What is a rate of rise heat detector?

RATE-OF-RISE: A temperature increase at the sensor of 15F (9C) or more per minute activates the rate-of-rise feature. This closes the contacts in the sensor to transmit the alarm condition to the fire alarm control panel. When the rate-of-rise element alone has been activated, the sensor is self-restoring.

How do fixed temperature heat detectors and rate of rise detectors operate?

Fixed-temperature detectors signal when the detection element is heated to a predetermined temperature point. Rate of rise detectors signal when the temperature rises to a level exceeding a predetermined degree. Overall, they are slower to activate than other detecting devices.

What is the most common fixed temperature heat detector used today?

The most common fixed temperature point for electrically connected heat detectors is 58°C (136.4°F).

Where should heat detectors be placed in kitchen?

Heat alarms are ideal for kitchens, garages, boiler rooms, lofts and other areas where there are normally high levels of fumes, smoke or dust. 1. Install a heat alarm as close to the center of the ceiling as possible. If this is not practical, mount no closer than 4 inches from a wall or corner.

When to use a rate of rise heat detector?

A rate-of-rise component is sometimes added to a fixed-temperature design. This way, when either the fixed temperature or a pre-set temperature increase rate is exceeded, the detector will alarm. Heat detectors with a rate-of-rise feature tend to produce a higher level of protection in many applications, but should be used with caution.

How does a fixed temperature heat detector work?

CR/CF Series heat detectors offer fixed temperature or combina- tion rate-of-rise and fixed temperature detection. RATE-OF-RISE:A temperature increase at the sensor of 15°F (9°C) or more per minute activates the rate-of-rise feature. This closes the contacts in the sensor to transmit the alarm condition to the fire alarm control panel.

When does a heat detector need to be restorable?

Because of thermal lag, however, if the rate of temperature rise is fast, the detector may actually alarm when the room temperature is higher than the set point. Furthermore, these detectors are not restorable after a field test. The alarm is destroyed. A rate-of-rise component is sometimes added to a fixed-temperature design.

How does a rate compensation heat detector work?

A rate compensation detector is a device that responds when the temperature of the surrounding air reaches a predetermined level, with the rate of temperature rise having minimal effect on response (low thermal lag). This makes them rather sensitive fixed-temperature detectors.