Megger S1-5010 User manual

M
S1-5010
Diagnostic Insulation Tester
User Guide

GSAFETY WARNINGS
•Safety Warnings and Testing Precautions must be read and understood before the
instrument is used. They must be observed during use
•The circuit under test must be switched off, de-energised and isolated before test
connections are made.
•The test terminal panel and side recess panel must be kept in a dry, clean condition.
•Circuits must be discharged before disconnecting the test leads - Capacitive loads
can be lethal. See ‘Testing Precautions’.
•Circuit connections must not be touched during a test.
•In certain circumstances, break-down of the circuit under test may cause the
instrument to terminate the test in an uncontrolled manner, possibly causing a loss of
display and warning indications while the circuit remains energised. In this event, it is
important that the circuit is discharged and the instrument is turned off, before
touching any connections.
•Replacement fuses must be of the correct type and rating.
•The instrument should not be used if any part of it is damaged.
•Refer to ‘Testing Precautions’for further explanations and precautions.
2
Symbols used on the instrument
GCaution: Refer to accompanying notes.
FRisk of electric shock.
cEquipment complies with relevant EU Directives
tEquipment protected throughout by Double Insulation (Class II).
NOTE
THE INSTRUMENT MUST ONLY BE USED BY SUITABLY TRAINED AND COMPETENT PERSONS.

Contents
Safety Warnings 2
General Description 4
Features and Controls 5
Battery or Mains Operation 6
Mains supply re-charging 6
12 V supply re-charging 6
Battery Charging Notes 6
Setting up procedures 7
Setup Language 7
Setup IR, SV and DD Tests 7
Setup PI Tests 7
Disable a Test Mode 8
Enable a Test Mode 8
Delete Stored Test Results 9
Set / Reset Date and Time 9
Set / Reset Printer Baud rate 10
Set / Reset PC Baud rate 10
Setup / Reset ‘Power On’ code 10
Setup / Reset ‘Setup’ code 11
Set / Reset Date format 11
Set / Reset Current limit 11
Set / Reset Data Output Rate 11
Set / Reset Locking test button 12
Operation 13
Testing Precautions 13
Performing tests - General 14
Using the Filter 15
Fault Conditioning (Burn) 16
Remote Operation 16
Test Mode Summary 17
Insulation Resistance Testing 17
Polarization Index Testing 17
Dielectric discharge Testing 18
Step Voltage Testing 18
Fault Conditioning (Burn) 19
Data Retrieve 20
Display stored Test results 20
Download stored Test results to a printer 20
Downloading Test results to a PC 20
Application Notes 21
Preventive Maintenance 21
Insulation testing concepts 22
Test Techniques 23
Using the Guard terminal 23
Measurements above 100 GΩ23
Circuit block diagram 24
Calibration Check 24
Appendix 1 25
Specification 26
Accessories 27
Repair and Warranty 28
3

The S1-5010 is an advanced insulation tester for all types of electrical equipment offering
measurement capability up to several T. The instrument performs automatic tests, enabling
consistent operation without operator input, stores results and can be operated from a PC. Flexible
power supply options and robust, portable construction allow the instrument to be used in a wide
variety of applications. It is particularly suitable for analyzing the insulation of large machines, HV
generators and cables. When turned On, voltage in excess of 50 volts across the + and - terminals
will be indicated on the display, together with the flashing HV symbols.
Switchable filtering allows stable readings to made when in the presence of high levels of 50 Hz or
60 Hz interference.
PP
PPoo oollllaa aarr rriiiizz zzaa aatt ttiiiioo oonn nn IIIInn nndd ddee eexx xx and DD DDiiiiee eellllee eecc cctt ttrr rriiiicc cc DD DDiiiiss sscc cchh hhaa aarr rrgg ggee ee tests are performed automatically, and test duration
and voltages can be adjusted according to user preference for these tests. A SS
SStt ttee eepp pp VV VVoo oolllltt ttaa aagg ggee ee test can
also be performed automatically, with a voltage of 2500 V or 5000 V and a fixed test duration of 5
minutes. It is also possible to restrict operation to user defined voltages, to disable the graph plotting
or to disable certain types of tests. This is all done using the ‘SS
SSee eett ttuu uupp pp’ screen. The settings can be
security code protected. It is also possible to set a general security code to prevent unauthorized use
of the instrument.
The S1-5010 can be powered from the main supply, or by the its own internal rechargeable battery
which provides for at least 8 hours of continuous testing. The battery symbol ,in the bottom
left of the display indicates battery capacity. Connecting power to the supply connector, or to the 12
volt connector in the side recess panel will automatically charge the battery whether the instrument
is switched ‘OO
OOnn nn’ or ‘OO OOff ffff ff’. A high level of internal isolation allows the S1-5010 to be used while the
battery is being recharged. An internal battery management system switches the instrument off after
ten minutes of inactivity. Test results and settings will not be lost when the instrument is switched off.
Test results are stored internally but the RS232 connection allows an external computer to receive
results in real time or to receive results previously stored.
Safe testing is achieved with a double insulated plastic case, double insulated test lead connectors,
a one second delayed start test button, high voltage warning symbols , flash on the display,
and the test terminal HV warning light flashes. A socket in the side recess panel provides a 5 volt
logic signal to drive an external warning light. Capacitive loads are automatically discharged at the
end of a test.
Beneath the display, four tactile keys normally control:-
- Electrical ‘noise’ Filter
- Contrast
- Back-light.
General Description
4
RS232 connection
Download ‘Real time’ or
‘Batch’ results to PC.
Remote operation.
12 V d.c. connection
Plug in supply of 10 - 15 V
to charge the battery
Battery Charge Indicator
Mains connection
Plug in supply of 95 - 265 V a.c.
to charge the battery.
Fuse
200 mA - 250 V
HV ‘On’ indicator connection
5 V logic signa output.
(To connect an external HV
indicator)
Side recess Panel

