User’s Manual 7M
6
BASIC DESCRIPTION AND OPERATION
The following chapter presents basic information about a three-phase energy meter 7M.38.8.400.xxxx required to understand
its purpose, applicability and basic features connected to its operation. In this chapter you will find:
• INTRODUCTION
• DESCRIPTION OF THE DEVICE
• THREE-PHASE ENERGY METERS APPLICATION
• MAIN FEATURES
• TYPE DIFFERENCES
INTRODUCTION
Regarding the options of a three phase energy meter, different chapters should be considered since it might vary in functionality.
TABLES
Supported functions and measurements are listed in tables. Symbols in tables indicate support of enabled functions for
different connection schemes. Additionally a legend is placed below table of used symbols. Meaning of symbols is:
Function is supported
Function is not supported
Symbol meaning varies and is described in the legend below the table
DESCRIPTION OF THE DEVICE
The three-phase energy meters 7M.38.8.400.xxxx are intended for energy measurements in three-phase electrical power
network and can be used in residential, industrial and utility applications. Meters measure energy directly in 3-wire and
4-wire networks according to the principle of fast sampling of voltage and current signals.
A built-in microprocessor calculates active/reactive/apparent power and energy, current, voltage, frequency, power factor,
power angle and frequency (for each phase and total sum) from the measured signals. This smart meter can also perform
basic harmonic analysis (THDU, THDI). This enables quick overview of harmonic distortion either coming from a network
or generated by the load. Microprocessor also controls LCD, LED, IR communication and optional extensions.
A capacitive touch button on the front of the energy meter enables access to switch between measurements and settings
in the menu. Connecting terminals can be sealed up against non-authorised access with protection covers.
The meters are built to be fastened according to EN 60715 standard.
Figure 1
: Appearance of three-phase electric energy meter 7M.38.8.400.xxxx
1
Current terminals – to load
2
AUX terminals (options):
• RS485 (MODBus)
• M-BUS
• PULSE INPUT AND OUTPUT (S0
1,2
)
3 NFC
4
Information display
5
DIN-Rail fitting
6
IR communication port – ON SIDE
7
LED indicator
8
Cap touch
9
Tariff clock input
10
Neutral input
11
Current terminal – source (max 80 A)
LCD Display type: Matrix (128 x 64)
Illumination: white (normal operation)
red (alarm indication)
LED Colour:
red
Pulse rate:
1000 imp/kWh
LED on:
no load indication