GREENLEE 5990A (01) PDF Document

The instrument is switched ON by pressing the ON/OFF key.

After turning on (Fig. 7), the GREENLEE 5990A Megohmmeter executes the auto-calibration (Fig. 8). If the auto-calibration procedure fails, the fail icon (X) will be displayed.

If batteries are defective or missing and the GREENLEE 5990A Megohmmeter is powered from mains supply, the instrument cannot be turned ON.

The test leads have to be disconnected during auto-calibration. If not, the auto-calibration procedure could fail.

After finishing the auto-calibration, the pass icon will appear; the instrument will go into Insulation Mode (Fig.9) and be ready for normal operation.

Auto-calibration ensures accuracy when measuring very low currents. It compensates for the effects caused by aging, temperature and humidity changes.

Performing a new auto-calibration is recommended when the temperature changes by more than 10 degrees Fahrenheit (5 degrees Celsius).

If the GREENLEE 5990A Megohmmeter detects a faulty state during the auto-calibration, the fail icon (X) will be displayed.

A common reason for failure is improper environmental conditions. This includes excessive humidity or excessive temperature. In this case it is possible to perform measurements by pressing the START/STOP button again but results could be outside of the technical specification.

Connecting the GREENLEE 5990A Megohmmeter to the mains supply while the instrument is OFF will charge the batteries. The instrument will remain OFF during this period. If the batteries are charging, a flashing battery indicator will appear in the upper left corner of the LCD.

Connecting the GREENLEE 5990A Megohmmeter to the mains supply while the instrument is ON will cause the instrument to be powered by the mains supply. If the instrument is not in Insulation Measuring Mode, the internal charger will charge the batteries. If the batteries are charging, a flashing battery indicator will appear in the upper left corner of the LCD.

It is not recommended to connect or disconnect the GREENLEE 5990A Megohmmeter to mains supply while the instrument is in Insulation Measuring Mode.

After turning the GREENLEE 5990A Megohmmeter ON, the LCD backlight is automatically turned ON. It can be turned OFF and ON by pushing the button.

After turning the GREENLEE 5990A Megohmmeter ON, the LCD backlight is automatically turned OFF. It can be turned OFF and ON by pushing the button.

The GREENLEE 5990A Megohmmeter can be switched OFF by pressing the ON/OFF button.

The purpose of the GUARD terminal is to lead away potential leakage currents (e.g. surface currents), which are not a result of the measured insulation material itself but are a result of surface contamination and moisture. This current interferes with the Insulation Resistance Measurement. The GUARD terminal is internally connected the negative test terminal (black). The GUARDs test clip should be connected to the test object so that most of the unwanted leakage current is collected.

It is recommended to use the GUARD connection when high insulation resistance (>10G Ω) is measured.

The components in the equivalent electrical circuit of insulating material are:

Riss1 and Riss2: the surface resistivity (position of optional guard connection)

Riso: the actual insulation resistance of material

Ciso: capacitance of material

Cpi, Rpi: represents polarization effects.

The overall test current is I_test = I_p1 + I_Riso + I_RISS, where:

Ip1 = polarization absorption current

IRISO = actual insulation current

IRISS = surface leakage current

The measurement procedure for Insulation Resistance is:

Step 1. Connect the test leads to the instrument and to the test object.

Step 2. Select INSULATION RESISTANCE mode by pressing the Ω button.

Step 3. Press the START/STOP button and release it. This will begin continuous measurement.

Step 4. Wait until the test result has stabilized then press the START/STOP button again to stop the measurement.

Step 5. Wait to remove the object under test until it is discharged.

To set up the test voltage for Insulation Resistance (Fig.13): Adjust test voltage using the ◄ and ► buttons.

The legend for displayed symbols in this mode includes:

To set up the Insulation Resistance Limit Value for Insulation Resistance (Fig.13a):

Step 1. Press the Ω button.

Step 2. Adjust the limit value using the ◄ and ► buttons.

Step 3. Press the Ω button again or the START button to return to the insulation resistance measurement menu.

