ABB DC drive trouble

I'm not an expert on ABB DC drives but, all communication is most likely stored temporarily in resident memory so, this would account for the communications errors. Because you are experiencing Communication and RAM errors, I would suspect a problem with the RAM or its associated I/O circuitry.

Hi TropicalSpeed,

Thanks for your valuable input. However, (if you don't mind) I would like to inquire further about the I/O circuitry you mentioned, which one are these, how do I locate them, does these also include the I/O circuit relevant to the connected external circuit like relays for outputs and switches for the inputs?

How do I locate the RAM in the card, and How do I test them?

Regards,

Sure. The I/O circuitry that I am referring to would be the control circuitry for the RAM, i.e, timing, control, address and data bus drivers and receivers. All of this circuitry would most likely be included on the same PC board that carries the RAM. My guess is you have a controller module on a DIN rail along with the I/O modules, power supply, etc.. If this is the case, then the controller module would probably need to be serviced as there is a RAM fault associated with this module. If you have a manual, check to see if it has a troubleshooting section. Sorry that I cannot be of more help. My knowledge of these drives is limited.

Unfortunately, it sounds like an electrical short or power surge took out the cards and memory. Return the unit to your ABB supplier or have the company rep out to your site and have them diagnose and repair.

Check the grounding of the unit. Did any electrical event take place prior to the failure? Plant wide or electrical service? Were any overloads or breakers tripped, fuses blown (supply or control power)?

Hi jcchiefeng,

Thanks for your insight. Yes you are right, we frequently encounter electrical power fluctuations while our mill is running, that we already have a lot of this ABB boards in question that were damaged, which we can't determine what caused its defect.

As such, is it advisable to install a UPS for power feed to the ABB drive's regulated power supply board which supplies the ABB control board containing the processor and PROM and RAM instead of supplying voltage to the ABB power supply board directly from the 220VAC mains? I would also add that the 2A fuse on the 220VAC supply to the electronics power supply board did not blow after the power fluctuations.

Can you suggest some alternative solutions that we can apply to our system to prevent the escalating destruction of our ABB boards from the uncontrollable power fluctuations?

Also, is it possible that the design of the ABB drive's electronic power supply board cannot sustain electrical transients? Because by comparison, we do also have Siemens drives and also eurotherm drives (aka SSD, aka parker) in our DC drive system but they don't exhibit this problems. I'm just wondering!!!

Regards,

Not knowing your UPS make/brand/setup, etc., it's hard to diagnose. Electrical "noise" or inductive currents in the grounding system after the UPS may be a cause. ABB may be susceptable to currents that your other drives can withstand. Are all drives in the same building or are the ABB's separate from the others?

You could also install MOV's on the incoming power supplies or local drive board power supplies? I would disect a drive after failure and find the reasons!

Have you made sure you don't have a Din Rail Problem as simple as dirty connection or knocked of feeder wire I was just thinking of some of the problems I ran into with an ABB drive more than 20 years ago and some of the solutions their drive course offered does the drive have a built in lithium battery that has never been changed?(Dc fault ,Ram fault)