Looking for reed relays for high voltage commutation

Question

I need to chose a reed relay for connecting a point to high voltage (probably between 7000V:15000V) or to GND signals. System will have 8 channels (pins). Some of 8 pins will be connected to high voltage signal throught a relay. The rest ones will be connected to GND signal throught its related relay.

As you know relays could be Single or double.

I was searching in digikey, mouser, farnell, etc.. providers and I can only find high voltage single relays (SPST). However, it seems not to be other kind of relays (ie: DPST) for high voltage available on these sites.

I have two questions:

1. Does it mean that DPST or DPDT are not manufactured? Do they exist?
2. What is the difference between Isolation and commutation voltage parameters?

Answer 1

DPST Reed Relays do exist but I have not found anything more than 500V. I suggest you figure out another solution.

The Breakdown Voltage is when Open.
The Switching Voltage is when opening or closing.

Answer 2

I have found, googling, COMUS relays that has DPST. I really am interested in SPDT option. DPST could make me save one device per point. This is better than nothing. They are 3390 series 1272 group:

https://produktinfo.conrad.com/datenblaetter/1500000-1599999/001573788-da-01-en-HV_REEDRELAIS_5V_3391_1290_056.PDF

I have found another HV option, SPDT:

https://www.gigavac.com/sites/default/files/catalog/spec_sheet/g81c.pdf

But I don't know the prices. Depending on it, relay could be useful or not for us. Because we don't need 10KV neither 10A of current. But this is the minimum HV and current that has SPDT version on gigavac site.