The NM4 is constructed with a durable NEMA 4X rated fiberglass cabinet. Terminal connectors allow for larger gauge wires to be connected for remote loads. The NM4 is supplied standard in an industrial grey fiberglass finish. NEMA 4X emergency lighting heads are available in grey die-cast aluminum. Integrated mounting holes ensure proper and secure installation. External test switch and monitor LED are standard.
BATTERY: The NM4 is designed with a maintenance free, sealed valve regulated lead acid battery that provides a minimum emer- gency duration of 90 minutes (for the listed rating). Recharge time of the battery is 48 hours. The maximum battery operating tempera- ture is +40°C and the minimum is +10°C without internal heater option, with the internal heater the minimum operating temperature is -20°C. Nickel Cadmium batteries are available in several config- urations.
CIRCUIT: The NM4 utilizes a high-efficiency to stage charger providing precise float voltage control with low voltage disconnect protection. All components used in the circuitry are temperature compensated. The charger also has brownout and short circuit protection. Charger status is easily determined via a dual diagnostic LED display which indicates AC/ON and High Charge. An external push button test switch allows maintenance personnel to quickly determine the operational status of the unit and lamp load.