New Industry Products

Pulizzi Intros New Latching Control Circuit

August 29, 1999 by Jeff Shepard

Pulizzi Engineering Inc. (Santa Ana, CA) introduced a new Latching control circuit for Remote On/Off and Emergency Power Off (EPO) requirements. The circuit is now available as an option on all applicable power distribution systems and mating remote control panels. According to Pulizzi, the Semiconductor S2-93A standard, OSHA, and many other safety standards and agencies require the latching circuit for optimum safety of equipment and personnel. The latching circuit places the power distribution unit (PDU) and connected equipment into a safe shutdown condition when emergency power off is activated or when there is a severe brown-out or blackout condition. Remote on/off and emergency power off are provided through the PDU industry-standard 3-pin I/O remote ports. Remote start requires two conditions, a maintained closure between pins 2 and 3 and a momentary closure between pins 1 and 3. Opening the closure between pins 2 and 3 shuts down the PDU immediately. Resetting the EPO switch will not power up the PDU after an emergency shutdown, according to Pulizzi. The user must also give the unit a momentary start as a second power up step. This two step process is intended to prevent sudden unmanned start-up of sensitive or dangerous equipment. If the remote control switch is accidentally disconnected from the PDU, the PDU will also shut down and will not power on until the connection is restored and the PDU is restarted. Additional features include EMI/RFI filtering, spike/surge suppression, Pulizzi's patented Multiple Time Delay Power Up and/or power down sequencing, automatic voltage sensing and switching, dual-input with primary to secondary power switching, single phase and three phase power.