Earth Testing

Question 1

How are earth faults indicated?

Answer 1

• Indicator light on PCP and SCP switchboards
• Audible alarm

Question 2

Why does he automated system not work for the 115V system?

Answer 2

• No physical connection between primary and secondary transformer windings
• Done at first fuse panel after transformer
• Usually done by insulation resistance test using the MIT 420

Question 3

What is the earth testing panel used?

Answer 3

• An earth fault test panel on the switchboard provides for testing the positive and negative side of the DC supply
• A push button with integral lamp is fitted to the switchboard

Question 4

What does the Electrical Distribution Panels have for earth fault indicator
?

Answer 4

• Each Electrical Distribution Panel has an earth fault indication
• This will illuminate if there is an earth fault on any circuit powered from the EDC up to and including the primary winding of a transformer

Question 5

What equipment do we Earth Bond?

Answer 5

All equipment generating or operating at greater than 35V AC or 50V DC must be earth bonded.