what would be the right SPD in terms of Up for a RS450/100?
4kV are fine or do I have to use 2,6kV or less?
According to the datasheet, the RS450 has an OVCII rating, so for 300V a voltage surge of 2,5kV and for 600V a surge of 4kV. Which value do I have to take when calculating Up for the SPD (Up is 0.8xsurge voltage of the RS450).
Citel DS 240-350DC has an Up of 1,6kV
@mvader (Victron Energy) @Daniël Boekel (Victron Energy Staff)
Maybe Victron could answer on that, as protecting the MPPTs with SPD should be a very common approach?
@Baxter The 450voc is a hard limit here. So you don't want anything above that coming through. Work on nominal rating. And also pv array sizing is max 8x float voltage so can change things a bit.
You are talking type 2 sonindirect surges.
And the number of SPDs also have a factor. Do you have more than one in the system for the RS?
It was my understanding that the higher the kv rating the better as it meant longer life or could handle more surges most are MOV based?
I am open to learning more here though. not an expert.
Also there are usually local regs to follow as well.
Uc of the SPD must be 450V or above.
I am asking about the Up value for the SPD. Up shoult be about 20% less then Uw, which is the rated impuls voltage of the RS450 (that is not Uc).
But what is Uw of the MPPT RS450 (overvoltage category II)? Based on Fig J24 of the following link, it could be either 2.5kV (for voltage line to neutral of 300V) or 4kV (voltage line to neutral of 600V). There is not rating for 450V, but I guess that the RS450 can be operated with an Uw of 4kV (so Up of 3.2kV or less)?
I am talking about Type1+2 SPDs, having one in place for the MPPT (as the distance between the pv array and the mppt is less then 10m)
Anyone? Which SPDs are you using when installing RS450? What is the requiered protection voltage Up?
The ones i use on all my clients systems are rated to 600vDC
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