The Cutsforth Premium Monitoring System monitors and reports the attached generator's shaft voltage, ground current levels, and the consumable components of the grounding system. The 12-inch (30.5 cm), touch-panel display constantly updates live measured values, unit status, and alarm status. Live values are updated even when monitoring is paused or unit status is GEN OFF.
-
The Premium Monitoring System captures waveform-level snapshots whenever predefined step-up conditions occur, when an operator initiates a snapshot, and when operator-controllable threshold levels are crossed on the ground current, shaft voltage, or rope wear indicator voltage measurements. The monitoring system comes from the factory with the thresholds intentionally set to levels that will never trigger a snapshot or an alarm. This ensures that plant personnel do not misinterpret any factory-set thresholds as being applicable to their generator. Thresholds may be different from generator to generator, even when two identical generators are operating at the same plant.
-
The Premium Monitoring System records a high-resolution waveform snapshot from all monitored inputs every 6 hours, regardless of user settings. It accumulates a minimum of two years' worth of archived data that can be downloaded and viewed on another computer.
-
Waveform snapshots are 0.02 seconds long. This represents 1.2 shaft revolutions at 3,600 RPM. Due to the high data acquisition rate, each snapshot is approximately 7.9 MB in size, but will vary depending on user-set snapshot length.
-
Generator on/off status is constantly monitored unless the generator is sensed as offline. When Unit Status is GEN ON, alarms indicate the following conditions:
-
The consumable ropes require replacement.
-
Thresholds have been crossed.
-
Grounding integrity should be inspected.
-
-
The Premium Monitoring System reports a ground lost condition if ground current falls below the minimum threshold in conjunction with shaft voltage stepping up at a rate that is greater than the system's set ratio limit.
-
One-year historical trending averages of the ground current and shaft voltage values are displayed.
-
Voltage:
-
+/- 100 V DC
-
0-100 V RMS
-
0-100 V 0-Pk
-
-
Current:
-
+/- 50 A DC
-
0-50 A RMS
-
0-50 A 0-Pk
-
-
Isolation: 1500 V
-
Accuracy: +/- 1 V and 5% of current in specified range
-
Operating Temperature: -20 to 55°C (-4 to 131°F)
-
Scope Characteristics:
-
Each channel measured at 1 million samples per second at 14-bit resolution during typical monitoring
-
Every six hours, the scope measures at 20 million samples per second at 14-bit resolution to record a high-resolution snapshot
-
-
The Premium Monitoring System provides on-demand waveform views for both shaft and rope sensor measurements.
-
You can download recorded waveform snapshots to a flash drive via the supplied USB 2.0 port for permanent offline data storage.
-
You can view waveforms offline using a TDMS (Technical Data Management Streaming) file viewer such as Signal.X Scout.
The Premium Monitoring System comes supplied with seven 4–20 mA output channels that the plant may or may not connect to their data collection system, depending on plant policy. While the monitoring system-to-plant connection is optional, the hardware is required for the monitoring system application to operate. When connected, the monitoring system supplies the following information to the control room on a continuously updating basis:
-
Shaft voltage average
-
Shaft voltage AC zero-to-peak
-
Grounding current average
-
Grounding current AC zero-to-peak
-
Exciter shaft voltage average
-
Exciter shaft voltage AC zero-to-peak
-
Warning of individual rope wear indicator alarms, loss of grounding, and unit status (GEN ON or GEN OFF)
All descriptions in this manual assume that the Premium Monitoring System is connected via signal wires to Cutsforth’s proprietary shaft grounding and voltage sensing hardware, with rope wear indicators installed on the generator shaft.