Description
96 x 48mm digital panel meters with 3.5 digit, 14.2mm high 7 segment LED’s. The products offer a wide range of AC or DC input parameters. Essentially there are 3 main product group types:- AC Volts, Amps, Milliamps, DC Volts, Amps, Milliamps, Millivolts, Frequency.
Application
With the combination of mA input M300-AD1 and the M100 series Power transducers, parameters such as kW, kV, Ar etc can be measured and displayed. Customer adjustment of botjh “ZERO” and “SPAN” is permissible via potentiometers, accessible from the rear of the product.
Meter rear view
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 rectfier. The resulting DC signal is presented to an analogue to digital A/D The A/D converter uses the dual converter 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 and 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 output signal to a DC signal. The resulting DC signal is fed into the A/D converter and the same process as in the AC and DC circuits previously described takes place.
General Specifications
| 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 | ± 1/5/10/20 |
| DC Amps | M300-AD2 | ± 100µA…199.9µa |
| DC Amps | M300-AD4 | 4/20mA |
| Frequency | M300-HZD | 35Hz…199.99Hz |
| IMPEDANCE | |
| M300-VAD | 10K Ohm/V |
| M300-VD1/2 | > 100K Ohm |
| M300-VD3/4 | 10K Ohm/V |
| BURDEN | |
| M300-AAD | < 2VA |
| M300-AD1/2/3/4 | 20mV drop |
| OVERLOAD | |
| Current | 4 x continuous |
| 25 x 1 second | |
| Voltage | 1.5 x continuous |
| 4 x 1 second | |
| Accuracy | ± 0.05% of reading ± 1 digits |
| Resolution | 0.05% |
| Linearity | ± 1 digit roll over error ± 2 digits |
| Conversion | Dual slope integration |
| CMR | AC 50dB 50 to 60Hz |
| DC 25 1K Ohm source unbalanced |
| Working Temperature | 0-60 deg C |
| Function Temperature | -25 to +70 deg C |
| Storage Temperature | -55 to 85 deg C |
| Temperature Coefficient | 0.01% per deg C |
| Relative Humidity | 0-95% non-condensing |
| Warm up time | 1 min |
| Shock | 30g in 3 planes |
| Test Voltage | 4kV RMS 50Hz 1 min |
| AC Voltage | 115/230/400 Volts (±25%) |
| 45 to 65 Hz Burden < 2VA | |
| DC Voltage | 24/48/110 Volts (± 20%) |
| Galvanic isolation. Burden < 3W |
| Digits | 1999 Full scale |
| Size | 14.2mm (0.56″) 7 segment red |
| Decimal Point | Internally selectable |
| Overrange indication | Displays “1” or “-1” |
| Update response time | < 1 second |
| Polarity | Automatic with (-) indicating negative inputs |
| DIN case | Dimensions 96 x 48 x 98 |
| Material | Black Polycarbonate Complying with UL94VO |
| Terminals | Screw type for 2 x 0.5-3.5mm |
| Weight | 0.4kg |
| Enclosure code | IP 54 NEM A 12 Optional IP65 NEM A4 |
a) All inputs (AC or DC) are connected via terminals 1 & 3
b) All Auxiliary supplies (AC or DC) are connected via terminals 6 & 8
c) Access to the “ZERO” & “SPAN” adjustment. Remove terminal
blanks in position 9 & 10. ZERO = 10,SPAN = 9
d) Optional externally selectable decimal point. 16=common, 15=1.999
14 = 19.99, 13=199.9 Link 16 as required.