Features and Controls
Power On / Off Switch
Press to turn On / Off.
Left Hand Cursor keys
Press to:-
i) Select and highlight the
required mode.
ii) Select test Results /
& Bargraph / Graph
in Enhanced mode.
(when test has run ≥1 minute)
HV Warning
Flashes when a test is in
progress or a hazardous
voltage is present. Right Hand Cursor
keys
Press to select and
highlight the required
voltage before
commencing test.
VARI position
Gives the option to:-
i) Select a non standard
voltage between 25 V
and 5000 V before
commencing test.
ii) Continuously vary the
voltage in 25 V steps
during a test.
Filter key
Press to:-
i) Sequentially select filter times.
(See ‘Using the Filter’)
ii) Initiate the ‘On screen’ display
above the key.
Contrast keys
Press to:-
i) Adjust the screen contrast.
ii) Initiate the ‘On screen’display
above the key
Backlight key
Press to:-
i) Switch backlight On or Off.
ii) Initiate the ‘On screen’
display above the key.
Mode setting
Date and time
Voltage setting
Battery Capacity Indicator
Test duration
Test Button
5
Negative Terminal Positive Terminal
Guard Terminal
Toinsert and lock in shrouded test plugs
Push in
To release shrouded test plugs
turn a quarter turn and pull out

The S1-5010 can be powered by:
• Internal rechargeable battery which provides at least 8 hours of testing.
• Mains input of 95 volts to 280 volts 50/60 Hz.
• 12 - 15 Volts d.c or a.c.
General
The S1-5010 is fitted with a 12 volt, 7 Amp-hour sealed lead-acid battery. The maintenance free
battery will last for at least 5 years if kept charged and not subjected to prolonged high temperatures.
(Occasional exposure to +50° C will do little harm but a continuous temperature >40° may cause
irreparable damage). It is advisable to fully charge the battery before the instrument is put into service
for the first time. Charging is carried out by external a.c. mains supply, or by 12 V d.c. or a.c. supply.
To fully recharge the battery after 8 hours of use takes about 16 hours. The battery capacity display
symbol indicates the state of charge.
Mains supply re-charging
The application of a mains supply of 95 - 265 V a.c., 50 - 60 Hz powers the instrument, and charges
the battery. The S1-5010 will operate on a supply as low as 90 volts, but this will not fully charge the
battery. Charging is automatic as soon as the mains supply is connected to the IEC 320 connector in
the side recess panel. Confirm that the red indicator lamp is illuminated.
12 V supply re-charging
The application of an external 12 - 15 volt d.c or a.c. supply powers the instrument and charges the
battery at the same rate of charge as the mains input. It is possible to connect both mains and a 12
volt input simultaneously, but this will not charge the battery any faster. The socket accepts 12 -15 volt
d.c. (any polarity connection) or 12 - 15 volt a.c. A charging lead fitted with an automotive cigar lighter
plug for charging the battery from a vehicle is available (See ‘Accessories’). Charging is automatic
as soon as the 12 V supply is connected to the 12 V DIN socket. Confirm that the red indicator lamp
is illuminated.
12 V DIN socket
Caution:- Applying more than 15 V to this socket may overcharge the battery.
Battery Charging Notes
• Do not leave battery in a totally discharged state. Frequent charging to keep the battery ‘topped
up’ will maximise battery life.
• When charging the battery indoors, the area should be well ventilated.
• The battery should only be charged at temperatures in the range 0 °C to 40 °C.
• No harm will occur to the battery is kept on charge indefinitely.
• If the instrument is idle for long periods, recharge the battery for at least 24 hours every 6
months (more frequently if the storage temperature is >40 °C).
Setting Up Procedures
6
Leave unconnected
Connection Connection

