Switchbay Control Units
Switchbay Control Units
(OP)
We have ABB's Switchbay Control Units (SCUs) installed in 4.16 kV and 34.5 kV switchgear. Since the past 7 months, we have had a series of failures on some of these SCUs. The display becomes totally blank. Upon inspection, we found that the capacitor in the power supply card had failed. The failures occurred in different switchboards in different locations, so voltage spike is ruled out as a cause. Also, the ambient temperature in the room is around 25 degrees, well below the allowed 55 degrees C by the manufacturer. Could you please help me diagnose the reason for the failures?






RE: Switchbay Control Units
You may want to check for power quality issues like harmonics and spikes(you can have them at more than one location), though this type of equipment should not be overly sensitive to them.
RE: Switchbay Control Units
We already contacted the manufacturer, but the response from them is not so encouraging as it is well-past the warranty period. So, we are left to fend for ourselves. The installation is 5 years old. The manufacturer's catalog specifically says that the average life of the capacitor is over 35 years! What puzzles us is that in all the failures, the pattern is the same, i.e., failure of the capacitors, even though they are located in different switchboards in different locations. Does anyone have a similar experience / suggestions?
RE: Switchbay Control Units
RE: Switchbay Control Units
RE: Switchbay Control Units
Perhaps you can also send a failed unit out for forensic analysis and determine more about the failures.
RE: Switchbay Control Units
Each of the outgoing feeders from the switchgear has one of these SCUs installed and there over 200 such outgoing feeders from various switchboards. You are right, we are seriously considering blacklisting the manufacturer. But for the moment we are stuck with this problem.
RE: Switchbay Control Units