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Metrel MI 3143 ST Multifunction Installation Tester

FREE Gift The Metrel MI 3143 ST is intended for measuring the effectiveness of automatic trip out protection in case of faults in transformers and other HV equipment.

Important Calibration Information

This instrument comes with a manufacturers calibration certificate.
Please see 'Calibration Options' in the description for more details.

Next Day Delivery (subject to availability)

£2,059.95 exc. VAT £2,471.94 inc. VAT £3,746.45 inc. VAT
  • 4-wire 220 A Z Line and Z Loop Impedance Tester
  • Android Compatible
  • CAT IV 600 V (3000 m)
  • Ground Fault Analysis
  • High range impedance measurements
  • Mains/Battery Powered
  • Rated IP65
  • Selectable test load
  • FreeDelivery
  • 30DayMoneyBack
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  • Description
  • Features & Specification
  • Resources
  • Delivery

FREE Gifts

This instrument comes complete with your choice of free gift from the drop-down menu above. Choose from a calibration voucher for next 
year, a 50m R2 wander lead or a set of quality silicone test leads. How about any one of the IET Guidance Notes, or a quality two-pole tester? 
Whatever you choose you can be sure you're getting a fantastic deal at Instrument Sales & Services.

Metrel MI 3143 STT Multifunction Installation Tester (Standard Set)

The MI 3143 STV is a multifunctional, portable battery (Li-ion) or mains powered test instrument with excellent IP protection: IP65 (case closed), IP54 (case opened). It can be controlled via an Android app A 1522 aMESM, MI 3152 EurotestXC, MI 3152H EurotestXC 2.5kV, MI 3155 EurotestXD or MI 3325 MultiServicerXD. The MI 3143 Euro Z 440 V is intended for measuring the effectiveness of automatic trip out protection in case of faults in transformers and other HV equipment. With its high precision line and loop impedance measurements on AC circuits, high current dR 300A loop and line measurements for testing partial voltage drops and contact voltage measurement, it is ideal for testing in industrial settings.

This instrument comes in two available configurations, Standard set and Euro set.
For the MI 3143-Euro Z 440v (Euro Set) please see this link.


*Important Calibration Information:

This instrument comes complete with the manufacturers calibration certificate. Please be aware that these certificates are generic and may also be time lapsed.
If you would prefer a personalised full traceable calibration certificate applied to the equipment before dispatch, then please select this option from the drop-down menu above, an additional calibration charge will apply.

The MI 3143-ST Set Comes Supplied With:

  • Instrument MI 3143-ST
  • Mains cable
  • RS232-PS/2 cable
  • Test lead, 2-wire, 2 pcs*
  • Crocodile clip, black, 2 pcs
  • Crocodile clip, red, 2 pcs
  • Test probe, black, 2 pcs
  • Test probe, red, 2 pcs
  • Metrel ES Manager BASIC license
  • Metrel aMESM Android app with P 1102 PRO license key
  • Short instruction manual
  • Calibration certificate
  • Protective bag for accessorie

* Replaced by 5 m and 20 m test leads in MI 3143 EU set.

Metrel MI 3143


Key Features:

  • High precision 4-wire 220 A Z Line and Z Loop Impedance Tester;
  • High range impedance measurements in 440 V / 16 ... 420 Hz AC Networks;
  • High current dR 300 A 4-wire partial voltage drops;
  • Ground fault analysis with contact, touch and step voltage;
  • Floating Voltmeter for partial contact results;
  • Selectable test load (33.3 % to 100 %);
  • Improved thermal performance;
  • Portable battery (Li-ion) or mains powered test instrument;
  • IP protection: IP65 (case closed), IP54 (case opened);
  • CAT IV 600 V (3000 m) safety category;
  • Bluetooth communication;
  • Black box design (remote-controlled via an Android device).