Note: † If pre-set, the ‘SETUP’ security code input screen will be displayed. Enter the 3 digit security
code using the ‘+’,‘-’ and ‘NEXT‘ keys. Press the ‘OK’ key to display the ‘SETUP‘
screen.
Setup Screens
Any changes made to the ‘Setup’ screens will be retained. Memory contents will only be lost in the
unlikely event of a power loss combining a failure of the main and the backup battery. When power is
restored, Setup conditions will revert to the default settings i.e. All tests enabled , all voltages enabled,
First PI value T1 = 1minute, Second value T2 = 10 minutes, Stop time (T3) = 10 minutes, and
enhanced test mode.
Setup Language §
1. From the first ‘Menu’ screen, use the left hand st cursor keys to select and highlight ‘SETUP’.
2. Press the ‘CHANGE’ key. †§ The ‘LANGUAGE SELECTION‘ screen is displayed.
3. Use the left hand cursor keys to select and highlight the required language.
4. Press the ‘YES’ key. The ‘SETUP‘ screen is displayed.
Setup IR, SV and DD Tests
Simple or Enhanced mode can be selected for each type of test (except DD test). ‘SIMPLE’ mode
provides basic test results during, and on completion of a test. ‘ENHANCED’ mode provides basic
test results and a graph plot and a Bargraph as the test progresses. Individual voltage ranges for
each type of test can be switched Off or On as required.
1. From the ‘Menu’screen, use the left hand cursor keys to select and highlight ‘SETUP’.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP‘ screen is displayed.
3. Use the left hand cursor keys to select and highlight the required test.
4. Press the ‘CHANGE’ key. The ‘SETUP MODE‘ option screen for the selected test is
displayed.
5. Press the ‘SIMPLE’or the ‘ENHANCED’key as required. The ‘TEST RANGES’screen is
displayed. Note:- selecting the ‘DISABLE‘ key will disable and remove the test from the
‘Menu’screen. See ‘Disable a Test’.
6. Use the left hand cursor keys to individually select and highlight any voltage ranges to be
switched Off or On. Press the ‘On’ or ‘OFF’ key, as appropriate.
7. On competion, press the ‘END‘ key to return to the ‘SETUP‘ screen.
8. Press the ‘END‘ key to return to the ‘Menu’ screen.
Setting Up Procedures
7

8
Example showing the setup of an enhanced SV Test
Setup PI Test
1. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘SETUP‘.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP‘ screen is displayed.
3. Use the left hand cursor keys to select and highlight ‘PI’. Press the ‘CHANGE’ key. The
‘PI TEST SETUP‘ screen is displayed.
4. Press the ‘PI TEST TIMES‘ key. The ‘PI TEST TIMES‘ screen is displayed.
5. Press the ‘NEXT‘ key to highlight and select the First Value, the Second Value or the Stop
Time as required.
6. Using the ‘+’ et ‘-’ keys, adjust the timing as required.
7. Press the ‘OK’ key to return to the ‘PI TEST SETUP‘ screen.
8. Use the left hand cursor keys to select and highlight ‘PI‘. Press the ‘CHANGE’ key. The ‘PI
TEST SETUP‘ screen is displayed.
9. Press the ‘SET PI TEST‘ key. The ‘PI TEST SETUP MODE‘ screen is displayed.
10. Press the ‘SIMPLE’ or the ’ENHANCED‘ key as required ‘TEST RANGES‘ screen is
displayed. Note:- selecting the ‘DISABLE‘ key will disable and remove the IP test from the
‘Menu’ screen. See ‘Disable the Test‘.
11. Use the left hand cursor keys to individually select and highlight any voltage ranges to be
switched Off or On. Press the ‘ON’ or ‘OFF’ key, as appropriate.
12. On completion, press the ‘END‘ key to return to the ‘SETUP’ screen.
13. Press the ‘END‘ key to return to the ‘Menu’ screen.
Disable a Test mode
When a test mode is disabled, it is removed fromthe ‘Menu’ screen.
1. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘SETUP‘.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP‘ screen is displayed.
3. Use the left hand cursor keys to select the test to be disabled.
4. Press the ‘CHANGE’ key. The ‘SETUP MODE‘ screen is displayed.
5. Press the ‘DISABLE‘ key. The ‘SETUP‘ screen is displayed.
6. Press the ‘END‘ key to return to the ‘Menu’ screen.
Alternatively, a test can be disabled by individually setting each test voltage to ‘OFF’.
Setting Up Procedures

9
Example showing the disabling of a PI Test
Enable a Test mode
1. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘SETUP‘.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP‘ screen is displayed.
3. Use the left hand cursor keys to select the test (identified as OFF) to be enabled.
4. Press the ‘CHANGE’ key. The ‘SETUP MODE‘ screen is displayed.
5. Press the ‘SIMPLE’ , or the ‘ENHANCED‘ key, as required. The ‘TEST RANGES‘ screen is
displayed.
6. Use the left hand cursor keys to individually select and highlight any voltage ranges to be
switched Off or On. Press the ‘ON’ or ‘OFF’ key, as appropriate.
7. On completion, press the ‘END‘ key to return tothe ‘SETUP‘ screen.
8. Press the ‘END‘ key to return back to the ‘Menu’ screen.
Alternatively, a test can be enabled by individually setting at least one test voltage to ‘ON’.
Example showing the enabling of a DD Test
Delete Stored Test results
1. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘SETUP‘.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP‘ screen is displayed.
3. Use the left hand cursor keys to select and highlight ‘TESTS STORED‘. Press the ‘CHANGE’
key. The ‘DELETE ALL TESTS - CONFIRM‘ screen is displayed.
4. Accept or reject the deletion by pressing the ‘YES‘ or the ’NO‘ key. The ‘SETUP MODE’
screen is displayed.
5. On completion press ‘END’key to return back to the ‘Menu’ screen.
Set / Reset Date and Time
1. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘SETUP’.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP‘ screen is displayed.
3. Use the left hand cursor keys to select the current Date and Tiime.
4. Press the ‘CHANGE’ key. †§ The ‘SETUP MODE‘. ‘SET CLOCK’ screen is displayed.
5. Press the ‘NEXT‘ key to highlight and select the Time / Date component to be adjusted.
6. Using the ‘+’ and ‘-’ keys, adjust the time / Date as required.

