Schneider Electric Capabilities of the Circuit Monitor During AN Event, Categories CM-4000

63230-300-212	Chapter 9—Disturbance Monitoring
April 2001	Capabilities of the Circuit Monitor During an Event

CAPABILITIES OF THE CIRCUIT MONITOR DURING AN EVENT

The circuit monitor calculates rms magnitudes, based on 128 data points per cycle, every 1/2 cycle. This ensures that even sub-cycle duration rms variations are not missed. Table 9–1shows the capability of the circuit monitor to measure electromagnetic phenomena in a power system as defined in IEEE Recommended Practice for Monitoring Electric Power Quality (IEEE Standard 1159-95).

Table 9–1: Capability of the circuit monitor to measure electromagnetic phenomena

Categories	CM-4000
Short Duration Variations
Instantaneous
Momentary
Temporary
Long Duration Variations
Voltage Imbalance
Waveform Distortion
Voltage Fluctuations
Power Frequency Variations	￿

When the circuit monitor detects a sag or swell, it can perform the following actions:

•Perform a waveform capture with a resolution up to 512 samples per cycle on all channels of the metered current and voltage inputs. Three types of automatic event captures are possible: disturbance, adaptive, and 100 ms. See “Types of Waveform Captures” on page 108 in Chapter 8— Waveform and Event Capture for more about waveform and event captures. Use SMS to setup the event capture and retrieve the waveform.

•Record the event in the alarm log. When an event occurs, the circuit monitor updates the alarm log with an event date and time stamp with

1 millisecond resolution for a sag or swell pickup, and an rms magnitude corresponding to the most extreme value of the sag or swell during the event pickup delay. Also, the circuit monitor can record the sag or swell dropout in the alarm Log at the end of the disturbance. Information stored includes: a dropout time stamp with 1 millisecond resolution and a second rms magnitude corresponding to the most extreme value of the sag or swell. Use SMS to view the alarm log.

•Force a data log entry in up to 14 independent data logs. Use SMS to set up and view the data logs.

•Operate any output relays when the event is detected.

•Indicate the alarm on the display by flashing the alarm LED to show that a sag or swell event has occurred. From the circuit monitor’s display, a list of up to 10 of the previous alarms in the high priority log is available. You can also view the alarms in SMS.

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