Manual

Chapter 1 Introduction
EM920 Power Quality and Revenue Meter 11
RMS envelopes; up to 20 pre-fault and post-fault
cycles
Programmable Logical Controller
• Embedded Programmable Controller: 16 control
setpoints
• OR/AND logic, extensive triggers, programmable
thresholds and delays, relay control, event-driven data
recording
• 8 digital counters for counting pulses from external
sources and internal events
• 4 programmable timers from 1 cycle to 24 hours for
periodic recording and triggering operations on a time
basis.
Time and Clock
• High-accuracy real-time clock with a lithium backup
battery
• 1-ms satellite-synchronized clock option (IRIG-B time-
code input)
• SNTP clock synchronization option
• 1PPM or 1PPS clock synchronization option via a fast
digital input
• One-time programmable or calendar scheduled
daylight saving time (DST) switch dates; configurable
DST start and end time
Extended Security
• 3-level password security for protecting meter setups
and accumulated data from unauthorized changes
Display
• Easy to read high contrast graphical 4-inch 320x240
pixel (1/4 VGA) LCD display with backlight
• Multi-page data display with auto-scroll; time, billing,
instrumentation and service data
• Menu-driven setups
Standard Digital I/O
• Two embedded fast digital inputs with 1 ms scan time
• One KYZ relay output
Expansion I/O slot
• 8DI I/O module with 8 opto-isolated digital inputs
• 6DO I/O module with 6 relay outputs – two
electromechanical EMR Form A relays and four solid
state SSR Form C relays