There are 5 levels of CPR Ratings – Fca being the lowest, B2ca the highest. A brief description is as follows:
| CPR Level | Explanation |
|---|---|
| B2ca | Same tests as Cca, but to higher standards. Highest level any thermoplastic sheathed cable will meet. |
| Cca | Same test as Dca, but to higher standards. Minimum requirement for BS6701 Regulations. |
| Dca | 3rd party tested to EN ISO1716, EN 50399, EN 60332-1-2, EN 61034-2, EN 60754-2 |
| Eca | Basic 3rd party testing to EN60332-1-2 |
| Fca | Cable will either not pass basic Eca testing [PE Sheathed cables for example] or has not been tested. |
This document from BASEC should help to explain the implications of CPR:
LSF is still PVC – it has been modified to have unquantified properties that are lower in smoke, and lower in fume than normal PVC, but it will still burn, still give off black smoke, and still give off fumes – which when mixed with water will create hydrochloric acid. Black smoke and hydrochloric gas are considered to be more deadly to people than the flames themselves. Once the smoke is inhaled, it mixes with moisture in the body and hydrochloric acid is created, which irritates the lungs causing coughing, shortness of breath. It is not LSZH
LSZH is not PVC, and is not LSF. The compound used will have a quantifiable fire / smoke performance [less than 0.5% hydrochloric gas] . This should be the bare minimum for all installations in all public buildings. LSZH is also known as LSNH / LSOH / Halogen Free / LSHF / OHLS
| Alarm Cable Type | Construction / Performance |
|---|---|
| Type 1 | Must Be Copper Must be LSZH Insulation Must be LSZH Sheath Maximum 100 Ohm Conductor Resistance |
| Type 2 | Must be Copper Maximum 100 Ohm Conductor Resistance |
| Type 3 | Normally CCA (Copper Covered Aluminium) Maximum 155 Ohm Conductor Resistance |
Ethernet cable frequency refers to the rate at which a network cable transmits signals, usually measured in megahertz (MHz). It indicates the frequency range of signals that the network cable can transmit. For example, a CAT5E network cable with a transmission frequency of 100 MHz can support a frequency range between 1 MHz and 100 MHz while signals beyond this range may be subject to loss or interference. Ethernet cable frequency plays a crucial role in determining the performance and speed of data transmission over the network. Therefore the higher frequency the more data a cable can handle.
| Category | Cable Frequency |
|---|---|
| CAT5E | 100MHz |
| CAT5E ENHANCED / HDBaseT | 350MHz |
| CAT6 | 250MHz |
| CAT6 ENHANCED / HDBaseT | 550MHz |
| CAT6A | 500MHz |
| CAT7 | 600MHz |
| CAT7A | 1000MHz |
| CAT8 | 2000MHz |
UTP / FTP / S-FTP ???
| Abbreviation | Construction |
|---|---|
| U-UTP | Unscreened |
| F-UTP | Overall Foil Screen |
| U-FTP | Individual Foil Screened Pairs No overall screen |
| F-FTP | Individual Foil Screened Pairs Overall Foil Screen |
| S-FTP | Individual Foil Screened Pairs Overall Braid Screen |
The larger the AWG [American Wire Gauge] Number, the smaller the conductor size.
| AWG | Cross Sectional Area |
|---|---|
| 12 | 3.10mm² |
| 14 | 1.90mm² |
| 16 | 1.20mm² |
| 18 | 0.80mm² |
| 20 | 0.56mm² |
| 22 | 0.35mm² |
| 24 | 0.22mm² |
CCA when written in capital letters would normally refer to Copper Covered Aluminium. This has been prevalent in the industry for around 15 years as it is a cheaper option to copper. It does, however, present problems in some cases.
| 1 – It has a higher conductor resistance to copper, which means it is only suitable for shorter runs |
| 2 – If used in CAT5E / CAT6 cables it is NOT suitable for POE installations (Power Over Ethernet) |
| 3 – It is weaker than copper – has less tensile strength. |
Where can it be found?
| Alarm Cable | BS4737 Type 3 was created to acknowledge & control the performance of CCA conductor alarm flex. |
| Telecom Cable | 2, 3, 4, 6 Pair telecom cables |
| CAT5E | Should not be used for POE |
| CAT6 | Should not be used for POE |
| Coaxial Braid Screening | Normally on cheaper CLASS E Screened Digital / Satellite coaxial cables |
Min. installation temperature -5°C
Operating and storage temp:
Many cables are referred to as CT100.
| “CT100” Cable Type | Description |
|---|---|
| RG6 Class E Screening Efficiency | Copper Covered Steel Conductor Aluminium Tape Screen Aluminium Braid Screen |
| C100 Class E Screening Efficiency | Copper Covered Steel Conductor Aluminium Tape Screen (Copper Coloured) Aluminium Braid Screen [This is essentially still RG6] |
| C100PREM Class E Screening Efficiency | Copper Conductor Aluminium Tape Screen (Copper Coloured) Aluminium Braid Screen |
| DFD100 CAI Approved. Class A+ Screening Efficiency | Copper Conductor Copper Tape Screen Copper Braid Screen |
Some helpful terminology of cable construction elements.
| Conductor | Can be stranded or solid. Is normally Copper, but cheaper cables can be copper covered Aluminium or Steel. Pure copper has lower resistance so can be run longer distances. |
| Insulation | The part that covers the conductor, normally colour coded for identification – but can be printed with numbers. |
| Pairs / Cores | A Pair is 2 cores twisted together to help avoid interference. A 2 core cable might also be referred to as 1 Pair. |
| Screening | This can be Foil or Braid It can be individual (around each pair) or overall (or both!) Foil is normally aluminium. Foil screen normally comes with a bare drain wire to earth the screen. Braid is normally copper (or copper covered aluminium) |
| Sheath | The outer part of the cable. Can be PVC, LSF (which is still PVC), LSZH for internal installations. PE for external. Some LSZH sheaths are UV / External. |
| SWA | In addition, you may also have SWA (steel wire armour) around the sheath, and then another overall sheath |
Cable sheath colours are usually referred to by a RAL Number which can then accurately identify the exact colour required. You can download a RAL Colours chart here:
Suggested conductor sizes for different power speakers based on the distance you need to run.
