Smart Power Analyzer Meter

EM835 SERIES

1. Introduction

The multifunction panel meter SMART EM835 series is a top new-generation intelligent panel meter, used not only in the electricity transmission and power distribution system but also in the power consumption measurement and analysis in high voltage intelligent power grid.

This document provides operating, maintenance and installation instructions for the SMART EM835 series. The unit measures and displays the characteristics of single phase two wires, three phase three wires and three phase four wires supplies, including voltage, frequency, current, power and active and reactive energy, imported or exported, Harmonic, Power factor, Max. Demand etc. Energy is measured in terms of kWh, kVArh. Maximum demand current can be measured over preset periods
of up to 60 minutes.

In order to measure energy, the unit requires voltage and current inputs in addition to the supply required to power the product. The requisite current input(s) are obtained via current transformers.

The SMART EM835 can be configured to work with a wide range of CTs, giving the unit a wide range of operation. Built-in interfaces provide pulse and RS485 Modbus RTU outputs. Configuration is password protected.

2. Features

Measures kWh, Kvarh, KW, Kvar, KVA, PF, Hz, dmd, V, A, etc.
Bi-directional measurement IMP & EXP
Plug-in solution saves 80% labor
3-in-1 CTs
Easy “clip-in”panel mounting
User programmable system configuration
Self-powered, no need auxiliary supply
Programmable CT/PT ratio
Pulse output/RS485 Modbus RTU

3. Unit Characteristic

Measurement and display parameters
Line voltage and THD% (total harmonic distortion) of all phases
Key factor and Crest factor
Line Frequency
Currents, Current demands and current THD% of all phases
Power, maximum power demand and power factor
Active energy imported and exported
Reactive energy imported and exported
Real time date and time
Password protected set-upChanging password
CT Ratio and secondary current
PT Ratio and secondary voltage
Pulse output setting
Demand Interval time
Supply system selection 1phase2wire
Current Transformer Current ratioThe unit can be configured to operate with CT ratio between primary and secondary current is 1 and 2000.
There are two options of secondary current input: 1A or 5A
RS485 Serial – Modbus RTUThis uses an RS485 serial port with Modbus RTU protocol to provide a means of remotely monitoring and controlling the SMART EM835 series.
Set-up screens are provided for setting up the RS485
port.
Pulse output
This provides 2 pulse outputs those clocks up measured active and reactive energy. The constant for both output are configurable.

4. Dimensions

5. Wiring Diagram

6. Technical Specification

Measured Parameters	Single phase, 3-phase-3 wire, or 3-phase-4 wire
Voltage and Current	Phase to neutral voltages 100 to 289V.a.c Voltage between phases 173 to 500V.a.c (3p supplies only) Percentage total voltage harmonic distortion (THD%) got each phase to N Percentage voltage THD% between phases ( three phase supplies only) Current on each phase – 1 to 9999A rang, set by external current transformer (Cts) Current THD% for each phase
Power factor and Frequency and Max. Demand	Frequency in Hz Power 0 to 999MW Reactive power 0 to 999MVar Volt-amps 0 to 999MVA Maximum demanded power since last demand power factor Maximum neutral demand current, since the last demand reset (three phases supplier only)
Energy Measurements	Imported active energy 0 to 9999999.9 kWh Exported active energy 0 to 9999999.9 kWh Imported reactive energy 0 to 9999999.9 kVArh Exported reactive energy 0 to 9999999.9 kVarh Total active energy 0 to 9999999. 9 kWh Total reactive energy 0 to 9999999.9 kVArh
Measured Inputs	Voltage inputs through 4-way fixed connector with 2·5mm 2 stranded wire capacity. 3-Phase 3-and4-wire and Single-phase 2-wire unbalanced. Line frequency measured from L1 voltage or L3voltage. Three current inputs (six physical terminals) with 2·5mm2 stranded wire capacity for connection of external CTs. Nominal rated input current 5A or 1A a.c. Rms.
Accuracy	Voltage 0.5% of range maximum Current 0.5% of nominal Frequency 0.2% of mid-frequency Power factor 1% of unity (0.01) Active power (W) ±1% of range maximum Reactive power (Var) ±2% of range maximum Apparent power (VA) ±1% of range maximum Active energy (Wh) Class 1 IEC 62053-21 Reactive energy (Varh) ±2% of range maximum Total harmonic distortion 1% up to 31st harmonic
Interfaces for External Monitoring	RS485 Modbus RTU Relay output for real-time measured energy (configurable) Pulse output 5000imp/kWh (not configurable) Note: The modbus configuration (Baudrate etc.) and the pulse relay output assignments (kW/kVArh, import export etc.) are configured through the set-up screens.
Pulse Relay Output	The pulse relay output can be set to generate pulses to represent kWh or kVAr. Rate can set to generate 1 pulse per: 0.001=1Wh/VArh 0.01 = 10 Wh/VArh 0.1 = 100 Wh/VArh 1 = 1 kWh/kVArh 10 = 10 kWh/kVArh 100 = 100 kWh/kVArh Pulse width 200/100/60 MS. Relay Rating 240V ac 50mA
RS485 Modbus RTU	For ModbusRTU, the following RS485 communication parameters can be configured from the Set-upmenu: Baud rate 2400,4800,9600,19200,38400 Parity none/odd/even Stop bits 1 or 2 RS485 network address nnn–3-digit number, 1 to 247 *Modbus™ Word order Hi/Lo byte order is set automatically to normal or reverse. It cannot be configured
Operating Temperature	-25°C to +55°C
Storage Temperature	-40°C to +70°C
Relative Humidity	0 to 90% non-condensing
Altitude	Up to 2000m
Warm Up Time	1 minute
Vibration	10Hz ti 50Hz, IEC 60068-2-6, 2g
Shock	30g in 3 planes

* Maximum operating and storage temperature are in the context of typical daily and seasonal variation.