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Fitting a Fused Connection Unit
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Electricity is dangerous and can be hazardous.
In doubt? Call a qualified electrician - Electricians

  Fitting a FCU


There are three types of fused connection units: - unswitched, switched with flex outlet and switched without flex outlet. Fused connection units are used as a means of connecting permanent appliances such as cooker hoods to the electrical circuits of the house.

Examples of uses of FCU are, cooker hoods (see Installing a cooker hood), hidden sockets for kitchen appliances (see Installing wiring for kitchen appliances), extractor fans (see Installing wiring for an extractor fan), shaver sockets (see Installing a Shaver Socket) and waste disposal units (see Installing wiring for a waste disposal unit).


To install a fused connection unit, break into the existing ring main or more likely run a spur from an existing socket (see Adding a spur to a ring circuit from a socket), or from a junction box (see Adding a spur to a ring circuit from a junction box). Once this has been completed and the cable is running to the position where the new FCU is required, fit a mounting box to hold the FCU securely in place, (see Installing a electrical mounting boxfor full details of how to complete this task).

If the FCU used doen’t have a built in flex outlet then run a cable to a new socket which it will supply or a separate flex outlet. See the pages mentioned above for examples.

When the cables are in place and the mounting box fitted, fit the FCU.

On the FCU there should be 6 screw terminals, 3 for the mains supply and 3 for the load. The flex for the appliance should be connected to the load terminals.

Strip and prepare the ends of the flex (see Preparing the cable for connection).

Connect the appliance flex to the 3 terminals. The FCU has three Load screw terminals marked L (Live), N (Neutral) and E or (Earth). The brown conductor should be fixed in the Live terminal (L), the blue fixed in the Neutral (N) terminal and the green/yellow conductor into the Earth terminal (E or ) and tightened securely.

Now the FCU is ready to be connected to the Mains supply. Strip and prepare the ends of the mains cable (see Preparing the cable for connection) and place a length of green/yellow sleeving over the bare earth wire.

Next connect the mains cable to the FCU. The FCU has three Mains screw terminals marked L (Live), N (Neutral) and E or (Earth). The red conductor should be fixed in the Live terminal (L), the black fixed in the Neutral (N) terminal and the bare wire with the green/yellow sleeving fitted into the Earth terminal (E or ) and tightened securely.

Finally screw the FCU in place.

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SubjectPosted by Replies Posted at
Forum Topic Extractor and Hidden Plugs jbourne 10 03 Jul 07 at 3:06
Forum Topic Fused connector? Parcystrade 3 08 Apr 07 at 18:30
Forum Topic Flex or T+E? Ejaz 8 11 Jan 07 at 14:17
Forum Topic FCU to Twin socket? flatrules 1 30 Aug 06 at 19:31
Forum Topic FCU on a 45amp radial cooker circuit? BEdwards 3 27 May 06 at 20:38
Forum Topic electric fire fcu yorkie333 12 07 Mar 06 at 18:11
Forum Topic Double/Twin FCUs??? jk5 8 04 Mar 06 at 16:19
Forum Topic FCU, spurred to lighting circuit. The destroyer 4 26 Feb 06 at 21:30
Forum Topic FCU 4 hood & cooker? gthecat 1 26 Jan 06 at 14:09
Forum Topic fused spur unit billy breidenbach 9 22 Nov 05 at 19:02
Forum Topic extractor fan drblct 2 11 Nov 05 at 23:10
Forum Topic Switched Fused Connection Unit + Oven GingerNinja2005 6 19 Jul 05 at 11:59
Forum Topic saniflow electrics help brenden 3 27 Apr 05 at 19:23
Forum Topic FCU\\\'s shadow 3 15 Mar 05 at 0:30
Forum Topic Showers Brayd 2 03 Dec 04 at 8:31
Forum Topic New FCU for bathroom floor heating longbloke 2 27 Nov 04 at 21:04
Forum Topic fused connection units rglister 2 13 Nov 04 at 14:39
Forum Topic imerssion switch actionmal 2 25 Aug 04 at 14:44
Forum Topic Installing a wall light pressld2 6 05 Aug 04 at 14:18
Forum Topic Fused Connection Unit jonjon 2 27 Apr 04 at 23:32
Forum Topic 45amp fuse for shower bluespam 9 27 Apr 04 at 16:13
Forum Topic electric shower jonah 26 15 Mar 04 at 15:36
Forum Topic fused connection units hark 44 24 Feb 04 at 13:26
Forum Topic Electric Fire richyd 9 10 Feb 04 at 8:48
Forum Topic Lighting StuMids 1 05 Nov 03 at 14:42
Forum Topic fused connection units smichie 1 05 Jun 02 at 12:36

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