There are 4 groups of screw terminal blocks for the output relays. Two of the groups each represent one relay, while the other two groups each represent three relays.
Relays 1 and 2 each have their own groups of 3 terminals. For relay 1 these are labeled NO1, C1 and NC1. C1 is the common, NO1 is the normally open contact and NC1 is the normally closed contact. This means that:
The logic for relay 2 is identical.
Note: Because the NC contacts are held closed in the de-energised state by a spring, we have found that they and are likely to open momentarily if bumped.
Relays 3, 4 and 5 share a single common terminal (C3,4,5), and have only their normally open (NO3, NO4, NO5) contacts accessible. That means whatever these three relays are driving must share a power supply terminal.
Relays 6, 7 and 8 share a single common terminal (C6,7,8), and have only their normally open (NO6, NO7, NO8) contacts accessible. That means whatever these three relays are driving must share a power supply terminal.