Diversion to water Heater

[Kedwards]

Looking for a recommended way to divert to a water heater.  Ive seen some old feedback on this but nothing recent or a definite best way to do it using MN 150"s.. Should I pursue a dc or ac solution?

[ClassicCrazy]

Looking for a recommended way to divert to a water heater.  Ive seen some old feedback on this but nothing recent or a definite best way to do it using MN 150"s.. Should I pursue a dc or ac solution?

It really depends on what you have there for solar equipment and what you want to accomplish.
Easy way is to use AC from  inverter to an SSR that is controlled by Aux on Classic.
here is a video I made about hot water heating with solar
https://youtu.be/s7trVpHLts4
Larry

[Kedwards]

Thanks Larry,
I have two MN150's , 7.5 KW of panels, and 12 Battleborn batteries in 48 volt configuration. My inverter is a 12KW Aimes inverter.  I have half of its capacity unrealized.  I'm incrementally adding loads and batteries trying to find the optimal for both battery backup to critical loads and to also harvest as much power as possible in the current configuration. Batteries are commonly topped out by early afternoon, driving my interest in diversion to water heater which is currently not connected to power. 
If I go the AC route it simplifies my wiring to the heater and uses some of the available inverter capacity.  I believe the elements are 4500 watts each. How do I determine what size element would be best?  I've read some comments on micro cycling batteries and certainly do not want to damage or shorten battery life.

[SolarMusher]

  I believe the elements are 4500 watts each. How do I determine what size element would be best?  I've read some comments on micro cycling batteries and certainly do not want to damage or shorten battery life.

2000 watts elements 120Vac or 240Vac will do the job.
Erik

[ClassicCrazy]

Thanks Larry,
I have two MN150's , 7.5 KW of panels, and 12 Battleborn batteries in 48 volt configuration. My inverter is a 12KW Aimes inverter.  I have half of its capacity unrealized.  I'm incrementally adding loads and batteries trying to find the optimal for both battery backup to critical loads and to also harvest as much power as possible in the current configuration. Batteries are commonly topped out by early afternoon, driving my interest in diversion to water heater which is currently not connected to power. 
If I go the AC route it simplifies my wiring to the heater and uses some of the available inverter capacity.  I believe the elements are 4500 watts each. How do I determine what size element would be best?  I've read some comments on micro cycling batteries and certainly do not want to damage or shorten battery life.

I don't think you will be microcycling the batteries if you use AUX 2 waste not on AC since it will only take power off above the battery absorb or float setpoints.

larry

[Kedwards]

Thanks for the feedback.  My water heaters are in series, first one not powered but circulates through geothermal system to carry off heat.  If I change to 2000 watt elements and use 220v would I need to use an SSR for both legs of power to the water heater?

Any suggestions on what the Aux 2 settings should be harvest max but not too wide to guard against micro cycling?

Ken

[ClassicCrazy]

Thanks for the feedback.  My water heaters are in series, first one not powered but circulates through geothermal system to carry off heat.  If I change to 2000 watt elements and use 220v would I need to use an SSR for both legs of power to the water heater?

Any suggestions on what the Aux 2 settings should be harvest max but not too wide to guard against micro cycling?

Ken

I never heard of micro cycling batteries before.
I have been using the default settings for the waste not on aux 2.
Not sure about your SSR question for 240v  - I  used mine on 110v system so was just switching the hot side with the ssr.

Larry

[Kedwards]

Not sure where I first g the question regarding microcycling the batteries. Ill look into that more as it could be an issue.  I saw a schematic in recent post by moosemaster re using two ssr's for 240V.. Makes a lot of sense to me. 

Thanks for the help..