LM-80NDA Series DC Ammeter (Mechanical Indicator)
Caution
- This product belongs in RoHS Directive under Category 9 "Monitoring and control equipment" with exclusion from the usage restriction of phthalate esters until 21 July 2021.
Product Description
A meter for measuring and displaying current from DC circuits.
[Features]
· Wide-angle meter, DC ammeter.
[Applications]
· Used for measuring current in power transmission/distribution lines, load equipment, etc.
· For measuring the amount of electricity, etc.
LM-80NDA Series DC Ammeter (Mechanical Indicator) Specifications
LM-80NDA external appearance
DC ammeter (direct) connection diagram
DC ammeter (combined with shunt) connection diagram
| Model | DC Ammeter | ||
|---|---|---|---|
| Accuracy Class (Grade) | 2.5 | ||
| Model Name | Size (mm) | 80 × 80 | LM-80NDA |
| Operating Principle | Moving coil type | ||
| Meter Rating | Direct | 300, 500 μANote 1 1, 3, 5, 10, 20, 50, 100 mA 200, 500 mA 1, 2, 5, 7.5, 10, 15, 20, 30 A | |
| Combined With Shunt, Multiplier Or Transformer | 1 to 7,500 A (combined with shunt) | ||
| Scale | Regular Scale | ◎ | |
| Cover Type | Black Cover (B) | ◎ | |
| Special Coating Color (F) | △ | ||
| Special Specifications | With Red Needle | ○ | |
| Special Accuracy Class Note 2 | ○ (class 1.5) | ||
| Non-Japanese Standards | △ | ||
| Special Environment | △ | ||
| Double Scale | ○ | ||
| Colored Lines/Bands | ○ | ||
| With Shunt | ○ | ||
| With Lead Wire | ○ | ||
| With Lead Wire Adjustment Resistors | ○ | ||
◎: standard specifications, ○: semi-standard specifications, △: special specifications
Note 1. Operating circuit voltage is 600 V or less.
Note 2. Please specify the frequency if requesting a special accuracy class with an AC meter.
| - | Wide-Angle Meter | ||
|---|---|---|---|
| L-N Series | |||
| Size (Width × Height) mm | 80 × 80 | ||
| Model Name | LM-80NDA | ||
| Operating Principle | Moving coil type | ||
| Accuracy Class (Grade) | 2.5 | ||
| Scale Length (mm) | 124 | ||
| Weight (kg) | 0.3 | ||
| Meter Rating | Maximum Scale Value | Internal resistance (Ω) or voltage drop | |
| Direct Meter Note 1 | 300 μA | 920 Ω | |
| 500 μA | 580 Ω | ||
| 1 mA | 180 Ω | ||
| 3 mA | 60 Ω | ||
| 5 mA | 8 Ω | ||
| 10 mA | 60 mV | ||
| 20 mA | |||
| 50, 100 mA 200, 500 mA 1, 2, 5, 7.5 A 10, 15, 20, 30 A | |||
| Combined With Shunt | 1 A to 7,500 A | 60 mV, 100 mV (current consumption: approx. 5 mA) | |
| Special Specifications | With Lead Wire Adjustment Resistors | Can be manufactured | |
Note 1. Operating circuit voltage for the L-N Series is 600 V or less.
