Solar contactor

[Dtwo 157]

Working through adding a couple of 100W panels.  I need to have a contactor in the feed so the lithium BMS can switch off the panels if necessary.  I've been recommended the Gigavac P115bda but I am having a real problem sourcing them for reasonable $$.

Any suggestions for an alternate?

Here is the P115 spec.

https://www.gigavac.com/products/p115bda

 

[Island Time 1,293]

Why would you use a mechanical relay? Consumes power with the coil.. What about a solid state (mosfet based) relay - about $20-30 on amazon... Use a normally closed, opens when BMS turns it off. Whats the solar controller? You need to be sure that it can either be switched off, or can deal with a disconnect.

[Dtwo 157]

6 minutes ago, Island Time said:

Why would you use a mechanical relay? Consumes power with the coil.. What about a solid state (mosfet based) relay - about $20-30 on amazon... Use a normally closed, opens when BMS turns it off. Whats the solar controller? You need to be sure that it can either be switched off, or can deal with a disconnect.

Do you have an example of the solid state relay?  The P115 is normally open and apparently is low power consumption (I wish I knew more about this stuff....).

Looking at the Victron Smartsolar MPPT, with the relay between panel and controller.

[Island Time 1,293]

Like this https://www.amazon.ca/LANTRO-JS-SSR-40DA-Output-24-380V/dp/B0924R6JD9/ref=sr_1_4?dchild=1&keywords=solid+state+relay+DC+40a&qid=1630919872&sr=8-4

[Island Time 1,293]

But if you go to this series victron SmartSolar MPPT 150/70-Tr they have a built in relay for this...

[Dtwo 157]

I'm only looking at the 75/10 or 75/15.  I'd run a separate controller per panel to deal with shading.

Thanks for the link!  That is a great help.

[Island Time 1,293]

200w panels you want the 15. 

 

[mcp 34]

If you are using a Victron Smart Solar MTTP,  you do not need a relay or a switch for a BMS.  You just need someone to program the Victron properly for you. PM me if you need help.

Also what BMS are you using?   Most are overly complicated for little reason. 

@Island Time Solid state relays generate heat when closed as well,  because of high internal resistance.  A mechanical latching relay would be the most idea relay for this instance,  if it can be controlled from the devices. 

[Island Time 1,293]

2 hours ago, mcp said:

If you are using a Victron Smart Solar MTTP,  you do not need a relay or a switch for a BMS.  You just need someone to program the Victron properly for you. PM me if you need help.

Also what BMS are you using?   Most are overly complicated for little reason. 

@Island Time Solid state relays generate heat when closed as well,  because of high internal resistance.  A mechanical latching relay would be the most idea relay for this instance,  if it can be controlled from the devices. 

Agreed, a latching relay would be ideal, but should not be needed with the Victron controller, which can be set up for Lithium...