7. Press the ‘END’ key to return to the ‘SETUP‘ screen.
8. Press the ‘END’ key to return back to the ‘Menu’ screen.
Note:- Date format can be also be changed as required. See ‘Set / Reset Date Format’.
Set / Reset Printer Baud Rate
This is the communication rate used when retrieving results to a serial printer.
1. From the ‘Menu’, screen, use the left hand cursor keys to select and highlight ‘SETUP‘.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP‘ screen is displayed.
3. Press the ‘NEXT‘ key. Use the left hand cursor keys to select and highlight ‘PRINTER
BAUD‘.
4. Press the ‘CHANGE’ key. †§ The ‘PRINTER BAUD‘ screen is displayed.
5. Use the ‘NEXT‘ key to select and highlight the Baud Rate as required.
6. Press the ‘END’ key.
7. Press the ‘END’ key to return back to the ‘Menu’ screen.
Set / Reset PC Baud Rate
This is the communication speed to your PC when retrieving results to a PC file and does not affect
the speed when using the S1-5010 with the remote control software. The default Baud rate is 9600.
1. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘SETUP‘.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP‘ screen is displayed.
3. Press the ‘NEXT‘ key. Use the left hand cursor keys to select and highlight ‘PC BAUD‘.
4. Press the ‘CHANGE’ key. The ‘PC BAUD‘ screen is displayed.
5. Use the ‘NEXT‘ key to select and highlight the Baud Rate as required.
6. Press the ‘END‘ key.
7. Press the ‘END‘ key to return back to the ‘Menu’ screen.
Security Codes
There are two security code systems to inhibit access by unauthorized persons. The user definable 3
digit ‘Power On’code controls access entry into the instrument. The user definable 3 digit ‘Setup’
code controls access to the Setup displays.
Set / Reset ‘Power On’ Code
to set or re-set the 3 digit ‘Power On’ code to control access enty into the instrument the ‘POWER ON
SECURITY CODE’ is switched to On in the ‘Setup’ mode. When the instrument is switched Off and
On again, the new code is entered, to operate the instrument. This ‘Power On’code must then be
entered by anyone wishing to use the instrument.
1. From the ‘Menu’, screen, use the left hand cursor keys to select and highlight ‘SETUP‘.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP‘ screen is displayed.
3. Press the ‘NEXT‘ key. The ‘SETUP MODE‘ screen is displayed.
4. Use the left hand cursor keys to select ‘POWER ON SECURITY CODE‘. Press the ‘CHANGE’
key to set the code to ‘ON‘ (or ‘OFF‘ as required). If an existing code is to be changed, set
the code to OFF; exit the screen; return back to the screen and then set the code back to ‘ON‘.
5. Press the ‘END‘ key to exit back to the ‘Menu’ screen.
6. Switch the instrument Off, pause, and then switch back On again. The ‘ENTER THE SECURITY
CODE‘ input screen is displayed.
7. Enter (and remember) the new 3 digit security code using the ‘+’,‘-’ and ‘NEXT‘ keys.
On completion, press the ‘OK’ key. The instrument powers up and the ‘Menu’ screen is
displayed.
Setting Up Procedures
10

