UEEEL0005 - Control1

Circuit diagrams are always drawn as

• Energised

• De-Energised

• All contacts CLOSED

• All contacts OPEN

Answer explanation

Circuit diagrams are always drawn showing the circuit with no power applied OR De-Energised

Contact "A1" is known as

• Interlock Contact

• Jog Contact

• Hold-in Contact

• Inching Contact

Answer explanation

Contact "A1" is a Hold-in contact OR Retain contact

When the relay is energised in the circuit, the condition of the two pilot lights are:

• L1 OFF

  L2 OFF

• L1 ON

  L2 ON

• L1 OFF

  L2 ON

• L1 ON

  L2 OFF

Answer explanation

Energising relay A/3 will cause contact A2 to close, thus turning L1 ON.

Contact A3 will open, causing L2 to turn OFF

How many contacts does Relay "R1" control?

(a)  

Answer explanation

Relay "R1" controls 3 contacts.

Contacts R1.1 R1.2 & R1.3

How many contacts does Relay "R2" control?

(a)  

Answer explanation

Relay "R2" controls 2 contacts.

Contacts R2.1 & R2.2

How does L2 energise?

• Pushing R1.3 & R2.2 Closed

• Pressing S1 & S3

• Closing R1.1 & R2.1

Answer explanation

The only way for us to energise L2 will be to press S1 & S3, which are both start buttons.

Contacts are only controlled via their relay.

Relays are controlled by an input device.

How is L1 turned OFF?

• Opening S1

• Pressing S2

• Pressing S4

• Opening R1.1

Answer explanation

S2 is the stop button that De-Energises R1, which will open contact R1.2 thus De-Energising L1.

When selecting contactors. What AC rating is used when supplying resistive loads (Heating Elements)

• AC1

• AC2

• AC3

• AC4

• AC5

When selecting contactors. What AC rating is used when supplying slip ring motors?

• AC1

• AC2

• AC3

• AC4

• AC5

When selecting contactors. What AC rating is used when supplying squirrel cage motors?

• AC1

• AC2

• AC3

• AC4

• AC5