The insulation resistance limit selection range is [10 KΩ .. 2–MΩ]. No limit selected indication is shown as —.

The measurement procedure for Voltage Measurement is:

Step 1. Connect the test leads to the instrument and to the measured source.

Step 2. Press the V button to select voltage mode and continuous measurement will automatically start to run.

Regarding electric shock and fire hazard:

• Do not expose this unit to rain or moisture.
• Do not use the unit if it is wet or damaged.
• Use test leads or accessories that are appropriate for the application. See the category and voltage rating of the test lead or accessory.
• Inspect the test leads before use. They must be clean and dry, and the insulation must be in good condition.
• Use this unit for the manufacturer’s intended purpose only, as described in this manual. Any other use can impair the protection provided by the unit.
• Failure to observe these warnings could result in severe injury or death.

Regarding electric shock hazard related to voltage application:

• Do not apply more than the rated voltage between any two input terminals, or between any input terminal and earth ground.
• Do not contact the test lead tips or any uninsulated portion of the accessory.
• Do not contact the test lead tips while performing the insulation resistance test.
• Failure to observe these warnings could result in severe injury or death.

Regarding electric shock hazard when opening the case:

• Do not operate with the case open.
• Before opening the case, remove the test leads from the circuit and shut off the unit.
• Failure to observe these warnings could result in severe injury or death.

Regarding electric shock hazard when measuring voltage:

• Unless measuring voltage, shut off and lock out power. Make sure that all capacitors are discharged. Voltage must not be present.
• Using this unit near equipment that generates electromagnetic interference can result in unstable or inaccurate readings.
• Failure to observe these warnings could result in severe injury or death.

Regarding electric shock hazard (CAUTION):

• Do not attempt to repair this unit. It contains no user-serviceable parts.
• Do not expose the unit to extremes in temperature or high humidity. See Specifications.
• Failure to observe these precautions may result in injury and can damage the unit.

Regarding working with the instrument (WARNING):

• Equipment under test must be switched off (i.e. de-energized) before test leads are connected to the equipment.
• Do not touch any conductive parts of equipment under test during the test.
• Make sure that the tested object is disconnected (mains voltage disconnected) before starting the Insulation Resistance measurement!
• Do not touch the tested object whilst testing it, risk of electric shock!
• In case of a capacitive test object (long tested cable etc.), automatic discharge of the object may not be done immediately after finishing the measurement – “Please wait, discharging” message will be displayed.

Regarding handling with capacitive loads (WARNING):

• Note that 40 nF charged to 1 kV or 9 nF charged to 5 kV are hazardous live!
• Never touch the measured object during the testing until it is totally discharged.
• Maximum external voltage between any two leads is 600 V (CAT IV environment).

The insulation ratings for the High Voltage Shielded Test Tips and High Voltage Alligator Clips are:

The insulation ratings for the Guard Test Lead with Alligator are:

• Guard test lead with banana connectors (green): 600V CAT IV (double insulation);
• Alligator (green): 600V CAT IV (double insulation).

The specifications for Insulation Resistance measurement on the GREENLEE 5990A Megohmmeter are:

Nominal test voltage: 250 V, 500 V, 1 kV, 2.5 kV, 5 kV

Current capability of test generator: >1 mA

Short-circuit test current: 5 mA.

Automatic discharge of tested object: Yes

Measuring Range Riso: 0.12 ΜΩ up to 999 GΩ*

The full-scale value of insulation resistance is defined according the following equation: RFS = 1GΩ * U_test[V] (if U_test > 1kV then RFS = 1TΩ).

For insulation resistance value under 5 ΚΩ the instrument will display the value 0 Ω.

The DC test voltage specifications for the GREENLEE 5990A are:

Voltage value: 250V, 500V, 1kV, 2,5kV, 5kV.

Accuracy: -0 / +10 % + 20 V.

Output power: 5 W max.

