USER MANUAL Insulation Tester + DMM Model MG325
Table of Contents 1. INTRODUCTION 3 2. SAFETY 3 3. METER DESCRIPTION 5 4. CONTROL BUTTONS 6 5. SYMBOLS AND ANNUNCIATORS 6 6. OPERATING INSTRUCTIONS 7 6.1 Display Backlight 6.2 Data Hold 6.3 Low Battery Indication 6.4 DC VOLTAGE MEASUREMENTS 6.5 AC VOLTAGE MEASUREMENTS 6.6 RESISTANCE MEASUREMENTS 6.7 CONTINUITY MEASUREMENTS 6.8 CAPACITANCE MEASUREMENTS 6.9 INSULATION RESISTANCE MEASUREMENTS 6.9.1 Disable Lock Mode for Insulation and Continuity Tests 6.9.2 Insulation Resistance Test Timer 6.
1. Introduction Congratulations on your purchase of the MG325 True RMS Insulation Resistance CAT IV 600V DMM. The MG325 features a rugged design for heavy duty use. The MG325 measures Insulation Resistance, AC/DC Voltage, Frequency, Leakage Current, Low Resistance, Continuity, and Capacitance. Insulation Resistance tests are automatic ranging with 5 test voltages from 50V to 1000V. The MG325 can store and recall up to 99 measurements.
PER IEC1010 OVERVOLTAGE INSTALLATION CATEGORY OVERVOLTAGE CATEGORY I Equipment of OVERVOLTAGE CATEGORY I is equipment for connection to circuits in which measures are taken to limit the transient over-voltages to an appropriate low level. Note – Examples include protected electronic circuits. OVERVOLTAGE CATEGORY II Equipment of OVERVOLTAGE CATEGORY II is energy-consuming equipment to be supplied from the fixed installation. Note – Examples include household, office, and laboratory appliances.
SAFETY STANDARDS This instrument is designed and produced strictly in accordance with the safety requirements for GB4793 electronic measuring instruments and IEC61010-1 safety standards. This instrument meets the double insulation over-voltage standard CAT IV 600V and pollution degree II. Failure to use the instrument as described in this user manual can weaken or negate the protections provided. Check the instrument, test leads, and test pen before use.
4. Control buttons 1. Data Hold on/off (short press) for AC/DC Voltage, 4 Resistance and Capacitance modes only. Also for display Backlight on/off (long press) 2. Short press to Recall stored readings. Another short press to exit this mode. Also used as an ENTER confirmation button in SETUP mode. 3. 6 7 8 3 2 1 9 Save reading (short press) and Clear all stored readings (long press) 4. 5. 5 Comparator (short press) and Zero (long press) PI and DAR test mode selection (short presses).
6. Operating Instructions WARNING: Risk of electrocution. High-voltage circuits, both AC and DC, are very dangerous and should be measured with great care. 1. ALWAYS turn the function switch to the OFF position when the meter is not in use. 2. If “>” appears in the display during a measurement, the value exceeds the maximum range of the meter. 6.1 Display Backlight Press and hold the button to switch the backlight on or off. Excessive use of the backlight will cause the batteries to drain quicker. 6.
6.5 AC VOLTAGE MEASUREMENTS WARNING: Risk of Electrocution. The probe tips may not be long enough to contact the live parts inside some 240V outlets for appliances because the contacts are recessed deep in the outlets. As a result, the reading may show 0 volts when the outlet actually has voltage on it. Make sure the probe tips are touching the metal contacts inside the outlet before assuming that no voltage is present.
6.6 RESISTANCE MEASUREMENTS WARNING: To avoid electric shock, disconnect power to the unit under test and discharge all capacitors before taking resistance measurements. Remove the batteries and unplug the line cords. WARNING: To avoid electric shock, never measure resistance on circuits or wires that have a voltage. 1. 2. Set the function switch to the k Ω position. Insert the black test lead banana plug into the negative EARTH jack (6).
