Frequently Asked Questions

With many years of experience within the cable industry, the Nexans Olex team have been assisting customers on a wide range of cable related topics. To assist you, we have listed our most commonly asked questions by product category. Should you have a question that is not answered in these pages, please feel free to send your question to Nexans Olex via the Contact Us form and one of our experienced sales or technical team will respond to your request.




 Low Voltage   (View our low voltage products)







What does the .6/1kV designation mean?




Medium/High Voltage   
(View our high voltage products)   Back to top

Can Olex manufacture submarine cables?

Olex have manufactured a range of cable designs for underwater applications. With our technical expertise and manufacturing experience, Olex are able to customise cable designs to provide the optimum mechanical and moisture protection to the cable. Consequently, Olex are able to provide cables which meet the customer’s various installation requirements.

Extra High Voltage    
(View our extra high voltage products)   Back to top

What is DTS?

Distributed Temperature Sensing (DTS) is a branch of condition monitoring whereby the temperature of an optical fibre, at any point long its route, can be determined with a high degree of accuracy.

Increasingly, high and extra high voltage underground cables are being manufactured with an optical fibre incorporated in such a way that it is either adjacent to the conductor insulation or as close as is practical. A profile of the conductor/s temperature can then be extrapolated from the fibre temperature and this temperature can then be used as a basis for a system rating calculation. 

Industrial    (View our industrial products)       Back to top




What is the purpose of the screens in instrumentation cables?













What is the voltage rating of Instrolex cables?




Why are some conductors tinned and others are not?


What is the difference between a cord and a cable?

There are two main differences between a cord and a cable.



Flexible cables are often used with oil or chemicals. How do you determine which cables will be suitable for these applications?

The circumstances of an installation have a large bearing upon the suitability for exposure to chemicals and oils.  This includes the anticipated length of exposure, the type of chemicals or oil involved, operating temperature, environment and application. If you are asked for a recommendation, obtain as much information as you can and refer to your local Olex sales office.

Why don’t manufacturers mix PVC and rubber in building a cable? For example, a PVC insulation and CSP sheath.

In determining the construction of a cable, the designer looks at the environment in which the cable will operate. For example, does it need to operate at low temperature, in oil or chemicals, will it be subject to mechanical damage, etc. This generally then determines the sheath that will be required. In selecting the insulation, the operating voltage and current need to be considered and then a selection is made so that it is compatible with the sheath. For example, PVC and CSP could not be combined because the PVC would melt when the CSP is cured at high temperature.

What type of flexible cord or cable is used on hot appliances?

The relevant application standards specify that for those appliances the cable must resist heat deformation. This is achieved by using either a rubber sheath or cotton covered PVC insulated cords for some appliances.

Are the Olex 4 core flexible cord core colours (Brown, Light Blue, White, Green/Yellow), in contradiction with AS/NZS 3000?

The Olex flexible cord colours are in accordance with the requirements set out in AS/NZS 3191 and are not intended to apply to flexible cords used in fixed wiring as outlined in AS/NZS 3000. The standard range of flexible cords (with colours highlighted below), should not be used as fixed wiring, as they have incorrect insulation colours. Flexible cords can be used as fixed wiring if the alternative insulation colour scheme (ie. as per fixed cables) is used and they are of the heavy duty type or installed in the appropriate wiring enclosure.

The standard range of Olex insulation colours for fixed and flexible cables designed to Australian Standards are as follows:

Fixed cables (450/750V & 0.6/1kV)
Active Cores:
red, white (uncoloured), blue
Neutral Core: black
Earth:  green/yellow

Flexible Cords (ordinary duty & heavy duty – standard)
Active Cores:
brown, white (black), orange
Neutral Core: light blue
Earth:  green/yellow

Can I use Flexolex® in reeling applications?

The flexible 3, 4 and 5 core cables offered are part of the standard and stocked Olex range of products. These cables are renowned for their flexibility and have been designed for ease of handling and bending. Under conditions of reeling with low tension and appropriate bending diameters, these cables will provide good performance for many years.

However, such designs do not suit tight bending and reeling under tension where the sheath can be squeezed and induced to move toward one end, thereby exhibiting the characteristics of “corkscrewing”. Another effect of reeling under tension with misaligned rollers or guides, is for the cables to roll on their axis which eventually causes conductor wire breakages. 

(View our data/communications products)   Back to top

What is the relationship between Austel and the Australian Communications Authority (ACA)?

Before July 1997, all telecommunications products needed Austel approval, involving an exhaustive and expensive system of testing and approval, which Olex met. Since the disbanding of Austel in 1997 and the establishment of the Australian Communications Authority (ACA), testing has become the responsibility of the manufacturer or supplier. Companies are now issued with an ACA Merchant Number which must appear on all products along with the “A tick” symbol to signify compliance with the ACA requirements. All Olex communication products comply with these regulations and are all marked in this way. In 2005, the Australian Communications and Media Authority took over the ACA. Regulations however have not changed.

What is Olex’s ACA Merchant Number?

Olex’s ACA Merchant Number is N10594.

Where is the Austel approval number?

The Austel approval number has been replaced with the ACA Merchant Number.

Is Figure 8, 24/0.20mm (Olex code JSF.75) 240 volt rated?

