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nadre25
19-06-2011, 03:53 PM
Our H-bridge IGBT inverter with DC rail of 315V is working on an industrial fan with voltage of 230VAC across it.

now when we used the same circuit in running our refrigerator, given that the voltage across out invter is 230VAC, the refrigerator wont start and started clicking.

When we measured the voltage across out inverter, it read around 30-40VAC only, can anyone tell us where the 200V went? thanks.

install monkey
19-06-2011, 04:28 PM
is ur compressor siezed? as ur inverter powers a fan ok proving the power module is ok,is the inverter rated sufficiently for the loading of a compressor on startup,can u decrease the ramp time to give more inertia on startup?

chemi-cool
19-06-2011, 05:17 PM
I would start with checking the power supply, what you describe [voltage drop] is typical for a bad connection or too small diameter wires.

nadre25
20-06-2011, 06:30 AM
@Chem-cool: we're thinking about making our DC rail higher, probably around 500-600VDC. replacing our bridge diodes with more capacity on amps. do you think it would solve the problem?

@install monkey: what do you mean about decreasing the ramp time?

We also learned that the compressor motors are different from industrial fans in terms of current. Does it explain that the current we provide for the compressor is not enough to turn it on? we only heard ticking sounds. thanks!

Yuri B.
20-06-2011, 04:36 PM
Nadr25, on your place I would ask on that forum:
LMPForum (Powered by Invision Power Board) (http://www.google.lv/url?sa=t&source=web&ct=res&cd=1&url=http%3A%2F%2Fwww.lmpforum.com%2F&ei=xm-mSvyKEM6NjAfQ4LiYDg&rct=j&q=lmp+forum&usg=AFQjCNF0bE58rwKQTZV4QeEzegrJ4wDNbQ)
What rated voltages are the inverter, the fan, and the refrigerator
What frequencies
Number of phases
Rated powers of the invertor, of the fan, and of the refrigerator
Provide all the info and post there