Replacement lamp ballast for Trojan UVLogic AL reactors, supplied against original Trojan part number 903988-01. 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. This is the wider-fitment ballast of the two UVLogic units in this catalogue: it covers the AL reactor and a range of UVSwift SC vessels as well as the 03AS20. Where the AS ballast (item 1529-0706) is listed for the 03AS20 alone, this one carries the full list below, so check the reactor model rather than assuming from the AS/AL letter pair. Supplied by cBallast on quote-to-invoice terms; lead time and freight are quoted per RFQ against the destination Incoterm.