11
Set / Reset ‘Setup’ Code
To set or re-set the 3 digit ‘Setup’ code, the code is switched from OFF to ON. The screen is then
exited and on re-entry, the required user definable 3 digit code is entered. This ‘Setup’ code must then
be entered by anyone wishing to access the Setup screens.
1. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘SETUP’.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP’ screen is displayed.
3. Press the ‘NEXT‘ key. The ‘SETUP MODE‘ screen is displayed.
4. Use the left hand cursor keys to select and highlight ‘SETUP SECURITY CODE’.
5. Press the ‘CHANGE’ key to set the code to ‘ON‘ (or ‘OFF‘). If an exisiting code is to be
changed, set the code to ‘OFF‘; exit the screen; return back to the screen and then set the code
back to ‘ON‘.
6. Press the ‘END’ key to exit back to the ‘Menu’ screen.
7. Highlight ‘SETUP‘, and press the ‘CHANGE’ key. The ‘ENTER THE SECURITY CODE’
screen is displayed.
8. Enter (and remember) the new 3 digit security code using the ‘+’,‘-’ and ‘NEXT‘ keys.
9. Press the ‘END’ key to return back to the ‘Menu’ screen.
Note:- Persons with access to the Setup mode will also be able to access (and control) the ‘Power
On‘ code.
Set / Reset Date Format
Date format can be selected as DD / MM / YY - YY / MM / DD - MM / DD / YY. Note that changes
to the Date format will only be shown in subsequent test data.
1. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘SETUP’.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP’screen is displayed.
3. Press the
‘NEXT’ key. The ‘SETUP MODE’ screen is displayed.
4. Use the left hand cursor keys to select and highlight ‘DATE FORMAT’.
5. Press the ‘CHANGE’key to select the appropriate sequence for Day (DD) Month (MM) and
Year (YY).
6. Press the ‘END’key to return back to the ‘Menu’ screen.
Set / Reset Current limit
1. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘SETUP’.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP’ screen is displayed.
3. Press the ‘NEXT’key. The ‘SETUP MODE’screen is displayed.
4. Use the left hand cursor keys to select and highlight ‘CURRENT LIMIT’.
5. Press the ‘CHANGE’key to select 2 mA or 5 mA.
6. Press the ‘END’ key to return back to the ‘Menu’ screen.
Set / Reset Data Output Rate - for ‘Real time’ output
1. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘SETUP’.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP’ screen is displayed.
3. Press the ‘NEXT’ key.
4. Press the ‘NEXT’key again. ‘DATA OUTPUT EVERY...’is displayed.
5. Press the ‘Change’ key. The ‘+’ and ‘-’ controls are displayed.
6. Using the ‘+’and ‘-’keys, adjust the Data Rate as required. Maximum = 1 second, Minimum
= 60 seconds
7. Press the ‘OK’ key.
8. Press the ‘END’key to return back to the ‘Menu’ screen.

12
Set / Reset Locking Test button
The red Test button defaults to locking, when pushed for more than 1 second. The button can be
set to ‘Locked’ or ‘Unlocked’.
1. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘SETUP’.
2. Press the ‘CHANGE’ key. †§ The ‘SETUP’ screen is displayed.
3. Press the ‘NEXT’ key.
4. Press the ‘NEXT’ key again.
5. Use the left hand cursor keys to select and highlight ‘TEST BUTTON’.
6. Press the ‘Change’ key to select ‘LOCKING’, or ‘NOT LOCKING’, as required.
Note:- If ‘NOT LOCKING’ is selected,‘Fault Conditioning’-(BURN) mode is not available.
7. Press the ‘OK’ key.
8. Press the ‘END’ key to return back to the ‘Menu’ screen.

Testing Precautions
•The S1-5010 can generate up to 5 mA at 5000 V. Circuit connections must not be touched
when testing.
•When turned On, voltage in excess of 5 volts across the +and - terminals will be indicated on the
display.
•The voltage indicator and automatic discharge features of the S1-5010 should be regarded as
additional safety features and not a substitute for normal safe working practice.
•When carrying out prolonged unattended tests, care should be taken ensure that harm or damage
cannot be caused.
•When using the‘BURN’ feature, care must be taken that no harm or damage can be caused.
•The test terminal area and side recess panel recess must be kept in a dry, clean condition.
•If any part of the instrument is damaged, it should not be used, but returned to the manufacturer
or an approved repair company.
•Fuse replacement must be of the correct type and rating. See ‘‘Specification’.
•Should the plug on the power cord not be the type for your socket outlets (receptacles), do not
use an adaptor. Use a suitable alternative power cord. Wires in power cords are coloured as
follows: - U.K / International U.S.A.
Earth (Ground Yellow/Green Green
Neutral Blue White
Phase (Line) Brown Black
If using a fused plug, a 3 Amp fuse to BS1362 should be fitted.
Operation
13
The circuit under test must be completely de-energized
and isolated before test connections are made
Working with Capacitive Loads
Charged Circuit Discharge
Capacitive circuits charged to several kV can be lethal.
Circuits must be discharged before handling and connecting the test leads, and
similarly before disconnecting the test leads.
At the end of a test, any external capacitance is discharged automatically and the warning
devices will continue to indicate until the terminals are in a safe condition. While the
instrument design incorporates maximum safety, safe working practice should assume that the
instrument discharge circuit and warning devices could fail, and a shorting link should be
connected across capacitive loads before handling them
*Automatic discharge must not be relied upon as an alternative to normal safe working
practice.
*Care must be taken to prevent capacitive circuits becoming disconnected during a test,
leaving the circuit in a charged state.
Dielectric Absorption
Some capacitive items exhibit an effect called Dielectric Absorption. The dielectric can absorb
charge during the test. After the item is discharged, the absorbed charge is released back onto
the capacitive ‘plates’ effectively raising the voltage of the item, possibly to dangerous
levels. Safe working practice dictates that tested items should be firmly shorted out with a
shorting link, after discharge, until required for use

