Ground Monitors and Ground Fault Relay Products
High Voltage Ground Monitor
The Line Power Manufacturing High Voltage Ground Monitor is an impedance-type ground monitor that can operate in either of two modes: UVR Mode or Non-UVR mode. Mode selection is made by changing the position of the “C1” lead on the rear of the unit. The unit is normally shipped wired in the UVR Mode. The UVR mode is fail-safe where the Non-UVR mode is not fail-safe.
In the UVR Mode, the monitor relay will energize when control power is present and the pilot-ground loop is complete with normal continuity. If the ground loop is “lost” (impedance increases 3 ohms or more after proper initial adjustment of the unit) the monitor relay will trip (de-energize) and the face plate indicator will indicate “Tripped”. The monitor is shipped wired for manual (“lockout” or “hand reset mode”) and can be wired for automatic reset by the addition of a jumper on the rear terminals. When this jumper is added, the trip indicator continues to function, but the relay will automatically reset when the ground loop is restored.
In the Non-UVR Mode, the relay is normally de-energized. The relay energizes to perform a trip function only when control power is present and the ground loop is open. To utilize the advantages of the monitor in the Non-UVR mode, the associated circuit breaker must employ a potential trip device. As with the UVR mode, the lock-out function can be defeated with a jumper. With this jumper (while in the Non-UVR mode) the relay states are reversed (lock-out puts the relay into an energized state instead of de-energized.)
Ground Fault Relay GT-137
This Line Power Manufacturing Ground Fault Relay is a compact and rugged ground fault relay designed for the harsh environment of underground mining. Referred to as GT-137, this unit has become the standard in ground fault relays for the mining industry.
In conjunction with its current transformer, a primary current injection, push-to-test ground fault is standard. This test, or an actual ground fault, will result in the trip of the manual reset breaker located on the ground fault relay and the trip of the associated output breaker, if closed. The manual reset breaker must be in a non-tripped position before the output breaker can close.
The Line Power Manufacturing GT-137 Ground Fault Relay is factory set at 5 amps, instantaneous, requires no field adjustment, and is designed for undervoltage or shunt trip applications.
Control Power: 115VAC, +/- 15% Continuous
Operating Temperature: +10° F to +120° F
Ground Keeper 1 Series Ground Monitors
Impedance-type ground monitoring combined with ground fault protection is conveniently packaged in the Groundkeeper 1 Series of Line Power Ground Monitors. Easy to understand indication lights and adjustments put all the information up front to show at a glance the condition of the circuit.
Ground Monitor Protection
The Groundkeeper 1 Series features easy to see lights on the front panel. The yellow “Control Power On” light shows when power is available to the unit. Next to it is the green “GM Picked Up” light which indicates the ground circuit is complete and the monitor is operational.
Also on the front cover are the “Test” button, “Polarity Switch” and “Adjust” knob. The “Test” button is provided to assist in initially setting the monitor and later to periodically check the operation of the monitor. When the test button is depressed, the “GM Picked Up” light should go out to indicate the monitor has been tripped. Next to the “test” button is the “Polarity Switch”. This switch reverses the polarity of the monitor current with respect to the induced voltages in the pilot wire/ground wire loop. Located in the center of the cover is the “Adjust” knob, for initially calibrating the monitor to trip as required by MSHA. (If desired, this knob can be easily relocated to an alternate position behind the front cover.) A simple set of instructions for ground monitor adjustment is printed on the front cover for operational convenience. The Groundkeeper 1 Series is MSHA accepted, B.T.S. #021177LPMC (1) - R3.
Easily Accessible Interior
The interior of the monitor is accessible from the front of the panel. The front cover may be taken off by removing two screws. This provides convenient access to the transformer taps used in adjusting the monitor and also to the relay, should replacement ever be necessary. The monitor may be used to operate either shunt trip or under-voltage release devices by moving a wire from one terminal to another.
Ground Keeper 143 Continuity-Type Ground Monitor
Fail-Safe Operation with Constant Ground Monitoring Machine Remote Control
Fail-safe control of machines stop and start operations and ground wire monitoring at the same time, is provided in a convenient package with the Line Power Groundkeeper 143. It can be used on remotely controlled machines or operator attended machines in achieving fail safe operation with freedom from nuisance tripping. The Groundkeeper 143B (P/N 17-0143B) is available for use up to 5KV applications.
Ground Keeper 145 Continuity-Type Ground Monitor
- Fail-Safe Operation With Constant Ground Monitoring
- Front Panel Design
- Machine Remote Control
Fail-safe control of machines stop and start operations and ground wire monitoring at the same time, is provided in a convenient package with the Line Power Groundkeeper 145. It can be used on remotely controlled machines or operator attended machines in achieving fail safe operation with freedom from nuisance tripping. The Groundkeeper 145B (P/N 17-0145B) is available for use up to 5kV applications.