Voltage spikes experienced with a vacuum bottle breaker 3

[relayman1000]

Comparing the voltage spikes produced with interruption of a medimum voltage vacuum bottle with those produce by an air blast breaker. Are they the same in new vacuum gear? What about in older vacuum gear? I know that the early ventage vacuum gear had surge capacitors but I have gotten the more i am believing that the modern vacuum contact designs did not need a surge a capacitor due to improved contacts. Bottom line is can we use vacuum medium voltage breakers on motors just as we can air blast breakers with no surge capacitors because they both have about the same voltage surges and spikes?

 

[EngCarlos]

Tanks oldfieldguy for your answer. We realy check the conections leads and put it near the botles for remove any conections in the way. We found in another breaker's manual, that had limits for change botles in case of contacts wear out. But they didn't said the value. Do you have any idea about this?
thanks

 

[oldfieldguy]

EngCArlos--

If the manufacturer doesn't give good data, then compare your sample with others of the same type. I would be suspicious of anything over a hundred micro-ohms measured directly across the bottle. Your I^2*R losses are going to be getting high with resistances you mentioned.

old field guy