1. EKAS 2.19.30 Flexible cords and plugs to 250 V
UEE31307 Certificate III in
Refrigeration and Air Conditioning
Stage 2A
Units: UEENEEPOO2B
Chris Hungerford
Wednesday, April 19, 2017

2. Flexible cords
Ordinary Duty
Light Duty
Heavy Duty A

3. How is a flexible cord different from other cables?
The conductors in a flexible cord are made up of many more strands of finer wire than an ordinary cable (0.3mm). This allows the cord to flex without breaking the conductors.
The maximum cross-sectional area (CSA) of a conductor in a flexible cord is 4mm2.
Finally, the maximum number of insulated conductors (or cores) in a single cord is five. A

4. Maximum length of flexible cords

5. Maximum current rating of flexible cords
NOTES:
1 Where a flexible cord is wound on a drum, multiply current-carrying capacity by the appropriate factor, as follows:
Number of layers:
Derating factor:
2 Flexible cords having tinsel conductors with a nominal cross-sectional area of 0.5 mm2 have a current carrying capacity of 0.5 A.
3 The current-carrying capacity is based on a cable maximum conductor operating temperature of 60°C in order to limit the surface temperatures for the expected use of such cables. Where flexible cords are used as fixed wiring, the current ratings are given in Tables 4 to 15 and 17. (Refer to Clause 3.3.2).
4 To determine the three-phase voltage drop, refer to the appropriate value in Table 46, Table 47 or Table 48. To determine the single-phase voltage drop, multiply the three-phase value by

6. Electrical cables Conductor Strand
3 Core & Earth Circular
An electrical cable is identified by its:
Conductor material e.g. copper or aluminium
Conductor size e.g. 1.5mm² CSA
Insulation material e.g. rubber, glass, PVC
Number of cable cores e.g. 7/0.50 – i.e. 7 strands of 0.50mm circular diameter
Voltage grading e.g. 0.6 / 1 KV; 250V / 440V
Sheathing
Protection
Conductor
Strand A
Steel Wire Armoured SWA

7. Ratings of cables
Voltage rating, all cables have a maximum operating voltage. This is directly related to the type and thickness of the insulation material.
Temperature rating, table 3.2 AS 3000: 2007.
Cables are NOT rated in Current Carrying Capacity. A cable's current carrying capacity is determined buy how it is installed as per AS/NZS (Australian). A

8. Selecting a cord Operating conditions;
Current carrying capacity of the cable.
Operating conditions;
temperature
voltage
installation factors such as in direct sunlight, mechanical protection, & thermal installation.
Number of conductors. A

9. Plugs and sockets
There are many types of plug tops, the most common being the 10A three-pin plug. A

10. A

11. A

12. A

13. International Protection Numbers

14. AS/NZS-3000:2007 SAA Wiring Rules
Flexible cords
Joints shall not be made in flexible cords.
Exceptions: Joint in flexible cords may be made -
Where used as installation wiring
By means of suitable cable couplers
Any flexible cord shall be installed so that undue stress on its connections due to a pull on the cord is alleviated by a pillar, post, grip, tortuous path, or other effective means.
Knotting of the flexible cord shall not be acceptable for this purpose. C

15. C

16. Accessories
All accessories must be suitable and as per Australian standards .
All accessories must be suitable for the application.
Wide variety of accessories can be accessed via suppliers catalogues. C

17. A=Excellent B=Good C=Fair D=Poor

18. AS/NZS-3000:2007, SAA Wiring Rules
3.7 ELECTRICAL CONNECTIONS
3.7.1 General
Connections between conductors and between conductors and other electrical equipment shall provide electrical continuity and adequate mechanical strength.
Solder less lugs
Crimps
Compression terminals
Soldered connections C

19. AS/NZS-3000:2007 SAA Wiring Rules
Preparation for connection
The insulation on a conductor shall not be removed any further than is necessary to make the connection.
For connections between insulated conductors the connection shall be insulated to provide a degree of insulation not inferior to that of the conductors.
Any damaged insulation shall be reinstated. C

20. Insulation of conductors
Masking tape
packing tape
sticky tape
silicon mastic
Yes
Electrical insulation tape
Epoxy kits
Heat shrink C

