1. In rung S5 the contact will connect 2 CR relay to the supply, bypassing the
temperature sensor contacts, keeping 2 CR energized.
2. In rung S6 the contacts will supply power to the alarm.
3. In rung S1 the 2 CR NC contact will turn OFF the supply to control relay
1 CR de-energizing the relay, which in turn will change the lights from red
to green and turn OFF the heating element.
The alarm will remain enabled until turned OFF by switch 3 PB via relay 2 CR.
Relay 1 CR can also be turned OFF by switch 2 PB.