PowMr 48 Volt 3500w inverter Fault code 20 Issue

smthball

New Member
Joined
Feb 28, 2022
Messages
2
I have a PowMr 3500W 48V inverter installed at my Cabin. Having some issues with the system i am trying to get worked out. Example of issue: Operating in winter conditions, inverter is secured in weatherproof cabinet ventilated but not heated or cooled within the cabinet. If the sun is shining on the panels and producing power the system works as intended(No issues). But once the sun goes down my batteries kick in(like they should) but usually within a few hours the system throws a fault code 20(inverter over temperature protection). When it does this i have been operating in below freezing conditions running only several LED lights. Any thoughts out there on why this occurs.
 

wattmatters

Photon Sorcerer
Joined
Apr 16, 2021
Messages
2,197
Any thoughts out there on why this occurs.
Are you able to monitor the unit in any way to see what the internal temperature sensor is saying prior to fault?

I notice the temperature of my PIP clone rises to its highest overnight with very little load. It sits about 7-10°C higher than during daytime when it's working. My daytime loads are typically not high though, <10% of inverter's (4kW) capacity.

This is what my solar output typically looks like over a regular 24-hour period with reasonable sun during the day:
Screen Shot 2022-03-01 at 7.32.03 am.png
Screen Shot 2022-03-01 at 7.32.30 am.png

Load is mostly a pool pump and a few sundry electronics running 24x7.

When the solar first starts producing in the morning, the reported inverter temperature drops quickly. I suspect something about the solar PV starting production triggers the internal fan to operate. It also tends to be triggered by applied load. As load is increased the fan steps up its speed. With no/very little load the fan seems to barely operate.

IOW the fan doesn't just seem to be controlled by temperature sensor but seems to have various triggers.

inverter is secured in weatherproof cabinet ventilated but not heated or cooled within the cabinet
Perhaps the cabinet needs some active ventilation to help dissipate heat? These inverters are supposed to have plenty of space around them.

One thing with my PIP inverter, and I understand it is reasonably common with these inverter types, is the fans are mounted in a direction to draw air in the through the top vents and blow it out the bottom vent. I never understood why it would do that. Makes more sense to me for them to draw air in from below and blow it out the top, the same direction natural convection would operate.

It is possible to turn the fans around but that would require opening up and modifying the inverter and presumably void whatever warranty you might have.
 

smthball

New Member
Joined
Feb 28, 2022
Messages
2
Are you able to monitor the unit in any way to see what the internal temperature sensor is saying prior to fault?

I notice the temperature of my PIP clone rises to its highest overnight with very little load. It sits about 7-10°C higher than during daytime when it's working. My daytime loads are typically not high though, <10% of inverter's (4kW) capacity.

This is what my solar output typically looks like over a regular 24-hour period with reasonable sun during the day:
View attachment 85594
View attachment 85595

Load is mostly a pool pump and a few sundry electronics running 24x7.

When the solar first starts producing in the morning, the reported inverter temperature drops quickly. I suspect something about the solar PV starting production triggers the internal fan to operate. It also tends to be triggered by applied load. As load is increased the fan steps up its speed. With no/very little load the fan seems to barely operate.

IOW the fan doesn't just seem to be controlled by temperature sensor but seems to have various triggers.


Perhaps the cabinet needs some active ventilation to help dissipate heat? These inverters are supposed to have plenty of space around them.

One thing with my PIP inverter, and I understand it is reasonably common with these inverter types, is the fans are mounted in a direction to draw air in the through the top vents and blow it out the bottom vent. I never understood why it would do that. Makes more sense to me for them to draw air in from below and blow it out the top, the same direction natural convection would operate.

It is possible to turn the fans around but that would require opening up and modifying the inverter and presumably void whatever warranty you might have.
When this occurred the day temp when the sun was shining was above 30 degrees and when the sun was down it was around 15 degrees. Cabinet door was left open and the load was only a few led lights so maybe 300w. Under these conditions I don’t find it logical that it is truly overheating.
 

wattmatters

Photon Sorcerer
Joined
Apr 16, 2021
Messages
2,197
Under these conditions I don’t find it logical that it is truly overheating.
Hence asking if you can monitor the inverter's temperature sensor data.

BTW - on my PIP clone over temperature is fault code 02, not 20.
 

Bobert

Solar Addict
Joined
Jan 15, 2022
Messages
927
I have a PowMr 3500W 48V inverter installed at my Cabin. Having some issues with the system i am trying to get worked out. Example of issue: Operating in winter conditions, inverter is secured in weatherproof cabinet ventilated but not heated or cooled within the cabinet. If the sun is shining on the panels and producing power the system works as intended(No issues). But once the sun goes down my batteries kick in(like they should) but usually within a few hours the system throws a fault code 20(inverter over temperature protection). When it does this i have been operating in below freezing conditions running only several LED lights. Any thoughts out there on why this occurs.
I am wondering if you ever solved your issue with the code 20. I use the same unit in my travel trailer. I have heard that some units have a low temperature sensor that triggers the same code as the high temperature sensor.
 
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