Assignment
Part A-
1. List three appropriate health and safety requirement which apply when inspecting and commissioning this electrical installation?
2. List two statutory and 4 non statutory documents which relate directly to the inspection testing and commissioning of this electrical installation.
3. List the information that is required by the inspector in order to conduct the initial verification of this electrical installation.
4. Complete the standard form schedule of inspections for initial verification from BS7671 identifying the relevant items which are to be inspected when carrying out the initial verification of the outside lighting in the car parking areas identified on drawing 2365-C1-03.All relevant items should be indicated with a tick and any items which are not applicable should be marked N/A.
5. The earthling and bonding arrangements for the new depot are to be inspected as part of the initial verification. Specify the items which are to be inspected for each of the following.
a. Earthing conductors
b. Circuit protective conductors
c. Main protective bonding conductors
d. Supplementary bonding conductors
6. Specify the checks required to prove that test instruments and leads are safe and functioning correctly
7. An insulation resistance test to DB2 produced the following results:
Live to Live=195M?.
Live to Earth=0.75M?
a. Determine whether these tests are acceptable.
b. State the actions to be taken should the test results be unacceptable.
8. Show with the aid of a diagram, the earth fault loop path for the compressor circuit identified on drawing 2365-C1-01
9. One of the lighting circuits supplied form the general lighting and power DB is tested for earth fault loop impedance. The circuit is protected by a 6A Type C circuit breaker to BS60898.
a. The tests to confirm automatic disconnection of supply was carried out Zdbwas measured for the general lighting and power DB. State the reason that this value needs to be obtained.
b. A value of R1 +R2 was measured and recorded as 0.46? and Zdbwas measured and recorded as 0.02? for the general power and lighting distribution board. Determine the value of Zsto be recorded for this circuit.
c. Determine whether the value from 9b) complies with the requirements of BS7671.
10. Describe two methods which can be used to determine Ipf(prospective fault current) for the distribution boards with in the installation.
11. Phase sequence is to be confirmed for the distribution boards and equipment during initial verification. State the
a. Two types of instrument used to check for the correct phase sequence
b. Locations at which phase sequence is to be confirmed for the circuits supplied from DB2.
12. Explain the effect of INCORRECT phase sequence to the three-phase compressor shown on drawing 2365-C1-01
13. Each socket outlet in the office is protected by a BS EN 61009 RCD with an I?nof 30mA
a. Describe the tests to be carries out to each 30mA RCD to confirm correct operation
b. State, for each test identified in 13a) above the actual test current applied and the maximum acceptable operating time.
c. State how the tests carried out on 30mA RCDs providing additional protection would differ from those carried out on 300mA RCDs.
14. On completion of the electrical tests in the shop and office area the functional checks are to be carried out.
a. State why functional testing is carried out.
b. Identify the items in the office and shop area which will need to be checked and what each check involves.
15. List the labels that should be fixed within the installation before it is handed over to the client and state where they will be located.
16. Detail the advice that should be given to the client regarding the documentation given to them on completion of the commissioning.
Part B-
1a. Select, with the aid of manufactures data, suitable wiring systems giving reasons for your choice.
1b. Show, on drawings/copies /overlays the proposed route of all wiring systems.
2. Show, on drawings/copies/overlays the installation divided in to final circuits giving each circuit unique form of identification.
3. Determine the design current (Ib) for each final circuit.
4. Select a suitable type of protective device for all final circuits, giving reasons for your choice. Consideration should be given to
- Load current
- Start-up current
- Breaking capacity
5. Determine, for the whole installation the
a) Maximum demand before the application of diversity
b) Maximum demand with the application of diversity using information considering IET onsite guide
6. Determine, for one of the high bay lighting circuits with in the workshop, the minimum cross sectional area of live conductors for current carrying capacity and voltage drop.
7. A trunking rum within the electrical switch-room area is to contain the following thermosetting stranded cables
- 35x1.5mm2
- 25x2.5mm2
- 12x4.0mm2
- 10x10.0mm2
- 5x16.0mm2
Determine the minimum size of trunking to be used.
Attachment:- Assignment.rar