Two-core flex has only the live and neutral conductors, coloured brown and blue. The outer sheath of a flex can be PVC or rubber or rubber/textile braided. Two-core flex can have a round or flat sheath.

Note: If you are replacing a cord on an old appliance you may find that the colours are different from those now available in shops. The old green is now striped green and yellow to be connected to earth or E, the old red is now brown to be connected to live or L, and the old black is now blue to be connected to neutral or N.

Choosing the flex

Size of conductor

To select the correct size of flex you must know the wattage of the appliance. This can be obtained from the rating plate on the appliance (4). Some appliances such as freezers, refrigerators and vacuum cleaners need a size larger than the wattage indicates. Select the size from Table 1 below.

Table 1

Wattage up to	(Amps)	Conductor size	Typical appliances
720	(3A)	0.5mm2	Table lamps, food mixers, certain hair dryers. Note: length must not exceed 2m
1440	(6A)	0.75mm2	Refrigerators, vacuum cleaners, electric drills, irons, high power hair dryers, televisions
2400	(10A)	1.0mm2	New kettles, 2kW fan heaters
3240	(13.5A)	1.25mm2	3kW fires, older kettles
3840	(16A)	1.5mm2	Storage heaters, immersion heaters

 

Number of cores

Three-core flex is used on appliances needing an earth, (usually metal cased appliances). Two-core flex is used for double insulated appliances. Look for the double insulated symbol (5).

 

Type of insulation

 

There are several types of flexible cord. The more common ones are listed in Table 2.

 

 

Table 2

Type of flex	Typical appliances
Parallel twin PVC	Clocks
Light duty PVC	Fridges, televisions, sewing machines, food mixers, domestic hair dryers, table lamps, plate warmers. All appliances not too hot to handle
Ordinary PVC	Washing machines, tumble dryers, vacuum cleaners, lawnmowers, toasters
Rubber with oil resistant sheath	Frypans – hot appliances
Rubber textile braid or ordinary duty PVC	Room heaters
Rubber/textile braided	Irons
85°C rubber high temperature cords	Immersion heaters, storage heaters
Light duty 85°C PVC cords	Pendant light fittings

 

When you have decided on size, number of cores and type, then you can select the correct flexible cord for your particular appliance.

Table 3 below is a ready reference guide showing which flexible cords can be used for certain typical appliances.

 

Table 3

Appliance	Typical wattage	Flex size mm2	Number of cores	Flex type
Iron	1200	0.75	3	Rubber/textile braided (unkinkable)
Toaster	1400	0.75	3	Ordinary duty PVC
Room heater	1400 2000 3000	0.75 1.0 1.25	3 3 3	Rubber insulated textile braided or ordinary duty PVC
Vacuum cleaner	400 to 1000	0.75	2 or 3†	Ordinary duty PVC
Lawnmower	700 to 1400	0.75	2 or 3†	Ordinary duty PVC
Kettle	1200 1500 2400 3000	0.75 1.0 1.0 1.25	3 3 3 3	Ordinary duty PVC. Recommended buy complete with connector
Extension lead	1000 3000*	1.0 1.5	3 3	Ordinary duty PVC *when fully uncoiled
Immersion heater Storage heater	3000	1.5	3	85°C rubber insulated high temperature cord
Clock	1	0.5	Usually 2	Parallel twin PVC, length not to exceed 2m
Slow cooker	1500	1.0	2 or 3…	Ordinary duty PVC
Deep fryer	1500	1.0	2 or 3…	Rubber with oil resistant sheath
Hair dryer Refrigerator Food mixer	1400	0.75	2 or 3…	Light duty PVC
Table lamp	40 to 100	0.5	2 or 3…	Light duty PVC. Length not to exceed 2m, if it does exceed 2m, use 0.75mm2 flex

 

† Where 2 or 3 cores are shown above replace as the maker intended.