Redundant, fall tolerrant AC/DC inverter 12VDC to 230VAC - in parallel?

Thread Starter

racmaster

Joined Feb 13, 2018
29
hello, can i use 2 SAME standard inverters (12vdc to 230vac) connected in PARALLEL to provide fall tollerant power supply for standard circulating water pump?

off course, both much enough stronger, then needed to cover max power input of the pump...

is it a good idea?
 

panic mode

Joined Oct 10, 2011
1,867
what is this water circulating pump used for? will someone's life support fail if pump is off for a moment while some circuit switches from one inverter to another?
 

Thread Starter

racmaster

Joined Feb 13, 2018
29
circulation water pump for solar water heating... if it will be a moment, no problem, but for longer time it can boil the circulating liquid and cause complete system failure... therefor im searching for a fall-tolerant sollution where power inverter will not be a single point of failure
 

LesJones

Joined Jan 8, 2017
2,845
Call the inverters "A" and "B" Have a DPDT relay with it's coil powered from inverter "A" Connect the output of inverter "A" to the NO contacts of the relay. Connect the outpur of inverter "B" to the NC contacts of the relay. Connect the load to the common contacts of the relay. If inverter "A" fails the relay will drop out and pick up the supply from inverter "B". If you used a 3 pole relay you could remove the 12 volts from inverter "B" when the relay was closed.

Les.
 

Thread Starter

racmaster

Joined Feb 13, 2018
29
does this require both inverters running all the time? or will only run the one being used?

to explain, if i understood correctly, this relay switch will be on 230v side of the inverter, maybe it could be possible to place relay before inverter(on 12v side), which will power only 1 inverter and switch to another in case of failure...?
 

MisterBill2

Joined Jan 23, 2018
7,749
does this require both inverters running all the time? or will only run the one being used?

to explain, if i understood correctly, this relay switch will be on 230v side of the inverter, maybe it could be possible to place relay before inverter(on 12v side), which will power only 1 inverter and switch to another in case of failure...?
YES, BUT it is not quite that simple, because you will also need to switch between the two inverter outputs. If the outputs are simply tied in parallel then power fed back into the non-functioning inverter will be wasted, at best, or it will be damaged, more likely.
If you don't have the inverters yet, consider that some of them are made with connections to run two or more in parallel. That could be the best of both situations.
 

MisterBill2

Joined Jan 23, 2018
7,749
can you pls reccomend me some example of parallel friendly inverter?
Unfortunately I no longer have access to that resource. But the relay concept, with switching both the 12 volt DC supply to the second inverter and at the same time switching the 230 volt output connection will work very well.
Another option that has not been mentioned is to have a 12 volt powered pump for the system.
 
Top