If the specs on a surge protector are not listed, or if it's above 330 volts clamping or let through voltage, move on. Any worthwhile protector will proudly have those specs listed.
^ That still may not tell you anything more than what their MOVs are rated for, not that it lacks the additional circuitry that better surge protectors have.
Remember that an MOV rated for 330V does not cost more than one rated for 500V. They're not penny pinching in that regard, rather a trade-off of lifespan. If your 330V MOV fails and you don't notice, so it provides no protection against an 800V surge that comes along, it might not have been so great to have it sacrifice itself before you needed it to. A lot of things can survive a sub-500V ms duration surge but the lower the voltage the more common such surges are. Even your refrigerator cycling off can cause a surge in excess of 330V and damage a surge protector.
^ It would be better if surge protectors provided audible alert and the MOVs were in a bladed cartridge like automotive fuses so when one blew out you could swap it, with any voltage value you wanted to.
Comments & Reviews (4)
Remember that an MOV rated for 330V does not cost more than one rated for 500V. They're not penny pinching in that regard, rather a trade-off of lifespan. If your 330V MOV fails and you don't notice, so it provides no protection against an 800V surge that comes along, it might not have been so great to have it sacrifice itself before you needed it to. A lot of things can survive a sub-500V ms duration surge but the lower the voltage the more common such surges are. Even your refrigerator cycling off can cause a surge in excess of 330V and damage a surge protector.
Thank you!