i know you can set the voltage points manually, just curious if the controller is capable of moving them around a bit based on the temperature of the battery bank.
It can if you configure one channel for a temperature input and put a temp sensor on the batteries. But it's not needed because it's not a charge controller. It's a voltage control system to keep the inverter from kicking out when the turbines are running in high winds. Normally the total combined 7.5 kW of heating load keeps it in check. My dump load is two 55 gallon Domestic water heaters. The bottom 2,500 watt element in the primary water heater is "normal" in that the thermostat on it is set at 125 degrees and it's on all the time so we always got hot water - at leat 55 gallons @ 125 degrees. The top element in that heater, plus both elements in the other (pre-heater) water heater are each controlled by the RD-1 in stages and are used only for dump load (they're fed with 240 volt power from the inverters).
But my dump load can only go to 170 degrees before the thermostats kick the elements out. I used to not have thermostats on there and I got the water heater so hot a couple times that it blew the popoff valve on the water heater. My wife gets really pi$$ed when that happens because it blows boiling hot water all over her laundry room in the basement.
So I found it necessary to cut that off at 170 degrees to prevent blowing the popoff valve on the heater. That required additional voltage control because when the water heaters are hot, now I got no dump load. Or I might not have enough load because the top element in the primary heater, which is turned on by channel one in the RD-1, might be at 170 degrees so it don't come on. The next one on channel two is the top element in the water preheater, and if that one gets to 170, then I only got the one element left (channel three on the RD-1) that will come on. So I figured the logical choice is to just shut the system down in stages when the voltage starts to climb above safe levels for the batteries, and keep the system under the high voltage kick-out setting on the primary inverter (the slave inverter shuts down based on what the primary does).
So being that it's not a charge controller, but more of an emergency over-voltage shutdown system, sensing battery temperature really serves no purpose. And it's only to keep turbines in check, really. The bank voltage can hit over 40 in the blink of an eye if both turbines get hit by the same big gust when the bank is fully charged and it has to deal with a 280-300 amp current surge from the turbines. That's hard on batteries and it makes the inverters kick out. Since I put it in, I've never had another problem and I've only seen both turbines get braked by the RD-1 only once that I ever remember. And it did what it was designed to do that one time I seen both turbines get braked - it held the voltage in check and the inverter stayed online.
I'm just using 24 volt starter relays to brake the turbines because the contacts in those starter relays will handle over 400 amps with no problem. The RD-1 energizes the coils in the relays and when the relay's contacts close it shorts the generator output (the AC side), which instantly kills the over-voltage current surge. It's not real complicated - just required a bunch of thought as to how I wanted it to work.
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Chris
Edit: I just recently added the second Morningstar RD-1 Relay Driver. I ordered it when I bought the MPPT 45. With the additional solar power we got way more power for our little 900 sq ft house, and my shop, than I need. And our bank is usually fully charged by 10:00 in the morning because we don't use hardly any power at night (maybe 3-4 kWh). If the wind is blowing at all, the system just spends the rest of the day maintaining the bank and heating water. But that's a good problem to have because then the generator is more of a yard ornament
