Fire resistant cables
PH30 and PH120: Learn more about fire resistant cables
When carrying out a fire alarm installation, all materials have to be fire resistant and compliant. This includes everything used, including the cabling. The British Standards recommends the type of cabling that should be used based on fire resistance testing carried out. Two of the most popular cables used in fire alarm installation are the PH30 and PH120 cables.
So what exactly are these cables?
These cables are known as enhanced fire resistant which simply means it has been developed specifically with certain scenarios in mind. Some buildings would require a longer fire alarm system activation and these cables are ideal for those fire alarm installations. For example, larger buildings may involve a multi phase evacuation process so the fire alarm would need to operate for a much longer time. High rise blocks of flats would be an example of a building that would need an enhanced fire resistant cable. Evacuating a building of this size that is on fire would be a longer than normal process.
The cables are tested by being placed in a direct flame and timed until the circuit breaks. From this experiment, they can work out the length of time that cable can survive in direct heat situations, typically around 830°C. The failure point is said to be when the cable does not maintain the voltage or breaks. The cables are then assigned a figure based on the number of minutes it survived, with 120 being the most.
These enhanced fire resistant cables are ideal for places like:
- Hotels
- Shopping centres
- High rise flats
- Theatres
- Cinemas
- Railway stations
- Underground tunnels
- Offices
- Schools
- Airports
- Hospitals
What is PH30?
PH30 is cable that is suitable for indoor fire alarm installations where the circuit must be maintained for up to 30 minutes. Made with superior low smoke zero halogen materials, it typically has a fixed operating temperature of up to 90 °C and a flex operating temperature of up to 60 °C.
Normally, the cable will meet the following requirements but check with the manufacturer:
| Flame Tests | IEC 60332-1, IEC 60332-3-24, (BS 4066 part 1&3), EN 50266-2-4 |
| Insulation Integrity | IEC 60331, BS 6387 C , W, Z, EN 50200 PH30 |
| Smoke Density | IEC 61034, BS 7622, HD 606 |
| Corrosive Gas Measurement | IEC 60754-2, BS 6425, EN 50267 |
What is PH120?
PH120 is cable that is suitable for indoor fire alarm installations where the circuit must be maintained for up to 120 minutes. Made with superior low smoke zero halogen materials, it typically has a fixed operating temperature of 90°C and a flex operating temperature of up to 60 °C.
Normally, the cable will meet the following requirements but check with the manufacturer:
| Flame Tests | IEC 60332-1, IEC 60332-3-24, (BS 4066 part 1&3), EN 50266-2-4 |
| Insulation Integrity | IEC / EN 60331, BS 6387 C, EN 50200 PH 120 |
| Smoke Density | IEC 61034, BS 7622, HD 606 |
| Corrosive Gas Measurement | IEC / EN 60754-2, BS 6425, EN 50267 |
Ensure you keep up to date with the recommendations for cabling and general fire alarm installation information as amendments are introduced when new technology and regulations come about.
If you would like to know more, why not join our Fire Alarm Installation course? It is packed with all the information you need to know to have a comprehensive understanding on the fire alarm industry. Our 3 day course is suitable for people with an electrical background and the course covers many objectives to ensure you are confidently able to install fire alarms. So contact us for more information or to book a place on our next available course.