Gas Fitter Practice Test

On an electrical schematic, how are all operating controls drawn?

1. In their energized positions

2. In their de-energized positions

3. Normally closed

4. Normally open

The correct answer is: Normally open

In an electrical schematic, operating controls are typically drawn in their "normally open" state to reflect their default position when no current is applied. This helps in understanding how the circuit behaves under standard conditions. A normally open control indicates that the circuit is open until the controlling device is activated, which is common in many systems where devices like switches and relays are utilized. The inclusion of controls in their normally open state gives technicians and engineers a clear starting point for troubleshooting and understanding circuit functionality. When engaged or activated, these controls would change state, but their default position aids in visualizing circuit interactions effectively. This approach allows for a more straightforward interpretation of how the system will operate under standard conditions, thus facilitating better design and maintenance practices. In contrast to this, operating controls represented in energized or de-energized states may lead to confusion, failing to represent their inherent default actions when not powered. Similarly, normally closed configurations serve a different purpose and are not the standard representation for operating controls.