Photo AI
7.1 State THREE advantages of hard wiring - NSC Electrical Technology Power Systems - Question 7 - 2024 - Paper 1
Question 7
7.1 State THREE advantages of hard wiring. 7.2 Refer to FIGURE 7.2 below and answer the questions that follow. 7.2.1 Draw the ladder logic diagram. 7.2.2 Complete... show full transcript
Worked Solution & Example Answer:7.1 State THREE advantages of hard wiring - NSC Electrical Technology Power Systems - Question 7 - 2024 - Paper 1
Step 1
State THREE advantages of hard wiring.
Answer
-
Ease of Troubleshooting: Hard wiring allows for straightforward tracing of circuits with devices such as multi-meters, facilitating quick identification of faults.
-
Physical Connection: This method offers physical connections, often improving reliability in systems where signals must be transmitted consistently without interference.
-
High Current Capacity: Hard wiring can support higher current flows, making it well-suited for operating larger machinery and devices.
Step 2
Step 3
Step 4
Step 5
Explain why an analogue input should be converted to a digital input in a computing device.
Answer
Computing devices can only interpret digital signals. Analogue signals can be subject to noise and fluctuations that introduce inaccuracies. Converting analogue inputs into digital format eliminates ambiguity and allows for precise data processing, which ensures that the system behaves reliably.
Step 6
Explain the concept latching.
Answer
Latching refers to the ability of a circuit to maintain its state even when the initiating signal or trigger is removed. This is crucial for ensuring operational continuity in automated systems, allowing processes to run without requiring constant inputs.
Step 7
Step 8
Step 9
Differentiate between ON-delay and OFF-delay timers.
Answer
An ON-delay timer activates its output after the specified delay time once the input becomes active. In contrast, an OFF-delay timer deactivates its output after the specified delay time following the deactivation of the input signal.
Step 10
In the ANSWER BOOK, redraw the PLC ladder logic diagram in FIGURE 7.4 below and complete it so as to execute the same function as the circuit in FIGURE 7.5 above.
Answer
The ladder logic diagram should accurately reflect the functional elements of the circuit provided in FIGURE 7.5, ensuring that conditions for START and STOP are clearly indicated, as well as the appropriate configurations for MC1 and MC2.
Step 11
Describe the basic principle of operation of a variable speed drive when it controls the speed of an AC induction motor.
Answer
A variable speed drive controls the frequency of the power supply to the motor. By adjusting the frequency, the speed of the AC induction motor can be increased or decreased, allowing for precise speed control depending on the application or load conditions.
Step 12
Describe the start-up and run profile of an induction motor.
Answer
During start-up, the torque increases, leading the motor to accelerate until it reaches the breakdown speed. After this point, as the load increases, the torque begins to decrease, yet the motor continues to operate efficiently as it maintains its desired speed.