Megger RCDT300 Series User manual

M
RCDT300 Series
Residual Current Device testers
USER MANUAL

GSAFETY WARNINGS
nSafety Warnings and Precautions must be read and understood before the instrument is used. They must be observed during use.
nContinuity of protective conductors and earthed equipotential bonding of new or modified installations must be verified before carrying out RCD tests.
nDo not leave the instrument connected to the mains supply when not in use.
nCircuit connections and exposed metalwork of an installation or equipment under test must not be touched.
nEnsure that hands remain behind guards of probes/clips when testing.
nDo not move the rotary selector knob position while a test is in progress.
nThe instrument should not be used if any part of it is damaged.
nTest leads, probes and crocodile clips must be in good order, clean and with no broken or cracked insulation.
nThe batterycover must be in place whilst conducting tests.
nVoltage indicator LED’s cannot reveal a N-PE supply reversal.
2
Users of this equipment and/or their employers are reminded that 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.
Some national safety authorities recommend fused leads for voltage measurement on high energy systems. If RCD or Loop tests are made it may cause the
fuse to rupture, and so they must be used with caution on voltage testing.
NOTE
THE INSTRUMENT MUST ONLY BE USED BY SUITABLY TRAINED AND COMPETENT PERSONS.

To replace batteries 17
Fuse blown indication 17
Preventive maintenance 19
Specification 19
Basic and service errors 20
Accessories and equipment 21
Repair and Warranty 22
Symbols used on the instrument are:
GCaution: refer to accompanying notes
tEquipment protected throughout by Double
Insulation (Class II)
cEquipment complies with current EU directives.
Equipment complies with ‘C tick’ requirements
CONTENTS
3
Safety warnings: 2
Introduction 4
General description 4
Case contents 5
LCD display 6
Top panel 6
Lid open/closure 7
Preparations for use 8
Batteries 8
Preliminary test lead check 8
General operating instructions 8
Display warning symbols 9
Setup procedure 9
Reverse polarity detection 9
Touch voltage 9
Test leads 10
Test lead connection. 10
LED indicators 11
Residual current device [RCD] testing 11
RCD type selection 12
1/2I RCD non-tripping measurement 12
1xI & 5xI RCD trip time measurement 12
0 or 180° testing 13
RampTest [RCDT320 and RCDT330 only] 13
DC sensitive RCD test 13
Auto RCD test (RCD320 and RCDT330 only) 13
Voltage measurement 14
Touch voltage 14
Frequency Hz (RCDT320 and RCDT330 only) 16
Replacing batteries and fuses 17
Low battery warning symbol 17
N1311

Feature RCDT310 RCDT320 RCDT330
3Phase safe nn n
Display backlight nn
Battery status indication nn n
Auto power down nn n
Fuse blown indication nn n
L-N-E polarity indicators nnn
Voltmeter n n n
Frequency measurement nn
Reverse polarity operation *
(can be disabled) nn n
1/2I, I, 5I RCD trip time test nn n
Auto sequence test nn
Max touch voltage selectable (25/50 V) nn n
RCD trip current test (RAMP) nn
0º/180º polarity selection nn n
Selective breakers nnn
*Not available on UK versions
INTRODUCTION GENERAL DESCRIPTION
4
Thank you for purchasing the Megger RCD Tester.
For your own safety and to get the maximum benefit from your
instrument, please ensure that you read and understand the following
safety warnings and instructions before attempting to use the instruments.
This user manual describes the operation and functions of the following
RCDT300 series of RCD testers:
RCDT310
RCDT320
RCDT330
The RCDT300 Series test instruments have
the following features:

Please complete the warranty card and return it to Megger Limited as soon
as possible to help us reduce any delays in supporting you should the
need arise.
Carton contents RCDT310, RCDT320 and RCDT330:
1xRCDT300 series RCD tester
1x2wire test lead with prods with clips (RCDT320, RCDT330 only)
8 x AA (LR6) batteries (fitted in instrument)
1 x Warranty card
1 x Calibration certificate
1xCD containing user manual
1xSafety instructions
1 x USB download lead (RCDDT330 only)
1 x Download manager CD (RCDT330 only)
1 x Printed quick startguide
1 x Mains plug test lead
CASE CONTENTS
5
Feature RCDT310 RCDT320 RCDT330
DC breakers (1/2 I, I, 5I) nnn
Programmable breakers n
30, 100, 300, 500 mA RCDs nn n
10 mA/1000 mA RCD nn
Plug ended test lead nn n
2wire test lead probe/croc clip ended nn
Calibration certificate nnn
IEC61010-1 300V CATIII n n n
EN61557 nn n
Results storage n
Downloading n
USB n

6
LCD DISPLAY FRONT PANEL
Refer to user
manual
Test lead
connections
Front panel
cover (folded
under cover)
Backlight
On/Off
(320/330)
RCD type
selector:
AC
AC selective
DC
DC selective
Test button
0º/180º
selector
Neck strap
slots
Supply connection
indicators
L-PE, L-N, N-PE
LCD display
RCD range select:
10 mA (320/330)
30 mA
100 mA
300 mA
500 mA
1000 mA (320/330)
Prog (330 only)
Test selector:
1/2 xI RCD trip time
1xI RCD trip time
5xI RCD trip time
AUTO (320/33)
Ramp (320/330)
V - AC RMS
Hz - Frequency
(320/330)
RCL, SND, DEL (330
only)
Mains noise
Battery
status
Ranges
Measured results
Touch voltage
bargraph
display
RCD test type
indicator
Fuse blown

