A vehicle fill depleted the high-pressure hydrogen inventory. The compressor turned on to refill the storage by compressing 60 psig gas from a liquid hydrogen tank up to the 5500 psig storage pressure. After running about 2 hours, a crankshaft bearing started to fail. This allowed greater movement of the shaft, which led to a shaft seal leaking hydrogen. The compressor shut down on low suction pressure and then the system was shut down using the e-stop by the emergency responders.
A gas detector was added in close proximity to the compressor shaft and a vibration switch is under consideration. Additional predictive measures are being considered to predict bearing failure. In addition, the manufacturer has been contacted and the bearing design is being analyzed to see if it can be improved.