| Product Type | Life Cycle | Description | Potential replacement options | Weblink | |
|---|
| AR high speed auxiliary relays | Classic | Ultra high speed auxiliary relay, four pole, non-adjustable pickup with a two millisecond operating time | | AR high speed auxiliary relays | |
| BL-1 temperature relay | Obsolete | For thermal overload and short-circuit protection of transformers and ac motors, usually rated 50 horsepower or more | Relion Relays (REX615) (Non Direct Replacement) | BL-1 temperature relay | |
| CA/CA-16 differential relay | Classic | Generator or transformer protection | HU-1 Relay(for CA-26 relay) | CA/CA-16 differential relay | |
| CM phase balance current relay | Classic | Designed to provide protection against unbalanced phase currents | | CM phase balance current relay | |
| CO/COM/COQ/COV overcurrent relays | Classic | Overcurrent protection | | CO/COM/COQ/COV overcurrent relays | |
| CP reverse phase voltage relay | Classic | Three-phase contact-making voltmeter which is used to detect reverse phase connections of lines, transformers, motors, generators, or synchronous condensers | | CP reverse phase voltage relay | |
| CR directional overcurrent relay | Classic | Disconnects transmission and feeder circuits | | CR directional overcurrent relay | |
| CRN1 single phase reverse power relay | Classic | Detects reverse power flow into ac generators | | CRN1 single phase reverse power relay | |
| CV/CVD/CVQ/CVX voltage relays | Classic | Voltage protection | | CV/CVD/CVQ/CVX voltage relays | |
| CW power relay zero degree characteristic | Obsolete | Single phase induction type relay | Relion Relays (REX615) (Non Direct Replacement) | CW power relay zero degree characteristic | |
| DGF field ground detection relay | Obsolete | Provides a reliable means for detecting grounds in the DC winding of the generator field | Relion Relays (REX640) (Non Direct Replacement) | DGF field ground detection relay | |
| DT3 power supply | Obsolete | Temperature protection of transformers, DC generators, and motors | None | DT3 power supply | |
| H-3 and HV-3 three phase directional relays | Obsolete | Polyphase direction relays which are used to obtain high speed directional discrimination during faults on power systems | Relion Relays (REX640) (Non Direct Replacement) | H-3 and HV-3 three phase directional relays | |
| HCB and HCB-1 pilot wire relay systems | Obsolete | Designed for the complete phase and ground protection of two and three terminal transmission lines | Relion Relays (REX640) (Non Direct Replacement) | HCB and HCB-1 pilot wire relay systems | |
| HRU instantaneous overcurrent relay with harmonic restraint | Obsolete | High speed relay used for the supervision of differential, overcurrent, or pilot relays | Relion Relays (REX640) (Non Direct Replacement) | HRU instantaneous overcurrent relay with harmonic restraint | |
| HU, HU-1, and HU-4 transformer differential relays | Classic | High speed relays used in the differential protection of transformers | | HU, HU-1, and HU-4 transformer differential relays | |
| ITH high dropout instantaneous unit | Classic | Solenoid operated device with an adjustable core screw which adjusts the ac current pickup of the device over a 2 or to 1 range | | ITH high dropout instantaneous unit | |
| JM annunciator and current indictor | Classic | Available in several different forms | | JM annunciator and current indictor | |
| KA-4 carrier auxiliary relay | Classic | Auxiliary relay used in a distance carrier relaying scheme | | KA-4 carrier auxiliary relay | |
| KAB high impedance BUS differential relay | Classic | Bus protection in most cases when bushing type CTs are in use, and in metal-clad equipment when CTs with toroidally wound cores having their windings completely distributed are employed | | KAB high impedance BUS differential relay | |
| KD compensator distance relays | Classic | Polyphase compensator type relay | | KD compensator distance relays | |
| KDTG distance and timer relay | Obsolete | Polyphase compensator type distance relay | KD-11, KD11 and TD5,Relion Relays (REX640) (Non Direct Replacement | KDTG distance and timer relay | |
| KDXG ground distance | Obsolete | High speed single phase distance relay | Relion Relays (REX640) (Non Direct Replacement) | KDXG ground distance | |