21. Conductor colouring AS/NZS 3000 Table 3.4
Function
Colour
Earth/bonding
Green/yellow
Neutral
Black
Light blue
Active
Red Brown, dark Blue, Grey, White, any colour other than green/yellow, green, black, yellow or light blue C

22. Terminations and connections
Connections must not be soft soldered before compression terminations.
Must be seated correctly.
Free of dirt and oxides.
Use a suitable lug or connector.
Insulated to the equivalent of the original insulation.
Earth connection must be painted if exposed to weather C

23. AS/NZS-3000:2007 SAA Wiring Rules
Mechanical stress
All cables and conductors shall be installed so that there is no undue mechanical stress on any connection.
Loosening of connections
Connections shall be made so that no loosening is likely because of vibration, alteration of materials or temperature variations to which the connections
are likely to be subjected in normal service. C

24. The eight visual checks recommended are:
Check for obvious damage or defects.
Check that flexible cords are properly anchored
Check for any damage to flexible cords.
Check that maximum load warning labels are intact.
Check that any controls such as switches are in working order.
Check that covers and guards are properly secured as intended.
Check that any safety devices are in good working order.
Check that vents or exhausts are unobstructed. D

25. Earth Continuity Test
Any Class I equipment with exposed metal parts must have its protective earth checked to ensure it is continuous from the earth pin of the plug to any exposed metal. The resistance must not be greater than 1Ω.
Instrument Low reading ohmmeter. D

26. Earth Continuity Earth Pin To Earth Socket 1
What is the value of earth continuity?
Instrument Low reading ohmmeter. D

27. Earth Continuity “Class 1”
1
Earth Pin To
Exposed Metal
1
What is the value of earth continuity?
Instrument Low reading ohmmeter. D

28. Insulation Resistance Test:
All equipment must be tested to ensure the integrity of the insulation, no electricity must be allowed to escape from the conductors or the appliance. D

29. Insulation Resistance “Class 1”
Switch ON
Active & Neutral To
Exposed Metal
1M
1
Q What is the value of insulation resistance?
Megohmmeter D

30. Insulation Resistance “Class 2”
Switch ON
Active & Neutral To
Exposed Metal
1M
1M
1
Q What is the value of insulation resistance?
Megohmmeter D

31. Insulation Resistance “extension lead”
1M
Active & Neutral To
Earth Pin
1M
1
Q What is the value of insulation resistance?
Megohmmeter D

32. Polarity Active Pin To Active Socket 1 low
What is the value of continuity?
Instrument Low reading ohmmeter. D

33. Polarity 1M Neutral Pin To Neutral Socket low 1
What is the value of continuity? D
Instrument Low reading ohmmeter.

34. 2.19.30.D Is this correct? V1 240v V2 240v V3 0v Is this correct?
What should the voltage be?
Is this correct?
V2=?
240v
V1 240v
V2 240v
V3 0v
V3=?
V1=?
240v 0v
Is this correct? 0v
Reversed polarity A-N 0v 0v
No Supply
Is this correct?
Is this correct? 0v
240v
240v 0v
240v
240v
Correct
Reversed polarity A-E

35. Minimum records that should be completed and maintained
A record of the inspection and test results.
A record of faulty electrical equipment (has it been repaired or destroyed).
Date of inspection
Appliance
Visual inspection
Earth continuity W
Insulation resistance MW
Polaritya = Correct
RCD test current
30 MA trip time
Milliseconds
0h h Test butt
2/7/09
Refrigerator ( LG model R Serial )
O.K
0.3
75M
N/A
Safetypac (Clipsal mod 56B, serial )
o.K.
0.8
187M a 22 18 D

36. D

37. Energising supply
Only after the visual inspections and safety testing as per AS/NZS 3000:2007 has proven that the circuit is fit for purpose are you to energise the circuit.
Remove only your Danger tag. If another worker has their danger tag on the isolated point then you can not energise.
If clear: Energise the circuit.
Test for the correct and safe operation of the circuit, i.e. rotation, system performance, current draw, voltage, etc.
Prepare all your safety and performance documentation. D