ALLOSUN EM480D Digital Earth Tester Instruction Manual

1. Introduction

The ALLOSUN EM480D is a professional digital instrument designed for measuring the grounding resistance of various electrical systems, equipment, and lightning protection installations. It also features the capability to measure AC voltage. This device is built for high stability and reliable performance, featuring a dust-proof and moisture-proof structure suitable for field operations.

Key features include:

• Accurate, reliable, and easy-to-use digital earth tester with high stability.
• Extra-large and clear 3.5-inch LCD display for easy readability.
• Strong anti-magnetic and anti-jamming functions.
• Over-range and low battery indications.
• Full function protection and anti-high voltage circuit design.
• Dust-proof and moisture-proof construction, ideal for field use.

2. Safety Information

Please read and understand all safety instructions before operating the ALLOSUN EM480D Digital Earth Tester. Failure to follow these instructions may result in electric shock, fire, or damage to the instrument.

• General Safety: Always use the instrument as specified in this manual. Do not use the instrument if it appears damaged or is not operating correctly.
• Electrical Shock Hazard:
  • Do not touch the test leads or the circuit under test during measurement.
  • Ensure all connections are secure before applying power or initiating a test.
  • Avoid testing in wet or damp conditions.
  • Always disconnect the test leads from the circuit before changing functions or ranges.
• Battery Safety:
  • Replace batteries when the low battery indicator appears to ensure accurate readings.
  • Do not mix old and new batteries, or different types of batteries.
  • Remove batteries if the instrument is not used for an extended period to prevent leakage.
• Environmental Conditions:
  • Operate the instrument within the specified operating environment (0℃-40℃, relative humidity: <85%).
  • Store the instrument within the specified storage environment (-10℃-50℃, relative humidity: <85%).

3. Package Contents

Upon opening the package, please verify that all items listed below are present and undamaged.

• 1 x ALLOSUN EM480D Digital Earth Tester
• 1 x Carrying Bag
• 1 Set x Test Leads (Red and Green simple-test leads)
• 2 x Auxiliary Earth Bars
• 6 x 1.5V AA Batteries
• 1 x English User Manual

Image: Contents of the ALLOSUN EM480D Digital Earth Tester package, including the meter, test leads, auxiliary earth bars, batteries, and manual.

4. Product Overview

The EM480D features a robust design with a clear LCD display and intuitive controls for ease of use in various environments.

4.1. Components and Controls

• LCD Display: 3 1/2 digits LCD with a maximum reading of 1999. Displays measurement results, overload indication, and low battery warning.
• Terminals: Input terminals for connecting test leads (E, P, C, V).
• Function Selector Knob: Used to select measurement ranges for grounding resistance (20Ω, 200Ω, 2000Ω) and AC voltage.
• TEST Button: Initiates the grounding resistance test.
• LOCK Button: Locks the display reading.
• HOLD Button: Holds the current measurement on the display.
• LED Indicators:
  • Green LED: Indicates normal operation.
  • Red LED: Indicates that the resistance between the "C" terminal and "E" terminal is outside the permitted range.
• Battery Compartment: Located on the back, holds 6 x 1.5V AA batteries.

Image: The ALLOSUN EM480D Digital Earth Tester showing its large display and carrying strap, highlighting its wide range capabilities.

Image: Close-up of the ALLOSUN EM480D's battery compartment (requiring 6 AA batteries) and the included auxiliary earth bars.

5. Setup

5.1. Battery Installation

1. Locate the battery compartment cover on the back of the EM480D.
2. Unscrew the retaining screws and remove the cover.
3. Insert six (6) 1.5V AA batteries, ensuring correct polarity as indicated inside the compartment.
4. Replace the battery cover and secure it with the screws.
5. The low battery indicator ("-+") will appear on the LCD when batteries need replacement.

5.2. Connecting Test Leads

The EM480D uses specific test leads for different measurements. Ensure proper connection for accurate and safe operation.

Image: The included 170cm green and red simple-test leads for the EM480D.

6. Operating Instructions

6.1. Grounding Resistance Measurement

This instrument measures grounding resistance using the three-pole method.

1. Preparation:
   • Insert the auxiliary earth bars into the ground at appropriate distances from the grounding electrode under test.
   • Connect the test leads to the EM480D terminals:
     • "E" terminal to the grounding electrode under test.
     • "P" terminal to the potential auxiliary earth bar.
     • "C" terminal to the current auxiliary earth bar.
2. Select Range: Turn the function selector knob to the desired grounding resistance range (20Ω, 200Ω, or 2000Ω). Start with the highest range if the resistance value is unknown.
3. Perform Test: Press the "TEST" button. The green LED should illuminate, indicating normal operation. The measurement will be displayed on the LCD. The response time is approximately 5 seconds.
4. Readings:
   • If the red LED illuminates, it indicates that the resistance between the "C" terminal and "E" terminal is outside the permitted range. Check connections and auxiliary earth bar placement.
   • If "1" is displayed, it indicates an over-range condition. Select a higher resistance range.
5. Hold/Lock: Use the "HOLD" button to freeze the current reading on the display. Use the "LOCK" button for continuous testing.

6.2. AC Voltage Measurement

The EM480D can also measure AC voltage up to 200V.

1. Connect Leads: Connect the test leads to the "V" and "E" terminals of the EM480D.
2. Select Range: Turn the function selector knob to the "ACV" range.
3. Measure: Connect the test probes to the AC voltage source. The AC voltage will be displayed on the LCD. The response time is approximately 2 seconds.

Image: Example of connecting the ALLOSUN EM480D to a wall socket for voltage measurement. The black test lead connects to the neutral/ground, and the red test lead connects to the live terminal.

7. Maintenance

7.1. Cleaning

Wipe the instrument with a damp cloth and mild detergent. Do not use abrasives or solvents. Ensure the instrument is dry before storage or next use.

7.2. Battery Replacement

When the low battery indicator ("-+") appears on the LCD, replace all six (6) 1.5V AA batteries as described in the "Battery Installation" section.

7.3. Storage

If the instrument is not used for a long period, remove the batteries to prevent leakage. Store the instrument in its carrying bag in a cool, dry place, away from direct sunlight and extreme temperatures.

8. Troubleshooting

9. Specifications

Image: Dimensions of the ALLOSUN EM480D Digital Earth Tester: 168mm length, 110mm width, 62mm height.

10. Warranty and Support

For warranty information and technical support, please refer to the warranty card included with your product or contact ALLOSUN customer service. Keep your purchase receipt as proof of purchase.

Manufacturer: Zhangzhou Eastern Intelligent Meter Co., Ltd