Dimensional Outline Drawing
LM-80NDA dimensional drawing (units: mm)
A dimension: 81 mm
Common Specifications
| Standards | Direct-acting electrical indicators: JIS C1102-2, JIS C1102-3, JIS C1102-4, JIS C1102-5 |
|---|---|
| Accuracy Class | Class 1.5 and 2.5 (class 0.5 and 1 for frequency meters, class 5 for power factor meters, class 5 for synchroscopes) |
| Operating Temperature Range | -5°C to +50°C (standard temperature: 23°C) |
| Operating Humidity Range | At a relative humidity of 40% to 75%, there are no adverse effects on indications |
| Mounting Orientation | Vertical (the scale plate is vertical with respect to a horizontal surface) |
| Scale Plate | Background color: white |
| Cover | Acrylic resin (with antistatic treatment) |
| Case | Steel plate or molded |
| Input Signal Peak to RMS Ratio | Sine wave (√2) |
| Measurement Category | CAT III (category for measurement performed in building facilities) |
| Pollution Degree of Operating Environment | 2 (degree at which only non-conductive pollution occurs) |
| Altitude | 2,000 m or less |
| Usage Location | Indoors |
| Mounting Panel | Metal panel |
| Voltage Test | Rated voltage 300 V: 2,210 V for 5 seconds, rated voltage 600 V: 3,320 V for 5 seconds (between electrical circuit and outer casing) |
| Insulation Test | 10 MΩ or more at a test voltage of 500 V (between electrical circuit and outer casing) |
| Storage Temperature | -20°C to +60°C |
Table of Maximum Allowable Lead Wire Values For DC Ammeter Combined With Shunt
| DC Ammeter With Shunt | Maximum One-Way Length (m) With 2‑mm2 Lead Wire (Manufacturer's Standard Lead Wire) | Maximum One-Way Length (m) With 3.5‑mm2 Lead Wire | ||
|---|---|---|---|---|
| Model Name | Meter Rating (mV) | Lead Wire Maximum Allowable Resistance Value (Ω) | ||
| LM-80NDA | 60 or more, less than 75 | 1.00 | 54 | 96 |
| 75 or more, less than 100 | 1.50 | 80 | 144 | |
| 100 or more, less than 150 | 2.40 | 135 | 230 | |
| 150 or more | 4.00 | 217 | 384 | |
Remarks. (1) For bidirectional deflection indicators, the meter rating is the sum of the absolute values of each rating.
Remarks. (2) If a lead wire length exceeding the values in the above table is required, use a lead wire with a large cross-sectional area, or use a shunt with a high rated voltage.
Table of Round-Trip Resistance Values According To Lead Wire Thickness and One-Way Length
| Cross-Sectional Area | One-Way Length | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Round-Trip Resistance Value (Ω) (Length: One-Way) | Lead Wire Resistance (Ω/km) | ||||||||||
| 0.5 m | 1 m | 1.5 m | 2 m | 2.5 m | 3 m | 4 m | 5 m | 10 m | 20 m | ||
| 0.75 mm2 | 0.028 | 0.055 | 0.083 | 0.110 | 0.138 | 0.165 | 0.220 | 0.275 | 0.550 | 1.100 | 27.5 |
| 1 mm2 | 0.020 | 0.039 | 0.059 | 0.079 | 0.098 | 0.118 | 0.157 | 0.196 | 0.393 | 0.786 | 19.6 |
| 1.25 mm2 | 0.017 | 0.033 | 0.050 | 0.066 | 0.083 | 0.099 | 0.132 | 0.165 | 0.330 | 0.660 | 16.5 |
| 2 mm2 | 0.009 | 0.018 | 0.028 | 0.037 | 0.046 | 0.055 | 0.074 | 0.092 | 0.185 | 0.370 | 9.2 |
| 3.5 mm2 | 0.005 | 0.010 | 0.016 | 0.021 | 0.026 | 0.031 | 0.042 | 0.052 | 0.104 | 0.208 | 5.2 |
| 5.5 mm2 | 0.003 | 0.007 | 0.010 | 0.013 | 0.017 | 0.020 | 0.027 | 0.033 | 0.067 | 0.133 | 3.3 |
DC Ammeter With Lead Wire Adjustment Resistor
DC Ammeter With Lead Wire Adjustment Resistor connection diagram
If a DC ammeter combined with a shunt is to be arranged in advance with the lead wire length indeterminate, use a DC ammeter with a lead wire adjustment resistor that can be adjusted according to the lead wire resistance after meter installation.
Lead wire resistance adjustment range
The lead wire resistance adjustment range is the same as the lead wire maximum allowable resistance value in the “Table of Maximum Allowable Lead Wire Values” above.
Adjustment method
Adjustment by voltage application
Disconnect the lead wires connected to the voltage terminals of the shunt, and adjust with the lead wire adjustment resistor so that the meter deflects fully when a voltage corresponding to the meter rating is applied to either end of the lead wires.