STAR-DELTA BOX

1. STAR-DELTA RELAYS STAR-DELTA BOX FAN 3 M 35 36 37 38 39 40 K3 45 5 K1 K2 1 2 3 N L1 L2 L3

2. From #6 of control box; conditions to be energised: 1) auxiliary circuit ‘ON’ 2) No lock out of control box 3) min air P.switch at stand-by position at beginning 4) max air P.switch closed 5) limit controls closed 6) fuel selected gas side: 7) leakage control OK 8) min gas P.switch closed = L STAR-DELTA MODE OPERATION 5 42 K1 K1 K2 K1 = 45 K4 K2 K3 K4 K1 K3 K2 N

3. = L STAR-DELTA MODE OPERATION 5 42 K1 K1 K2 K1 = 45 K4 K2 K3 K4 K1 K3 K2 N

4. = L STAR-DELTA MODE OPERATION 5 42 K1 K1 K2 K1 = 45 K4 K2 K3 K4 K1 K3 K2 N

5. = The fan motor turns by slow speed, as supplied at star voltage L STAR-DELTA MODE OPERATION 5 42 K1 K1 K2 K1 = 45 K4 K2 K3 K4 K1 K3 K2 N

6. Few seconds later two contacts of the relay K4 (it’s a slow operating relay) change their position = L STAR-DELTA MODE OPERATION 5 42 K1 K1 K2 K1 = 45 K4 K2 K3 K4 K1 K3 K2 N

7. Few seconds later two contacts of the relay K4 (it’s a slow operating relay) change their position = L STAR-DELTA MODE OPERATION 5 42 K1 K1 K2 K1 = 45 K4 K2 K3 K4 K1 K3 K2 N

8. Few seconds later two contacts of the relay K4 (it’s a slow operating relay) change their position = L STAR-DELTA MODE OPERATION 5 42 K1 K1 K2 K1 = 45 K4 K2 K3 K4 K1 K3 K2 N

9. The fan motor turns by high speed, as supplied at delta voltage = L STAR-DELTA MODE OPERATION 5 42 K1 K1 K2 K1 = 45 K4 K2 K3 K4 K1 K3 K2 N