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Lists three-phase TOV relay models and their corresponding descriptions.
Lists single-phase TOV relay models and their corresponding descriptions.
Details special TOV relay models with specific timing or contact configurations.
Specifies the operating and storage temperature ranges in Fahrenheit and Celsius.
Details insulation test requirements between terminals and ground, and independent circuits.
Lists the different operating voltage ranges available for the TOV relay models.
Provides the rated and operating ranges for the auxiliary DC/AC power supply.
Specifies the continuous, make/carry, and break capacity of the trip contacts.
Details the capacity for continuous, make/carry, and carry operations of auxiliary contacts.
States the voltage and time accuracy specifications for the relay.
Specifies the maximum ambient humidity the relay can withstand without condensation.
Lists the rated, effective, and operative frequency ranges for single and three-phase models.
Provides burden values (VA) for different voltage ranges at specific tap settings.
Specifies the maximum continuous voltage ratings for different voltage ranges.
Lists various electrical type tests including insulation, impulse, and noise tests with standards.
Specifies the instantaneous and definite time ranges for relay operation.
Explains input transformers, rectification, level detection, and trip indication for three-phase models.
Explains features like third harmonic filter and mode selection for single-phase models.
Describes the steel construction of the TOV case and provides general dimensions in a figure.
Explains that the model is on the nameplate and should be checked against the description section.
Illustrates external connections for both three-phase and single-phase TOV relay models.
Describes the single printed circuit board and its connection via a rear connector.
Shows the location of controls (switches) and indicators (LEDs) on the front panel.
Discusses internal controls like jumpers for configuration and notes factory calibration.
Instructs to verify nameplate data and check for damage after receiving the relay.
Introduces the electrical tests required to verify relay operation and factory calibration.
Recommends a clean, dry, well-lit environment and mounting on a vertical surface.
Explains how to set the trip level using the upper switch block based on a formula.
Refers to the ACCEPTANCE TESTS section for installation tests according to user criteria.
The GE Power Management TOV relay is a modular solid-state device designed for voltage protection in distribution systems. It functions as either an overvoltage or undervoltage relay, capable of operating in both single-phase and three-phase configurations. The relay offers instantaneous tripping or a fixed time delay, adjustable from 0.1 to 25.5 seconds. Settings for the relay are conveniently adjusted using switches located on the front panel of the device.
For single-phase versions, the TOV relay incorporates a filter for the third harmonic, which helps to ensure accurate measurements in environments where harmonic distortion might be present. Three-phase models, however, do not include this specific filter. The relay is supplied in a 1/8 rack case, making it suitable for integration into existing distribution systems.
The core function of the TOV relay is to monitor input voltages and initiate a trip when these voltages exceed or fall below a predefined threshold, depending on whether it's configured as an overvoltage or undervoltage relay.
In three-phase versions (TOV4000), input voltage transformers provide a secondary voltage that is adequate for internal operation at low voltages and ensures electrical insulation from the internal electronic circuits. The measuring signals are rectified and then compared against the set trip level by internal level detectors. When a fault condition (either overvoltage or undervoltage) is detected, a "pickup" indicator (Vs) illuminates. The relay can then be configured for either instantaneous tripping or a time-delayed trip. If the fault persists beyond the set time delay, the relay trips, and a "TRIP" indicator illuminates. This TRIP indicator remains lit until a RESET button is pressed, even if the fault condition has cleared.
Single-phase versions (TOV5000) operate similarly to the three-phase models but may include a third harmonic filter before the rectifiers. This filter is crucial for maintaining accuracy in single-phase systems where harmonic content might be a concern. Users can select the operating mode as either undervoltage or overvoltage. Once a pickup occurs, the tripping logic and indications follow the same pattern as the three-phase models.
Both single-phase and three-phase versions incorporate a power supply supervision circuit. This circuit monitors the auxiliary power supply, and if the voltage drops by 20% below its rated value, the relay automatically shuts down to prevent any incorrect operations that could arise from an unstable power supply.
The TOV relay is designed for ease of use and integration into various protection schemes. Its modular design allows it to be part of a larger distribution system, fitting into a standard 1/8 rack case.
The front panel of the relay features several controls and indicators that facilitate its operation and monitoring:
The relay's operating input voltage can be selected from various ranges (e.g., 20 to 275 VAC, 50 to 305 VAC, 3 to 66 VAC), offering versatility for different applications. Similarly, the auxiliary power supply range can be chosen from options like 24/48 VDC/VAC, 48/125 VDC/VAC, or 110/240 VDC / 110/220 VAC.
Common applications for the TOV relay as an undervoltage device include instantaneous detection of undervoltage in automatic transfer equipment and fault detection for line protection equipment, especially in scenarios where one terminal does not contribute to a fault in a three-terminal line. As an overvoltage device, it's used in time delay applications where operation security depends on voltage, protection against overvoltage in three-phase systems with adjustable delays, and protection against phase-to-ground faults in insulated ground systems or AC rotating machines.
The TOV relay is designed for reliability and ease of maintenance, with several features contributing to its long-term performance and serviceability.
General| Type | Time Overvoltage Relay |
|---|---|
| Manufacturer | GE |
| Function | Overvoltage Protection |
| Mounting | Panel Mount |
| Standards | IEC 60255 |
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