Victron 100/20 - 48V load question (appropriate relay!?)

[edibleacres]

I have spent an immense amount of time trying to understand how to do what I would have thought was a very simple thing. Perhaps it is and I'm missing something. Please let me know!
I have a Victron 100/20 MPPT working with an EG4 battery. 48V system, it charges the battery up to 56.8V
All that works just fine.
I'm interested in having a situation where, when the battery is happy and super full and nice and there isn't a lot being asked of it, that the load port is triggered to allow excess to be sent to hot water heating elements. The strange bit with the 100/20 is at 48V the load port I believe is .1A max. So clearly it has to run a relay to work.
The control voltage it offers on this port is matched to the battery state, so I'd need a relay that is DC that is content with low amps but nearly 60V.
The solar is 2s2p and roughly 90 volts and 18 amp at peak.
Is there an appropriate relay folks know of or a way to approach this that is safe and reasonable that I'm just not understanding?

DC relay at a reasonable price with up to 60V control side and up to 100V active side?

Help and thank you for reading!!

 

[Goboatingnow]

60V power relays are available from electronic component suppliers like mouser.com digikey etc.

 

[edibleacres]

I looked into a bunch of options but it is still new enough to me to feel overwhelming to know which to go for. Is there a model you are aware of that can easily accept up to 60+ volts on the control leg and allow a pass through of up to 100v on the line side?

 

[Goboatingnow]

loads from Digikey , heres and example https://www.digikey.com/en/products/detail/idec/RV8H-1L1-AD60/8344967

 

[pollenface]

48v relays are common online at amazon, ebay, etc.

I have used up to 250vac on the active side without issue on normal automotive type relays.

 

[Goboatingnow]

48v relays are common online at amazon, ebay, etc.

I have used up to 250vac on the active side without issue on normal automotive type relays.

yes but amazon is for amateurs, but components from mouser or digikey

 

[MrThisIsME]

I have used up to 250vac on the active side without issue on normal automotive type relays.

If using an AC relay for DC how are you limiting current?

 

[Goboatingnow]

If using an AC relay for DC how are you limiting current?

I think he means the switching contacts , but id use a better relay for high voltages then automotive, I provided a link to a quality brand relay gooD
for 16A at main voltages

 

[edibleacres]

It seems what I'm reading here is a theme that it may not matter if a relay is made for DC or AC so long as the volts and current are in the specifications? For some reason I understood them to be AC/DC specific and needing to be all DC for the application I have in mind.
Also, thanks everyone for your input so far, I am learning here and getting some ideas.

 

[Goboatingnow]

Just be careful. A 60V AC rated coil will overheat on 60V DC. Equally contact rating for AC will higher then equivalent DC contact rating , especially interrupt rating

 

[edibleacres]

It seems like the safer thing is to avoid using AC elements for a DC application, right?
Question comes back to the basic of is there a good quality/safe DC relay that is happy to be controlled up to 60V DC and can allow up to 90V or 100V at up to 20A DC to flow through the live side when the contacts are closed. There must be some reasonably priced solution for this very specific (and reasonable?) setup?

 

[Goboatingnow]

It seems like the safer thing is to avoid using AC elements for a DC application, right?
Question comes back to the basic of is there a good quality/safe DC relay that is happy to be controlled up to 60V DC and can allow up to 90V or 100V at up to 20A DC to flow through the live side when the contacts are closed. There must be some reasonably priced solution for this very specific (and reasonable?) setup?

I did send you a link
To a specific suitable relay , 60v dc relays are common enough.

Note that a 60 dc relay should be ok to about 50 v

 

[edibleacres]

I ended up going down another path with this, I'll share notes if there is any interest. I bought an 18 dollar dc-dc step down that takes in 48V (but can take up to 60V) and puts out 12V on the other end. That would then very easily speak to a standard solid state relay rated for 3-32VDC and I bought a SSR that can handle up to 200V and 40A so it should be WAY happy to handle the load I'm asking it do. An extra step to be sure, but the buck converter could be swapped out for other applications if needed so perhaps a two step process will get me the solution I need...

 

[HRTKD]

I have the same Victron 100/20 MPPT. While I don't currently have plans for the load port, I do find it odd that the load port ratings for 12v/24v/48v are 20A/20A/1A. I'm on a 12 volt system so I'm not concern, but it's still odd.

 

[John Frum]

I have the same Victron 100/20 MPPT. While I don't currently have plans for the load port, I do find it odd that the load port ratings for 12v/24v/48v are 20A/20A/1A. I'm on a 12 volt system so I'm not concern, but it's still odd.

The load port may have a soft switch that is marginal at 48 volts.

 

[edibleacres]

I have the same Victron 100/20 MPPT. While I don't currently have plans for the load port, I do find it odd that the load port ratings for 12v/24v/48v are 20A/20A/1A. I'm on a 12 volt system so I'm not concern, but it's still odd.

Yeah, it's super odd and pretty frustrating that their documentation basically says "use a relay" but (and I've searched very far and wide) offer no specifics of what relay to use or how to wire it. There seems to be no tech support available from Victron either, so it's a tough one!