6.7 CONTINUITY MEASUREMENTS WARNING: To avoid electric shock, disconnect power to the unit under test and discharge all capacitors before taking continuity measurements. Remove the batteries and unplug the line cords. WARNING: To avoid electric shock, never measure continuity on circuits or wires that have a voltage. 1. 2. Set the function switch to the position. Insert the black test lead banana plug into the negative COM jack (5). TEST Insert the red test lead banana plug into the positive jack (4).
6.8 CAPACITANCE MEASUREMENTS WARNING: To avoid electric shock, discharge capacitors before measuring them. 1. Set the function switch to the position. 2. Insert the black test lead banana plug into the negative EARTH jack (6). Insert the red test lead banana plug into the positive 3. Use the jack (7). button to choose the Capacitance mode (the button toggles Capacitance and Resistance modes). F 4. Touch the test probe tips across the circuit or part under test. 5.
6.9 INSULATION RESISTANCE MEASUREMENTS Note: Disconnect the unit under test from all power sources and isolate it from any stray resistance. 1. Connect the red test lead to the meter’s INSULATION (+) jack (7) and the black test lead to the EARTH (-) jack (6). Connect the probe end of the test leads to the circuit under test. 2.
6.9.1 Disable Lock Mode for Insulation and Continuity Tests To disable test lock mode and use manual test mode, press and hold the button until the lock icon switches off and then press and hold the TEST button for the duration of the test (TEST will be displayed). Release the button to stop the test. 6.9.2 Insulation Resistance Test Timer Please read and understand the sections on Insulation Resistance testing and Safety before continuing.
6.9.4 Polarization Index [PI] Insulation Testing Read and understand all operations and safety information contained in the Insulation Resistance measurement section above and the Safety section before continuing. 1. Connect the meter to the device under test as shown in the Insulation test section above. 2. Select the desired output test voltage using the rotary function switch. 3. Use the PI/DAR button to access the PI test mode. 4.
7. Data Recording The MG325 can store, recall, and clear up to 99 readings (01-99). 1. Press the button to save a displayed reading. 2. The displayed counter increments to the next available memory location. 3. To recall a reading, press the button (RECALL will be displayed). Use the arrow buttons to scroll the stored readings. The stored reading counter keeps track of the memory location again to return to the normal mode. (01-99). Press 4. button for 2 seconds to erase all memory location data.
9. Maintenance WARNING: To avoid electric shock, disconnect the test leads from any source of voltage before removing the back cover or the battery or fuse covers. WARNING: To avoid electric shock, do not operate your meter until the battery and fuse covers are in place and fastened securely. This Instrument is designed to provide years of dependable service, if the following care instructions are performed: 1. KEEP THE METER DRY. If it gets wet, wipe it off. 2.
10. Specifications Function Range Resolution Accuracy DC Voltage ±600V 0.01V to 1V (2.0% reading + 3 digits) 0~600V 0.01V to 1V (1.5% reading + 5 digits) AC Voltage Frequency Continuity Resistance Specified from 5% of range to 100% of range Input impedance: 10M Frequency 45~400Hz (unspecified for frequency >400Hz) Input protection: 600V DC and AC rms 45~1kHz 0.1Hz (0.
500V (0%~+20%) (250~600V) 500kΩ 250VAC/DC 1mA ≤2mA 1000V (0%~+20%) (500~1200V) 1MΩ 250VAC/DC 1mA ≤2mA Operating range per EN61557: 0.10MΩ~1.00GΩ (output voltage >/= 50V) Short-circuit current: 2mA (0%~50%) Leakage current accuracy: ± (10% + 3 digits) Test voltage output step range is 50%~120% in 10% steps Note: Accuracy is stated at 23oC (75oF) and 45~75% RH. Note: Calibration interval: 1 year maximum Note: Temperature coefficient: 0.
