Are ELCB/RCDs directional?

Yes they are a top down feed design.

While the suggestion from TCMTECH may be valid... Connect the line and load conductors to the device according to the markings on the device. Do not assume that it is either a feed from the top or a feed from the bottom.

This is good advice for ALL electrical gear. Never ever assume, the life you may save may be your own.

The only time it really matters is when the test button is pressed. Fed from bottom to top the test PB and resistor remain live after the unit has tripped.

Functionally it makes no difference.

Thank you for all your inputs.

http://www05.abb.com/global/scot/scot209.nsf/veritydisplay/d6bc2ce12fb154f0c125721b00504231/$file/F%20200_2CSF423001D6402.pdf says "Power supply The devices can be fed from either the upper or lower terminals." and that's where it got me confused.

It may be a claim by the manufacturers ( to avoid two variants). Check if The device electronics is designed to be energised only when The device is on or allways. Generally the electronics should be In circuit only after the breaker is on Check where the device electronics are connected on top or Bottom. Decide based on this and inform the manufacturers. Many largish manufacturers will accept the error and correct. But the smaller minded will continue with their mistake and Maintain huge risk for their customers.

If the device is marked LINE / LOAD then it is directional, if not then it can be fed either direction.

It still doesn't affect it's functionally. It will trip but depending on type the sensing circuit will remain live.

Friends,

The post from 3PhaseDesign is important. (And welcome to CR4.) To be safe, legal, and free from liability, your work must comply with any information or instructions given by the manufacturer. Unfortunately, sometimes this is in fairly small print or not even packaged with the product. So, check with the manufacturer and their engineering department.

--JMM