Model HI921 is a plug-in, (2) two-wire thermal (heat) detector, compatible with Cerberus PRO Modular | FireFinder XLS/V and Model FC9-series FACPs. Each Model HI921 detector has microcomputer-chip technology and highly stable, solid-state electronic circuitry. Model HI921 detectors utilize a modern, accurate and shock-resistant thermistor to sense temperature changes. This electronic-sensing method virtually eliminates thermal lag associated with mechanical temperature-sensing devices and provides almost instantaneous temperature status to the FACP. Model HI921 provides indication of potential water freezing for sprinkler systems, via configuration for reporting a low-temperature warning of 40°F (4.4°C). This feature is compatible with Cerberus PRO Modular systems, as well as with FireFinder XLS/V and Cerberus PRO FC/FV922 or FC/FV924 FACPs.
Operating Temperature: +32° – +120°F (0° – +49°C) [with 145°F (63°C) | 155°F (68°C)
| 165°F (74°C) and 175°F (79°C) alarm-threshold settings] +32° – +100°F, (0° – +38°C) [ with 135°F (57°C) alarm threshold setting]
Thermal Rating: Model HI921 provides seven (7) field-selectable, preprogrammed temperature settings:
• Fixed 135°F (57°C)
• Fixed 145°F (63°C)
• Fixed 155°F (68°C)
• Fixed 165°F (74°C)
• Fixed 175°F (79°C)
• Rate-of-Rise: 15°F / min. (8.3°C) at fixed 135°F (57°C)
• Rate-of-Rise: 15°F / min. (8.3°C) at fixed 175°F (79°C)
Relative Humidity: 0 – 95% (non-condensing)
Air Pressure: No effect
Input Voltage Range: 16VDC – 30VDC
Alarm Current Max: 410μA
Standby Current Max: 250μA
Maximum Spacing: 50–ft. (15.24 m.) centers (2500 sq. ft. | 232.3 sq. m.), per NFPA 72 and ULC-
S524
Detector Weight: 0.317 Lbs. (0.144 kg.)
Approvals:
UL 521 Listed
ULC Listed
FM Approved:
CSFM Approved