Memory control keys:
STORE:.................... Store initiates the storing of a test result.
LAST/NEXT:............ Selects the type of location; ie Job,
distribution board, circuit, phase etc.
ESC:.........................Aborts a save at any time.
OK:.......................... Final operation to save the result.
sSelects the job, db, circuit number; ie
t01,02,03 etc
Lid open/closure
1. Open lid by lifting up front panel tab (1).
2. Fold-away underneath instrument (2 & 3) and push into retaining slot
(4).
Connection Panel
RCDT300 Series test lead connections
Additional RCDT330 Controls
7
Phase connection Earth connection
USB
connection
Max. 300 V
Phase to earth
Mains plug
test lead
connector
Max. 300 V
Phase to
earth
Warning!
Read user manual

PREPARATIONS FOR USE (ALL INSTRUMENTS) GENERAL OPERATING INSTRUCTIONS
8
Test inhibit
The following condition may cause the instrument to inhibit testing:
Out of range supply voltage
If an out of range voltage or frequency exists on the circuit under test,
or on a very noisy mains supply, testing will be automatically inhibited.
The RCD tests requires a minimum supply voltage to operate.
If the warning <***V is displayed, the supply voltage is below that
required to perform an RCD test.
*** = supply voltage indication.
Overheating
Repetitive RCD Ramp testing and some high current RCD trip testing
generates heat within the instrument. If this heat becomes excessive
the instrument will warn the operator by displaying the hot symbol,
and prevent further testing until the instrument has had a chance to
cool down.
Fuse Blown
Afuse blown will prevent the instrument from making further tests.
The fuse indicator will be displayed.
Default voltmeter
The default voltmeter automatically operates in all test modes, indicating
connection to a live system.
Auto power-down
To extend battery life the instrument will automatically switch off six
minutes after the last operation.
It can be switched off manually by selecting [OFF] with the rotary switch,
Batteries
The Megger RCDT300 series instruments are supplied with batteries fitted.
When batteries become exhausted, refer to page 17, battery replacement.
Warning: Do not switch the instrument on with the battery cover
removed.
Preliminary test lead check
Functional verification
Before each use of the instrument, visually inspect the test leads, prods
and crocodile clips to confirm that their condition is good, with no
damaged or broken insulation.

or switched back on again by pressing the [TEST] button.
Backlight operation (RCDT320 and RCDT330 only)
The RCDT320 and RCDT330 LCD display may be backlit. The backlight
function can be selected at any time while the instrument is switched on by
pressing the BACKLIGHT Jbutton.
The backlight function will switch off automatically 15 seconds after the
instrument has finished testing.
Display warning symbols
GRefer to user manual.
Any time the warning triangle is displayed the operator should refer to the
user manual for further information.
Battery condition indication. Refer to page 17.
fFuse blown indicator, appears when an instrument fuse has failed.
Refer to page 16.
>280V Indicates a supply voltage in excess of the allowed is present.
<50 V* Supply voltage too low/missing
hot Indicates the instrument needs to cool down before it can continue
RCD testing
*May vary depending on RCD test and instrument type.
Setup procedure
Note: Line reversal and RCD touch voltage configuration features are only
available on the instruments as per the relevant tables in the specification
section of this document.
Reverse polarity detection (not available on the UK version)
/Touch voltage setting
To select Polarity reversal acceptance or rejection:
1. With the instrument switched OFF, hold down the [TEST] button and
turn the range knob to any ON position.
2. Keep the button held down until the instrument displays the ‘SET’
warning.
3. Now release the [TEST] button.
4. Press the [TEST] button again to view the current setting for
line/neutral swapping.
5. The display shows ‘L+L’ (instrument will perform tests with L & N
swapped) or ‘L+N’ (instrument will not perform tests with L & N
swapped).
NOTE: LED’s will illuminate to indicate:-
L-PE ON = No reverse polarity
L-PE & N-PE ON = Reverse polarity allowed.
6. Press the [0/180º] button to change the setting.
7. Press the [TEST] button to go to the next item in the setup menu.
RCD touch voltage selection
To set the touch voltage inhibit limit:
1. With the instrument switched OFF, hold down the [TEST] button and
turn the range knob to any ON position.
2. Keep the button held down until the instrument displays the ‘SET’
warning.
9

10
Test lead connection
The supplied test leads should be connected to the appropriate sockets on
the rear of the instrument marked L0 and L1, or to the 3 way test socket.
Standard test probes and crocodile clips are supplied for connection to the
circuit under test with the RCDT320 only.
Application
This instrument may be connected live to earth or between live conductors
of systems that have a rated voltage of 300 V a.c. rms to earth and an
installation (overvoltage) Category III or lower.
This means that the instrument may be connected to any fixed wiring of a
building installation, but not to primary supply circuits such as overhead
cables. Tomaintain user safety and ensure accurate measurements, only use
the test leads supplied by Megger.
System diagram - Whereto use each test
3. Now release the [TEST] button.
4. Press the [TEST] button twice to view the current settings for the touch
voltage.
The display shows the fault voltage limit, ‘25 V’ or ‘50 V’.
If the fault-voltage display is active, a bar-graph display will also appear.
5. Press the [0º/180º] button to change the limit setting from 25V to 50V
and back.
6. Press the [TYPE] button to turn bar-graph display ON or OFF.
7. Press the [TEST] button to exit from the set-up menu.
Test leads
All test leads form part of the measuring circuit of the instrument and must
not be modified or changed in any way, or be used with any other electrical
instrument or appliance.
The colour code of the cord is:
Earth (Ground) Yellow/Green
Neutral Blue
Phase (Line) Brown
NOTE: Aplug severed from the power cord must be destroyed, as a plug
with bare conductors is hazardous in a live socket outlet.