Megger BM100/4, BM101/4 User Manual

500 V. Analogue Insulation & Continuity Testers

M BM100/4 and BM101/4

User Guide
Guide de l’utilisateur
Gebrauchsanleitung
Guía del usuario

SAFETY WARNINGS

Safety Warnings and precautions m u s t be read and
understood before the instrument is used. They m u s t

be observed during use.
The circuit under test must be de-energised and

isolated before Insulation, Resistance, or Continuity
tests are made.

During an insulation test, the circuit must not be
touched.

After insulation tests, capacitive circuits must be
allowed to discharge before disconnecting the test

leads.
Test leads, including prods and crocodile clips must

be in good order; clean, and with no broken or
cracked insulation.

Replacement fuses must be of the correct type and
rating.

BM 100/4 Only

U.K. Safety Authorities recommend the use of fused
test leads when measuring voltage on high energy
systems.

When making a voltage measurement, the 'T est' push

must not be pressed.

NOTE

T H E I N S T R U M E N T S M U S T O N Y B E U S E D B Y S U I TA B LY T R A I N E D A N D C O M P E T E N T P E R S O N S

.

Symbols used on the instrument

Caution: Refer to accompanying notes.
Equipment protected throughout by Double Insulation

(Class II).
Equipment complies with relevant EU Directives

Refer to Safety Warnings before using the instrument

OPERATION

Preliminary Test lead check

1. Before each use of the instrument, inspect the test leads to confirm that
their condition is good, with no damaged or broken insulation.

2. Insert the red and black test leads, terminated with the appropriate
prods or clips, to their respective ‘+’ and ‘-’ terminal sockets.

3. Short the test lead prods or clips together. Set the selector switch to ‘2 ’ .

4. Press the ‘Test’ push. Check that the instrument reads zero. If a higher
resistance reading is obtained check all connections. If the reading
remains high, suspect that the test leads may be at fault, or that the 2A
non replaceable fuse has ruptured.

Continuity Testing

1. Set the selector switch to ‘2

’, or ‘200 ’, as appropriate.

2. Connect the test leads across the isolated item / circuit under test.

3. Press and hold the ‘Test’push button; allow the needle to settle. There
is a separate scale for each range so each reading is direct. Take the
reading from the appropriate scale of the instrument.

4. Release the ‘Test’ push button and disconnect the test leads.

Insulation Testing

1. Set the selector switch to ‘200 MΩ.’

2. Connect the R e d test lead to earth, equipment frame, or cable sheath etc.

3. Connect the Black test lead to the circuit under test or cable core.

4. Confirm that Voltage is not indicated on the instrument. (BM100/4
only)

5. Press and hold the ‘Test’ push; allow needle to settle, and take the
reading from the top scale of the instrument.

6. Release the ‘Test’ push button.

7. Wait a few moments before disconnecting the test leads, to allow any
circuit capacitance to discharge. The BM100/4 will automatically
monitor the discharge on its Voltage range, indicating when it is safe to
remove the test leads.

Resistance Testing (BM101/4 only)

1. Set the selector switch to the 1MΩ resistance range.

2. Connect the test leads across the isolated item / circuit under test.

3. Press and hold the ‘Test’ push button, allow the needle to settle. Take
the reading from the 1MΩ range scale.

4. Release the ‘Test’ push button and disconnect the test leads.

SPECIFICATION

Range:

BM100/4 BM101/4

Insulation 0,01 - 200 MΩ 0,01 - 200 MΩ
Resistance - 0,01 - 1 MΩ
Continuity (¡) 0,01 - 200 Ω 0,01 - 200 Ω

(¡¡) 0,01 - 2 Ω 0,01 - 2 Ω

Insulation Test Voltage: 500V d.c. 500V d.c.
Open Cct. Terminal Voltage:

Insulation Range <600V d.c. <600V d.c.

