Lighting glossary and FAQ

Ingress Protection Rating (IP)

Defines the degree of protection against intrusion (body parts such as hands and fingers), dust and moisture provided by the luminaire enclosure.
IP ratings are defined in European standard EN 60529.

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ik10

Impact Protection Rating

It is an international numeric classification for the degrees of protection provided by enclosures for electrical equipment against external mechanical impacts.

IK ratings are defined in European standard EN 62262.

The classification ranges from IK00 (not protected) to IK10, which offers protection to an impact of 20 Joules (equivalent to the impact of 5 kg mass dropped from 400mm above impacted surface), tested using a pendulum hammer (as per EN 60068-2-75).

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Electrical Safety Classification

Defines the degree of protection against intrusion (body parts such as hands and fingers), dust and moisture provided by the luminaire enclosure.
IP ratings are defined in European standard EN 60529.

Fittings comply with Class II double insulated electrical requirements (i.e. without an earth termination).

Specification of Mounting Type and Operating Range

Colour Rendering Index (Ra)

The higher the CRI, the better the colour rendering ability.

It is a quantitative measure indicating how accurate a light source is at rendering colour when compared to a reference light source.

Colour Temperature

A descriptive term for the appearance of light expressed in Kelvin (K).

 > 5,000K

 cool colour (bluish white)

 > 5,000K

 cool colour (bluish white)

 3,500 – 4,000K

 mid-range colour

 3,500 – 4,000K

 mid-range colour

 2,700 – 3,000K

 warm colour (yellowish white through to red)

 2,700 – 3,000K

 warm colour (yellowish white through to red)

Frequently Asked Questions

Frequently Asked Questions

Q1:     Why does the dimmable Fern Howard fitting I purchased not work with my existing dimmer switch?

Ans:

Please check your dimmer switch. Is it a phase cut (leading or trailing edge) domestic dimmer switch? Our fittings do not work with domestic phase cut dimmers.

This type of dimmer switch has only two connections, a live and a neutral. Designed for traditional lighting technology, it is only suitable for lower power domestic lighting and is not suitable for dimming Fern-Howard luminaires.

Our fittings are 1-10V analogue dimming. They require a 1-10V analogue dimmer switch with four connections: live, neutral + and – 1-10V signal wires.

Q2:     When should I use 1hour or 3hour Emergency Lighting?

Ans:

BS 5266-1: 2016 Code of practice for the emergency escape lighting of premises states ‘’The time required to evacuate premises depends upon their size and complexity.’

Q3:     Why doesn’t my light fitting have an Earth connection?

Ans:

If you have a light fitting without Earth terminal, it will be because your fitting is Class II.(Please refer to Electrical Safety Classification)

Class II means that the product is double insulated. The plastic termination block provides the basic insulation from the Live and Neutral mains connections. Additional insulation is provided by the plastic enclosure. The two separate layers of insulation protect the user against the risk of electric shock. Earthing is not required.

If you have a metal based product, this will be a Class I fitting. This can be indicated by the following symbol:

Class I fittings will have an Earth terminal and you will be required to sufficiently Earth the metal housing to protect against the risk of electric shock.