Hello,

I could use a bit of help from the group, I have a machine running in the usa with two AB1305 drives, one 375W and the other 750W. the 750w drive has been working Ok except for a fuse blowing problem on installation, for two years. Recently the drive has been tripping out due to overload. The operators tell me that the trip happens when the machine is idling, in fact as it comes off load. the trip is set at 1.9A but the machine is fairly light duty, the motor and gearbox have been changed, the cable length is about 20m and excepting the arrival of spring, they can't think of anything that has changed. any ideas ?

marc sinclair

 

If everything on the output of the drive is known to be good, then you have a bad drive (faulty IGBT). Hang an Amp probe (set on "Max")on one leg and wait for it to happen again. If you don't record an overload, then it is in the Drive. If you do get an see current over 1.9, then you still have a load problem. Have the motor leads been Megged?

 

What alarm flags are displayed?

Regards,
Phil Corso, PE
Boca Raton, FL
[[email protected]] ([email protected]) {[email protected]}

 

Was your problem resolved?

Regards,
Phil Corso, PE
Boca Raton, FL
[[email protected]] ([email protected]) {[email protected]}

 

hi,

My problem still exists, the local technicians replaced the drive and, yes the AB1305 drive still trips with FAULT CODE 7 - overload!!!
The cable is about 50m (145 foots) long and I am told it checks out. could the problem be external, say spikes on the power feed?

All of the mechanical drive has been changed, and the fault happens shortly after coming off load - is that the clue??

marc sinclair

 

Set up a recording power monitor and see if there is a possiblity the machine is reflecting any unusual loading in the form of current spikes. These may be be appearing on a clamp on meter for whatever reason. I've had a similar problem on a 1336, which was ulitmately "chain slap".

Ken Grant

 

Aha - the normal running current is about 1.6A. The resident technician reckons the overload is about 0.5A which is enough to trip out the drive, which is set at its maximum of 1.9A. As it happens the cable length is nearer 50m, (54yards 2 feet 11 inches 1 barleycorn I would expect to be losing 0.75A of power in the cable, what would a normal 0.75kW drive be taking? The ambient temperature of the control room has just increased by some 10 degrees Celsius - (18 Degrees Fahrenheit) - springtime in washington (america) Should this affect the drive? - I would hope not! I suppose I'm going to have to fly over there armed with a meter, and have a look. Any words of wisdom would be gratefully received.

 

Well - here is the solution, We sent an engineer out there to find that the ventilation fan had burned out - the onsite technicians had replaced the 220v blower with - yes - a 110v unit. this had been some time ago, but surprisingly the motor had been soldiering on for the winter, but with the arrival of spring and the higher ambient temperatures, the current consumption went over the limit.

marc