Performing Tests - General
•Ensure that all test leads are clean and in good condition, and firmly connect them to the
instrument and to the isolated circuit under test.
•Switch the instrument On by pressing the yellow ‘On / Off’ switch once. The calibration check
runs to check the operation of the measurement system and correct any small calibration errors
which may occur during the life of the instrument.
•The ‘Menu’ screen is displayed on completion of the calibration check. If necessary, adjust the
contrast setting using the .key.
•The key allows the back light to be switched On or Off. (Switching the back light off, will
conserve battery power by 10%).
•Select the required Test mode using the left hand cursor keys.
•Test time shown in the bottom right hand corner of the display indicates maximum test duration
before it is stopped automatically. (Maximum test duration is 90 minutes). Accept the default test
time or use the right hand cursor keys to select and highlight the time indicator. Press the
‘CHANGE’ key, followed by the ‘+/ -’ keys to set the required time.
•The required Test Voltage is selected with the right hand cursor keys. For specific types of test,
pre-determined default voltages are set. For instance, the Step Voltage test only offers test
voltage options of 2500 or 5000 volts. The ‘VARI’ position gives the option to select a non-
standard voltage between 25 and 5000 V d.c., or to continuously vary the voltage in 25 V steps
during a test by using the right hand cursor keys.
• Battery condition indication is given in the bottom left hand corner of the display. If the battery
becomes completely exhausted the instrument will refuse to operate. Recharge the battery as
soon as possible. If the battery is not recharged it could degrade to a state where it will not
recharge.
Note:- Test results and settings are protected by a backup battery so these will not be lost.
• To start a Test, press the red button for at least one second. Two bleeps are sounded and the
F, flashing test terminal indicator light, and symbols warn that a test is in progress.
•If Enhanced tests have been selected, after one minute, three types of result screen can be
selected (Results / Bargraph / Graph) using the left hand cursor keys either during, or after a
test.
• To stop a test at any time, press the red test button. If the red test button is not pressed, the
test will terminate at the end of the set test duration
•Allow the item to discharge.
•A test will automatically terminate if:-
- The set test duration is completed.
- Excessive electrical noise occurs.
- The circuit insulation under test suffers a complete breakdown.
- The battery becomes exhausted.
- The 200 mA Guard fuse ruptures (when the Guard terminal is in use).
Operation
14

- An internal fault occurs.
- When the test is terminated the item under test will be automatically discharged.
• To return to the menu display and start another test, press the ‘Menu’ key.
•To switch the instrument Off, press the On / Off button once. Auto switch-off operates after 10
minutes inactivity.
•On completion of a test, the item under test is automatically discharged. The high voltage
warnings continue to operate until the terminal voltage falls to less than 50 volts. If the test has
run for more than one minute, three types of result display can be selected (Results / Bargraph
/ Graph) using the left hand cursor keys.
Using the Filter
If stable readings are being obtained it is not necessary to use the filter. The multi-pole electrical
interference filter system enables measurements to stabilise in a few seconds while rejecting 50Hz
and 60Hz interference currents, up to 4 mA. Under adverse conditions it may be necessary to switch
in additional software filtering. A steady reading will then be obtained at the expense of a longer
settling time.
Filter settings available:
No Filter. Fastest settling time. Rejects a.c. interference up to 1 mA.
Default- FILT 3: Hardware filter. Approximately 3 second settling time. 4 mA a.c. rejection.
FILT 10: Adds software filter giving moving average over 10 seconds.
FILT 30: As above, for 30 seconds.
FILT 100: As above, for 100 seconds.
At the start of a test, the default setting FILT 3 is set. This provides very good interference rejection,
allowing measurements to be made quickly. Pressing the filter key will sequentially advance filter
settings. To optimise the settling time, toggle the filter key several times to turn the filter Off. Note that
if the filter is turned On again (either manually or automatically) it may cause a transient change in the
reading which can last up to several seconds.
Tip: If a long time constant filter is in use, toggle the filter key to re-start the filter and obtain the
required reading faster.
Note:- When testing at less than 500 volts, the tolerance to external interference is reduced. This is
because of voltage regulation problems caused by a.c. current flowing into the positive terminal
impedance of about 80 kΩ. Such a condition will be evident by the fact that the terminal voltage will
change from its set value.
Note:- Selecting a new filter time discards all previous readings and begins building up a new average.
The displayed value will move to the most recently acquired result. e.g. If FILT 3 is in operation and
the filter key is pressed once (to select the FILT 30) the most recent unfiltered result is displayed.
This will be followed by the average of two results, three results, four results etc. until it showing the
average of the last 30 results. Note that averaging is performed on measured current (not calculated
resistance). This is the best way to reject incoming a.c. interference but it can produce some unusual
settling characteristics when observing resistance measurements.
15

