Hi Guys,
In reponse to your questions here is some information about the Wagobox Junction Box System, Wago connectors and the MF Logo
What is the MF logo?
The MF logo was introduced in BS5733:2010 "General Requirements for electrical accessories" as a marking that can be used on accessories to indicate that the accessory doesn't require further inspection, testing or maintenance after installation.
What is BS5733:2010?
BS5733 is a British Standard which specifies tests to check the safety in normal use of electrical accessories not covered by other specific British standards.
Is the MF logo mentioned in BS7671: Requirements for Electrical Installations?
Yes, the MF logo is mentioned in BS7671 Amendment No. 1. 2011 in Section 526.3 (vi).
Section 5 deals with the Selection and Erection of Equipment.
Subsection 526. Electrical Connections:
Requirement 526.3 Every connection shall be accessible for inspection, testing and maintenance except for the following:
...
526.3(vi) Equipment complying with BS5733 for a maintenance free accessory and marked with the symbol MF and installed in accordance with the manufacturers instructions.
How has this changed from the previous edition of BS7671?
In the previous edition of BS7671 the regulation 526.3(v) was "A joint forming part of the equipment complying with the appropriate product standard."
This was widely accepted as a BSEN60670-22 junction box with maintenance free terminals as this is indicated in Appendix 15 of BS7671: Ring and Radial final circuit arrangements: "A junction box to BSEN60670-22 with screw terminals must be accessible for inspection, testing and maintenance or alternatively use maintenance free terminals."
The Wagobox and Wago terminals are still Maintenance Free, that hasn't changed. It's BS7671 that has changed and now requires an accessory to use terminals tested to BS5733 Maintenance Free screwless terminals.
So is BSEN60670-22 not an applicable junction box standard anymore?
BSEN60670-22 is still the applicable standard for junction boxes and continues to be referenced in many places within BS7671.
What does the MF mark mean?
The MF mark indicates that an accessory "does not require further inspection, testing or maintenance after installation in a circuit and incorporates screwless terminals (re: 14.5 Terminals for use within maintenance free accessories) and cable clamps to secure associated cables" (From section 3.31 BS5733:2010).
Section 14.5 within the BS5733:2010 details a number of tests that need to be performed on the screwless terminals to establish that they are appropriate for use in a MF marked accessory.
Can the Wagobox have the MF mark?
In order to put an MF mark on the Wagobox we must use terminals which satisfy the tests set out in BS5733 for maintenance free screwless terminals.
The Wagobox and Wagobox - Light boxes are designed to be used with the Wago 773, 222 and 224 ranges of screwless terminals. These terminals are already tested compliant with BSEN90998-1 (Connecting devices for low voltage circuits for household and similar purposes), as well as:
Mechanical Tests
* Pull-Out Test to IEC/EN 60947-7-1, IEC/EN 60998-2-2, IEC/EN 60999-1
* Shock Test to IEC/EN 60068-2-27, 60068-2-30; Railway Applications IEC/EN 61373
* Vibration Test to IEC/EN 60068-2-6; Shipbuilding GL, LR, DNV; Railway Applications EN 61373
Electrical Tests
* Temperature-Rise Test to IEC/EN 60947-7-1, IEC/EN 60998-1, IEC/EN 1-61984
* Derating Curve to IEC/EN 60512-5-2
* Voltage Drop Test to IEC/EN 60947-7-1
* Short-Time Withstand Current Test (Short-Circuit Withstand Capacity) to IEC/EN 60947-7-1
* Insulation Parameters to IEC/EN 60664-1
* Power-Frequency Withstand Voltage Test to IEC/EN 60998-1
* Rated Impulse Withstand Voltage Test to IEC/EN 60664-1
* IP Ratings for Electrical Equipment to IEC/EN 60529
Material Tests
* Needle Flame Test to IEC/EN 60695-2-2
* Glow-Wire Test to IEC/EN 60998-1, IEC/EN 60695-2-11
Environmental Tests
* Temperature Cycling Test to IEC/EN 60947-7-1, IEC/EN 60998-2-2
* Industrial Atmospheres to EN ISO 6988, IEC 60068-2-42, IEC/EN 60068-2-60
* Salt Spray Test to IEC/EN 60068-2-11, Marine Applications GL, LR, DNV
* Quick Change of Temperature to IEC/EN 60068-2-14
* Damp Heat, Cyclic (12 + 12 Hour Cycle) to IEC/EN 60068-2-30, Marine Applications GL, LR, DNV as a wide range of Mechanical, Electrical, Material and environmental tests.
They have also been extensively tested and approved by many safety standards (e.g. UL,KEMA EUR, DVE, CSA etc) for use in different geographic areas around the world.
Incredibly, BS5733:2010 only references one (Vibration Test to IEC/EN 60068-2-6) of the above internationally recognised tests. All the other MF terminal tests in BS5733 are neither documented or used in any other internationally recognised product standard.
Despite all of the above and the flawless operation of billions of Wago 773, 222 and 224 terminals around the world, these new tests will still need to be performed on the Wago 773, 222 and 224 terminals before we can consider putting an MF symbol on the Wagobox or Wagobox-Light for the UK market.
These tests are being done and when we have had verification that the Wago terminals comply with the MF terminal requirements set out in BS5733 we will then be able to mark the Wagobox system with an MF.
Why is it taking so long?
Wago are a large multinational company with an excellent safety record that has spent millions of Euros developing and testing their products to internationally recognised product standards. BS5733 is not a product standard and the MF terminal tests detailed in BS5733 are not required anywhere else other than in BS7671 which is a UK standard. The new tests include very long duration tests which take an extended period to complete and are consequently very expensive. This additional need for further tests on a product already in production has taken some considerable commitment and effort by Wago in Germany to include this further testing into their scheduled program of work.
How does this effect my past installations?
It doesn't. Standards are never applied retrospectively.
What about installations I've done recently?
Please refer to 511.2 in BS7671. At this stage it's a case of the designer of the installation being satisfied that the use of the product offers the same degree of safety as afforded by compliance.
I hope that this has been helpful, if you have any further queries regarding MF and the Wagobox system then please do get in touch and we will be happy to try and answer any questions.
