Clearance and mounting — what the 10/20/10/10 mm spacing means
These are the minimum air gaps to the next component or enclosure wall — not a suggestion. On a panel layout, the 20 mm forward gap is the one that catches people out: you need that clearance for the arc chamber's venting and for the coil replacement tool access. Side-by-side mounting is supported, so multiple contactors can sit flush without additional spacing between them, as long as the external clearances to the enclosure are met.