Home |
Search |
Today's Posts |
|
Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
|
|||
|
|||
Testing 3 phase motors
I am testing a couple of 3 phase motors I have acquired. I have a single
phase to 3 phase 3/4 hp rotary converter that generates the 3 phase field. I have checked a couple motors but when I tested 2 Baldor motors I tripped my fused switches. The first heated my switch red hot and the second turned slowly then killed my FRS 5 fuses in my converter set up. Both were 2-3 hp but I checked a different manufacturer 3 hp motor and it ran fine. So at this point I need to get more fuses. I had the motors wired for low voltage to match my 240 supply. I checked these wiring configurations thoroughly. How do I test these 3 phase motors? I checked resistance between a 3 leads and measured a couple of ohms each. No spikes. Also, I am looking to use these 3 phase motors for an idler in a separate rotary phase converter. I have read about getting a balanced voltage. Would this be just measuring the 3 voltages from the 3 different combinations of leads? What is a decent balanced voltage supply - say for mills or lathes? Thanks Pal |
#2
|
|||
|
|||
Testing 3 phase motors
"Pal" wrote in message news:HncIc.68899$XM6.28243@attbi_s53... I am testing a couple of 3 phase motors I have acquired. I have a single phase to 3 phase 3/4 hp rotary converter that generates the 3 phase field. I have checked a couple motors but when I tested 2 Baldor motors I tripped my fused switches. The first heated my switch red hot and the second turned slowly then killed my FRS 5 fuses in my converter set up. Both were 2-3 hp but I checked a different manufacturer 3 hp motor and it ran fine. So at this point I need to get more fuses. I had the motors wired for low voltage to match my 240 supply. I checked these wiring configurations thoroughly. How do I test these 3 phase motors? I checked resistance between a 3 leads and measured a couple of ohms each. No spikes. Also, I am looking to use these 3 phase motors for an idler in a separate rotary phase converter. I have read about getting a balanced voltage. Would this be just measuring the 3 voltages from the 3 different combinations of leads? What is a decent balanced voltage supply - say for mills or lathes? Thanks Pal Pal You seem to be doing the testing of the 2 or 3 HP 3 phase motors properly. If the motor is possibly faulty, maybe you can evaluate it by connecting a 12 VDC battery to any two of the leads to the 3 phase motor and test the resistance to 'twisting the rotor shaft'. If you want any additional assistance with your testing you are welcome to E-mail me at home. Jerry |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
3 phase electrics | UK diy | |||
General stuff on phase converters | Metalworking | |||
Phase Converters vs. VFDs | Metalworking | |||
Bridgeport single phase motors ? | Metalworking |