Megger MHP1 User manual

Withstand Testers
MHP1 & MHP2
User Guide MEGGER®

Safety Warnings 2
General Description 4
Features, Controlsand Connections 5
Operation
Testing Precautions 11
Before each testing sequence 12
Carrying out a test 12
Switched Low Voltage probe LP2 13
120 kΩresistance Box 14
Specification 15
Accessories 16
Repair and Warranty 17
Symbols used on the instrument
Caution:Refer to User Guide
Risk of Electric shock
Danger of death
Protective Ground (Earth) Terminal
Equipment complies with current EU Directives.
Contents Guide de l’utilisateur - p18 Gebrauchsanleitung - s34 Guía del usuario - p50
2

3
SAFETY WARNINGS
✱High Voltage testing is hazardous. Safety Warnings and Precautions must be
read and understood before the instrument is used. They must be observed during
use.
✱Testing must only be carried out in a dedicated, demarcated, High Voltage testing
area which is clearly marked. National and local safety codes and standards must be
observed.
✱For safety, the instruments must be properly grounded (earthed). A separate
protective ground (earth) lead mustbecorrectly connected from the Protective ground
(Earth) terminal to a reliable ground (earth) before testing. This is in addition to the
ground (earth) wire in the power (mains) lead which must also be connected to
provide a double level of safety.
✱Suitable external interlocks must be used. The remote control unit is not a safety
interlock and must not be used as such.
✱The instrument, HV test probe, Low voltage test lead (or LV probe) and any remotely
connected equipment must not be used if any part is damaged.
✱The HV test probe and Low Return lead (or LV probe) must be confirmed as being in
good order, clean, with no broken or cracked insulation before each test sequence.
✱Exposed metal parts, including the HV probe tip, LV probe tip, Low return lead clip and
the item under test must notbetouched during testing, or until completely discharged.
✱The High Voltage probe must only be held with the fingers and thumb behind the
hand guard.
✱Replacement fuses, parts and accessories must be of the correct type and rating.
NOTE
THE INSTRUMENT MUST ONLY BE USED BY SUITABLY TRAINED AND COMPETENT PERSONS

The MHP1 and MHP2 Testers are designed for general Withstand (Flash) testing of electrical
equipment and insulating materials. The instruments are operated from a nominal 115 V or
230 V 50/60 Hz mains supply pre-set at the factory, and have a variable output voltage providing
up to 3 kV a.c. (MHP1 and MHP2) and up to 4 kV d.c. (MHP2 only). The instruments are self
contained in a sheet steel cabinet, with simple to use controls on the front face of the unit.
Customer terminals, accessed behind a rear panel enable connection for external relay control,
external indicator beacon and external safety interlocks. An optional remote switch facility is
available. The instruments have been designed for indoor use only and as such should not be
used in harsh conditions or outside. The instruments are designed for Installation Category II
use. Installation Category II relates to transient overvoltages likely to be met on grounded
(earthed) receptacles (socket outlets). The instrument is supplied with a 3 wire power cord. The
instrument must be used with a grounded (earthed) supply, and all 3 wires must be connected.
The colour code of the cord is :- U.S.A. U.K./International
Ground (Earth) Green Yellow/Green
Neutral White Blue
Line (Phase) Black Brown
Safety features include:-
✱Interlock terminals enable automatic disconnection of the test voltage when
accessing the device under test.
✱High Voltage warning terminals provide a connection for a high
visibility beacon.
✱Two methods of control allow the user to select the best method for the
type of testing undertaken.
✱Two independent methods of grounding (earthing), supply cord ground and
an additional protective Ground (Earth) terminal located at the rear of the
instrument, both of which must be used.
General Description
4

Features, Controls and Connections
5
FAIL
VOLTS
POWER
TRIP mA
0.3
0.5
1.0
2.0
3.5
5.0
10
HI-POT
MHP2
MEGGER®
BREAKDOWN
BREAKDOWN
TRIP/
TRIP
STOP START STOP
0
0
2
1
34
12
10
67
5
8
9
1. Illuminated mains On / Off switch
2. Voltage control knob
3. Trip Level Switch
Sets the current trip limit when testing with the trip or breakdown/trip mode. This level can be set
to: 0.3 mA, 0.5 mA, 1.0 mA, 2.0 mA, 3.5 mA, 5.0 mA, 10.0 mA peak a.c. (or d.c. on MHP2).
Warning:- The Trip level Switch does not limit the instantaneous current that can flow
from the instrument prior to switchoff. Up to 1⁄2cycle delay will occur before switch off.
4. Test mode select switch
There are two methods of automatically disconnecting the supply:-
i) Breakdown
The test voltage is applied until insulation breakdown (a sharp increase in current
independent of continuous leakage current), or user intervention.
ii) Breakdown / Trip
As for Breakdown above, but the test voltage will also be removed automatically if
the leakage current exceeds the limit set on the Trip Level Switch.
iii) Trip
The test voltage is automatically removed if the leakage current exceeds the limit set on
the Trip Level Switch.
Note:-The test voltage will only be removed automatically if the leakage current exceeds the limit
set on the Trip Level Switch.
5. Visual ‘Test Fail’ indicator
Illuminates to indicate when test conditions have been exceeded. An internal buzzer will also
sound when the visual indication is active.
6. Output volt meter
Used in conjunction with the Voltage control to set, and give an accurate indication of output test
voltage. After a d.c. test the voltmeter will indicate capacitive discharge voltage at the terminals.
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