Yes. It is rated in accordance with Australian Standard 3191. This product is also approved for use to AS/ACIF S008:2001.

What does the term Extra Low Voltage (ELV) mean?

Extra low voltage is cable that is rated at 50V AC/ 120V DC. This is defined as such in AS/NZS 3000:2000, known as the “Wiring Rules”.

Why is solid copper conductor preferred over copper clad steel conductor in closed circuit television applications?

The copper clad steel conductor was specifically developed for use in coaxial cables intended for RF use. RF implies that the signal being carried by the coax is of “high frequency”. All conductors that carry alternating currents have losses that are associated with the conductor’s resistance. Due to skin effects, the resistance increases when an alternating current flows in it. This effect causes the current to flow more in the outer region of the conductor and not in the centre, and is due to inductive effects. This effect also increases with the magnitude of the frequency of the alternating current. So much so that at RF, only the very thin surface layer is useful for carrying currents.

Therefore, to reduce the cost of the cable, the centre of the conductor is replaced with a low cost material such as steel. Closed circuit television applications employ the base video signal, which consists of alternating currents of much lower frequency than RF. At these frequencies, the skin effect is not as significant so a greater proportion of the conductor can be utilised for carrying the video signal current. Therefore, the solid copper conductor will have a lower loss for video signal when compared to a copper clad conductor, so it is preferred for CCTV applications.

Back to top

Which cables are approved for use in mines?

The answer is dependent on the State in which the mine is located.

In NSW, the system is that approval is needed from the Department of Mineral Resources for compliance to the NSW Coal Mines Regulation Act, 1982.

Olex have a Certificate of Approval. Olex is covered by Approval No: MDA ex 1355 – File No: M82/2882, Dated 27th February. 1985. The approval covers all cables made to AS1802 and AS1972 where applicable. I also understand there are amendments which Alfred Eiden had and could have covered AS2802.

In QLD, the system is that approval is needed from the Department of Minerals and Energy for compliance to the Queensland Coal Mining Act, 1925-1990. This Act stated that cable made and in conformance with Australian Standards 1802, 2802 and 1972 is deemed suitable to be used subject to the cable being installed, operated, maintained and overhauled in accordance with the provisions of the Act.

For cables made to other Standards, then specific approval must be obtained from the Inspector of Coal Mines at the Department. As our equipment is of an electrical nature, the approval would come from the Principal Electrical Inspector.

Olex have a Certificate of Approval, number QMD 91 6984 X  for the use of 95mm2 XLPE 12.7/22kV PVC SWA PVC.

In Western Australia, Western Power (formerly SECWA) that hold jurisdiction in this area and authorises approvals.

Fire Rated    (View our fire rated products)    Back to top





What does a two hour fire rating mean?


How is the resistance to mechanical impact measured?


What does the cable system consist of?


Special Applications   Back to top

Is it OK to use EPR/PCP Mine Trailing Cables in submersible applications?

Olex does not view our PCP sheathed cable as being a long term solution for submersible applications. The PCP contains Magnesium Oxide (as a curing agent) which will absorb water.

A better solution would be to utilise a CPE sheath, as used on our Flexolex® range, which does not contain Magnesium Oxide. It has also been tested at elevated water pressures and has been found to be suitable for submersible applications such as submersible pump motor connections.

Both cables contain cores which are insulated with EPR. The insulation itself gives good protection from water penetration although it would be preferable for the sheath to do so also. Therefore, for this application, CPE is the preferred sheathing material rather than PCP.

General   Back to top

How do I determine the rating of a cable?

•Conductors’ DC resistance;
•Thermal resistance of the insulating sheathing materials; and





How do I measure the amount of current a cable can carry over a particular distance?


I =     x V x  1000  
    100            L x Vc

I  = cable current that produces the maximum voltage drop
L = circuit length




Vc =  5  x V x  1000   
       100          L x I





What is the correct lug for use on compacted conductors?



What is the correct lug for use on flexible conductors?



Further information on crimping techniques can be obtained from lug manufacturers.

Terminology   Back to top


Ceramifiable® Registered Trade Name for a type of polymer composition that becomes a ceramic when burned, continuing to provide insulation to the conductor.






Flexolex® Registered Trade Name for a range of cables insulated with EPR and sheathed with CPE. These cables include flexible conductors and are suitable for flexing applications. The cables are constructed to comply with AS/NZS 5000.1 (power and control), AS/NZS 3191 (cords), AS/NZS 1995 (welding), and IEC 60245.4 (cords). The range includes TCWB screened cables. A range is also available with pilot cores for use with submersible pumps.

FR Flame Retardant.

GSWB Galvanised Steel Wire Braid.


Halogen Free.

HFFR Halogen Free Flame Retardant.

HOFR Heat, Oil and Flame Retardant.


LSZH, LS0H Low Smoke Zero Halogen.



Registered Trade Name for a range of fire resistant and flame retardant cables made of materials that are LSZH and pass tests such as AS/NZS 3013, IEC 60332 (all parts), IEC 60754, BS 4066, and BS 6387. The Pyrolex® range includes cables insulated with Ceramifiable®.


TCWB Tinned Copper Wire Braid.




XLPE Cross Linked Polyethylene. A high grade insulation material.

ZH Zero Halogen.