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Megger RCDT320 RCD Tester

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£381.77 £318.14
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Megger's mid-range RCD tester (part of the RCDT300 series), the RCDT320 improves upon the basic functionality of the RCDT310 and has several advanced features not available on the previous model.

This residual current device (RCD) tester is suitable for use on a wide variety of RCD types, including selective breakers, DC breakers (1/2 I, I, I and 5I), 30/100/300/500mA and 10mA / 1A RCDs and is used to evaluate that they are correctly implemented into electrical systems and trip out at the appropriate level.

One of the main differences between this tester and the RCDT310 is the inclusion of ramp and auto sequence testing procedures. The ramp function automatically gradually increases the current level applied during the tester while the auto sequence testing automatically cycles through the necessary testing procedures to get quick, accurate and comprehensive results with minimal input from the user.

You can view the exact difference between each model in Megger's RCDT300 series by taking a look at the table in the tech specs section further below.

Megger RCDT320 RCD Tester Key Features

  • Performs 1/2 I, 1 x I and 5 x I tests on RCDs rated at 30mA, 100mA, 300mA and 500mA
  • Suitable for use with both general and selective (time-delayed) RCD types
  • Also suitable for testing RCDs rated at 10mA and 1000mA
  • DC RCD testing
  • Selectable polarity - test at 0 or 180°
  • Measurements of touch voltage at the start of the test (with selectable voltage inhibit of 25V or 50V)
  • Rubber-armoured casing - protects the tester from harm at all times in even the most arduous industrial environments
  • Rigid display cover - folds down and protects the screen and tester functions when not in use
  • Colour-coded ranges - easily choose what you need (user guide also included in tester lid)
  • Ramp testing - current level is slowly increased until the RCD trips
  • Automatic testing - all this mode requires is you to reset the RCD each time the test completes. All results are stored on the meter for reference

What's Included?

  • Megger RCDT320 RCD Tester
  • Mains Plug Test Lead (BS1363)
  • 2-Wire Test Lead With Prods and Clips


There are a number of accessories available for the Megger RCDT320 RCD Tester. Please contact our sales team for further information or to add an item listed below to an order. 

Our SKU Megger's Part Code Product 
MEGRCDA1 6231-601 UK Mains Plug Test Leadset 3-pin 1 wire (BS1363 plug)
MEGLTA2 1001-883 Test lead set 3-wire Red/Black/Green with prods/clips (exposed tip)  
1001-976 1003-132B Test Lead Set Red/Green Unfused (Boxed)  
1000-562 1000-562 Test Lead Replacement Probe Cap [Clear] Bag of 20  
6220-810 1004-323B SIA10 Socket Interface Adaptor UK to 3 Leads x 4mm (Boxed)
1005-469 1005-469 SIA10 Socket Interface Adaptor LTW  
1004-610 1004-610 Lead USB Type A  to Type B 1.8m Data/Printer Cable
1007-003 1007-003 Blow Moulded Case Catch - Pack of 10  
1007-167 1007-167 Blow Moulded Case MIT/LT/RCDT 300 Series  
Accessories related to this product:
  1. megger uk mains plug leadset 3 pin 1 wire bs1363 plug
    £16.80 £14.00
  2. Megger Clear Probe Caps for MFT 1500 Series - Bag of 20
    £20.70 £17.25
  3. Megger 1007-167 Blow Moulded Case
    £18.90 £15.75
  4. Megger Test Lead Set 2 Wire Lead Set
    £33.26 £27.72
  5. Megger 1004-610 Data/ Printer 1.8m Lead - USB Type-A to Type-B
    £9.90 £8.25
  6. Megger SIA10 Socket Interface Adaptor
    £34.01 £28.34
  7. Megger 1005-469 SIA10 Socket Interface Adaptor
    Megger 1005-469 SIA10 Socket Interface Adaptor
    Lead Time: 1-2 Weeks
    £38.70 £32.25
  8. Megger 1001-883 3-Wire Test Lead Set
    £43.14 £35.95
  9. Megger 1007-003 Blow Moulded Case Catch
    £14.40 £12.00
Part CodeRCDT320-EN-BS

Megger RCDT300 Range Differences

Model NumberRCD310RCDT320RCDT330
1/2 I, 5I RCD Trip Time Test
Selective Breakers
DC Breakers (1/2 I, I, 5I)
30, 100, 300, 500mA RCDs
10mA/1A RCDs -
RCD Trip Current Test (RAMP) -
Auto Sequence Test -
0/180° Polarity Selection
Touch Voltage Display Inhibit (Selectable)
Max Touch Voltage (25V/50V)
Operating Range 100 to 280V - -
Operating Range 50 to 280V -
Programmable RCDs - -
Frequency Measurement -
3-Phase Safe
Large, Clear Display
Backlight -
Battery Status Indication
Auto Power Down
Fuse Blown Indication
IP54 Weatherproof
Result Storage - -
Downloadable - -
USB Interface - -
IEC61010-1 CAT III 300V

Megger RCDT300 Series Technical Specifications

RCD Test Ranges (to EN61557-6) 
Supply Voltage RCDT310 100 V - 280 V 45 Hz to 65 Hz RCDT320 50 V - 280 V 45 Hz to 65 Hz
RCDT330 50 V - 280 V 45 Hz to 65 Hz
Minimum voltage 71 V for 300 mA RCDs, 100 V for 500 mA RCDs and 205 V for 1000 mA RCDs
Test Current Accuracy 
No Trip Test (1/2I) –8% to –2%
Trip Test (I, 5I) +2% to +8%
Trip Time ±1% ±1ms
Voltage Measurement (All Models)
Range (AC) 0 V - 300 V 25 Hz to 450 Hz
Accuracy ±2% ±2 digits
Frequency (RCDT320/RCDT330 Only) 
Range 25 Hz to 450 Hz
Accuracy 25.0 Hz to 199.9 Hz ±0.1 Hz
200 Hz to 450 Hz ±1 Hz
Fault (Touch) Voltage 
Displayed Range 0 V to 50 V
Error +5%/+15% ±0.5 V
Programmable RCD Step Increments 10 mA to 50 mA - 1 mA steps
50 mA to 500 mA - 5 mA steps
500 mA to 1000 mA - 10 mA steps
Test Result Storage (RCDT330 Only) 
Job Number 256 locations
Distribution Board Number 99 locations
Circuits 99 locations
Phases P1, P2, P3
Other Last recorded result may be recalled to the display. All data can
be downloaded to a PC using Download Manager (supplied) or
Megger Powersuite Professional Windows software
Temperature and Humidity
Operating Range -5°C to +40°C
Operating Humidity 3% R.H. at +40°C max.
Storage Range -25°C to +70°C
Maximum Altitude 2000m
Environmental Protection IP54
Requirements Meets the requirements of IEC61010-1 Cat III 300 V phase to
IEC61557 Complies with the following parts of EN61557, Electrical safety
in low voltage systems up to 1000 V ac and 1500 V dc-
Equipment for testing, measuring or monitoring of protective
Part1-General Requirements
Part4-Residual current devices
Power Supply 
Batteries 8 x 1,5 V cells IEC LR6 type (AA alkaline).
Rechargeable 8 x 1.2 V NiCd or NiMH cells.
Battery Life 2000 consecutive tests
Weight and Dimensions 
Weight All units 980 gms
Dimensions All units 203 x 148 x 78 mm
E.M.C In accordance with IEC61326-1
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