Minilec offers motor load monitoring relays - cos d2 and pmr d2 - by sensing the power factor [pf] or the power drawn by the motor. These relays offer protection against no load condition, dry running and overloading. These relays are available for 380 v or 415 v system supply connected with 3 phase balanced loads. Cos d2 is motor load monitor sensing the pf. If the motor load drops so does its pf. If the pf reduces below the set value the cos d2 relay trips with time delay adjustable up to 10 sec. The relay resets automatically or manually as per selection. The adjustable start up delay of 1-10 secs enables the user to avoid nuisance tripping during start up operation. This is very effective for monitoring the dry run condition of very low rating pumps or slip belt failure of blower motors, free running conveyor motors. It can also be used as a back up monitoring of automatic pf correction using capacitor banks. The cos d2 can give alarm if the pf is not getting corrected even with the capacitor switching. Pmr d2 is a motor power monitoring relay which senses the load by measuring the power drawn by the motor with setting range of 10%-100% of under and over power. Separate start up delay avoids nuisance tripping of motors. The pmr d2 relay is to be used with minilec power sensor pts d1. These relays are useful for delta-star switching high rating motors, compressors especially with fluctuating loads, fry running of magnetic drive pumps, conveyor drive motors, submersible pumps, belt failure conditions of blowers, fans.
