ABB ACS800 A1>min Fault (8110)

hi guyz,
i have ABB frequency driver ACS800, sometimes showing alarm message A1>Min Fault (8110), once it's reset then it is gone. during running ever trip due this alarm also. i have checked the analog input wire from DCS for frequency setpoint and no loose wiring. and from DCS confirmed no tight shutoff which means there will be no current less than 4mA in 0% setpoint.my questions are ;
1. is the any other possibility for creating this alarm ?
2. in manual mentioned we can disable it, so what the benefit to put A1>min Fault there ?
3. is there any time delay we can configure in case any false fault signal of this?

thanks alot for ur help,

Two things. First, tune your minimum signal to the drive alarm setting. You can do this in Group 13 Parameter 06. Set your signal to the lowest possible level and then select TUNE. The drive will check your signal and match the setting to it.

Second, if that doesn't do it and you want the alarm anyway, you can set up automatic reset for that alarm only in Group 31. Be careful tho. You don't want a hazardous situation where the machine automatically resets with an operator nearby or worse, inside the machine!

Otherwise, just turn it off. You haven't lost anything really important. At worst, the drive will start and run at minimum speed with no input signal.

thanks for the reply,
1. any possiblity of cycle time scan so machine reset automatically by himself which causing min fault alarm ?
2. how to turn it off and any option to put in there with time delay to fault ?
3. group 30.01 mentioned the analog input minimum setting must be set to 0.5V (1mA)or above. i checked my configuration is set 0V. what is the impact ?

i'm just new for dealing with this frequency driver,
again thanks alot in advance,

Group 31 sets up an automatic reset and restart. Parameters 31.01, 31.02, and 31.03 set the number of trials and the timing between attempts. Turn 31.07 on and all the other fault sources off.

You can turn it off at 30.01 but there is no time delay option.

Since you are using a 4-20ma speed input signal, you must have it connected to Analog Input 2. Then you must have Parameter 13.06 set for 4ma or the tuned value I mentioned in my earlier post. If you have 13.06 set for 0ma and you are still getting the AI less than Min fault, your current loop is dropping to 0ma when it faults. Probably should fix that, too. Also, if 13.06 is set to 0ma and your signal has a 4ma minimum, then the input signal will never be able to command speeds under 20% of maximum speed. Your actual signal span and the settings for 13.05 and 13.06 should match.

Thank you sir for your valuable reply,but i am still not clear about my question 1. any possiblity of cycle time scan so machine reset automatically by himself which causing AI< min fault alarm ? what the other things could be possible trigging the AI

I answered your question 1. Please refer to Group 31, Parameters 31.02 and 31.03 for delay time and time between attempts.

The only cause for this alarm is analog input current falling below the designated minimum level in Group 13.

thank you Mr. expert, your response is really valuable for me. do you have idea why we need to put A1<minimum fault for trip, and if we disable it, based on your experience what are the consequences from safety issue or process issue ?
awaiting for your experience sharing,

I can see an issue if minimum speed is 0 but you ran a 4:1 ratio motor. If the 4-20mA wire break, the motor would run at 0 speed having it to heat up without any cooling (Standard squirel motor with shaft mounted fan)
in manny case, the motor can't handle a very low frequency where in some case it is useless to go so low (Fan, pumps) So i usually lock the lowest speed 25% or higher and at the worst, the motor will run healty at is lowest speed until someone see the problem...

but each case is different and need to be studied...

the case is about fault trip of this VFD due to AI<min fault alarm, i do agree with you that we should go to min speed acceptable, not go to TRIP. In case if any emergency based on safety interlock will work also to trip this motor, so far i have not seen benefits to put in fault trip on AI<min alarm.
any body has the experience to put this AI<min fault alarm to trip the motor ? i have it on my VFDs and I need the feedback from your experiences and from ABB's expert recommendation on this issue, either we keep it or we remove it.

Dear Mr. DickDV,
for example I put AI<min function alarm parameter 30.01 on CONST SP 15, It means while we have this alarm and The drive will generate a warning AI < MIN FUNC (8110) and sets the speed to the certain value which is defined by parameter 12.16.
and after this AI value is getting back to healthy again (no AI<MIN FUNC (8110) alarm), can we normalize the control of the speed setpoint by this analog input again ?

thanks in advance,