| KF underfrequency relay | Classic | High-speed under-frequency relay | | KF underfrequency relay | |
| KH directional relays | Classic | Series of directional relays | | KH directional relays | |
| KLF loss-of-field relay 50/60 hertz | Classic | Loss of field relay | | KLF loss-of-field relay 50/60 hertz | |
| KO-1 overcurrent relay | Obsolete | High speed overcurrent relay | CO,Relion Relays (REX610,REX615,REX640) (Non Direct Replacement) | KO-1 overcurrent relay | |
| KP three phase voltage and phase sequence relay | Obsolete | Undervoltage or overvoltage fault detector/check the phase sequence of a three phase voltage | Relion Relays (REX610,REX615,REX640) (Non Direct Replacement) | KP three phase voltage and phase sequence relay | |
| KS out-of-step blocking relay | Obsolete | Polyphase compensator distance type relay | Relion Relay (REX640) (Non Direct Replacement) | KS out-of-step blocking relay | |
| KV-1 undervoltage relay | Obsolete | High-speed single phase undervoltage relay particularly suited for applications where high drop-out ratio is desirable | SSV-T,Relion Relays (REX610,REX615,REX640) (Non Direct Replacement) | KV-1 undervoltage relay | |
| LC-1 linear coupler relays | Classic | Bus differential protection | | LC-1 linear coupler relays | |
| MDF microprocessor frequency relay | Obsolete | Digital frequency relay intended to sense hazardous under frequency (or over frequency) conditions | Relion Relays (REX610,REX615) (Non Direct Replacement) | MDF microprocessor frequency relay | |
| MG6 multi-contact auxiliary relay | Classic | Designed for applications where several independent circuits may be energized or de-energized upon the operation of a single primary relay contact or where the capacity of the primary relay contact is inadequate for the energy required | | MG6 multi-contact auxiliary relay | |
| PM pilot-wire monitoring and transferred tripping relays | Classic | Continuous monitoring of a pilot-wire circuit | | PM pilot-wire monitoring and transferred tripping relays | |
| POQ high-speed relay | Classic | Sensitive detection of unbalances or unbalanced faults | | POQ high-speed relay | |
| RC automatic reclosing relay | Obsolete | Automatic reclosure of AC or DC electrically operated circuit breakers | RER620/RER615 (Non Direct Replacement) | RC automatic reclosing relay | |
| SC and SC-1 instantaneous adjustable current relays | Classic | Suitable for any application where an instantaneous plunger relay of high accuracy is required | | SC and SC-1 instantaneous adjustable current relays | |
| SDG static ground distance relays | Classic | Single zone ground distance relays used to detect faults | | SDG static ground distance relays | |
| SG auxiliary relay | Classic | Intended for use in the applications requiring increased current-carrying or interrupting capability in a contact | | SG auxiliary relay | |
| SI-T overcurrent relay | Obsolete | High speed overcurrent device | | SI-T overcurrent relay | |
| SKD compensator distance relays | Obsolete | Polyphase compensator type distance relays | KD; REX640 (Non direct replacement) | SKD compensator distance relays | |
| SPP surge protection relays | Obsolete | Surge protection package | None | SPP surge protection relays | |
| SV instantaneous adjustable voltage relay | Active | Adjustable over a wide range of voltage | | SV instantaneous adjustable voltage relay | |
| SX toggle relay | Obsolete | Toggle type relay intended for auxiliary service | MG6 | SX toggle relay | |
| TD-4 timing relay | Obsolete | Used for timing application requiring a two-stage timing interval | TD-5,Relion Relays (REX610) (Non Direct Replacement) | TD-4 timing relay | |
| TD-5 timing relay | Classic | Used for applications requiring a time delay | | TD-5 timing relay | |
| TD-52 timing relay | Classic | allows utilization of two completely independent timing circuits | | TD-52 timing relay | |
| TR-1 auxiliary tripping and indicating relay | Classic | Auxiliary relay energized by protective relays | | TR-1 auxiliary tripping and indicating relay | |
| TRB zener tripping unit | Classic | Auxiliary device energized by protective relays | | TRB zener tripping unit | |