Does the installed direction of a CT matter?

Does the CT direction matter?

In this Blog we clear up what is sometimes missing in the user manuals of meters and transducers, or CT's. Does the direction of the CT matter?

The simple answer is yes. Most meter brands, or transducers can determine if the CT is connected correctly and autocorrect, however it is also useful to understand and for fault finding that the CT orientation does matter. In particular with import/export measurements are required. if the CT has been installed in the incorrect direction then the fastest solution woudl be to reverse the Secondary connections to correct the reading. If the reading is still inorrect, then we suggest to check the meter priimary and secondary ration setting and the wire length and terminations. For more dtaisl see our CT Cable Losses Blog.

If the CT is connected to the incorrect terminals, or the current direction of the load is not correct with respect to the curent carrying conductor. 

CT's need to be orientated according to the terminals and load. generlaly the internal arrow ont he CT shoudl be pointing towards the tradtional load, I.e. House/Factory/Shop.

1) Small Split Core moulded case CT's have arrow moulded into the case.

The direction of the arrow should point to the load.

2) German CT's they normally have white and black , or white and red cables

K (S1) = "Meter side"  -> Black Wire

L (S2) = "Load side"   -> White/Red Wire

3) For UK/Euro style CT's we buy they are as follows

4) For 0.333V square type CT's we have the following

 

You can find a wide range of Split Core and Solid Core CT's in our online store.

If you have any questiosn feel free to contact our freindly sales team at Fastron Electronics