- Assurance Monitoring System
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A Cutsforth product which monitors shaft voltages and shaft currents to provide real-time data locally and data outputs for integration into a DCS or historian.
- DC average
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The average of the DC component measurements during a sample period as calculated by ΣX/n, where X is the array of samples acquired and n is the number of samples.
- ground conductor
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8 AWG, green ground conductor that carries the shaft current to the unit case ground location.
- ground current
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The electrical current between the shaft and the unit case ground through the ground conductor.
- ground rope
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The left rope in the Shaft Grounding Assembly, which provides the primary path to unit case ground through the 8AWG ground conductor.
- ground rope HI
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A user-set threshold at which a ground rope fault is triggered, calculated as a ratio of PERIOD1 / PERIOD2. Shown on the Rope Stats Page as LIMITS.
- High-Frequency Drain (HFD)
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A 12 AWG conductor that splits off from the meter rope, runs through a low-inductance resistor, and then connects to unit case ground in less than 4 ft 6 in (1 m 15 cm). The HFD ensures that high frequency voltage spikes are grounded properly.
- junction box
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An enclosure that contains the current-sensing equipment and is placed between the Shaft Grounding Assembly and the grounding location.
- Metering Rope HI
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A user-set threshold at which a metering rope fault is triggered, calculated as a ratio of PERIOD1 / PERIOD2. Shown on the Rope Stats Page as LIMITS.
- meter rope
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The right rope in the Shaft Grounding Assembly which provides a shaft contact point at which shaft voltage readings are taken.
- oscilloscope resolution
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A measurement that describes the granularity of a waveform (like the resolution of a photograph).
- Premium Monitoring System
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A Cutsforth product that connects to Cutsforth’s Shaft Grounding Assembly to provide waveform-level shaft voltage and ground current settings and to store historical data for trending purposes.
The monitoring system can also be connected to plant DCS systems for real-time data in the control room.
- RMS
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Root Mean Square. A method of measuring the voltage or current of an AC waveform calculated by Xrms = sqrt[ (1/n) * (SUM(Xn ))], where X is the array of samples acquired and n is the number of samples acquired.
- Shaft Grounding Assembly (SGA)
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A Cutsforth product designed to provide a best-in-class ground connection, as well as a shaft contact point at which shaft voltage can be measured.
- shaft voltage
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The voltage potential between the shaft and the unit case ground as measured by the metering rope.
- signal cable
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Shielded cable that carries the voltage signals from the SGA and the SCA to the monitoring system.
- soft reset
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A Premium Monitoring System Application subcomponent restarts when not functioning properly or efficiently. The Premium Monitoring System Application does not close and the computer does not have to reboot.
- TC/TC-ER
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Ratings that describe the crush and impact requirements for cable types. For more information, see Type TC vs. Type TC-ER Cable at http://www.ecmweb.com/nec/type-tc-vs-type-tc-er-cable.
- unit case ground
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The lower half of the turbine case, generator case, or coupler case near the Shaft Grounding Assembly to which the shaft can be grounded.
- zero-to-peak
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A measurement of a signal calculated by |max(x)| or |min(x)|, whichever is greater, during a given period of time, where x is the array of samples acquired during that period.
A Cutsforth product which monitors shaft voltages and shaft currents to provide real-time data locally and data outputs for integration into a DCS or historian.
The reduction of the amplitude of a signal due to excessive cable length.
American Wire Gauge
The average of the DC component measurements during a sample period as calculated by ΣX/n, where X is the array of samples acquired and n is the number of samples.
Distributed Control System
Fluorinated Ethylene Propylene (high-temperature cable jacket material)
8 AWG, green ground conductor that carries the shaft current to the unit case ground location.
The electrical current between the shaft and the unit case ground through the ground conductor.
The left rope in the Shaft Grounding Assembly, which provides the primary path to unit case ground through the 8AWG ground conductor.
A user-set threshold at which a ground rope fault is triggered, calculated as a ratio of PERIOD1 / PERIOD2. Shown on the Rope Stats Page as LIMITS.
A 12 AWG conductor that splits off from the meter rope, runs through a low-inductance resistor, and then connects to unit case ground in less than 4 ft 6 in (1 m 15 cm). The HFD ensures that high frequency voltage spikes are grounded properly.
The resistance to change in the current of a circuit.
An enclosure that contains the current-sensing equipment and is placed between the Shaft Grounding Assembly and the grounding location.
Lockout/Tagout
A user-set threshold at which a metering rope fault is triggered, calculated as a ratio of PERIOD1 / PERIOD2. Shown on the Rope Stats Page as LIMITS.
The right rope in the Shaft Grounding Assembly which provides a shaft contact point at which shaft voltage readings are taken.
A measurement that describes the granularity of a waveform (like the resolution of a photograph).
A Cutsforth product that connects to Cutsforth’s Shaft Grounding Assembly to provide waveform-level shaft voltage and ground current settings and to store historical data for trending purposes.
The monitoring system can also be connected to plant DCS systems for real-time data in the control room.
Root Mean Square. A method of measuring the voltage or current of an AC waveform calculated by Xrms = sqrt[ (1/n) * (SUM(Xn ))], where X is the array of samples acquired and n is the number of samples acquired.
A rope assembly that can be used as a ground rope or a meter rope.
A Cutsforth product designed to provide a best-in-class ground connection, as well as a shaft contact point at which shaft voltage can be measured.
The voltage potential between the shaft and the unit case ground as measured by the metering rope.
Shielded cable that carries the voltage signals from the SGA and the SCA to the monitoring system.
A Premium Monitoring System Application subcomponent restarts when not functioning properly or efficiently. The Premium Monitoring System Application does not close and the computer does not have to reboot.
Ratings that describe the crush and impact requirements for cable types. For more information, see Type TC vs. Type TC-ER Cable at http://www.ecmweb.com/nec/type-tc-vs-type-tc-er-cable.
Technical Data Management Streaming (file format)
The equipment monitored by the Cutsforth monitoring system.
The lower half of the turbine case, generator case, or coupler case near the Shaft Grounding Assembly to which the shaft can be grounded.
A component that reduces the voltage in a circuit by a predetermined ratio.
A measurement of a signal calculated by |max(x)| or |min(x)|, whichever is greater, during a given period of time, where x is the array of samples acquired during that period.