A Power Pack is a plenum-rated device that uses a relay to switch 120/277V lighting loads and power up to 14 low-voltage sensors with 15VDC. It protects the relay contacts from damage caused by the inrush surge of electronic ballasts through a patented alternistor technology that absorbs the surge, and if damaged, a mechanical spring breaker trips to protect the unit.

1. What is a Power Pack? A Power/Relay Pack (PP20) is a plenum rated device used to switch lighting loads and power low voltage sensors. Key Specifications Switching 120/277 VAC Rated for switching 20 Amps Power Transforms 120/277 VAC line voltage to 15 VDC Sources 150 mA, enough for up to 14 sensors Power Packs

2. What is Inrush? Electronic ballasts (T8, T5) have capacitors that create an instantaneous surge of current (sometimes up to 1000A) upon initial power up This surge can damage a relays contacts over time, eventually leading to failure Power Packs Relay Contact Protection What is Relay Contact Protection? Patented technology by Sensor Switch that absorbs this “inrush” surge with a semi-conductor device called an alternistor Once surge is over, normal power load is carried by the relays Protects relay contacts (tested to over 400K cycles) If protection circuit is damaged due to extreme electrical conditions, an additional protection mechanism is provided by a mechanical spring breaker inside unit that trips the out protection circuit before unit is damaged Unit will continue to function