Viessmann Vitodens 200-W Series Installation Instructions Manual page 61

Ladder Diagram
Fig. 55
Legend
-X1 [40] power supply 120 VAC
-X1 [20A] pump, HTG system w/o
mixing valve, 120 VAC
-X1 [21] pump DHW tank 120 VAC
-X1 [20] pump boiler tank 120 VAC
-X1 [50] fault alarm 120 VAC
-X2 [28] pump, DHW recirculation,
120 VAC
IMPORTANT
Total max. output current 10A
-X3 boiler power supply 230
VAC
-K1, -K2,
-K3, -K4,
-K5 operating contacts
-F1, -F2 fuses (slow blow)
-T transformer
H1 communication board
Appendix
61