XALK boxes can accommodate a maximum of 3 contacts per hole, in any configuration of N/O and N/C.

Please bear this maximum in mind, particularly when adding to an already complete part.

E.g. XALK178F is a complete enclosed emergency stop pushbutton, that comes with 2 normally closed (N/C) base mounted contact blocks. You may add a single additional contact block of either the normally open (N/O) or normally closed (N/C) type, to achieve the maximum of 3 contacts.

Note that the most common type of contact for XALD/XALK is the base mounting contact, which have connections on the rear to clip onto a rail that's mounted within the box. Part numbers are:

N/O contact: ZENL1111
N/C contact: ZENL1121

It is still possible to use the standard ZBE101/ZBE102 contact blocks which fit onto the back of the operator. However, you should not mix different types i.e. you should always use either all ZENL**** or all ZBE***.

The benefit of using base mounting contacts is that you can install your contact blocks in the base and wire them up, then mount the heads to the enclosure lid. This means you can remove the enclosure lid without disturbing the contact wiring.

Released for: Schneider Electric Ireland