Schneider Split core current transformers

[AndersDahlskog]

Hi

In datasheet PowerLogic™ Current Transformers (CT) Technical Datasheet | Schneider Electric

page 4 is an application example based on 2,5mm2 cable (very common to use). In our split core models on on page 14 METSECT5Hxxxxxx it seems to be a fixed soft cable with 1,5mm2 area.

Then calculating as in the application example and the requirements is 2,5mm2 can this existing 1,5mm2 used to shorting block and then switch to 2,5mm2.

How to think, calculate and use our split core CT,s with this existing cable ?

In this case the CT s is to be used with PowerLogic PM5110

BR/Anders

PAE EcoStruxure Power, Sweden

[Charles_Murison]

Hello @AndersDahlskog ,

If I understand your question, you are wanting to extend the CT lengths by using wire with 2.5mm2 area. Have a look at https://www.se.com/ca/en/faqs/FA221505/ for information.

Regards,

Charles

[AndersDahlskog]

Hello @Charles_Murison 

Thanks for your reply, I understand the FAQ. It is a good example and the solution here is to use approx AWG 10 (6mm2) copper cable all the way from CT to meter (shorting block included). What I don`t understand is how to calculate/act to use our H models split core CT´s on page 14 in datasheet  PowerLogic™ Current Transformers (CT) Technical Datasheet | Schneider Electric the cable is a fixed soft cable with approx 16 AWG (1,5mm2) copper cable length approx 2 feet (60cm). There is no secondary screws/lugs for the possibility to use other cable (eg AWG10 as in FAQ example.)

Need some direction/advise how to use/calculate our CT with this model for a correct installation, new file attached.

BR/Aders

[Charles_Murison]

Hello @AndersDahlskog .

If I understand your question, you are asking for help to connect The CT leads to a different wire. There are likely local regulations that electrical contractor for your region would know more about. One option could be to use terminal strips and connect CT on one side and larger gauge wires on the other. Perhaps electrician is able to splice cables. Different areas have different regulations so there is unlikely to be a one size fits all solution.

Regards,

Charles

[AndersDahlskog]

Hello@Charles_Murison

Thanks for your answer, no my question is: when I have done a calculation a need to use AWG10 (6mm2) cable between CT and meter (like the example in FAQ you mentioned). But Schneider split core CT eg METSECT5HAxxx range has a fixed soft AWG16 (1,5mm2) approx cable attached to it, (see picture in attached file) can´t see that this soft cable can be replaced to calculated need for the installation (in this case AWG10 (6mm2):
How to use this Schneider split core CT eg METSECT5HAxxx range ?, Only limited to use in installations with a calculated need of max AWG16 (1,5mm2) cable between CT and meter ?

Hope this clarify my question and concern

BR/Anders

[Charles_Murison · Accepted solution]

Hello @AndersDahlskog 
Lets assume that you have METSECT5HA025 CT. The maximum burden that this CT can support is 1VA, the Meter has burden of 0.15 VA, therefor the wiring cannot exceed 0.85VA. The wire you have to extend the CTs is 14 Gauge wire (the mm2 is not an exact conversion). Using the first image the impedance is roughly 0.035 Ohms.

The maximum distance you could extend this wire is very small, way less than 10 feet.

Now if you had METSECT5HA020, the Burden rating of the meter is 1.5VA. Wire maximum burden is 1.35 VA. Impedance is roughly 0.05

The maximum distance would be a little less than 10 feet.

To extend the distance between CT and meter the options are to either use thicker wire, or have CT with a larger burden. CTs with larger burden tend to not be as accurate. 

Note that these calculations are to EXTEND the leads of the CT, not replace the leads. The CT's burden ratings already account the the CT leads. How the wire to extend the leads is attached is not a universal answer and different regions have slight different electrical codes so I cannot give a answer specific to your region. You would need to contact an electrician in your area to discuss options.

Regards,

Charles

[AndersDahlskog]

Hello@ Charles_Murison

A big thank you fore this accurate and good answer

BR/Anders