Schneider Electric PM850, PM820, PM810 manual Capabilities of the PM870 During an Event

63230-500-225A2	PowerLogicTM Series 800 Power Meter
3/2011	Chapter 9—Disturbance Monitoring (PM870)

— Use waveform capture to determine exact disturbance characteristics to compare with equipment sensitivity

— Justify purchase of power conditioning equipment

— Distinguish between equipment malfunctions and power system related problems

• Develop disturbance prevention methods

— Develop solutions to voltage sensitivity-based problems using actual data

• Work with the utility

— Discuss protection practices with the serving utility and negotiate suitable changes to shorten the duration of potential sags (reduce interruption time delays on protective devices)

— Work with the utility to provide alternate “stiffer” services (alternate design practices)

Capabilities of the PM870 During an Event

The PM870 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.

The power meter is configured with 12 default voltage disturbance alarms for all voltage channels. Current sag and swell alarms are available by configuring custom alarms. A maximum of 12 disturbance alarms are available. When the PM870 detects a sag or swell, it can perform the following actions:

•Perform a waveform capture with a resolution from 185 cycles at 16 samples per cycle on one channel down to 3 cycles at 128 samples per cycle on all six channels of the metered current and voltage inputs (see Figure 8–1 on page 63). Use PowerLogic software to set up the event capture and retrieve the waveform.

•Record the event in the alarm log. When an event occurs, the PM870 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 PM870 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 PowerLogic software to view the alarm log.

NOTE: The Power Meter display has a 1 second resolution.

•Force a data log entry in up to 3 independent data logs. Use PowerLogic software 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 maintenance icon to show that a sag or swell event has occurred.

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