(>500V at 0,5MΩ) >500V at 0,5MΩ)

Resistance Range - 53V d.c.(nom.)
Continuity Ranges (¡) 0,76V d.c.(nom.) 0,76V d.c.(nom)

(¡¡) 4,7V d.c.(nom.) 4,7V d.c.(nom)

Typical Terminal Characteristics Limiting value curve

Short Cct.Terminal Current:

Insulation Range 1,6 mA 1,6 mA
Resistance Range - 325 µA
Continuity Ranges (¡) 12,3 mA 12,3 mA

(¡¡) 217 mA 217 mA

Movement: Robust Taut Band type. 250 µA F.S.D.
A.C. Voltage Measurement (BM100/4 only):

The Voltage range is automatically selected when the switch is in any
position and the ‘Test’ push button is not pressed. When connected across
the circuit under test, the BM100/4 will indicate if the circuit is energised
(a.c. or d.c.), and measure a.c.voltage up to 600 V.

Voltmeter Input Impedance: 330 kΩ
Automatic Discharge: Capacitive circuits are automatically

discharged via an internal (<500kΩ) resistor, when the ‘Test' push button
is released following an insulation test.

Accuracy (at 20°C): ± 2,5% of scale length on all ranges (e.g.± 1,9 mm

on Insulation range). Insulation range is marked with a white band (Class
1,5 as VDE 0413). Other ranges are Class 3.

Humidity: Operation: 90% R.H.max. at 20°C

Temperature Range: Operation: -5°C to + 40°C

80% R.H. max.at 35°C

Storage 95% R.H. max. at 35°C

Storage -20°C to + 70°C

Temperature Coefficient: ±0,1% per °C
Power Supply: Single 9V Alkaline battery I.E.C. 6 LR61 type
Current consumption: 110 mA max on Insulation

40mAmax on Resistance
220 mA max on 2 Ω range

Battery life: Not less than 1800, 5 second operations on 2Ω range.
Battery Condition Test: The battery condition test position checks the

battery voltage on a simulated load, when the ‘Test’ push button is
pressed. The instrument pointer should deflect clockwise to within the
‘Battery Check’ arc on the scale. Remove the battery if the instrument is
not to be used for an extended period of time.

Battery Replacement:

For safety reasons, the battery compartment must not be opened if the
test leads are connected. To remove the battery cover, release the screw
in the centre of the cover and lever the cover upwards.

Replaceable Fuse: 500 mA, 250V. H.B.C. type (F) (20mm. x 5mm)

To check this fuse, open circuit the test leads, switch to the 200

range
and press the ‘Test’ push button. A reading of <200Ω indicates a ruptured
fuse. Located in the battery compartment, this fuse can be replaced by the
user. The replacement fuse must be of the correct type and rating.To
replace the fuse, disconnect the test leads, remove the battery cover by
releasing the screw in the centre of the cover and levering the cover
upwards. Aspare fuse is clipped onto the battery cover.

Non Replaceable Fuse: 2A - 500 V H.B.C. type (F) 50 kA. Fitted for
overall safety protection, this fuse is not replaceable by the user. No
response from the instrument to an insulation test, with the leads shorted
together is likely to mean that this fuse has ruptured. The instrument must
be returned to the manufacturer, or an approved agent for repair.

Safety: Meets the requirements for double insulation to IEC1010-1

(1995) EN61010-1 (1995) to installation Category III***, 300 V
phase to earth (ground) and 500 V phase to phase, without
the need for separately fused test leads. If required, fused test
leads are available as an optional accessory. Indicates circuit
discharge after insulation test, 600 V Category II **.

*** Relates to transient overvoltage likely to be found in fixed

installation wiring.
** Relates to transient overvoltage likely to

be found in portable equipment and appliances.

E.M.C. In accordance with IEC61326 including amendment No.1
Standards: BS 7430 (1992) - VDE 0413 (1982)
Weight: 485g
Dimensions: 175 mm x 95 mm x 57 mm.
Cleaning: Wipe disconnected instrument with a clean cloth dampened

with soapy water or Isopropyl Alcohol (IPA).