5.3.2 RS485/Mbus Output for Modbus RTU
*For A-400MT/-M
For Modbus RTU, the following RS485 communication parameters can be configured from the
set-up menu:
Baud rate 2400, 4800, 9600, 19200, 38400
Parity none / odd / even
Stop bits 1 or 2
RS485 network address nnn - 3-digit number, 001 to 247
*For A-400MB only
For Mbus, the following communication parameters
can be configured from the set-up menu:
Baud rate 300,600,2400, 4800, 9600
Parity none/ odd / even
Stop bits 1 or 2
Mbus network primary address nnn - 3-digit number,001 to 250 Mbus network secondary
address 00 00 00 00 to 99 99 99 99
Please contact us if your require the Modbus/Mbus protocol document.
5.4 Accuracy
Voltage .......................................
Current.......................................
Frequency..................................
Power factor..............................
Active power (W).......................
Reactive power (VAr)................
Apparent power (VA)................
Active energy (Wh)....................
Reactive energy (VARh)............
THD.............................................
Response time to step input...
5.5 Reference Conditions of Influence Quantities
Influence Quantities are variables that affect measurement errors to a minor degree. Accuracy
is verified under nominal value (within the specified tolerance) of these conditions.
Ambient temperature.......................
Input waveform.................................
Input waveform.................................
5.6 Environment
Operating temperature............
Storage temperature................
Relative humidity.......................
Altitude.......................................
Warm up time............................
Vibration.....................................
Shock..........................................
* Maximum operating and storage temperatures are in the context of typical daily and
seasonal variation.
5.7 Mechanics
DIN rail dimensions..................
Mounting...................................
Sealing........................................
Material......................................
6. Dimensions
The meter is a 72mm x 94.5mm panel mounted
meter with a depth of 65mm The cut out hole for
the panel meter is 72mm x 94.5mm.
WARNING
Important Safety Information is contained in sections 7-8. Familiarize yourself with this
information before attempting installation or other procedures. Symbols used in this document:
Risk of Danger: These instructions contain important safety information. Read them before
starting installation or servicing of the equipment.
Caution: Risk of Electric Shock
7. Wiring Diagrams
5. Specification
5.1 Measured Parameters
The unit can monitor and display the following parameters of a single phase two wire(1p2w),
three phase three wire(3p3w) or four phase four wire(3p4w) system.
5.1.1 Voltage and Current
Phase to neutral voltages 100 to 289V a.c. (not for 3p3w supplies).
Voltages between phases 173 to 500V a.c.
Percentage total voltage harmonic distortion (THD%) for each phase to N ( not for 3p3w supplies).
Percentage voltage THD% between phases (three phase supplies only).
Current THD% for each phase
5.1.2 Power factor and Frequency and Maximum Demand
Frequency in Hz
Instantaneous power:
Power 0 to 99999 W
Reactive power 0 to 99999 VAr
Volt-amps 0 to 99999 VA
Maximum demanded power since last Demand reset Power factor
Maximum neutral demand current, since the last Demand reset (for three phase supplies only)
5.1.3 Energy Measurements
Imported/Exported active energy........
Imported/Exported reactive energy.....
Total active energy................
Total reactive energy............
5.2 Measured Inputs
2 Voltage inputs through 4-way fixed connector with 25mm stranded wire capacity. single phase
two wire (1 p2w), three phase three wire (3p3w) or three phase four wire (3p4w) unbalanced.
Line frequency measured from L 1 voltage or L3 voltage.
5.3 Interfaces for External Monitoring
Three interfaces are provided:
RS 485 communication channel that can be programmed for Modbus RTU protocol
Relay output indicating real-time measured energy (configurable)
Pulse output 3200imp/kWh (not configurable)
The Modbus configuration (baud rate etc.) and the pulse relay output assignments (kW/kVArh,
import/export etc.) are configured through the set-up screens.
5.3.1 Pulse Output
The pulse output can be set to generate pulses to represent kWh or kVArh.
Rate can be set to generate 1 pulse per:
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
www.autometers.co.uk
14
3 phase 4 wire
3 phase 3 wire
1 phase 2 wire
3 phase 4 wire
3 phase 3 wire
1 phase 2 wire
7.2 Wiring Diagrams
L1 L2 L3 N
L1 L2 L3 N
1
2
3
4
5
6
7
8
L1 L2 L3 N
L1 L2 L3 N
1
2
3
4
5
6
7
8
L1
L2
L3
L1
L2
L3
1
2
3
4
5
6
7
8
L1
N
L1
N
1
2
3
4
5
6
7
8
L1
L2
L3
L1
L2
L3
1
2
3
4
5
6
7
8
L1
N
L1
N
1
2
3
4
5
6
7
8
The A-400 can be supplied with two wiring configurations: Mains entering at the top, load at the
bottom - see fig.A; or mains entering at the bottom, load at the top - see fig.B.
MAINS
LOAD
MAINS
LOAD
Fig.A Mains at the top
Fig.B Mains at the bottom
