As a general purpose dual-voltage isolation transformer for step-up (120 to 240 VAC), step-down (240 to 120 VAC), or straight 1:1 isolation (120 to 120 VAC or 240 to 240 VAC). Models with a suffix “UC” are provided with a safety jack for access to the transformer secondary center tap (connected to the transformer center tap only in the 240 VAC output setting). This connection may be used in conjunction with a Dielectric Voltage Withstand test.