EWRB Theory Exam Prep QUESTIONS & ANSWERS(RATED A)
7 views 0 purchase
Course
EWRB
Institution
EWRB
ANSWERS(RATED A)
When carrying out testing on a low voltage electric
What is the minimum value of the permitted test result for the insulation resistance test of a three-phase, 400V, mains cable? - ANSWER 1MΩ
al installation, which document details the tests and checks required to be carried ...
EWRB Theory Exam Prep QUESTIONS &
ANSWERS(RATED A)
What is the minimum value of the permitted test result for the insulation resistance test of a three-
phase, 400V, mains cable? - ANSWER 1MΩ
When carrying out testing on a low voltage electrical installation, which document details the tests and
checks required to be carried out? - ANSWER AS/NZS 3000
What is the minimum or maximum test result value you would consider acceptable for an Earth
Continuity test? - ANSWER 1Ω or less
State TWO types of electrical protection provided by a RCBO. - ANSWER ANY TWO:
- Earth Leakage
- Overload
- Short Circuit
If the voltage and current are known, what TWO other factors are required to calculate the power
consumed by a three-phase motor? - ANSWER √3 & Power Factor
What type of single-phase motor can be reversed by reversing the connections to the run winding? -
ANSWER ANY ONE:
- Split-Phase Motor
- Capacitor Start Motor
- Cap-Start, Cap-Run Motor
What type of single-phase motor can be reversed by reversing the connections to the armature brushes?
- ANSWER ANY ONE:
- Universal Motor
, - Series Motor
State ONE reason why the metal frame of a Class 1 electrical appliance is earthed. - ANSWER ANY ONE:
- To ensure the operation of a protective device under fault conditions.
- To keep the frame of the appliance at earth potential under fault conditions.
Calculate the fault current if a short circuit occurs on a 230V final subcircuit with an earth loop
impedance test result of 0.32Ω. - ANSWER 718.75A
MEN switchboards have characteristics that are NOT FOUND on a distribution board. Name TWO of
those characteristics. - ANSWER ANY TWO:
A MEN switchboard:
- Has a MEN link between the neutral and earth busbars.
- Has a connection to earth via an earthing lead to an earth electrode.
- Is electrically closest to the point of supply.
- Can supply to another MEN switchboard.
Why do three-phase induction motors run smoother and quieter than single-phase induction motors? -
ANSWER They have a constant rotating magnetic field.
State TWO reasons for using reduced voltage starting for a three-phase induction motor. - ANSWER ANY
TWO:
- Reduced starting current.
- Reducing voltage fluctuation/surges.
- Limiting mechanical shock.
What is the permitted protective earthing conductor test result for a test between the earth pin of an
appliance supply plug and the earth led accessible metal? - ANSWER 1Ω Max
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller shantelleG. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.99. You're not tied to anything after your purchase.
