The BZ-150 is a full-featured power pack, providing 24 VDC operating voltage to Watt Stopper's low voltage occupancy sensors. In addition, the BZ enables special hold-ON, hold-OFF and load shed applications when used with lighting control panels or building management systems.
The BZ consists of a transformer and a high current relay. The transformer has a primary high voltage input of 120 or 277 VAC. The secondary output, which provides the operating power for Watt Stopper occupancy sensors, is 24 VDC, 150 mA. This 150 mA output is available with the power pack??_s relay connected. The power packs receive input from occupancy sensors or light level sensors and switch lighting on and off. For example, when an occupancy sensor detects motion, it electrically closes an internal circuit which sends 24 VDC to the power pack. This closes the power pack relay and turns the lights on.
The BZ is UL 2043 plenum rated with teflon coated low voltage leads and plenum rated plastic. This means that the power packs do not need to be installed in the junction box, but can be installed in the plenum. They are housed in ABS, UL-rated 94V-0 plastic enclosures.
BZ power packs can control lighting circuits, self contained air conditioners, pumps, fans, motors, VAV systems, motorized damper controls and setback thermostats. The hold-OFF input can be used to perform load shedding. During a power alert or during peak demand, a signal from a BMS or utility meter triggers the BZ to shed non-critical lighting loads. The hold-OFF function also works with a security system to hold some lights off during a security walk-through. The hold-ON input is ideal for retail and commercial facilities that want to hold certain lighting ON during normal business hours. After-hours, a time clock signals the BZ to no longer hold lights ON, allowing occupancy sensors to resume control.