Description
The CRM-72TO is a multifunction time relay that keeps timing according to its set function even after the power supply has been disconnected — a “True OFF” delay behavior not offered by standard time relays. This makes it particularly suited for delayed switching off of backup power supplies and safety-critical systems during a power failure, such as emergency lighting, emergency ventilation, and electrically/automatically operated doors on lifts and escalators.
The relay offers 8 selectable timing functions (4 “True OFF” functions in two behavior groups), with time delay conveniently set via rotary switch across four ranges from 0.1 seconds to 10 minutes, plus fine adjustment via potentiometer. Functions a–d reset and restart the delay if a power outage shorter than the set time occurs, while functions e–h ignore such short outages and complete the original delay uninterrupted — giving installers precise control over how the relay should behave during momentary supply interruptions (which must last only tens to hundreds of milliseconds for the true-off timing to function correctly). It runs on a universal AC/DC 12–240 V supply and provides one 16 A SPDT output plus one 8 A DPDT output, with a multifunction red LED indicating operating status.