IP55 Photocell Switch Wall Mounted Dusk to Dawn Timer - Black

The Knightsbridge OS006B is an IP55-rated photocell switch with a dusk-to-dawn timer function, housed in a black polycarbonate case measuring 105mm × 79mm × 36mm. The unit automatically switches connected lighting on at dusk and off at dawn, with selectable duration settings of 2, 4, 6 or 8 hours to override the dawn sensor if needed.

Designed for outdoor security lighting, shop window displays, and advertising signage, the photocell mounts directly to an external wall via four fixing points and connects inline between the mains supply and the lighting circuit. The IP55 rating protects against dust ingress and water jets from any direction, making the switch suitable for exposed positions under eaves, on outbuildings, and in commercial forecourts where rain and condensation are present.

The ambient light memory function allows the photocell to learn the light level at which it last switched on, so it adapts to seasonal changes in daylight hours without manual intervention. Switching capacity is rated at 1000W for incandescent loads, 500W for fluorescent or inductive loads, and 200W for LED loads on 230V 50Hz mains. The Class II construction means no earth connection is required during installation.

The photocell sensor sits behind a small lens on the front face of the unit and should be positioned where it has a clear view of the sky rather than facing artificial light sources or reflective surfaces. The duration override is useful for security applications where you want exterior lighting to remain on for a fixed period after dusk rather than burning until dawn.

Product Specification Sheet

What does the ambient light memory function do?

The photocell learns the light level at which it last activated and uses that threshold for future switching cycles. This means it adapts automatically to seasonal changes in daylight hours without needing manual adjustment or reprogramming.

What's the maximum LED load it can switch?

The unit is rated at 200W maximum for LED loads on 230V. For incandescent loads the rating is 1000W, and for fluorescent or inductive loads it's 500W. Exceeding these ratings may damage the switching mechanism or cause premature failure.

How do the duration settings work?

The 2/4/6/8 hour duration settings override the dawn sensor. If you set 4 hours, the photocell switches on at dusk and then switches off after 4 hours regardless of whether it's still dark. This is useful for security lighting where you want a fixed burn time rather than all-night operation.

Does the IP55 rating mean it can be mounted in fully exposed positions?

IP55 protects against dust ingress and water jets from any direction, so the unit can handle rain and exposed mounting positions. However, mounting under an eave or soffit extends the lifespan by reducing direct exposure to UV and heavy weather.