GB2222245A

GB2222245A - Testing lighting equipment

Info

Publication number: GB2222245A
Application number: GB8817893A
Authority: GB
Inventors: Peter Colenso Walton
Original assignee: GALVANIC DEVICES Ltd
Current assignee: GALVANIC DEVICES Ltd
Priority date: 1988-07-27
Filing date: 1988-07-27
Publication date: 1990-02-28
Also published as: GB8817893D0

Abstract

For testing the operation of self-contained luminaires (10) (eg in battery powered emergency lighting equipment) which are connected in parallel with conventional lighting and operable upon power failure thereto, the luminaires are connected through a test unit (16) respective distribution board (12). The unit (16) comprises a timing unit connected to a relay to break the circuitry to the luminaires and thereby to actuate them for a preset period. The unit (16) also includes a plurality of photo-detectors each viewing a respective luminaire via a fibre optic cable (18) to register whether the light intensity of each luminaire during a test remains above a predetermined level. Indicators are provided on the unit (16) to show whether each luminaire has provided the required light output throughout a test. The units (16) may be connected to a monitor (20). <IMAGE>

Description

Lighting Test Apparatus This invention relates to lighting test apparatus and particularly but not exclusively to apparatus for testing emergency lighting equipment and especially for testing self-contained luminaires.

Emergency lighting equipment is increasingly being fitted into buildings such as hospitals, hotels, shops and offices. Such equipment requires regular testing. This equipment is often in the form of self-contained luminaires with their own batteries. These luminaires are normally wired in parallel with the conventional lighting equipment, being operable upon failure of the electrical supply to the conventional lighting.

The use of self-contained luminaires has a number of advantages in that no wiring to a conventional battery is required, and additional luminaires can be readily added to a system without having regard for the spare battery capacity available.

However, conventional testing of self-contained luminaires is very time consuming. Unless dedicated switching is provided in the installation, which is not often the case, it is up to the testing operative to find each and every sub-circuit distribution board and isolate those circuits to which emergency luminaires have been added. This is often not convenient when primary lighting is switched off at the same time. Duration testing of emergency luminaires is at times impossible because of prolonged isolation of primary lighting and the time involved for personnel.

Furthermore, British Standard 5266 stipulates that testing of self-contained luminaires should be carried out a least once per month for a short period of time to check for correct changeover and that the luminaire is providing a reasonable level of light output. A more prolonged test is to be performed once every six months for at least one hour, principally to check that the battery is receiving sufficient charge. There is also a recommendation that three hour duration luminaires should be tested for their full rated duration period every three years. Since virtually all luminaires fall into this category, provision should be made for three hour tests.

According to the present invention there is provided light testing apparatus comprising a light sensor, means for locating the light sensor adjacent to a light source to be tested, timer means operatively connectible to the light source such that the light source can be automatically actuated for predetermined periods of time, and means for indicating if the light intensity measured by the light sensor is below a predetermined level at any time during the predetermined period of time.

Preferably the timing means provides for the light source to be automatically actuated for a plurality of predetermined time periods at predetermined intervals of time.

The timer means is preferably electrically operated with a back-up supply for example in the form of a battery.

The light source is preferably of the type required to operate upon power failure to further lighting equipment, and is connected in parallel to the same power source, and the timer means is desirably connected to the power source for the light source only, such that the power to the latter is disconnected during the predetermined time periods whereby to enable actuation of the light source without disconnecting the further lighting.

The indicating means may comprise a light and/or audible alarm. The predetermined light intensity may be substantially 2200 lux.

Delay means is preferably incorporated in the timer means such that the sensor does not measure the light intensity until after a predetermined delay subsequent to the commencement of the predetermined period of time.

The light sensor may include a fibre optic cable substantially directed towards the light source to be tested and connected to a photo-detector.

The apparatus may comprise a plurality of light sensors, means for mounting each sensor adjacent a respective one of a plurality of light sources to be tested, and means for connecting the light sensors to the timing means.

With a plurality of light sensors a monitor may be provided which gives an indication of the status of each individual light source.

An embodiment of the present invention will now be described by way of example only with reference to the single figure of the drawings which shows a circuit diagram for apparatus according to the invention.

The drawing shows a circuit diagram for a system for testing twenty three self-contained luminaires 10. Each of the luminaires 10 is connected to one of four distribution boards 12 by wiring 14 through a test unit 16. Four distribution boards 12 are provided, three of which each serve six luminaires, the other serving five. The luminaires 10 are operable upon sensing a power failure to nearby conventional lighting (not shown) which is connected in parallel to the luminaires 10 to a power source through the respective distribution board 12.

The test units 16 each comprise a timing unit connected to a relay. The latter is connected in the circuitry from the distribution board 12 to the emergency lighting, the relay being connected to break the circuitry to the emergency lighting upon actuation of the relay. The timer may be, for example, in the form of a CMOS timing circuit arranged to actuate the relay at set timings for set periods of time, to provide testing of the luminaires as stipulated in British Standard No. 5266. A lithium battery is provided to power the timing circuit in the eventuality of a failure in the power supply thereto.

