A four-channel electronic ballast for UltraAqua UV systems, driving up to four 220 W UV lamps from one unit and providing a Modbus interface for monitoring and control. A UV ballast (lamp driver) is not a simple transformer. It strikes the arc in the lamp and then holds the discharge current constant for the rest of the lamp’s life, because a gas discharge has a negative resistance characteristic and would otherwise draw increasing current until it destroyed itself. Germicidal output is a direct function of that current being held correctly, so a failing or mismatched ballast shows up as under-dose long before it shows up as a dead lamp. The Modbus port is the practical difference from the plain two-lamp unit: lamp status, operating state and fault conditions can be polled by a PLC or SCADA system instead of being read off the panel, which is what makes it usable in an unattended or remotely supervised installation. It is listed for UltraAqua systems taking 220 W lamps, including the UV8PP, UV12PP and MR6PP. Supplied by cBallast on quote-to-invoice terms; lead time and freight are quoted per RFQ against the destination Incoterm.