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LOOP-IN SYSTEMS 

Loop-in lighting wiring is the modern cabling arrangements used in most installation. Generally it uses less materials and is quicker to install than radial (junction box) wiring - it can however, be a bit more complicated to work out the actual wires at a ceiling rose.

This page shows the various wirings found at a ceiling rose of an installation using loop-in lighting wiring.

Note that the colours shown connected to the ceiling rose are the old standard - red, black and yellow and green, the modern standard being brown, blue and yellow and green (the yellow and green being the earth connector which is typically uninsulated but fitted with a yellow and green sleeving.)

Unlike radial lighting wiring, loop-in wiring is more complicated at the ceiling rose:

  1. Common loop-in wiring
  2. Wiring for end of loop
  3. Wiring for two lights on one light switch
  4. Lighting with connected extractor fan

1 Common loop-in wiring

1A - This is the most common loop-in wiring arrangement you are likely to see. It shows three cables; one cable (L+N+E) either from the mains board or the last ceiling rose, one cable (L+N+E) out to the next ceiling rose, and one cable (L+S/L +E) that goes to the wall or pull switch within that room. The latter cable is referred to as the switch live (S/L) provides electric to the light when the switch is turned on.

Common loop-in ceiling rose wiring
Fig 1A
  common loop-in wiring
Fig 1B

If you have to disconnect and remove the cores from the ceiling rose reconnect them as shown in 1B.

key for common loop-in wiring

If the light fitting you have purchased has just two cores - live (brown) and neutral (blue), connect the live to the switch live terminal and neutral to the neutral terminal. If the fitting has an earth core, it must be sleeved with a yellow and green coat and connected to the Earth terminal.

Important: Where Earth cores are present, they must ALL be connected together in the same terminal.


2 Wiring for end of loop

2A - This wiring arrangement would indicate that this is an end of the loop light fitting. It has one less live, one less neutral and one less earth core because the loop-in has reached the end and doesn't need to pass power on to another ceiling rose.

End loop-in ceiling rose wiring
Fig 2A
  End loop-in wiring
Fig 2B

If you have to disconnect and remove the cores from the ceiling rose reconnect them as shown in 2B.

Key for loop-in end ceiling rose

If the light fitting you have purchased has two cores - live (brown) and neutral (blue) connect the live to the switch live terminal and neutral to the neutral terminal. If the fitting has an earth core, it must be sleeved with a yellow and green coat and connected to the Earth terminal.

Important: Where Earth cores are present, they must ALL be connected together in the same terminal.



3 Wiring for two lights on one light switch

3A - This wiring arrangement would indicate the presence of two lights in a room on the same light switch. If there were one less red (live),one less black (neutral) and one less yellow/green (earth), this would indicate that this is the end of the loop.

lights on one switch loop-in ceiling rose
Fig 3A
  lights on one switch wiring
Fig 3B

If you have to disconnect and remove the cores from the ceiling rose reconnect them as shown in 3B.

Key for 2 lights on one switch loop-in wiring

If the light fitting you have purchased has two cores - live (brown) and neutral (blue) connect the live to the switch live terminal and neutral to the neutral terminal. If the fitting has an earth core, it must be sleeved with a yellow and green coat and connected to the Earth terminal.

Important: Where Earth cores are present, they must ALL be connected together in the same terminal.


4 Lighting with connected extractor fan

A - This wiring arrangement would most frequently be found in a bathroom, or kitchen that has an extractor fan with a run-on timer. If this was at the end of the loop, it would have one less red (live), one less black core (neutral), and one less yellow/green (earth).

Lighting with connected extractor fan ceiling rose
Fig 4A
  Lighting with connected extractor fan wiring
Fig 4B

If you have to disconnect and remove the cores from the ceiling rose reconnect them as shown in 4B.

Key for lighting with connected extractor fan

If the light fitting you have purchased has two cores - live (brown) and neutral (blue) connect the live to the switch live terminal and neutral to the neutral terminal. If the fitting has an Earth core, it must be sleeved with a yellow and green coat and connected to the Earth terminal.

Important: Where Earth cores are present, they must ALL be connected together in the same terminal.

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