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Megger
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BM5200
Operating Manual
36 pgs493.56 Kb0
Data sheet
2 pgs159.04 Kb0

Megger BM5200 Operating Manual

BM5200 5 kV Digital Insulation Tester
USER MANUAL MANUAL DEL USUARIO
M
MANUAL DO UTILIZADOR
CONTENTS
Safety warnings ............................................................................................................................................................................... 3
Symbols used on instrument ............................................................................................................................................................ 4
Cleaning ................................................................................................................................................................................... 4
General description .......................................................................................................................................................................... 5
Preparations for use ......................................................................................................................................................................... 6
Operating instructions ...................................................................................................................................................................... 7
Preventative maintenance ................................................................................................................................................................ 9
Battery replacement .................................................................................................................................................................. 9
Technical specifications .................................................................................................................................................................. 10
Repair and warranty ....................................................................................................................................................................... 11
MANUAL DEL USUARIO ................................................................................................................................................................. 13
MANUAL DO UTILIZADOR .............................................................................................................................................................. 24
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G SAFETY WARNINGS
Safety warning must be observed during use:
n The circuit under test must be switched off, deenergised, isolated and checked to be safe before insulation test connections are made. Make
sure the circuit is not reenergised whilst the instrument is connected.
n Circuit connections must not be touched during an insulation test. n After completing a test, capacitive circuits must be completely discharged before disconnecting the test leads. Capacitive charges can be
lethal.
n Tested items should be firmly shorted out with a shorting link, after discharge, until required for use. This is to guard against any stored
dielectric absorption charge subsequently being released thereby raising the voltage to potentially dangerous levels.
n The voltage indicator and automatic discharge features should be regarded as additional safety features and not a substitute for normal safe
working practice.
n It is rare, but in certain circumstances, breakdown of the circuit under test may cause the instrument to terminate the test in an uncontrolled
manner, possibly causing a loss of display while the circuit remains energised. In this event, the unit must be turned off and the circuit discharged manually.
n Test leads, including crocodile clips, must be in good order, clean and with no broken or cracked insulation. n The instrument should not be used if any part of it is damaged. n Insulation testing in wet weather conditions might be hazardous. It is recommended that this instrument is not used in these circumstances.
If this is unavoidable, the user must take all necessary precautions.
n This instrument is not intrinsically safe and must not be used in hazardous atmospheres. n If this equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be impaired. n Rechargeable batteries should not be used on this instrument.
NOTE
THE INSTRUMENT MUST ONLY BE USED BY SUITABLY TRAINED AND COMPETENT PERSONS. Users of this equipment and/or their employers are reminded that National Health and Safety Legislation requires them to carry out valid risk assessments of all electrical work so as to identify potential sources of electrical danger and risk of electrical injury such as inadvertent short
circuits. Where the assessments show that the risk is significant then the use of fused test leads may be appropriate.
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Symbols used on this instrument
G Caution: refer to accompanying notes F Caution: risk of electric shock t Class II double insulated instrument
Do not dispose of in the waste stream
Equipment complies with current Australian C-Tick directives
+
Battery
Terms used in this manual
The word must is used to indicate that the instructions following should be followed under all circumstances. Failure to follow these instructions could result in damage to the instrument and / or a hazard to the operator.
The word ‘should’ is used to indicate that the instructions indicate best practice.
Cleaning
Disconnect the instrument and wipe it with a clean cloth slightly damped with soapy water or Isopropyl alcohol (IPA).
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General description
BM5200 insulation tester has a digital and analogue arc display designed for high voltage insulation resistance testing in the maintenance and servicing of cables, rotating plant machinery, transformers, switchgear and industrial installations.
DC insulation tests are performed at 250 V, 500 V, 1000 V, 2500 V and 5000 V. Insulation resistance measuring range is 100 kΩ to 1000 GΩ. Automatic discharge for capacitive circuits under test is provided and decaying voltage displayed.
The guard terminal can be used to minimise the effects of surface leakage and hence erroneous measurements when carrying out insulation resistance tests.
Insulation resistance test modes
Three insulation resistance (IR) test modes are provided, (InS, PI, t) and selected from any insulation range by pressing the left arrow key depicting PI-t.
In insulation resistance test mode (InS) tests are initiated by pressing and holding down the TEST button for two seconds. Once an insulation test has initiated it will terminate on the next press of the TEST button. The reading is held on screen until TEST is pressed again or another range is selected.
