[sentraelectric]

Hello.

I hope somebody can help me becuase I don't know what else to try.

I bought a KingLeo electric AC compressor which is supposed to work from 70 to 160V. My electric car is a converted sentra with 20 6V lead acid batteries for a nominal voltage of 120V. It can sag to 80V when I step full throttle, but I cannot even get to that, because the 30-amps fuse burns as soon as the voltage drops below120V and the amps go to 1000 amps. I tried to use a 40 amps fuse, and the relay in the AC controller got burned-damaged this time. I got a brand new controller now, but it still doing the same as before and burning the fuse.

I installed the compressor, a new evaporator, hoses, recommended freon pressure, etc, and it all works OK until I step in the accelerator of the car. The manufacturer says that they are using these compressors in plenty of Lead-Acid conversions.

I am not an expert on this by any means, but I think that the 1000 amps would be going to the car controller and not to the AC Compressor Controller. The AC compressor is consuming from 2 to 3KW, but it does the same failure regardless of the speed it is on, even at the slowest speed.

I am attaching a diagram of the installation and a video showing the problem here.

Diagram:
http://www.tampaelectriccar.com/ac_diagram.bmp

Video:
http://www.youtube.com/watch?v=Lg3EbOt78Ac

Help please.

Thank you.

 

[major]

Hello.

I hope somebody can help me becuase I don't know what else to try.

I bought a KingLeo electric AC compressor which is supposed to work from 70 to 160V. My electric car is a converted sentra with 20 6V lead acid batteries for a nominal voltage of 120V. It can sag to 80V when I step full throttle, but I cannot even get to that, because the 30-amps fuse burns as soon as the voltage drops below120V and the amps go to 1000 amps. I tried to use a 40 amps fuse, and the relay in the AC controller got burned-damaged this time. I got a brand new controller now, but it still doing the same as before and burning the fuse.

I installed the compressor, a new evaporator, hoses, recommended freon pressure, etc, and it all works OK until I step in the accelerator of the car. The manufacturer says that they are using these compressors in plenty of Lead-Acid conversions.

I am not an expert on this by any means, but I think that the 1000 amps would be going to the car controller and not to the AC Compressor Controller. The AC compressor is consuming from 2 to 3KW, but it does the same failure regardless of the speed it is on, even at the slowest speed.

I am attaching a diagram of the installation and a video showing the problem here.

Diagram:
http://www.tampaelectriccar.com/ac_diagram.bmp

Video:
http://www.youtube.com/watch?v=Lg3EbOt78Ac

Help please.

Thank you.

Hi sent,

Here is a quick take. Your A/C (air conditioner) runs from an AC (Alternating Current) motor and has a DC/AC controller connected to the high voltage battery which is also connected to the Sol1 DC motor controller. So the A/C compressor works fine until the Sol1 starts driving the DC traction motor. Then the 30A fuse for the compressor motor controller blows. The Sol1 is drawing a large ripple current from the capacitors in the compressor DC/AC controller.

This same problem happens with DC/DC converters. The solution is to put an inductor in the branch circuit feeding the DC/DC converter. It has been addressed several times on threads on this forum and, so I'm told, addressed in the Sol1 manual. It could be that you are experiencing the same problem with your system.

That's a possible source which comes to mind.

major

 

[Tesseract]

...
I bought a KingLeo electric AC compressor which is supposed to work from 70 to 160V....

Is it one of these Chinese electric A/C compressors? If so, you will probably need an inductor to protect it from controller ripple, as major already mentioned. RebirthAuto sells a high current inductor specifically for this purpose, but I'll need to know how much current the A/C compressor actually draws in operation to tell you if it will work or not.

And yes, this is mentioned on p7 of the manual an in a FAQ on the Evnetics website...

 

[sentraelectric]

Hello Major, Tesseract.

Yes, it is exactly that chinesse electric AC compresor. They are made by a company named KingLeo.

At the following link is the amps consumption table they gave me. It looks like it uses about 3000W max and between 1500 and 2000 in normal use:
http://www.tampaelectriccar.com/120v_power_cconsumption.pdf

I will look today to the manual and the FAQ questions of the evnetics site. I thought until now that this was a problem with the AC controller and not a controller ripple.

Thank you.

Jose.

 

[GizmoEV]

Is it one of these Chinese electric A/C compressors? If so, you will probably need an inductor to protect it from controller ripple, as major already mentioned.

Could it be that he also needs a diode to keep the capacitors in the A/C unit from back feeding due to the sudden drop of pack voltage? IIRC, that is what kept blowing the 30A fuse in Jack Rickard's mini conversion.

 

[Tesseract]

...I thought until now that this was a problem with the AC controller and not a controller ripple.
....

Oh, it's still very much a problem with the electric A/C compressor, and not the controller. Apparently, the electric A/C system expects the voltage from the traction battery to be pure DC, free of sags, spikes and ripple. That's a rather foolish assumption to make, and perhaps the manufacturer should be apprised of the situation, rather than us bandage over it with diodes and inductors and such.

Could it be that he also needs a diode to keep the capacitors in the A/C unit from back feeding due to the sudden drop of pack voltage?...

See above...

 

[sentraelectric]

I got the inductor and I will test it today or tomorrow and see if it fixes the problem.

I contacted the manufacturer and they are very interested to know how this test goes. I think they may add these inductors in future models depending on how my test goes.

Thank you for your responses. I will post the results here after the test.

Jose.