Technical Data:

  • Dimensions (w x h x d): 360 mm x 160 mm x 330 mm
  • Weight (without accessories): 6,5 kg 

Standards Applied:

  • IEEE 81-2012
  • IEC/EN 60909-0
  • IEC/EN 61557 series
  • IEC/EN 61557-3


Electrical Power Systems

  • Distribution
  • Safety
  • Connections / Bondings

Industrial Systems

  • LV Installations Safety / Quality
  • Switchboards / Controlgears
  • Machines / Power Loads

About Metrel

Metrel was established in 1957 as a factory for the production of electrical measuring instruments and components for the domestic market and grew from there to become one of world’s leading manufacturers of measuring and testing equipment. They are one of the few companies in the industry that develops and manufactures products at a single location, starting with design and ending with final assembly, quality control and calibration.

Metrel MI 3143 ST Specification
Function Measuring Range  Resolution  Accuracy 

Impedance [Z]

Z line mΩ

Z loop mΩ

0.1 mΩ … 199.9 mΩ 0.1 mΩ ±(5 % of reading + 3 mΩ)
200 mΩ … 1999 mΩ 1 mΩ
2.00 Ω … 19.99 Ω 10 mΩ ±(5 % of reading + 3 digits)

Impedance [Z]

High current ΔR

0.1 mΩ … 199.9 mΩ 0.1 mΩ ±(5 % of reading + 3 mΩ)
200 mΩ … 1999 mΩ 1 mΩ
2.00 Ω … 19.99 Ω 10 mΩ ±(5 % of reading + 3 digits)

Earth potential [U]


0.0 V … 199.9 V 0.1 V Calculated value
200 V … 999 V 1 V

Earth potential [U]


1 mV … 1999 mV 1 mV ±(2 % of reading + 2 digits)
2.00 V … 19.99 V 10 mV
20.0 V … 199.9 V 0.1 V

Orders requiring calibration 

Whilst we take the greatest care to get all orders dispatched and delivered to you in the stated time frame, orders received PM and requiring
calibration may on occasion miss dispatch that day, according to the complexity of the calibration. Be assured they will ship on the next dispatch
this in most cases should not add more than 24 hours to your delivery.

Bank/Public Holidays

Predicted delivery times are based on regular trading days Monday to Friday. Public holidays, bank holidays and weekends are outside the usual scope 
of our dispatch and subject to activities/holidays of our carriers and therefore may incur additional days lead time to your order.

*UK Mainland (Temporarily revised June 2020)

Please note that regrettably, we have had to realign our delivery service options to those available from our carriers.
During the current situation surrounding the effects of the Coronavirus pandemic, logistics from every company are under immense pressure to deliver goods on time.
We have taken the decision to temporarily limit our services rather than let our customers down.
We hope you will understand our position on this and we apologise unreservedly for the inconvenience we know this will cause.
We look forward to restoring our full delivery service schedule just as soon as we are able.

Standard FREE 1-2 Day Courier Delivery – UK Mainland only - Zones A & B

Included in the price for all orders over £75.00 (exc vat). Sent using express courier, delivered within 1-2 working days from the date of your order, subject to availability.


Next Day Anytime Delivery (Excluding Saturday & Sunday) – UK Mainland only - Zones A & B
Sent by express courier, delivered next day (excluding weekends) from the date of your order, subject to availability.


Orders must be placed before 3:00pm for a qualifying next day delivery and a telephone number supplied, subject to availability.

New Postage Map Sept 2018>

Delivery Surcharges

Because of the high cost of carriage, we need to apply a surcharge on all deliveries made in the following regions bringing the carriage charges to:

  • Zones A & B  - Mainland delivery rates apply. 
  • Zone C - Scottish Highlands (Charges are calculated at the checkout).
  • Zone D - Outer Hebrides, Orkney Isles, Shetland Isles, Isle of Man, Scilly Isles, and Channel Islands (Charges are calculated at the checkout).
  • Zone E - Northern Ireland (Charges are calculated at the checkout).
  • Zone F - Republic of Ireland (Charges are calculated at the checkout).

Offshore Services

All offshore deliveries are a 2 day service as standard. This includes Channel Islands, Northern & Southern Ireland, Scottish Islands, Isle of Man and the Scilly Isles.

International Delivery

International delivery charges are automatically added to your order at the checkout. For any questions regarding international deliveries please contact us at


All export inquiries should be directed to the export division before placement of order.

If no shipping option is available to your selected country please call us FREE on 0800 0224 060 to purchase your items.
All stated prices are subject to VAT at the current rate where applicable E&OA