Low battery automatic transfer inverter (PROBLEM SOLVED)

fblevins1

Solar Enthusiast
Joined
Aug 14, 2021
Messages
92
OK folks, I am having issues with my transfer switch or a Gremlin is loose in my home. So with a little help from wiseacre, I was able to figure out how to set the setpoints for low and high voltage switch points and so I brought it home and hooked everything up and for a week I enjoyed suspiciously great battery performance. I decided to up the amount of power I was using in an attempt to get the battery voltage down enough to switch over to power and even when I ran a 400 watt ceramic heater for hours the battery voltage stayed above 12.8 volts. I was concerned that my solar panels were not outputting enough power but the reason for that is because the batteries we full. So I decided to wire up my larger inverter with blue tooth phone app and put an even bigger 1200 watt heater into the test now I have a phone I can easily control and measure the voltage and power and of course it was measuring the voltage but would not measure power....hmmmmm, so, I use the phone to turn off the inverter and the heater was still running. I double checked that the transfer switch was telling me that it was using the batteries. So I said screw it and I unplugged the house power and the heater turned off. So even though the transfer switch was telling me it was using battery power, it was using house power. I double and triple checked my wiring and it was fine. So I figure OK screw it, and I simply reversed the connections from house and inverter and that took care of the problem. It was reversed but it was now working. This morning I wake up and see that the battery has dropped down to 12.2 volts and the switch is telling me that the power is now coming from the house. Nope, it was still using the inverter power even though the switch is telling me house power. So....I reversed the house and inverter wires and am now back to normal operation. What the hell guys? Seriously, what in the hell is going on? Oh, and I do not have the set up grounded, just using line and neutral from both my wall and inverter outputs.
 
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12VoltInstalls

Photon Sorcerer
Joined
Jan 18, 2021
Messages
2,040
Location
Vermont
Contact the seller’s support folks?

it certainly ain’t making sense

What make/model is that? Maybe it’s in a prior post, I didn’t re-read the whole thing to figure it out.
There’s a reason I don’t like aio or multifunction units although I understand the higher end stuff works well…
 

wiseacre

Solar Addict
Joined
Aug 8, 2021
Messages
213
Location
North of the Adirondacks
Contact the seller’s support folks?

it certainly ain’t making sense

What make/model is that? Maybe it’s in a prior post, I didn’t re-read the whole thing to figure it out.
There’s a reason I don’t like aio or multifunction units although I understand the higher end stuff works well…
I can't make sense of the gremlins either. I have the same ATS and never had a problem.

This is a stand alone separate unit, not an AIO.
Grid and inverter power are wired to their respective inputs with only one output. Working properly the ATS will run on solar until a set low battery voltage is reached and then the unit switches over to grid. When a set higher battery voltage is detected the ATS flips back to solar.
 

fblevins1

Solar Enthusiast
Joined
Aug 14, 2021
Messages
92
I can't make sense of the gremlins either. I have the same ATS and never had a problem.

This is a stand alone separate unit, not an AIO.
Grid and inverter power are wired to their respective inputs with only one output. Working properly the ATS will run on solar until a set low battery voltage is reached and then the unit switches over to grid. When a set higher battery voltage is detected the ATS flips back to solar.
It is a stand alone unit that works with my house power, inverter and has a battery sense terminal to monitor the battery voltage. Fairly straightforward operation. Essentially it is two switches that send either house power or inverter power to my electronics., depending on the the voltage it reads from my batteries. It switches when it is supposed to, but where it gets the voltage from is what the problem is. It seems to have a random ghost that makes the voltage come from where the display indicator tells me it is not coming from. It would be too easy if I simply wired it wrong, but at this point I have done what I can do as far as simply verifying that the inverter is going where it is supposed to and the same with the wall power. I did not want to break it down and haul it all into work where I can control the process to find out if it is the box, but something tells me it is not the box., or at least it is not the control board. The fact that it reversed symptoms after I have switched the inverter and wall just confuses me even more. What I am thinking about doing if I do have to take it into work is hook the grid side to a normal outlet and hook the inverter side to a variac and set it so I have a definitive voltage difference and hook a DMM to the appliance (load side) and use a power supply to simulate the battery voltage so I can control the switch points easier and then see if the unit properly switches between wall and inverter power. If it does and it does so repeatedly, the problem has to be at home. Probably Gremlins.
 

fblevins1

Solar Enthusiast
Joined
Aug 14, 2021
Messages
92
OK folks, I brought the unit into work and it didn't take long to figure out that the control wire/connector between the ATS sense board and the relay section was disconnected. I noticed right off the bat that when I varied the DC voltage below the set point the relays were not clicking and when I brought the voltage above the set point, it still was not clicking. I took the case screws off and the control cable was disconnected. I connected the cable and could hear the glorious sounds of the relays engaging when I varied the DC below and above the setpoints. I just checked the outputs when the ATS switched between the grid voltage of 120 VAC and the variac voltage of 105 VAC, and it works!!!!!. Just FYI folks, if you want your ATS to switch to grid power at (for example) 12.3 volts Dc....Set it for 12.4 volts. If you set it for 12.3 it won't switch until 12.2 volts. Think of it as a limit and if you have it set for 12.3 and it reads 12.3 it won't switch until the voltmeter on the ATS drops below 12.3 and since the ATS has a very low resolution voltmeter it won't switch until the control board sees it drop below 12.3. I calibrated the display so 12.3 volts out of my calibrator reads 12.3 on the ATS Voltmeter, it was .1 volts off. I don't really care about the high set point because even though I set it for 12.8 volts high, during the day the solar panels send more than 13 volts or more to the system so one way or another that bad boy will switch over to inverter at some point during the day.
 
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fblevins1

Solar Enthusiast
Joined
Aug 14, 2021
Messages
92
So, once I got the system fixed and was actually putting demand on my solar panels, I was able to get a high enough current reading to figure out how much my 3 panels were putting out and how the power was distributed between the panels and I had about 4 amps coming out of each of the panels for a total of 12 amps being supplied to the charge controller. I tasked my batteries too low yesterday because of my defective ATS, so the panels could only get them up to 12.6 volts. But that OK, there are always going to be good and bad solar days. Hopefully now, I just let the system do its thing and see how the savings average out. Thanks guys for putting up with my butt crazy way of posting and learning things.
 
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