information needed on dc/dc converter 48vdc to 24vdc

[simetek]

Hi Guys I need help from you. I'm an refrigeration technician with little skills in electronics. I'm doing a project with a 48vdc source and I need to drop it to 24 vdc.
I have try with an dc dc converter with a 6,3 amp output (150watts) and it turns out that when i'm i full load the voltage drop to 15 volt. I have a total of 140 watts on my output. Am I overloading the converter ? If yes would a 200 Watts would be enough ?

Thanks
PAtrick

 

[Reloadron]

When the converter is loaded and the output voltage drops what is the input voltage on the 48 volt side of things? That would be the first question. Next question is the converter getting hot? Most units like this require a heat sink. Finally do you know what the actual load current is? If the load is exceeding 6 amps then the converter output will drop. If when the output voltage drops the input is remaining a steady 48 volts then I would venture a guess you are overloading the converter assuming it has proper cooling. Should that be the case then I would consider going with something like this using the model # CBS2004824 with a heat sink and make sure your load does not exceed about 8 amps. Actually if the load is 6 amps I would still use an 8 amp 200 watt unit to allow some overhead.

Ron

 

[simetek]

Hi Reloadron and thanks for your fast reply !

I did not check the input voltage but I think it didn't drop because i'm hook on a big stack of battery around 800 amp hour ( cell site ) . when I draw 3 amp all is ok but as soon as I plug my 2nd motor the voltage drop. I was drawing 6 amp when the voltage drop . So if I go with a 200 watts will the converter handle the load ?

Thks

 

[Reloadron]

Hi Reloadron and thanks for your fast reply !

I did not check the input voltage but I think it didn't drop because i'm hook on a big stack of battery around 800 amp hour ( cell site ) . when I draw 3 amp all is ok but as soon as I plug my 2nd motor the voltage drop. I was drawing 6 amp when the voltage drop . So if I go with a 200 watts will the converter handle the load ?

Thks

As long as the supply side at 48 volts can, then yes and keep heat sinking in mind. Long as the input voltage is a stable 48 volts a 200 watt 8 amp unit should do just fine at 6 amps.

Ron

 

[KeepItSimpleStupid]

Whoops. You said a motor? All bets are off. What's all of the information on the nameplate of the motor(s)? If there is more than one, do they, or have to, start at the same time?