M300 Introduction

There are 3 main product types :-
AC Volts, Amps, milliamps.
DC Volts, Amps, milliamps, millivolts.
Frequency.
With the combination of a mA input the M300-AD1 and the M100 series Power Transducer, parameters such as kW, kVAR etc. can be measured and displayed.

M300 specification

Input (accuracy range)
INPUT...........TYPE............RANGE
AC VOLTS.. M300-VAD.. 0.....600V
DC VOLTS.. M300-VD1 ...± 50/60/75/100/150mV
DC VOLTS.. M300-VD2 ...± 50mV ..... 1999mV
DC VOLTS ..M300-VD3 ...± 2V.....199.9V
DC VOLTS ..M300-VD4 ...± 200V....600V
AC AMPS ..M300-AAD.. 1 or 5 AC (0.2 TO 10A)
DC AMPS ..M300-AD1 ...± 1 / 5 / 10 / 20mA
DC AMPS ..M300-AD2 ...± 100uA..... 199.9uA
DC AMPS ..M300-AD3... ± 20mA......10A
DC AMPS ..M300-AD4 ...4/20mA
FREQUENCY M300-HZD 35Hz..... 199.9Hz

Overload
Current 4 x continuous 25 x 1 second
Voltage 1.5 x continuous 4 x 1 second

Accuracy
± 0.05% of reading ± 1 digit
Resolution 0.05%
Linearity ± 1 digit roll over error ± 2 digits
Conversion - Dual slope integration
CMR 50dB 50 to 60 Hz
DC 25 1k Ohm source unbalanced.
Normal mode rejection 25dB 50 to 60Hz

Auxiliary Voltage
AC 115 or 230Volts (± 25%) 45 to 65 Hz.
Burden < 2VA DC 24 / 48 / 110 Volts (± 20%) Galvanic isolation. Burden < 3W Display
Digits - 1999 full scale
Size - 14.2mm (0.56") 7 segment red
Internally selectable decimal point
Overrange indication
Update response time < 1 second Polarity  - automatic with (-) indicating negative inputs Impedance
M300-VAD 10k Ohm/V
M300-VD1/2 >100k Ohm/V
M300-VD3/4 10k Ohm/V

Insulation
Test Voltage:
4kV RMS 50Hz 1 min

Burden
M300-AAD < 2VA M300-AD1/2/3/4 20mV Environment
Working Temperature 0 to +60 °C
Function Temperature - 25 to +70 °C
Storage Temperature -55 to +85 °C
Temperature Coefficient 0.01% per °C
Relative Humidity 0-95% non condensing
Warm up time 1 min.
Shock 30G in 3 planes

Enclosure
Standard DIN case 96 x 48 x 94 mm
Panel mount via retaining side brackets and screws
Panel cut-out - 92 + 0.8mm x 45 + 0.8mm
Material - black polycarbonate complying with UL 94 VO
Terminals - screw terminal for 2 x 0.5-3.5mm
Enclosure code - IP54 NEMA 12
Weight 0.4kg

General
All units built and tested for safety, accuracy, quality and reliability.
Units are delivered fully calibrated, however adjustments to "ZERO" and "SPAN" can be made by removing the appropriate covers on the rear of the instrument.
These products must be installed by a qualified engineer.
VOLTAGES dangerous to human life may be present at some of the terminals of this unit.
Exercise extreme caution during installation.

M300 More Information

THEORY OF OPERATION:

AC Inputs
Both AC Voltage and Current circuits are average sensing RMS calibrated.
The input signal is transformed to a low level of AC
The transformer secondary voltage is fed to a precision active rectifier, the resulting DC signal is presented to an analogue to digital converter.
The A/D converter uses a dual - slope integration method of conversion.
The resulting digital information is used to drive the LED display.

DC Inputs
DC Voltage and Current inputs are fed into high stability ranging components.
The ranging components reduce the input signal to a 2 Volt level. If the input is below 2 Volts an amplifier is employed to derive 2 Volts.
The 2 Volt signal is then presented to the A/D converter which provides the digital information to drive the LED display.

Frequency Inputs
A frequency to Voltage F/V converter is used to convert the input signal to a DC signal. The resulting DC signal is fed in to the A/D converter and the same process as in the AC and DC circuit described above takes place.