Hey Guys,
I’m going to replace one of my mppts with a different version to support more panels on that string.
Now, when I remove the “old” mppt from the system (and vrm?) - What happens to historical data of this year in VRM? Will it be preserved? If so, how do I select stats from the “advanced” view, if the device is removed?
Or do I have to keep that removed device in VRM, until i no longer need the data?
no one ever replaced a mppt and could probably answer this? 
Just a guess, but as I’ve seen here, by “error”, the VRM database retains old information. So it may well be there.
Anyway, it seems that the decision of replacing is taken so, I believe, in a short while the mystery will unveil… 
Hi @dognose
System level data on the dashboard will be retained and seamless, you won’t see any difference. That overall system level data is kept for 5 years+
In the advanced section you will see a new device appear and your old MPPT will show that it’s no longer being updated (last updated x months ago)
Eventually you can choose to delete it from the device list and its detailed advanced data will be deleted automatically after 6 months.
You can keep the device in VRM, no reason to manually remove it before 6 months has passed.
Hi Guy @guystewart
In the light of what you’ve said and the problem I have (see my previous message), how one can delete a not anymore (or false) existing device?
Many thanks,
Alex
Hi @alexpescaru,
Unfortunately there is no way for the end user to do it short of deleting the entire site and all system data completely and starting new.
The solution is to just ignore it. Technically direct database access might be possible for one of the VRM system engineers, but that is not a service we offer.
I’ll answer the same in your other post as well.
Thx for the answer. Alright, then I will remove the device, when I no longer need the detailed data.
Just was afraid that removing the device will also result in a lowered summary for earlier months / years.
Once the system level data is stored for the dashboard history it is no longer distinguished by individual product. It is a single sum total, so removing any individual item will not affect it.