B-Line 16.2 mm Pushbutton Key Operated Switch

The Q18S3 is a 16.2 mm pushbutton-style key operated switch, so it drops into the standard 16.2 mm panel cutout used across the RMQ-57 line. The face plate above the panel measures 18 x 18 mm, so allow that much clearance around the hole when you are laying out a crowded enclosure door.

It springs back. The Q18S3 is a momentary three-position key switch, so the key returns to center when you let go of either side. If your control scheme needs the contact to stay made after the operator walks away, a momentary device is the wrong choice and you want a maintained-position key switch instead.

The Q18S3 is the key operator and front face plate. Contact blocks are the separate rear elements in the RMQ-57 system and are selected to match your circuit, so order the normally open or normally closed blocks you need alongside it.

Yes, it has three positions with a center rest, which is what you need for a two-direction momentary jog such as open/stop/close or forward/off/reverse. Because it is momentary, the machine runs only while the key is held over.

A key operator restricts who can run the function. On a maintenance override, a bypass, or a two-direction jog on machinery, a key switch keeps unauthorized staff from actuating it, which a plain pushbutton cannot do. The Q18S3 combines that with momentary three-position action, so the function is both restricted and released the moment the key is let go.

No. It is a non-illuminated device, so there is no lamp block or LED to feed and no separate light supply to run to it. If you need the operator position indicated on the panel face, plan a separate 16.2 mm pilot light beside it.

Black actuator with the square 18 x 18 mm face plate, which is the standard look across the RMQ-57 operators, so a row of them lines up consistently on a panel face.