ABB OVRT23N40320PTSU Surge Protective Device Brand: ABB. Part Number: OVRT23N40320PTSU. ABB Surge Protective Device, 320/640 V, 50/60 Hz, 4 Pole, 200 kA Short Circuit Current Rating, 20 kA Nominal Discharge, Modes of Protection: L-L /L-N /L-G /N-G, <25 ns Response, Class: II, NEMA 1 Enclosure, DIN Rail Mount, Gray, 71.2 mm W x 64.8 mm D x 98.5 mm H. Additional Description: ABB -OVRT23N40320PTSU (N) OVR SPD 3P+N 40KA 320V P TS 3RD ED. Catalog Description: Three pole OVR DIN rail surge protection device with a surge capacity of 40 kA and maximum voltage of 320V..