Hi all, sorry for my english

Has somebody had problems with PLC's of series 90-30 of GE-Fanuc? We have an installation of less than two years with 3 of this type and racks CPU's and I/O units are damaged with too much frequency. I thank for commentaries of users of these PLC having indicated in that environment use them.

Atentament

Santi

 

My experience with GE Fanuc 90-30 has been very positive. We have them in our polymer extruders for many many years. One most be careful of the load on the output card. We buffer with relays that have diodes in parallel with the coil. This was done many years before I came to work at my current job and seem they will last forever.

Joe

 

hi santi,
We have PLC 90/30 installation with some analog input cards. It is working fantastic except one problem with CPU card. Whenever we down the power to the rack CPU should remain in RUN mode after power is restored . But in our case it is not happening. We tried to sort out this problem with Fanuc India....and we bought one 500VA battary backup UPS in 1/4th cost which Fanuc has quoted!!.
otherwise it is going very well.

I didnot get your problem with the system?? You have mensioned that the problem occured due to 'freq'.. Does your rack having DG power?? if so , Plz put power conditioner with built in AVR to tackle power problem. You can discuss in more detail on "[email protected]", mailto:[email protected]

With regards,
yogesh

 

Santi:

We have installed hundreds of 9030 PLC's with all kinds of I/O, and they are working perfectly. There must be something wrong on the installation or the field (overload, interference, grounding, etc).

Good luck,


Alvaro Rodriguez
REDES ELECTRICAS
Bogota - Colombia

 

I do not have any specific experience with this PLC but this does not sound like a PLC problem. It sounds like it might be an externally generated problem. I would look at your power, grounding, wiring, ambient environment, EMI environment, abuse environment, etc.

Bill Mostia
=====================================================
William(Bill) L. Mostia, Jr. P.E.
Partner
exida.com
Worldwide Excellence in Dependable Automation
[email protected](b) [email protected](h)
www.exida.com 281-334-3169
These opinions are my own and are offered on the basis of Caveat Emptor.

 

Santi,

I have been working with GE-Fanuc 90-30 and 90-70 products for about ten years now. I am very positive about the performance of these products. Like you however, I have experienced on certain projects a high degree of damages. In almost all of the cases it was found eventually that the problems were caused by too high voltages (absolute as well as common mode).

Especially you must be careful with the SNP programming port connection. It is stated in the manuals that the common mode voltage should not exceed seven volt. Take this serious, and analyse carefully how higher voltages could occur. Always use one common earthing point only, since difference in earth potential can easily exceed allowable values in case of an electrical power short circuit. Use isolators or surge arrestors if you cannot be sure that voltages are kept within range. I found that with overvoltage on the 15-Pin port it is very easy to damage not only the SNP communcation port but even the PLC and the whole backplane (rack).

Regards,
Wijnand Beke
System Integrator
P.O. Box 56610
3309 Limasol - Cyprus

 

You do not say what kind of I/O that you are using or what kind of cards that cause problems. This PLC may be used with Versamax series of I/O which works very well, but has what I consider a serious flaw in the design of some of the 4 to 20
milliamp current input cards. -They have insufficient input resistance to limit current on the loop. During testing or maintenance if you hook a 24 volt d.c. power supply to the input, then it will blow that input channel. This is a wiring mistake, but it can be an easy one to make. This is also the only 4 to 20 milliamp
input that I have ever seen from any manufacturer that failed in this manner.

-Arnold Dillon