Transient/Surge Absorbers (TSAs) provide system designers with a cost-effective method of protecting sensitive electrical and electronic equipment from damage caused by switching transients, coil and motor backlash, and near miss lightning strikes. There are 3 models available: single-phase (1P), 3-phase delta 3-wire (3PD), or 3-phase wye 4-wire (3PY). Each model is available to cover nominal AC voltages of 120, 208, 240 and 480. TSAs are designed using a ceramic and metal oxide technique which causes the resistance of the device to decrease abruptly if the rated voltage is exceeded. Voltage ranges are achieved by varying the types of oxide used in each model.