The 347 VAC Power Packs are the heart of the Low Voltage Sensor System. The PP20 transforms 120 or 277 Volts to class II 15 VDC to power remote sensors. Utilizing patented relay circuit protection the PP20 also switches the lighting load On and Off. This feature has been tested to over 400000 cycles at rated load! Although plenum rated the elongated mounting nipple allows for the PP20 to be mounted either directly thru a 1/2 inch knockout in a junction box or to be located inside an adjacent box for specific local code requirements. Up to 14 sensors may be connected to one PP20. Multi-circuit control can be handled by multiple PP20s or in combination with Slave Packs SP-20-3 . PP20s can be wired continuously hot line side or on the switch leg load side without nuisance delays upon turn On.