Graco Lube Sentinel II Instructions Manual page 6

Installation
Terminals 15 - 20, Zone 2 Fault Relay:
Relay data for Zone 2 is the same as for Zone 1. Pole "A" (for Zone 2) uses terminals 15 (nc), 16 (com) and 17 (no).
Pole "B" (for Zone 2) uses terminals 18 (nc), 19 (com) and 20 (no). (See F . 4.)
IG
Ignition Shutdown Magneto Grounding
External Flow/No Flow Lights Energize External Load (relay coil, etc.)
F . 4: Wiring Examples when Zone 1 and Zone 2 are used.
IG
6 313903B