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Renewable Energy Q&A / Re: Max winding temp
« Last post by Pete on April 18, 2022, 03:03:12 am »LH, a bit more information.
If the winding of the motor is B class then it will have insulation that used to be called elephant hide. It is a blue insulation with mylar on one side. The insulation between the winding phases is usually then a varnished fibreglass cloth.
If it is E or F class it will probably be Nomex slot insuation ( stiff white looking paper stuff). The insulation between phases will be either terylene ( E class) or Nomex for F class.
Of course it is difficult to measure the temperature of the windings when the motor is running, unless thermistors are embedded in the windings. Some motors have them but not many.
As far as the toroid goes that sounds pretty hot but then you are running a lot of power through it.
I have button type thermostats in my inverter that are 40degree C set point.
I hear the fan come on sometimes when I am using loads over a long time but it goes off pretty fast.
Maybe you could put some more vents in the inverter case to get the heat out faster.
you must have some serious battery banks to take 4 to 5 kw back charging.
I just picked up some new panels that came with an SMA 2kw GTI inverter. I am thinking of connecting it up as a mini grid but obviously need to have a voltage sensitive relay on the batteries to prevent overcharging.
So far I have never seen my batteries take more than 2kw in. My panels are way over sized here to take into account the cloudy , misty mountain weather.
Hope you get the compressor sorted
pete
If the winding of the motor is B class then it will have insulation that used to be called elephant hide. It is a blue insulation with mylar on one side. The insulation between the winding phases is usually then a varnished fibreglass cloth.
If it is E or F class it will probably be Nomex slot insuation ( stiff white looking paper stuff). The insulation between phases will be either terylene ( E class) or Nomex for F class.
Of course it is difficult to measure the temperature of the windings when the motor is running, unless thermistors are embedded in the windings. Some motors have them but not many.
As far as the toroid goes that sounds pretty hot but then you are running a lot of power through it.
I have button type thermostats in my inverter that are 40degree C set point.
I hear the fan come on sometimes when I am using loads over a long time but it goes off pretty fast.
Maybe you could put some more vents in the inverter case to get the heat out faster.
you must have some serious battery banks to take 4 to 5 kw back charging.
I just picked up some new panels that came with an SMA 2kw GTI inverter. I am thinking of connecting it up as a mini grid but obviously need to have a voltage sensitive relay on the batteries to prevent overcharging.
So far I have never seen my batteries take more than 2kw in. My panels are way over sized here to take into account the cloudy , misty mountain weather.
Hope you get the compressor sorted
pete