MTZ Restricted Earth Fault Protection.

[Peter_Hall]

We are seeing a big rise in the number of enquiries for battery storage systems and renewables in general. there seems to be a big push (in the UK) for earth fault protection. We cover this with the ML4 trop units on NSX and M6.0X on MTZ. However there seems to be a growing requirement to have REF protection (earth fault protection looking back into the transformer secondary winding). 

Can anyone in the MTZ development team advise the time line to include this protection on the MTZ offer as previously offered on NW/NT? 

[Kiran_Lagwankar]

In MTZ ACBs, Restricted Earth Fault protection is available as in MasterPact NW/NT. The terminology used is SGR (Source to Ground)protection. It involves external sensor( SGR Sensor) to measure the transformer Neutral current and MDGF Module.

Please refer our Detailed catalogue of MTZ for SGR protection.

Hope this answers your question.

Best Regards

Kiran Lagwankar 

[Fabien_Mastrot]

Hello Peter, you meant , designing a Masterpact MTZ with a 4 poles breakers but with no protection for Neutral inside the breaker ? Thanks 

[Peter_Hall]

Hi Fabien,

No, let me explain a bit clearer.

We are looking for an ACB with overcurrent protection. However we would also like to protect the cables & the transformer LV winding 'upstream' via and earth fault protection. Normally this is achieved by:

MTZ ACB with M2.0/5.0X trip unit.

Aveva (Was Alstom/GEC) MCAG14 relay with 4 x CT's, N/E link fitted downstream of the CT's (before the ACB).

Battery charger to trip the MTZ ACB Sht on relay operation.

The MCAG 14 CT's are the limit of the 'zone'. Therefore any earth fault occurring between the transformer LV winding and the CT's is detected and trips the ACB i.e. an in zone fault.

Hope that this makes sense?   

[Ludovic_Soudril]

Dear Peter,

Just to be 100% sure of your request.

Do you want to achieve with MTZ the same feature (Restricted Earth Fault Protection) as the one proposed with NW in the doc attached below?

Best regards

Ludovic

[Peter_Hall]

Hi Ludovic,

That is exactly the application.

Best regards,

Peter Hall.

[Ludovic_Soudril · Accepted solution]

Hi Peter,

Restricted Earth Fault is not available today on MTZ.

REF is planned to be implemented in MTZ via a dedicated Digital Module in 2022.

Today, the only solution for REF on ACB is with NW (special configuration).

Best regards

Ludovic

[Peter_Hall]

Hi Ludovic,

That is great. Thank you for clarifying this.

Best regards,

Peter Hall.

[brettjduncan]

Hi, has this feature been included in the MTZ range yet?

regards,

Brett