Operation
16
Fault Conditioning (Burn)
BURN disables the normal ‘breakdown’ detection and enables the Insulation test voltage to
continue even after breakdown at any weak point of the circuit insulation. This will enable the
location of the failure to be seen or heard.
Note:- The Test Button must be be set to ‘LOCKED’ position to use the BURN mode
1. Setup the Test Button to the ‘LOCKED’ position. See ‘Set / Reset Locking Test button’.
2. From the ‘Menu’ screen, select’ INSULATION RESISTANCE’ using the left hand cursor keys.
3. Use the right hand cursor keys to select and highlight the time indicator. Press the ‘CHANGE’
key, followed by the ‘+/ -’ keys to set the required time.
4. Set the required Test Voltage with the right hand cursor keys.
5. Press, and hold the red button for at least five seconds. Two bleeps are sounded. To warn that
a test is in progress, BURN is displayed, alternating with , symbols. The test terminal
indicator light flashes.
6. Test progression is shown by a Bargraph. Using the left hand cursor keys a Results or
Graph result screen can be selected either during, or after a test.
Break-down of the circuit and the related noise interference may cause the instrument terminate
the operation, possibly causing a loss of display while the circuit remains energised. In this
event, it is important that the circuit is discharged before touching any connections. If necessary,
switch the instrument off, and then on again to reset the display.
7. To stop the test at any time, press the red test button. ‘DISCHARGING‘ is displayed, until the
circuit is in a safe condition.
8. To return to the menu display press the ‘Menu’ key.
9. If required,
Setup the test button to the ‘NOT LOCKED’ position.
Remote operation
A software package S1-S1 is available for controlling the S1-5010 directly from a PC. You may also
automatically define certain test sequences. See ‘Accessories’.
Care must be taken that no unintentional harm or damage can be caused

Insulation Resistance Testing
This test mode measures insulation resistance continuously at the selected voltage. The test is
applied for a short but specific duration, immediately after which a reading is taken. Test duration is
typically 30 or 60 seconds and the S1-5010 will allow you to set this duration, and the test will finish
automatically. The reading will not necessarily be the maximum value but if the same duration is used
each test, then the same point on the curve of increasing apparent resistance is being compared. On
installation these readings will be compared to the required minimum specification. Further readings
taken for maintenance purposes must be monitored for any trend that they show. The readings are
subject to variation from temperature and humidity and these factors may require the insulation
reading to be corrected. Information on temperature correction is given in the MEGGER publication
‘A Stitch in Time’. Alternatively, a Polarization Index (PI) test may be used.
Example of IR Graphic display
Polarization Index (PI) Test
Time resistance tests are successive insulation readings at specified times, taking the ratio of
dielectric absorption into account, and are independent of temperature. Good insulation generally
shows an increase in resistance over a 10 minute period. With contaminated insulation, absorption
effects are masked by high leakage currents and the readings are therefore fairly flat.
The PI test is a particular example of the time resistance method, and takes the ratio of the insulation
values at 1 minute (designated T1) and at 10 minutes (designated T2) - this is the Polarization Index.
The PI test also has the advantage of not requiring temperature correction.
Example of PI display
Test Mode Summary
17

Test Mode Summary
18
The value of PI can often help in the situation where past test record frequency are limited, by giving
a rough guide to condition of insulator. The figures should always be interpreted in the context of the
equipment history and your experience.
There are two specific conditions to be aware of when interpreting PI test results, particularly if a
history of the equipment is unavailable.
1) Dry, brittle insulation (e.g. on windings) on can give a high PI but fail under shock conditions.
2) If multi-layered insulation fails in one of the layers while the others retain high resistances, the
effect on the test current will tend to increase the PI value, masking possible problems from
surface leakage caused by dirt and contamination.
Dielectric Absorption Ratio is the term applied to a Polarization Index at other time intervals using
‘Setup’. Whatever times are set, these will be carried through to the Dielectric Discharge (DD) test
which produces a PI value while it is doing the DD test.
Dielectric Discharge Testing
The Dielectric Discharge (DD) Test is a diagnostic insulation test that allows ageing and deterioration
of insulation to be assessed. The result is dependent on the discharge characteristic, so the internal
condition of the insulation is tested, largely independent of any surface contamination. The charge that
is stored in the insulation material under test, is measured during the discharge phase.
The charge that is stored during the insulation test is automatically discharged at the end of the test
when the discharge resistors are switched across the terminals. The rate of discharge depends only
on the discharge resistors and the amount of stored charge from the insulation.
The capacitive current quickly decays from a high value with a relatively short time constant (a few
seconds). The absorption (or re-absorption during a discharge) current starts from a lower level but
has a much longer time constant (up to several minutes). This is caused by ions and dipoles re-
aligning themselves within the insulation. When an electric field is applied some ions are able to move,
and some dipoles align themselves within the field. These effects reverse themselves slowly when the
test voltage is removed, caused by particles returning to their natural random state.The DD test
measures the discharge currents 1 minute after an insulation test has been completed. At this time
the capacitive current has usually become insignificant compared with the re-absorption current. The
level of re-absorption after this time shows the condition of the insulation material, providing that the
insulation material has been fully charged for full absorption to take place (typically 10 to 30 minutes).
A high re-absorption current shows that the insulation has been contaminated, usually by moisture. A
low current usually shows that the insulation is clean and has not absorbed much moisture.
The dielectric discharge test measures the discharge current 60 seconds after the insulation test is
completed. This is converted to a figure of merit which gives a figure for the quality of the insulation,
independent of the test voltage. This value is temperature dependent so it is important to test at a
reference temperature, or record the value.
The DD value is defined as:
Current flowing after 1 minute (mA) =I1min
Test Voltage (V) x Capacitance (µF) V x C
PI TEST RESULT INSULATION CONDITION
<1,0 Unsatisfactory
1,0 to 2,0 Dubious
2,0 to 4,0 Good
>4,0 Very Good

