FREQUENCY CONVERTER

[m_herrera202]

I have a Enviromental simulation unit made in Germany
with a 400 volts, 3 phase, 7.6 amps, 50 HZ
nominal power 4.5KW, over curren protection 16 amps
also inside the unit it has 1 compresor of 220/120 volts and a fan
what size of frequency converter shall I use?

 

[beanland]

400V

400V

You are also going to have to get 400V. Is this unit an electric resistance heater? You might be able to run the compressor and fan from a small VFD. That would allow taking 480V 60H and generating 400V 50Hz. Resistance elements do not care if they are 50Hz or 60Hz.

 

[GoldDigger]

You are also going to have to get 400V. Is this unit an electric resistance heater? You might be able to run the compressor and fan from a small VFD. That would allow taking 480V 60H and generating 400V 50Hz. Resistance elements do not care if they are 50Hz or 60Hz.

If the motor speed is not critical (and the load on the motor does not increase critically with speed), it may not be necessary to change the frequency, since the motor losses will be lower at a higher voltage.
But a VFD can allow you to get both frequency and voltage conversion at the same time.

 

[templdl]

If the compressor is belt driven you may even consider changing one of the sheaves to compensate for the increase of the motor rpm at 60hz. You may also look at the fan in that the additional rpm will change the fan loading and the cfm. Is that a big issue?
The is an outside chance that you my get away with little additional expense.
The only other point to address is the 400v bean land pointed out.
You could consider a commonly available transformer with a 480v secondary which you may get on the resale market that has +(2)2-1/2% FCAN and(4)2-1/2% FCBN taps and use a few tricks. It is common for the supply voltage to be less than 480, that when d with using the highest tap of +5% FCAN may be lucky enough to reduce the secondary voltage enough to be able to use a buck transformer to end up with a voltage of 400v. If you have a maximum voltage range of +10% your max voltage would be 440v. With all things considered you may be able to achieve that with a buck transformer should you start with 460v using the existing 480v system which I believe you should be able to buck 32v or 460-32=438v.
If the equipment isn't real fussy this may be stretching it a bit.