1. Throw Pole Throw Pole nc no

2. Electric symbols Single pole single throw normally open Single pole single throw normally closed double pole single throw normally open single pole double throw double pole double throw

3. Electric symbols Alternate single pole double throw Normally closed circuit breaker Heating thermostat opens on drop of temp Cooling thermostat opens on rise of temp

4. Electric symbols Pressure switch opens on rise in pressure Pressure switch opens on drop in pressure Humidistat opens on rise in humidity Timer switch closes on time delay

5. Electric symbols Heater Light Solenoid Alternate solenoid 2d alternate solenoid Contactor single pole

6. Electric symbols Contactor double pole Step up or step down transformer Overload

7. Electric symbols common Run start Split phase motor

8. L1Neutral Load Switch