Ceiling surface-mounted plug-in photocell switches


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Switches the lights on when there is not sufficient ambient light available and off when there is sufficient ambient light available.

For surface mounting onto solid ceiling.

  • Built-in differential ensures the artificial lights do not affect the photocell.
  • Built-in time delay of 1 minute avoids unnecessary switching.

Product code: CEPH NO

Requires socket, order code: CESO SQ or CESO

Ceiling surface mounted versions: CESF NO and CESF PHRE are also available
on request.


ceph-no-main-1Manual wall switch
retained for overriding OFF





For saving lighting energy in offices, factories, sports halls and so on.


CEPH NO Plugs into CESO SQ Ceiling socket (or CESO Ceiling socket). CESO SQ can be mounted on a square pattress box (or CESO can be mounted on a BESA box).
Photocell range: Switches on at between 100 and 1000 lux falling on the working plane
Loading: Up to 6 amps (1500W) of resistive loads.
Up to 6 amps (1500W) of fluorescent loads.
Up to 3 amps (750W) of electronic and wire wound transformer loads.
Up to 2 amps (500W) of CFL, 2D lamps, LED Drivers and LED lamps and fittings.
Up to 1 amp (250W) of fans.
Dimensions: 88 x 88 x 47mm