I have a problem with a VFD Drive with blowing fuses at radom it might work one day or maybe 3 or 4 days then blow two fuses at a time
It call for a 30 amp time delay fuse but if you use time delay fuses in this version of VFD drive it will blow the IGBT module before it ever blows the fuses
I was using 30 amp fast acting fuses then when to 40 amp and now when to 60 amp fast acting fuses ( JJS version fuses ) I do not have any results from the 60 amp fuses I just put them in today
But yesterday it blew all three fuses weird
Now this is even more weird and that is the motor plate say running amp 20 amps @ 480 volts
Ramp up time set at 15 seconds 26 amps from 8 HZ to 35 HZ until it reaches 28 HZ then levels off to about 7 amps
Now if I change the ramp up time to 30 seconds ( this is the maximum setting) the same 8 HZ to 35 HZ then we are looking at about 12 amp until it reaches about 25 HZ then level out at 6.6 to 7.5 amp
One note the ramp down amperage is normal
Now I have done quite a few VFD drives to motor and not have this problem most of the time the amperage is less than what motor plate says
Now this motor does not hum or sound like it single phasing the motor sounds good
One note it is for an overhead crane and it probably about 30 years old
Anyone have any ideas what might be going on
One other note the original VFD ( over 10 years old) took a shit it tripped a 50 amp breaker and VFD drive did not smell very good ( did not try to put power to it again ) that is this one (Over Head Crane Current Sensing Board recap this board ) about five years ago
more than likely it is a shorted IGBT module failure
I have not done an autopsy of this drive yet but when I have some time I will do one and let you know what I find
It call for a 30 amp time delay fuse but if you use time delay fuses in this version of VFD drive it will blow the IGBT module before it ever blows the fuses
I was using 30 amp fast acting fuses then when to 40 amp and now when to 60 amp fast acting fuses ( JJS version fuses ) I do not have any results from the 60 amp fuses I just put them in today
But yesterday it blew all three fuses weird
Now this is even more weird and that is the motor plate say running amp 20 amps @ 480 volts
Ramp up time set at 15 seconds 26 amps from 8 HZ to 35 HZ until it reaches 28 HZ then levels off to about 7 amps
Now if I change the ramp up time to 30 seconds ( this is the maximum setting) the same 8 HZ to 35 HZ then we are looking at about 12 amp until it reaches about 25 HZ then level out at 6.6 to 7.5 amp
One note the ramp down amperage is normal
Now I have done quite a few VFD drives to motor and not have this problem most of the time the amperage is less than what motor plate says
Now this motor does not hum or sound like it single phasing the motor sounds good
One note it is for an overhead crane and it probably about 30 years old
Anyone have any ideas what might be going on
One other note the original VFD ( over 10 years old) took a shit it tripped a 50 amp breaker and VFD drive did not smell very good ( did not try to put power to it again ) that is this one (Over Head Crane Current Sensing Board recap this board ) about five years ago
more than likely it is a shorted IGBT module failure
I have not done an autopsy of this drive yet but when I have some time I will do one and let you know what I find
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