i am facing the above siad F05 Fault on 20 HP 1336 Plus II BFD in Jute Mills on spinning frame in whose descrtion "DC bus voltage exeeded maximum voltage" & action "Monitor the AC line voltage or transient conditions. Bus overvoltage can be caused by motor regeneration. Extend the Decel Time or install dynamic brake option.

with reference to the above said fault and related to action, i set the parameters as below

accel Time 20 secs
Decel Time 40 Secs
Stop 1 Ramp
Stop 2 Ramp

i increased the deceleration time but in vane. Can anybody guide me that what p[arameters i have to set to rectify it ASAP. In our case the system Voltage is 400VAC, 50 HZ

Regards

 

High voltage spikes from any source can and do cause an overvoltage fault on VFDs. You did not indicate the power source as being a WYE or DELTA but if it is an ungrounded power system we have only found one solution that always works.

There have been various ways to help this condition but the only positive solution that suppresses all the spikes on all equipment fed from a power transformer. That is one unit per plant not one per drive. The solution to this problem has been the installation of a Phaseback EMTVSS from http://www.applied-energy.us

 

You are experiencing high bus volts on the DC-Link bus (the DC link between the input rectifier and output inverter inside the drive), which is caused by regeneration voltage coming back from the motor. This is a result of high momentum loads fluctuating on your output motor shaft.

Given your input voltage is steady at rated voltage of the drive, you will need external braking resistors to connect to the drive and possibly an external braking unit to switch the resistors in/out of the DC link circuit.

I've installed a smaller 1336 before. Your ramp up/down times are huge and should be ok. Try to increase more if your application allows you to do so.

I'm not sure if you can connect braking resistors directly to this drive, but if the ramp time increases do not have an affect, you will need to consult your AB drives rep, and get prices on braking resistors / braking units.

 

Make sure that Bus Limit Enable parameter (#11) is set to "Enabled". For some unknown reason, A-B sets this parameter in the default mode to "Disabled". When enabled, the drive can automatically lengthen the decel rate if the bus voltage rises too high. A-B drives are notorious for tripping out on DC Bus Overvoltage.
If this does not correct the problem and you do not need a fast stop, set the Stop Select to "Coast". This will prevent the drive from tripping while stopping but will not help when changing from a high to low speed. Only a Brake Chopper and resistor will help in this situation.

 

If this occurs on deceleration you probably are encountering regeneration of rotational energy back onto the VFD DC bus. At some point, the drive decides the DC bus voltage is too high and trips the drive. The only cure for this is to install the dynamic brake option to bleed off the excess voltage from the DC bus. I doubt this is happening if you have your decel set for 40 seconds, but I suppose it is possible.

If it occurs during steady state conditions, it could indicate that the load is actually providing energy back into the drive. This can happen if its a lift when it is going down. Again, the dynamic brake option will cure this problem, although you need to do some calculations to make sure.

Its also possible that you have not set the parameter correctly that tells the drive what the expected incoming voltage is.

Bob Peterson

 

Not sure about the physical dynamics of your application but you may need a Bigger dynamic brake unit to Bleed of DC bus volts if your load is causing the VF drive to overhaul. We had similar problems and solved them in this way.

Neil Firmin

 

If controlling the speed during the shutdown is not necessary then simply set the "stop 1" and "stop 2" to "coast" and that should eliminate the dc overvoltage condition. If speed control is necessary during shutdown then you might need to install a (dynamic braking type) external resistor to control buss voltage during regen.

Good luck !
Bob ~