The WB1JB428 is a low-consumption contactor coil from the TeSys range, designed for the CV1B and CV3B contactor frames. It accepts both 110 V DC and 127 V AC at 50 Hz, with a coil resistance of 76.3 Ohm at 68 °F (20 °C). The control circuit type is AC/DC, meaning a single coil handles either supply without rewiring.
The dual-voltage rating — 110 V DC or 127 V AC — means the coil can be driven from either a DC control bus or an AC control transformer without changing the part. The operational voltage limits are 0.85 to 1.1 times Uc at 50 Hz and 60 Hz, up to 131 °F (55 °C). That gives you a working window: at 110 V DC the coil holds in from roughly 93.5 V to 121 V; at 127 V AC from about 108 V to 140 V. The 76.3 Ohm resistance at 20 °C lets you calculate steady-state current draw for your control transformer sizing — roughly 1.44 A inrush at 110 V DC, settling to holding current.
Deployment context
The low-consumption design reduces heat buildup inside the enclosure, which matters when multiple contactors share a confined panel space.