The specifications for Voltage (AC or DC) measurement on the GREENLEE 5990A are:

The specifications for Frequency of External Voltage measurement on the GREENLEE 5990A are:

Note:

• For a frequency between 0 and 45 Hz frequency, result is shown as —
• For a frequency over 65 Hz frequency, result is shown as —
• For a voltages under 10V frequency, result is shown as —

Input resistance: 3 MΩ±10 %

The general specifications are:

The protection and category specifications for the GREENLEE 5990A are:

The environmental conditions specifications for the GREENLEE 5990A are:

The Auto-Calibration of Measuring System for the GREENLEE 5990A occurs every time after turning power on.

The connecting system specifications for the GREENLEE 5990A are:

Discharging is performed every time after measurement completion. The Discharging Resistance is 300 ΚΩ ± 10 %.

When inserting batteries for the first time into the GREENLEE 5990A, note the following:

• Disconnect any measurement accessories or mains supply cable connected to the instrument before opening the battery cover to avoid electric shock.
• Remove the battery cover.
• Insert batteries correctly (see Fig. 15), otherwise the test instrument will not operate!
• Replace the battery cover and fixed the cover back in place.
• Connect the instrument to the mains power supply for 14 hours to fully charge batteries. (Typical charging current is 300 mA).
• When you charge the batteries for the first time, it normally takes about 3 charge and discharge cycles for the batteries to regain their full capacity.

When the low-battery indication appears (Err), the batteries have to be recharged. Connect the GREENLEE 5990A to the mains power supply for 14 hours to recharge cells. Typical charging current is 300 mA.

Note: Operator does not need to disconnect the instrument from mains supply after the full recharging period. The instrument can be connected permanently.

Fully charged rechargeable batteries can supply the instrument for approx. 4 hours. (Continues testing at 5kV)

Nominal power supply voltage is 7.2 V DC. Use six NiMH cells of C size (dimensions: diameter = 26 mm, height = 46 mm).

If the batteries have been stored for a long time, it normally takes about 3 charge and discharge cycles for the batteries to regain full capacity. In case of defective batteries note the following:

• Turn the power off and disconnect any measurement accessories and the mains supply cable before opening the battery cover to avoid electric shock.
• Remove the battery cover.
• All six cells have to be replaced.
• Insert the batteries correctly (see Fig. 15), otherwise the test instrument will not operate and the batteries may be discharged.
• Replace the battery cover.
• The Instrument will only work when rechargeable batteries are inside the instrument.

The available replacement parts for the GREENLEE 5990A are listed below:

Accuracy is specified from -20°C to 40°C.

For the Display Range 5 – 999 ΚΩ, the Resolution is 1 ΚΩ, and the Accuracy is ± (5% of reading + 3 digits).

For the Display Range 100 – 999 GΩ, the Resolution is 1 GΩ, and the Accuracy is ±(10% of reading + 3 digits).

The full-scale value of insulation resistance (RFS) is defined according to the following equation: RFS = 1GΩ * U_test[V] (if U_test > 1kV then RFS = 1TΩ).

The accuracy for the DC test voltage on the GREENLEE 5990A is: -0 / +10 % + 20 V.

For the Display range test voltage (V) 0 – 1999 ΚΩ, the Resolution is 1 V, and the Accuracy is ± (3% of reading + 3 digits).

For the Voltage AC or DC Display range test voltage (V) 0 – 600, the Resolution is 1 V, and the Accuracy is ± (3 % of reading + 4 V).

For the Frequency of External Voltage Display range test voltage (V) 0 and 45 to 65, the Resolution is 0.1 Hz, and the Accuracy is ± 0.2 Hz.

The Input resistance for the GREENLEE 5990A for frequency measurements is 3 MΩ±10 %.

The general specifications for dimensions and weight are:

The temperature ranges for the GREENLEE 5990A are:

The humidity ranges for the GREENLEE 5990A are:

The Nominal Altitude for the GREENLEE 5990A is Up to 2000m.

The values are:

The connections are:

• Two Safety Banana Sockets: +OUT, -OUT (5kV CAT I, Double)
• Two GUARD Banana Sockets: GUARD (600V CAT IV, Double)