Simoreg 6RA2781 Fault F04

We have a spindel drive with a 75kw DC motor which has been working well over 15 years with little trouble other than replacing speed feedback tacho. The drive is now playing up every couple of hours with fault 04 which I believe is phase failure on armature. I have checked the armature main DC circuit including the DC motor and can not see any problem. As I don't have a manual for this drive in english can someone please suggest what triggers fault F04 and is there any parameters that can be monitored or changed.

Sammy

Here's the text from the manual:

F04 - phase failure, mains fuse or electronics power supply was switched off in the presence of DRIVE ENABLE signal (at terminal 64)

This sounds like the incoming supply - cracked fuse ?

Thanks for feedback will check today and will also check main contractor which is also on main AC side.

Sorry meant contactor which is on the AC incoming supply
Sammmy

Note that you can edit your own posts (within a certain time limit) to correct typos.

It could also be possible that your AC power is getting noisier due to changes and additions made elsewhere in your plant.

If the obvious stuff like loose connections, fuses, etc. doesn't do it, I would check to see if there is a drive isolation transformer or at least series reactors on the three AC phase lines. If not, you might need to add those to keep the SCR's firing properly.

Today I have checked all the obvious stuff including connections and main incoming fuses on the AC side (I have changed the fuses just case) still having the same problem F04. There is a main 3 phase contactor which was also checked and that was fine. The 3 phase overload unit is sealed so did not check. There is a inductor in series with the incoming supply which is 15 to 18 years old. This unit has not been checked the only thing that we have checked the 3 phase incoming at the drive using a multi-meter the incoming volts can vary from 435 to 410 across 2 phase. We do not have an isolating transformer this installation has worked well for over 15 years. Not having the manual for the drive does not help is there any parameter that can be changed to change the level of trigger?
F04 can also be the incoming control supply to the drive which when we measured was 360v there is no isolating transformer on this circuit.

Hi Sammy.

First of all some questions.

Does it happen during start, during normal run or when you are stopping the drive?

1. During start:
The enable signal is earlier high than the main contactor.
(result: enable without power)

2. During start or normal run:
Check the wires of the thyristor firing impulse (X12, X14, X16)
Maybe one or some of the thyristors is/are going to die.

3. During stop:
The main contactor opens faster than the enable signal.
(result: enable without power)
Shut off the main contactor with a short delay.
(We had this problem on a 6RA70xx drive.)

This is my solution based on your information.

Good luck and have a nice weekend.

ZIMBO

Thanks for replying to my post.
The drive seemed to trip only when it is run and have noticed when it trips is in the progress of changing from 1 to 11 (that's on display)

G'day Sammy.

Here you will find the manual in English language.

https://support.automation.siemens.com/WW/llisapi.dll?aktprim=0&lang=en&referer=%2fWW%2f&func=cslib.csinfo&siteid=cseus&caller=SR&caller=view&extranet=standard&startNode=4000024&nodeid0=21826615&objaction=csopen

br
Zimbo

Zimbo

Thanks for replying I have noticed your last post does not appear on thread anyway I have pasted below.

The information that you have provided is it valid for 6RA 2781 (I think it is only valid for the 6RA 70 looking at the menu there is no parameter P089.

I have managed to find a spare control board and after installing this the drive had the same problem.
I have noticed at reduced speed and load we seemed to have less trips.

Sammmy
G'day Sammy.

The operation status o11.0 only means, that there is an error.

You can check the parameter P047.00 (fault diagnostic memory display)

For F004 is means:

1 = Voltage failure in the armature supply (1U1, 1V1, 1W1)
2 = Delay time according to parameter P089 expired in operation status
o4
3 = Fuse failure in the SITOR set
4 = Voltage failure longer than the time set in parameter P086 (if this
is >0 )

br
ZIMBO
***************

Hi Sammmy.

You're right, the information was taken from the 6RA24xx-manual and i apologise for the confusion.
I posted this before i got the 6RA27-manual from Siemens. Later on i found out my mistake and deleted this post. You didn't reply at that time so i thought i hadn't do any harm.
Because the alarm F004 has the same meaning for all 6RAxx-drives and because i thought 6RA27 was a kind of upgrade of 6RA24 i assumed it was ok.
Again ... Sorry!

Nevertheless, because all of this drives are DC-drives and the alarm has the same meaning (logically) also the cause must be the same. There should be a parameter which has the same function.
If it's a hardware failure it also should have the same effect.

To get realy qualified help you should contact Siemens Support Request.
https://support.automation.siemens.com/WW/llisapi.dll?aktprim=99&lang=en&referer=%2fWW%2f&func=cslib.cssr&nodeID0=4000024&foldersopen0=-72-71-&siteid=cseus&extranet=standard

b r
Zimbo

Hi Sammmy.

Another try to help.

Check parameter P87.
To narrow down the reason of the failure you could set P87 to 1 or 3.
(Automatic restart after phase failure, on condition that the phase recover within 400ms)

b r
Zimbo

And another one.

You can disable the monitoring F04 by setting P91 but to me it seems dangerous.
In fact i don't know what happens during a phase fault without monitoring or rather if there is a risk of damaging and/or harm.

Nevertheless you will find the explanation of P91 in attach.
Zimbo

Zimbo,

Thank you for the information in fact two days ago I changed P87 from 1 to 3 this stops the fault from coming up on the drive (no need for anyone to reset the drive) but the drive still outputs to the PLC which means the enable signal is lost and the operator has to restart the drive which is not too bad. At this stage I have not changed P91 due to risk. I would like to have resolved this but due to lack of reliable spares I am looking at upgrading to 6RA70.