ACS 800 fault # 4380 - TEMP DIF 3 U

This post is about fault number 4380 TEMP DIF 3 U. Long history short: clean your air filters. Other cause that I can think of is a hot spot on the connections on top of the modules. Good luck!

To give a little bit of context it must be said that underground mine environment has -despite control measures- presence of dust, humidity and fume due to other equipment operations, ventilation system airflow and others. Additionally, mining is a dynamic activity where you can see your quiet working space transformed into an area fully packed with workers and equipment (and their pollution) in just a couple of shifts.

This was how we ended experiencing fault 4380. An increase in pollution in the area where our beloved ACS800 drive works led to a clogged air filter despite we clean them monthly. Temperature got above failure threshold and voilá there was a new failure what to post about. Afterwards we decided to clean air filters quarterly and so far it is giving good results.

                     4380 fault message 

                          Air filter clogged 

ACS 800 F081 EMS STOP FAULT

The F081 fault was showing at the drive panel. It didn't show a regular pattern since it occurred both during movement of skips and when they were stopped at discharge position.

Figure 1. F081 fault.

First day we of course started by checking all emergency push buttons in the drive, PA console, at the LD and LL panels. Nothing wrong here and fault still happening.

Second day we checked drive inverter modules since Drive Windows' fault log showed a START INHIBI fault. This fault is (according to the manual) is linked to the ASTO control board. We check the drive modules and cleaned them up but fault still happening.

Figure 2. SYSTEM START fault

Figure 3. START INHIBI fault.

We finally checked PA.1 fault log again. We noticed that it showed a list of faults that are not really linked each other in the field. Kevin (one of the electrical guys here) then found a diagram that showed most of the components in the fault list. It was the one that shows connections of power sources at the AHC panel. We switched them off and voilà! we got same fault list. New power sources were installed and there was no problem since then. So please consider to change or upgrade your power sources every 4 years.

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Figure 5. New power sources installed.

ABC. 1 GP1 Valve 57 flt

This post is about "ABC.1 GP Valve 57"  fault and how we solved it . 

Fault has been occurring ever since we started operations but it didn't happen often so we didn't do further research until it hit us twice in a week causing my boss to panic and ended giving me the task to find the root cause of the fault.

Figure 1. The very moment when fault occurred.

In this particular case the fault occurred due to operation of the selector switches at the control panel PA.1. This happened because the placement of two switch selectors (clutch mode switch and operation mode switch) in the operator panel were side to side making possible for the operator to make the wrong selection. Usually the attention of the operator is focused on the CCTV monitor or in the HMI panel.

Figure. Usual operator posture

Figure. Original placement of switch selectors in control panel PA.1. Clutch mode and Operation mode switches are in the middle side to side.

Figure. New placement for switch selectors. Now "Clutch Mode switch" and "Operation Mode switch" are as far as they can be. It makes hard for the operator to get the wrong switch.

Additionally, due to the research done, other causes for this fault were found:

* Inductive sensors in valve 57. This is the first thing we inspected since it is linked to the description at the fault. We checked wiring connections and we watched the functioning during hoist operations.

Figure. Inductive sensors at v57 valve in GP.

* Clutch and sprag limit switches. Somehow during investigation somehow moved one of the limit switches at the clutch mechanism and this v57 fault appeared. Then we tried the same with the sprag limit switch and gave us the same result. I wonder that if these limit switches are loose you may have this fault too.

Figure. Manipulation of clutch limit switches.

Figure. Sprag limit switch.