THE Sprecher + Schuh CEP 7-B electronic overload relay from NHP Electrical Engineering is an enhanced version of the standard CEP 7. Covering motors up to 48kW and up to 85 amps at 415 volts, this overload relay takes the basic CEP 7 overload relay and adds some new features.
Some of the new features include increased tripping accuracy, rapid phase failure detection, ground fault protection, jam/stall protection, low thermal dissipation, adjustable selection of motor run up times (10, 15 or 20 selectable via dip-switches), auto/manual reset, visible trip indication and test button.
It is a self-powered unit that also houses 1 N/O 1 N/C electrically isolated alarm contacts.
The jam/stall function of the CEP 7-B will detect motor currents higher than 400 per cent of the set current, tripping the overload in 0.5ms, protecting both the motor and the equipment.
The CEP 7-B detects ground faults at levels before they become short circuits thus allowing protection against greater damage that would occur under short circuit conditions.
This protection feature is controlled by a dip-switch located on the front of the CEP 7-B. The sensitivity of the relay is between 40 and 60 per cent of the current dial setting. The CEP 7-B is part of the popular ACS system which incorporates the CA 7 range of contactors. NHP 03 9429 2999.