The ESL 521NCSXT belongs to the 500N and 521 Series of photoelectric smoke detectors.
The ESL 500N series two- and four-wire conventional photoelectric smoke detectors bring together trusted technology and a full line of features to meet the demands of every type of application.
The 500N offers sounder models in two- and four-wire applications, specifically to meet residential code requirements, and are more sensetive to smoldering fires - the most common type of fire that occurs in homes - than ionization detectors
The ESL 500N series also offers choices for optional auxiliary relays and isolated heat sensors, not available before in the ESL 500 series. ESL 500N Series includes multiple criteria heat algorithms and self-diagnostics features.
Standard Features 500N Series Built-in sounder available in two- and four-wire models Patented CleanMeŽ feature Built-in dust compensation Field-replaceable optical chamber Small, low profile design blends in with any environment
The ESL 521 Series self-diagnostic, two-wire smoke detectors are the industry's first conventional direct-wire smoke detectors with analog features such as remote maintenance/trouble reporting (CleanMeŽ), drift compensation, and multi-criteria detection.
The 521 Series continually monitor their own sensitivity and operational status, and provide a visual and remote trouble condition if they drift out of the sensitivity range or fail internal diagnostics. This meets NFPA 72 field sensitivity testing requirements without the need for external meters.
The 521 has a unique feature enabling it to send a signal (CleanMe) to the ESL 505 module (sold separately) when it has drifted outside of its UL Listed sensitivity range or has failed its internal diagnostics test. The 505 is an interface module that will signal a 24V panel via relays when the 521 is dirty.
Several 12V and 24V control panels have the CleanMe software built in, eliminating the need for the 505 module. When CleanMe is not desired, simply leave the switch on the 521 off and it will work as a normal two wire detector. CleanMe allows the installer time to schedule a service call and avoid a false alarm.
Time between cleaning detectors is dramatically increased because of the 521's built-in drift compensation. This feature, usually only available in analog systems, allows the detector to automatically adjust its sensitivity over time as it becomes dirty, increasing the life of the detector. And when the 521 has told you that cleaning is necessary, it's literally a snap with ESL's patented field replaceable optical chamber.
Standard Features 521 Series CleanMeŽ remote maintenance reporting reduces false alarms Smart dual fixed/rate of rise heat works with photo chamber to catch fires faster Built-in drift compensation reduces false alarms Field replaceable optical chamber makes servicing a snap Small, low profile design blends in with any environment