A Polarisation Index (PI) mode performs a ratiometric test that calculates the ratio of insulation resistance at ten minutes to insulation resistance at one minute.
The timer (t) mode facilitates a single fixed duration IR test based on the set time interval t.
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Automatic discharge
For capacitive test objects the instrument will automatically dis­charge through an internal resistor and indicate voltage across the terminals in the range 25 V to 600 V with higher voltages indicated by ‘>600 V’. This feature will give decaying voltage indication following the testing of equipment possessing capacitance. When the voltage indicator no longer shows it is safe for the user to disconnect the test leads.
Lead set
Three recessed sockets are provided, and marked ‘+’, ‘-’ and ‘G’. These have safety covers which open when the plugs are inserted. When inserted into the sockets, the shrouded test lead plugs lock into position. They are released by twisting the plug a quarter turn and pulling out.
For this reason, only the test leads supplied or suitable Megger replacement ones should be used.
Instrument power
The BM5200 is powered by eight 1.5 V IEC LR6/AA alkaline cells. Rechargeable batteries should not be used on this instrument.
Instrument safety
Design safety features include:
n External voltage indication, AC or DC displayed. n Load automatically discharged at the end of a test, and
decaying voltage displayed.
n Test leads can lock into the case to prevent accidental disconnection.
Preparations for use
1. Unpack the shipping box and locate the BM5200 instrument, carry case, test leads, batteries, quick start and user guides.
2. Ensure that the main range switch is in the OFF position.
3. Locate the battery compartment and open it using a PZ2 pozidrive screwdriver.
4. Remove the battery module and insert the eight 1.5 VLR6/AA alkaline cells ensuring correct orientation according to polarity.
5. Connect the battery module to the battery lead ensuring correct polarity.
6. Replace battery module and battery cover into the case and replace the two screws tightening by hand only.
7. As an initial check, without any leads connected, switch the instrument on by turning the main range switch to any position other than OFF. Ensure that the instrument display responds. Switch off the instrument. If the instrument display does not respond return t to step 2, repeat the process and check all eight battery orientations are correct.
8. If the instrument still fails to respond use a voltmeter to check battery module voltage which should be 12 V assuming all cells are at their rated 1.5 V.
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Operating instructions
Instrument controls and indicators
1. Backlit LCD display with analogue arc and dual 3-digit display.
2. Backlight on/off switch
3. Four arrow buttons, PI-t function on left arrow button
4. Main range switch Setup functions plus AC and DC voltmeter (25 V to 600 V)
5. Main range switch with DC insulation tests at 250 V, 500 V, 1000 V, 2500 V and 5000 V.
6. TEST button to initiate and terminate insulation tests
7. Warning High Voltage (HV) indicator
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2
3
7
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Before switching on the BM5200 the test leads should be connected to the instrument.
There are three test terminals marked +, - and G. These terminals are designed to accept only the test leads supplied. Shutters across the terminals prevent accidental ingress of dirt and other objects. Test leads lock in the terminals to prevent accidental removal during a test, rotate the plug until the locking action is engaged. Terminal plugs can be removed by rotating through a quarter turn.
At the end of a test ensure that the voltage has decreased to a safe value, i.e. <50 V, before removing the test leads. Reactive loads may take some time to dissipate stored energy through the instrument’s internal discharge resistors.
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5
The BM5200 is turned on by rotating the main range switch to insulation test, voltage test or setup function.
The terminals are located on a panel to the rear of the instrument and marked +, - and G meaning Guard terminal.
The battery level indicator is located at the top right of the display and contains four pairs of segments depicting charge level.
Battery level indication of 50% of battery life.
Battery level indication of a flat battery.
Use of guard terminal (G)
For basic insulation resistance tests where there is little possibility of surface leakage affecting the measurement, it is not necessary to use the guard terminal i.e. if the insulator is clean and there are unlikely to be any adverse current paths. However in cable testing for example, there may be surface leakage paths across the insulation between the bare cable and the external sheathing due to the presence of moisture or dirt. To obtain an accurate measurement, particularly at high testing voltages, a bare wire may be bound tightly around the insulation and connected via the
third test lead to the guard terminal ‘G’.
