The Case of the Non-Sensing Sensor
THE MYSTERY One of ACES’s municipal water customers had an issue with the external display for an ultrasonic sensor, which sits above a tank and measures the liquid level. The unit was displaying a fault and the customer could not get it to reset. THE CLUES One of the...The Case of the Shorted-Out Exhaust Fan
THE MYSTERY A municipal water customer was having an issue with the exhaust fan on one of their lift stations: When they flipped the switch to start the fan manually, it tripped two breakers. They called an ACES Control Systems Inspector (CSI) to the scene to...The Case of the Smoking Control Cabinet
THE MYSTERY The ACES CSI (Control System Investigator) was just finishing up a service call at a wastewater plant. He was testing the work he’d done on a controller, which runs a coagulation unit removing heavy metals from water. This is a high-current, low-voltage...The Case of the Temperamental Comms System
THE MYSTERY A large municipality hired ACES to upgrade their telemetry system from MDS serial to MDS Ethernet radios. We replaced almost twenty radios and installed two access points. After the replacement one access point periodically locked up. Cycling power would...The Case of the Overeager Pump
THE MYSTERY The freshwater division of a municipal water works complained that one of three pumps at a lift station was running constantly, causing the hydrostatic chamber to drain empty. This, in turn, caused the other pumps to come on, and eventually put so much pressure on the system that the pipes burst. The system was only rated for 93 psi, but with the other pumps running the pressure shot up to 130 psi.