All versions include harmonic restraint as well as phase shift and tap compensation for use in transformer applications. Detailed differential check report provides confirmation of proper CT connections.

Features include:

• Up to 4 sets of 3 phase current inputs, plus standard 3 phase voltage and independent ground inputs provide complete protection and metering for 2 to 4 terminal differential applications.
• 10 to 14 contact outputs and 8 to 12 contact inputs, all BESTlogic programmable, plus a dedicated alarm output.
• "Virtual Circuits" allow internal summing of 2 or 3 sets of currents for use in protection and metering.
• Non-volatile storage of all target, oscillography, fault records, and SER data.
• Variable sample rate for frequency tracking allows for high accuracy in generator and motor differential applications.
• BESTlogic provides the user with complete flexibility in configuring a protection and control system. User programmable variable and switch names make the CDS240 relays completely self-documenting.
• Each CT circuit is low burden and isolated to allow improving zones of protection with fewer costly CTs.
• Large Bit Addressable LCD display allows the relay to replace local indication and control functions such as panel metering, alarm annunciation, and control switches.
• Expansion slot for communications coprocessor module provides a future upgrade path for Ethernet, IEC 61850, and other high-speed protocols.
• Three independent communications ports allow integration with distributed control systems, modems, and fixed or portable PCs. DNP protocol is available as an option. Consult factory for availability of Modbus™ protocol.
• Current circuits not used for differential protection can be used for independent overcurrent protection functions.
• The CDS240 uses a drawout module with automatic CT shorting facilities and fits cutout and drilling dimensions for many common Basler Electric, GE (BDD), and Westinghouse (HU) differential relays.
• BESTCOMS GUI software available to aid in setup.