Overvoltage protection in PV system - Page 1
Forum section: electronics / projects

author: 22
author_rank: Contributor
timestamp: June 25, 2017, 02:52:07 pm
content: Hi, can anyone tell me if this overvoltage protection :http://new.abb.com/products/2CTB804201R0100/ovr-t2-40-275is suitable for use in photovoltaic system ? Thanks.

author: 22
author_rank: Contributor
timestamp: June 29, 2017, 01:52:05 pm
content: Still need help

author: Zero999
author_rank: Super Contributor
timestamp: June 29, 2017, 09:01:11 pm
content: Quote from: 22 on June 29, 2017, 01:52:05 pmAnd how is anyone supposed to help you without enough information about your problem?The device you've linked to is AC for a start, yet solar cells are DC. It may help to protect the mains side a grid tie inverter but will be useless for the DC side.

author: 22
author_rank: Contributor
timestamp: June 29, 2017, 09:24:08 pm
content: yeah but it also has: Voltage Rating DC: 350 V. So i suppose it might also be suitable for DC . Or I need a specific part only for DC ?

author: Zero999
author_rank: Super Contributor
timestamp: June 29, 2017, 09:49:33 pm
content: Quote from: 22 on June 29, 2017, 09:24:08 pmHow the heck can anyone know, without knowing the nominal voltage of the solar array?

author: 22
author_rank: Contributor
timestamp: June 29, 2017, 10:17:45 pm
content: The open circuit voltage of one panel is 38V. 6 panels are connected in series. The 350V arrester should be ideal for my purpose so thats why Im looking for something different that 600V 1000V types that are available everywhere. I saw this one is typically for AC but it also have DC rating. So my question is the same: Is that rating means that this arrester is also suitable for DC side?

author: fourtytwo42
author_rank: Super Contributor
timestamp: June 30, 2017, 08:01:46 am
content: Quote from: 22 on June 29, 2017, 10:17:45 pmWhat are you trying to arrest ? A PV panels output will never exceed VOC anyway! Any downstream devices such as inverters should have suitable input protection integrated anyway. If you are trying to protect against lightning strike that's a whole different ballgame as others have said you need to properly describe what you are trying to do and protect against before anybody can offer you any potential solutions.

author: 22
author_rank: Contributor
timestamp: June 30, 2017, 10:49:46 am
content: Im trying to protect input side of inverter from indirect lightning stroke. The maximum voltage of inverter is 380V. The DC side is going to be fully isolated from ground.

author: MagicSmoker
author_rank: Super Contributor
timestamp: June 30, 2017, 12:16:57 pm
content: Quote from: 22 on June 30, 2017, 10:49:46 amLook, I see you are from Slovakia and so won't expect your English to be very good, but why didn't you state that in the first post instead of waste a bunch of time - literally days - waiting for us to play 20 questions with you?You don't use an overvoltage protection relay to protect against indirect lighting strike; that is what Metal Oxide Varistors (MOVs), Gas Discharge Tubes (GDTs) and Transient Voltage Suppressors (TVS diodes) are for.Understand that you can only guess what kind of energy or peak power vs. time rating the transient protection will need and, of course, if the "indirect" strike is to the building next door there won't be much you can do about it.