Type 53A25: Miniature electric fire detection switches with thermal glass bulb



Simple device for fire detection in buildings. This device is operating electrical contacts for remote alarm and simultaneous control of electrical servo-controls such as electric cylinders, electric motors or solenoids, for opening or closing air conditioning dampers, doors, sunroofs, and openings in building facades.


Main Features

Thermal sensitive part: Thermal bulb.

Operation: The break of the bulb operates an electric switch.

Mounting: Body with 2 holes for mounting on the wall or ceiling.

Electrical contact: Opening when the bulb breaks.

Rating: 16A (4A) 250V alt.; 10A (1A) 400V alt.; 4A (100mA) 24 and 48VDC. Compatible with 24V and 48V, 500 N electro-magnet.

Selection of of gold-plated silver contact avoids oxidation, and allows use on low level electronic circuits.

NB: use on circuits with a voltage greater than 12V and at more than 1A may vaporize the protective gold layer.

Body: 17 x 58 x 22 mm ceramic, with UV-resistant black PA66 cover,

– Flammability: UL94V0 and GWFI 960°C.

– Deformation temperature under load: 225°C. (ISO 75-2, 1.8 MPa).

– Room temperature class T200°C.

Electrical connection:  Screw terminals for wires up to 2.5mm².

Maintenance: The replacement of the 5x20mm thermal bulb is possible after unscrewing the PA66 cover

Options: Customization and customer labelling, plastic cover in red or cream color



2D&3D Drawing

Main references  

Operating temperature  References with silver contact  References with gold plated silver contact
Without thermal bulb 53A25PS000 53A25PG000
57°C (135°F) orange color bulb 53A25PS057 53A25PG057
68°C (155°F) red color bulb 53A25PS068 53A25PG068
79°C (174°F) yellow color bulb 53A25PS079 53A25PG079
93°C (199°F) green color bulb 53A25PS093 53A25PG093
141°C (286°F) blue color bulb 53A25PS141 53A25PG141
182°C (360°F) purple color bulb 53A25PS182 53A25PG182