Push Button Switches
ALX-HB4-BS142 Mushroom Head Key Release Push Button | 22mm 40mm 1NC
22 mm mushroom head push button with key-release reset, 40 mm red cap, 1 NC contact, zinc alloy chrome bezel, screw terminals, 600 V AC 10 A. Key-controlled reset for supervised machinery.
The HB4-BS142 is the key-controlled version of the maintained mushroom button. Pressing the cap latches the contact open; releasing it needs the key, which means only a supervisor can put the machine back into service after a stop. It is the usual choice where a restart must be logged or restricted, rather than left to whoever is at the panel.
Technical Specifications
Item | Specification |
Mounting hole | 22 mm (22.3 mm cutout) |
Bezel / head material | Zinc alloy, chrome plated |
Contact housing | Plastic |
Contact configuration | 1 NC |
Operation | Maintained, key release |
Actuator | Mushroom head, 40 mm dia. |
Actuator colour | Red |
Illumination | None |
Rated voltage / current | 600 V AC, 10 A (AC-15 duty) as marked on the contact block |
Termination | Screw terminals |
Reset requires the key supplied with the switch. Keyed-alike and keyed-different sets can be quoted for multi-panel installations.
Design Features
- Key-release reset: the latched stop can only be cleared by turning the key, not by pulling the cap
- Normally-closed contact stays open from the moment the cap is pressed until the key resets it
- 40 mm red cap gives a clear target while the key barrel sits inside the cap, out of the way of the operator's hand
- Chrome-plated zinc alloy bezel with metal clamping ring, aligned for repeated key operation
- Key can be removed in the reset position, so the same key cannot be left in two panels at once
Model Options
Model | Cap diameter | Contact |
HB4-BS142 | 40 mm | 1 NC |
Quote the quantity of panels when ordering, so the keys can be supplied keyed-alike across the installation.
Applications
Supervised machinery, maintenance-only reset points, school and laboratory equipment, and any panel where restart authority has to be controlled.