Va-et-vient unit wiring

[Ian 56]

I am replacing our existing consumer unit (tableau électrique) which dates from 1977 with a larger modern one with a disjoncteur différentiel. Most of the work seems straightforward although the in the old one all the negative wires go to a common terminal block and only the positives pass through the fuse units. Sorting that out is not rocket science.

However I am puzzled by the wiring for the va-et-vient circuit. The 3 hall and landing lights are controlled by 4 push-button switches. I can identify the wires which lead from these units and also the positive imput to the old switch unit which was a Legrand 49127. The helpful chap in Leroy Merlin sold me a unit to replace this which is an ABB E251T-230 which has 4 terminals. There is a sketchy wiring plan on this which makes no sense to me and I am not convinced it is the right unit anyway.

Can anyone help with information for the correct replacement unit and of the connections to it?

Ian

[Rich1972]

[quote user="Ian 56"]I am replacing our existing consumer unit (tableau électrique) which dates from 1977 with a larger modern one with a disjoncteur différentiel. Most of the work seems straightforward although the in the old one all the negative wires go to a common terminal block and only the positives pass through the fuse units. Sorting that out is not rocket science.

However I am puzzled by the wiring for the va-et-vient circuit. The 3 hall and landing lights are controlled by 4 push-button switches. I can identify the wires which lead from these units and also the positive imput to the old switch unit which was a Legrand 49127. The helpful chap in Leroy Merlin sold me a unit to replace this which is an ABB E251T-230 which has 4 terminals. There is a sketchy wiring plan on this which makes no sense to me and I am not convinced it is the right unit anyway.

Can anyone help with information for the correct replacement unit and of the connections to it?

Ian[/quote]

I tried doing this in the UK once and got so confused that I had to get an electrician in to sort it out [:$]

[Anton Redman II]

The push buttons are bouton-poussoir as opposed to two way switches / Va et Vient. There are two wires to a possoir as oppsed to three to a VetV. When the button is pushed it completes a circuit and the current flows via a telerupteur to neutral. The telerupteur which is a relay flips on or off each time the current passes through it when a poussoir is pressed. The power output from the telerupter then fows to the lamp or lamps through the bulb and hence back via neutral.

http://entraidelec.com/schema-6-Allumage-par-Boutons-Poussoirs-telerupteur.html

The four terminals on the telerupteur are :

Power in from a  disjointer divisionnaire

Power to light fitting

Feed from possoirs

Neutral for feed from Poussoirs back to the disjoiter divisionnaire. 

The above assumes a simple telerupteur unipolaire.

[Ian 56]

Anton thank you very much for your clear and helpful explanation. I know know exactly what to get.

ian