The maximum DD value that can be measured (assuming the default test voltage of 500 V) is typically
20, if the capacitance of the test sample is 1µF, but decreasing to 2 for a capacitance of 10 µF. If the
maximum value has been exceeded the result will show a ‘>’ symbol in front of the number (e.g.
‘>20’).
Step Voltage Testing
This test is based on the principle that an ideal insulator will produce identical insulation readings at
all voltages, while an insulator which is being over stressed, will show lower insulation values at
higher voltages. The selected voltage (2,5 kV or 5 kV) steps from zero by one fifth of the final value
every minute, for 5 minutes, taking successive measurements until the final voltage value is reached.
Example of Step Voltage Testing display
Fault Conditioning (Burn)
For a normal Insulation resistance test, when a Burn test is not initiated, the voltage will be turned Off
after a breakdown. This reduces the possibility of unintentional damage to the insulation by carbon
tracking, or by arcing. Burn test mode disables the ‘breakdown’ detector and allows the Insulation
resistance test voltage to be continued until it causes burning and insulation breakdown at a weak
point of the circuit. If a Burn test is initiated, the instrument will maintain the high voltage even after a
breakdown is caused, enabling the location of the failure to be seen or heard.
DD Test Result (in mA V-1F-1)
>7
>4
2 - 4
<2
Insulation Condition
Bad
Poor
Questionable
O.K.
19

20
Data Retrieve
Results are automatically stored when a test runs for more than one minute. Tests are identified by
date and test number. At each date change, test numbering restarts at 1.The time of the test (24 hour
clock format) is also stored. A maximum of 75 tests can be stored. Attempting to store more than 75
tests will cause the oldest test results to be erased. A warning message will appear before test results
are automatically erased.
Display Stored Test results
1. From the ‘Menu’ screen, use the left hand cursor st keys to select and highlight ‘RETRIEVE’.
2. Press the ‘START’ key. The output device list is displayed.
3. Use the left hand cursor st keys to select and highlight ‘DISPLAY’.
4. Press the ‘OK’ key. The first test results are displayed.
5. Press ‘NEXT’ and ‘LAST’ keys to display subsequent or previous test results.
6. On completion press the ‘END’ key to return back to the ‘Menu’ screen.
Download stored Test results to a Printer
An external Printer can be connected to the optically isolated RS232 connector in the side recess
panel. It is safe to connect a printer to this socket while tests are being performed. Test results can be
sent in real time, and the data output rate can be adjusted from 1 to 60 seconds via the Setup screen.
The default Baud rate is 9600, and this can be adjusted via the Setup screen. Test results are sent to
the RS 232 socket every 5 seconds. The format of the output data is comma delimited ASCII.
1. Connect and set up the Printer.
2. From the ‘Menu’ screen, use the left hand cursor keys to select and highlight ‘RETRIEVE’.
3. Press the ‘START’ key. The ‘SELECT OUTPUT DEVICE LIST’ screen is displayed.
4. Use the left hand cursor keys to select and highlight ‘PRINTER’.
5. Press the ‘OK’ key. The first test results are displayed.
6. Press ‘NEXT’ and ‘LAST’ keys to display the required test results.
7. Press the ‘START’ key. The message ‘PRINTOUT IN PROGRESS’ is displayed.
8. When the completed message is displayed, press the ‘MENU’ key to return back to the
‘SELECT OUTPUT DEVICE LIST’ screen.
9. Press the ‘END’ key to return back to the ‘Menu’ screen.
Downloading Test results to a PC
Test results may be downloaded to a PC in one of two ways..... ‘Real Time’ (downloading while
carrying out a test) or ‘Batch’ (downloading a single or multiple results after a test(s) has been
completed and stored in the memory of the S1-5010). In both cases, the download of results takes
place via the RS232 port of the S1-5010 to a COM port of the PC.
‘Real Time’ downloading uses the AVOLOAD DOS program on the diskette supplied with the
instrument.
‘Batch’ downloading uses the AVODNLDR DOS program on the diskette supplied with the
instrument.
Examples of a ‘Real Time’ display, and ‘Batch’ displays are given in ‘Appendix 1’.
Instructions on how to use both programs are contained in the README file on the diskette.
Alternatively, the S1-S1 ‘Windows’program can be used to set up and control the S1-5010
instrument, and download ‘Real time’ and ‘Batch’ data. See ‘Accessories’.