying if you replace it with a TVR10471 and cut one of the feeds to the voltage doubler, it can be used on a 220V circuit. Thanks, I’m not sure why I didn’t think to look up a schematic.
1 Like
I can find some on amazon, but there is a difference in number. The N is a D. 10D271. What is the difference? Are they interchangable?
I am sorry to say that I was not able to verify the difference in the varistor “N Type” vs “D Type” materials
I was able to locate what looks like similar items based on the specifications I had found for the 10N271.
Additionally
Are you using the “48-59-1812” with a 220v wall power?
Im not currently. But i was contemplating putting a switch in so i have a charger that is capable of doing either. This varistor blew out because the neutral bar in my fuse box broke and half my house was suddenly 240v.
Hi Alund1990,
Regarding the “N” vs. “D” difference, I’m pretty certain that this is just the abitrary nomenclature used by different vendors. For instance, for the Joyin JVR10N271 datasheet that I found here, the “N” just calls out “Standard” surge capability, which for their part is 2.5kA and 40 joules. Similarly, Bourns uses the “D” for their standard series and the “K” for their high surge variants.
Any of these should meet or exceed that rating.
Regarding modifying your charger for 240Vac, that seems highly risky and I wouldn’t advise it. It would seem much more practical (and safer) to put your resources into prevention to make sure you never have your system spontaneously convert to 240Vac again.
Pretty much every other first world country runs on a higher voltage. Things are discovered from experimenting. Gotta take some chances in life. Lol. Thank you for the information.
Sounds like you plan on going for it. Just make note that any varistor which can handle 240Vac without damage will provide much more limited protection for 120Vac systems since it will not start to shunt voltage away from downstream components until somewhere above 400V, basically making it irrelevant to the circuit.
If you could figure out a way to switch in one value when in 120Vac operation mode, and a different one when in 240Vac mode, then you could have protection in both modes.
Best of luck to you, and be safe!
2 Likes
im a sparky. normally, if your breaker panel lost neutral, your 220v circuits would remain on, and your single-phase 120v circuits would Not be energized.
1 Like
Yes, i plan to have a toggle switch that is connected to 2 different Varistors, and i toggle to disable 1 side of the voltage doubler.
Id thought the same. The bar literally broke in half. So the half of the house that wasn’t connected to neutral anymore was now at 240V because it has circuits hooked up to both legs, and was backfeeding through the broken bar.