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#1 psl


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Posted 27 March 2007 - 04:28 AM

two 5.5kW air-conditioners start at the same time and draw 45amps for about 2 seconds and then stabilize at 13amps, due to this high start-up current the generator trips, im forced to buy a 12kva generator instead of a 8kva generator. problem with my business is i have to buy many 12kva generators and the price difference between 8kva and 12kva is very big. how can i solve this tripping problem?

#2 AB2005


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Posted 27 March 2007 - 06:36 AM

It depends on the starting torque requirement of your compressor. These types of compressors start and stop through a pressure control switch. The compressor motor is under load when switch starts the motor for filling the air tank during automatic operation.
I think your motor is started through DOL starter. You can use a Star Delta starter which would reduce the current at 1/3rd limit and also reduce the torque. Check, may be your problem would solve.

"Don't assume any thing, always check/ask and clear yourself".

#3 kens



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Posted 27 March 2007 - 08:29 AM

Hi psl, the first thing that leaps to mind is to control the system so that the individual compressors do not start at the same time. However there may be a good reason for not doing this. Could you provide a little more detail? What is your voltage and no of phases. It seems to me that you have 2 single phase systems each with a cooling output of 5.5kW and an input of around 2.5 kW, is this correct? If they are single phase units the options are reduced.

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#4 marke


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Posted 27 March 2007 - 10:34 AM

Hello psl

Welcome to the forum.

Firstly, in order to provide you with a meaningful answer, we need to have more information.

What are the voltage, current, frequency and power ratings of the motors in the airconditioners?
Are they single phase or three phase?

If the motors are single phase, are they capacitor start or induction start?

Best regards,

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