week #9 Flashcards
What are the 6 things electricians need to know when building ladder diagrams and schematic diagrams?
The 6 things are not specified in the text.
What are the 3 things electricians need to know when building wiring diagrams?
The 3 things are not specified in the text.
Which drawing should be performed first among ladder diagrams, schematic diagrams, and wiring diagrams?
The drawing that should be performed first is not specified in the text.
What is circuit sequencing?
Circuit sequencing is not defined in the text.
Can you put the same devices in different places throughout the circuit to create a different function or affect the sequencing? Give one example.
Yes, you can. An example is not provided in the text.
What 3 factors do electricians need to keep in mind when considering sequencing and device location?
The 3 factors are not specified in the text.
Why are the majority of the diagrams incorrect in this textbook?
The reason is not specified in the text.
Can you put OL contacts on the Neutral side of a control transformer, if it is a floating neutral?
Yes, OL contacts can be placed on the Neutral side of a floating control transformer.
What is electrical interlocking? Why do we do it? Give one example?
Electrical interlocking is a safety mechanism that prevents certain operations from occurring simultaneously. We do it to ensure safety and prevent equipment damage.
Example: Preventing a motor from starting while a related safety guard is open.
What is mechanical interlocking? Why do we do it? Give one example?
Mechanical interlocking is a physical mechanism that prevents certain operations from occurring simultaneously. We do it to enhance safety and reliability.
Example: A lock that prevents a switch from being turned on when a door is open.
When comparing mechanical interlocking as compared to electrical interlocking, which of the two are typically automatic?
Electrical interlocking is typically automatic.
What is an E-Stop? Why do we use them? Give one example?
An E-Stop, or emergency stop, is a safety device that allows for the immediate shutdown of machinery. We use them to ensure the safety of operators in emergency situations.
Example: An E-Stop button on a conveyor belt.
What type of pushbutton would we use for an E-Stop? Why?
We would use a large, red, mushroom-shaped pushbutton for an E-Stop because it is easily recognizable and can be activated quickly.
How do latching pushbuttons attempt to create a failsafe state?
Latching pushbuttons maintain their position until manually reset, ensuring that the system remains in a safe state until the operator intervenes.
Which circuit typically utilizes the contacts from an E-Stop button?
The safety circuit typically utilizes the contacts from an E-Stop button.
Can we use an E-stop button in the branch circuit to stop a motor or group of motors fed from the same power supply that does not have a control circuit? Explain?
No, an E-stop button should not be used in the branch circuit without a control circuit, as it may not provide the necessary safety functions.
E-Stop contacts are typically NO, or NC?
E-Stop contacts are typically NC (Normally Closed).
What are holding contacts, and why do we use them?
Holding contacts are electrical contacts that maintain the state of a device after the initial activation. They are used to keep the circuit closed once the start button is pressed.
Do holding contacts typically power the coil to the device in which the contacts are controlled by? Why?
Yes, holding contacts typically power the coil to maintain the operation of the device, ensuring it remains active after the start button is released.
How does the stop button work in a simple Start Stop Circuit?
The stop button interrupts the circuit, cutting power to the coil and stopping the device.
Do we have to use a latching button as the stop button?
No, a latching button is not required for the stop button; a momentary push button can also be used.
If we chose to use a latching button for the stop button, name one positive aspect and one negative aspect of using a latching button.
Positive aspect: It can provide a clear visual indication of the stop state. Negative aspect: It may require additional steps to reset.
Can we use a latching pushbutton for the start function instead of using holding contacts? Why?
No, a latching pushbutton does not provide the same functionality as holding contacts, which are necessary to maintain the circuit.
Can we use momentary contact buttons for an e-stop? Why?
No, momentary contact buttons are not suitable for an e-stop as they do not maintain the stop state when released.
How many E-stop stations can be used? Where would you physically locate these devices?
Multiple E-stop stations can be used, and they should be located in accessible areas around the machine for quick access.
What type of Motor Control best describes the Manual portion of the control circuit in Quiz 5?
The Manual portion of the control circuit in Quiz 5 is best described as Direct Control.
What is the design flaw in the control circuit of Quiz 5?
Currently, there is a design flaw in the control circuit of Quiz 5.
How can the flaw in Quiz 5 be proved?
Prove the flaw by analyzing the control circuit.
What is the solution to the design flaw in Quiz 5?
Add 3 E-stop stations to the circuit.
What are the wire numbers and colors for the circuit?
Control circuit wires are to be red, branch circuit wires are to be black (BK).
What is the specification for the control circuit’s neutral?
Control circuit is to have a floating neutral.
What materials should be used for drawing devices in the circuit?
Devices are to be drawn in pencil.
What hint is provided for adding wire colors?
You may want to use color pens.
