Dear all

we have a frequent failure of INFI 90 Power supply (MPS11). All power supply modules SYS01, FLD48 status showing OK. only MON01 monitoring module shows PFI (Power failure interrupt). that caused all control and I/O modules on the panel to stop. All information on the HMI lost. Resetting the PFI, all modules shall reset. information came back but unit tripped. That event repeated 2 times. All power supply modules are replaced with one from store (10 years old). CB, fans and distribution bus bar are inspected with no finding.

Later we have a similar event/trip

Do anyone faced the same? Please advise.

 

We have over 100 cabinets with power systems of various types, some from ~1983. With the amount of equipment and time involved, we have had a few instances of the power fail interrupt (PFI). The intermittent nature and lack of high speed diagnostics make this one of the more difficult items to resolve. Here are some of the more common (although "common" is not really an appropriate term given the proven robustness of the design) causes on an MPSII system (which is what you described):

1. Poor quality factory crimps on the large orange jumper cables from the rear of the power system to the vertical bus bar. The solution is to order new cables from ABB. An alternative is to remove the cables and fill the connector with solder. But given the cost of a trip I would replace them.

2. Poor quality connections of any of the jumper cables (large or smaller) between the rear of the power system and the vertical bus bar

3. Poor quality connections between the vertical bus bar and the module mounting units (MMU)

4. Old power supply modules, with one of them with an intermittent problem. Consider the age of the capacitors.

For the remainder, I've only seen these once each:

5. Faulty intermittent monitor module (IPMON01)

6. Faulty controller in an MMU that is dragging down one of the power busses (could be the + or -15 VDC depending on how the IPMON01 jumpers are configured)

7. Faulty source UPS with significant spiking on the ground.

If the cabinet is 15-20 years old or older, consider at a minimum removing all of the power jumpers, then inspect, clean, replace as needed, and reinstall.

If this is causing significant production issues, depending on the value, go ahead and upgrade to an MPSIII with all new jumpers. Since the cost of the MMUs are low, depending on the age and condition of the cabinet, we are starting to replace those as well.

 

Thank you John for these valued information. I will do all check you mentioned.

At the moment the PFI signal is disconnected from the panel bus and we monitor it. Signal is not coming since 5 days after cleaning the Power supply modules and back plane. But still i am not 100% confidant to connected back.