B-Line Electrically Held Lighting Contactor- Open Type

The CN35BN3HB is an electrically held contactor. The coil stays energized the whole time the contacts are closed, so the load drops out on any loss of control power. If you need the lighting to stay on through a control power interruption, or you want to avoid continuous coil draw and coil hum in an occupied space, you want a mechanically held (latching) contactor instead.

Three poles rated 20A. That covers three switched lighting circuits, or a three-phase lighting branch, at up to 20 amps per pole. If your panel schedule calls for more than three circuits off one contactor or a load above 20A, this is the wrong size and you need a higher pole count or higher ampere frame from the CN35 family.

No. It is the open type, meaning a panel-mount chassis with no enclosure or cover. It is meant to be installed inside a lighting panel, a control cabinet, or a separately purchased NEMA enclosure. If the contactor is going on a wall or in a mechanical room on its own, you need an enclosed version or a third-party enclosure sized for it, plus the mounting hardware for that box.

Yes, that is the normal application for an electrically held contactor. The time clock, photocell, or building automation relay switches the low-current coil circuit, and the three 20A power poles do the actual load switching. Because the CN35BN3HB is electrically held, the control contact must stay closed for the lights to stay on, so a momentary pulse output from a BAS will not work with it without a maintained relay.

Only if the unit you are pulling is the same CN35 open type, three-pole, 20A, electrically held build. Contactor footprints and mounting centers vary by frame and by manufacturer, so match the outgoing catalog number first. Confirm pole count, ampere rating, operation type (electrically versus mechanically held), and coil voltage all match before you cut wire.