As illustrated in the diagram, the guard terminal is at the same potential as the negative terminal. Since the leakage resistance is effectively in parallel with the resistance to be measured, the use of the guard causes the current flowing through surface leakage to be diverted from the measuring circuit. The instrument therefore reads the leakage of the insulator, ignoring leakage across its surface.
Setup procedure
The setup function is used to set the internal timer (t). Default value is set at 1 minute and can be adjusted using the up and down arrows. When the desired time setting is displayed the PI-t (left arrow) key is pressed and a beep confirms the new setting.
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Polarisation index (PI)
Polarisation Index (PI) test performs a test that calculates the ratio of insulation resistance at ten minutes, IR resistance at one minute, IR indication of insulation polarisation when subjected to high voltage DC. A high PI value indicates a high degree of insulation polarisation and therefore good insulation condition. Generally the PI value should be two or above.
Polarisation occurs at different rates ranging from minutes to several hours which led the IEEE to create a ratiometric PI test. The IEEE standard 43-2000, “Recommended Practice for Testing Insulation Resistance of Rotating Machinery,” limits the use of PI test on winding systems to those with IR MΩ.
Timed insulation resistance
The timed IR test is a test that automatically terminates after a user adjustable time (t). Users can select SETUP on the range switch and adjust timer (t) using up and down arrow buttons to set the desired time followed by a single press of the PI-t (left arrow) button. Default time (t) is set at one minute because IR1min is frequently referred to in international standards.
. This test provides a simple
1min
1min
to insulation
10 min
being less than 5000
Preventative maintenance
No user serviceable parts
There are no user serviceable parts in the BM5200 except for the batteries.
If an instrument’s protection has been impaired it should not be used, but sent for repair by suitably trained and qualified personnel. The protection is likely to be impaired if for example, it shows visible damage, fails to perform the intended measurements, has been subjected to prolonged storage under unfavourable conditions, or has been subjected to severe transport stresses.
Battery replacement
G WARNING
The battery contacts are not isolated from the test leads. Remove the test leads from the instrument before opening the battery compartment.
The cells are housed in a battery compartment in the base of the instrument. To change the cells, use a PZ2 pozidrive screwdriver to remove the battery cover securing screws and lift off the battery compartment cover. Observing the correct polarity as marked on the battery housing, install 8 replacement IEC LR6 (AA) cells. Replace and secure the battery compartment cover on completion.
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Technical specifications
The following specifications apply at 20 °C unless otherwise stated:
Electrical specifications
Insulation range 0.1 MΩ to 1 TΩ
Nominal test voltages 250 V, 500 V, 1000 V, 2500 V, 5000 V
Terminal voltage accuracy <1000 V 0 to 10% of nominal test voltage ≥100 V 0 to +5% of nominal test voltage
Insulation accuracy Up to 1 GΩ: All ranges ±5% ±2 digits
Over 1 GΩ: 5000 V ±5% ±0.04% per GΩ 2500 V ±5% ±0.08% per GΩ 1000 V ±5% ±0.2% per GΩ 500 V ±5% ±0.4% per GΩ 250 V ±5% ±0.8% per GΩ
Short circuit current 1.4 mA ±0.5 mA Maximum load capacitance 5 μF Voltmeter accuracy (DC or AC) 3% ±3 V Frequency measurement 45 Hz to 65 Hz Frequency accuracy ±2 Hz Voltage range (DC or AC) 25 to 600 V AC or DC
Power supply 8 x LR6/AA batteries
Battery life 5 hours @ 5 kV into 100 MΩ with AA Alkaline LR6
Guard 2% error guarding 5 MΩ leakage on 100 MΩ load
Environmental specifications
Operating temperature range -20 ºC to +55 ºC
Operating humidity 90% RH, 0 ºC - 40 ºC 70% RH, 40 ºC - 55 ºC
Storage temperature -30 ºC to +65 ºC Insulation protection IP40
Maximum Altitude 2000 m
Service error with stated environmental limits is twice intrinsic error
Safety protection
Insulation CAT III 600 V - applicable standard IEC 61010-1:2001
Measurement Category III is applicable to test and measuring circuits connected to the distribution part of the building’s low­voltage mains installation. This part of the installation is expected to have a minimum of two levels of over-current protective devices between the transformer and possible connecting points.
EMC The product conforms to IEC 61326-1:2005
Dimensions (W x H x D) 220 mm x 115 mm x 163 mm
Weight 1.45 kg
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