Datasheet

Honeywell Sensing and Control 15
Figure 12. 2450A/2455RA Heat Detection Thermostats
The 2450A/2455RA Series is a single pole, single throw,
snap-acting, non-adjustable thermostat designed for easy
mounting in devices such as fire alarms, security devices
and smoke detectors. A temperature-sensitive bimetal disc,
electrically and thermally isolated from the switch, is used to
actuate the normally-closed contacts. Contacts open when
surface or ambient temperatures increase to the operating
set point of the calibrated bimetal disc. Devices are UL
recognized and designed for use in both photoelectric and
ionization type smoke detectors. Thermostats are available
with and without collectors and meet UL spacing
requirements for 15 ft, 30 ft and 50 ft. They are available to
open or close on a temperature rise of 47
°
C [117
°
F] to
107
°
C [225
°
F]. Devices feature gold contacts for low
voltage requirements and are epoxy sealed at the cap and
terminal for long storage life of the application. Collectors
are available in silver, black, beige, gold or bronze finishes.
All versions are UL approved.
Potential applications:
• Smoke alarm/heat detectors in industrial, residential and
commercial
NOTICE
Final approval of a fire detection system is determined by UL as outlined in UL #521 and UL #217 for the suitability of the
combination of the thermostat (2450A/2455RA) and the user’s mounting base, together with its intended application of the total
fire detection system. To assist the use with design and testing , a minimum of 0.25 in extension beyond the housing is
recommended.
Table 20. 2450A/2455RA Series Standard Temperature Characteristics
Detection (Close on Rise) Release (Open on Rise)
Close
°C [°F]
Open
°C [°F]
Open
°C [°F]
Close
°C [°F]
47 ±3 [117±5] 30 min [85 min] 57 ±3 [117 ±5] 30 min [85 min]
57 ±3 [135 ±5] 32 min [90 min] 57 ±3 [135 ±5] 32 min [90 min]
69 ±3 [156 ±5] 32 min [90 min] 69 ±3 [156 ±5] 32 min [90 min]
85 ±4 [185 ±7] 32 min [90 min] 85 ±4 [185 ±7] 32 min [90 min]
107 ±4 [225 ±7] 32 min [90 min] 107 ±4 [225 ±7} 32 min [90 min]
Notes:
• Additional switches can be provided as long as they fall between 47,2 °C to 107,2 °C [117 °F to 225 °F] close on rise or open or
rise.
• Please consult Honeywell for tolerances and temperatures not listed.