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Metrel MI3143-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)

£1,899.95 exc. VAT £2,279.94 inc. VAT £3,404.14 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
Required Fields
  • Description
  • Features & Specification
  • Resources
  • Delivery (updated)

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

Delivery Notices (Updated March 29th 2021)

During the current situation surrounding the effects of the Coronavirus pandemic, logistics from every company are under immense pressure to deliver goods on time.
Coupled with manufacturers on reduced output due to more stringent working practices and a global shortage of component parts to supply UK manufacturing, we have taken the decision to 
temporarily limit our services rather than let our customers down amid these unprecedented circumstances.
We hope you will understand our position on this and we apologize unreservedly for the inconvenience we know it will cause.

Please note that ALL orders placed before 3:00pm are shipped same-day (subject to stock and any additional services required).
The stated transport times above have some scope for adjustment built-in for the Covid-19 situation. Carriers themselves also have their own extended workload and limitations at this time which are unfortunately beyond our control.

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 (Revised March 2021)

Service  Price 
Standard FREE 2-3 Day Courier Delivery – UK Mainland only - Zones A & B - Order value OVER £75.00 ex VAT - Order by 3:0pm FREE
Standard FREE 2-3 Day Courier Delivery – UK Mainland only - Zones A & B - Order value UNDER £75.00 ex VAT - Order by 3:0pm £4.75
Next WORKING Day (excludes Saturdays, Sundays and public holidays)  – UK Mainland only - Zones A & B  - ANY order value - Order by 3:0pm      £7.75
Saturday ANYTIME Delivery - Order by 3:0pm £9.95

New Postage Map Sept 2018>

Delivery Surcharges

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

  • 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 3-4 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.