Each of the test units 16 also includes a plurality of photo-detectors set to register whether the light intensity of each luminaire being read during a test remains above a predetermined level, for example 2200 lux.

A delay is built into the timing circuit so that the light intensities are not measured for a short period, for example five seconds, after the luminaires are first lit to allow them to warm up. The photo-detectors are each operatively connected to a respective length of fibre-optic cable 18, the remote end of which directly faces at a respective one of the luminaires 10.

Each of the test units 16 is provided with a plurality of light indicators, which may be LEDs. The LEDs may be of three different colours for example red, amber and green. A green light is provided which when lit, signifies that the luminaires are receiving power and thus their batteries are being recharged. An amber light is provided which when lit, represents that a test of the luminaires is in progress. A red light is provided for each luminaire and illustrates when lit, that a luminaire has failed during a test i.e. the light intensity recorded by the respective photo-detector fell below the predetermined level. An audible alarm may be provided to accompany the red light.

Each of the test units 16 is connected, for example by duplex twin-axial cable, to a monitor 20 sited at a location remote from the luminaires. The monitor 20 includes a display, for example, such as an LCD alpha-numeric display, to convey messages about the status of the test sequence and/or the condition of the luminaires. Light may be provided to indicate the condition of the back up batteries for the timing circuits. The use of a duplex link between the test unit 16 and the monitor 20 permits signals to be sent either way. The monitor 20 may be such as to indicate all the above mentioned conditions, thus removing the need for the indicator lights as all the messages could be provided on the alpha-numeric display.

In use, the timing units provide a test sequence of the luminaires for five minutes every 30 days, one hour every six months, and three hours every three years.

Before a test, the green LED should be lit indicating that all the luminaires are receiving power and are thus having their built in batteries charged. When the test commences the power to the emergency lighting is disconnected and the luminaires are thus actuated. The amber LED will light, and, after a five second delay, the photo-detectors will monitor the light intensity of the luminaires. If the intensity of any luminaire at any time during the test drops below 2200 lux, the respective red LED will light and the alarm sound. When a red LED lights up the green LED will be extinguished. The red LED will remain lit until the next test.

A manual test override switch is provided on the test units or the monitor. This switch is operable by a key and permits a test to be carried out at any time as may be required for example by the Fire Brigade. If this switch is left on for over three hours the test unit will automatically re-energise the emergency lighting to prevent total discharge from the batteries in the luminaires. An alarm and light will be actuated to show that his has happened. Any test which is scheduled for within twenty four hours after a manual test has occurred, will be delayed until after this period to allow a full recharge of the luminaire batteries.

Upon power-up of the system the monitor automatically detects how many test units are connected thereto and checks each duplex line for breaks or power failure. Each luminaire is identified by a number and a letter corresponding to the test unit to which it is connected. The alpha-numeric display shows relevant messages, examples of which are given below, to illustrate the status in the apparatus.

"Last Test Passed" "Emergency Lights Nos. B6, D2 Failed During 1 Hour Test" "Test Ended, Please Return Manual Test Switch" "Manual Test In Progress" "Replace Battery in Monitor" "Replace Battery In Unit E" "Link With Unit G Broken" The above example thus describes a totally automatic system for monitoring luminaires. This system permits the luminaires to be monitored according to the requirements of BS 5266. The system is relatively simple and can thus be relatively inexpensively manufactured. The system is also sufficiently flexible to permit extra units to be added onto it.

Various modifications may be made without departing from the scope of the invention. For example, the indicator lights on the test units, could be omitted. Furthermore indicator lights could be provided on the monitor instead of the alpha-numeric display. A different value could be set for the failure level of the luminaires. The light intensity of the luminaires could be measured in a different manner. A printer could be connected to the monitor to provide a print-out recording the results of each test.

The monitor may be omitted from the system, particularly if a smaller number of luminaires are involved. In this instance all the information concerning the status of the system is presented on the or each test unit.

In many premises only a few luminaires need be installed, and in this instance a test unit could be provided for each luminaire. A simpler timer could be used in such test units and in this case it would be advisable for testing to be carried out a little more regularly to allow for variation in timings. Single green and red indicator lights and an audible alarm could be provided on each test unit to indicate whether the luminaire passes the tests. A switch may be provided to silence the alarm. If a fuse is provided in the test units this will permit the luminaires to be readily isolated to permit maintenance.

Such units are obviously of relatively simple construction and are thus inexpensive to manufacture.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. Light testing apparatus comprising a light sensor, means for locating the light sensor adjacent to a light source to be tested, timer means operatively connectible to the light source such that the light source can be automatically actuated for predetermined periods of time, and means for indicating if the light intensity measured by the light sensor is below a predetermined level at any time during the predetermined period of time.

2. Apparatus according to claim 1, in which the timing means provides for the light source to be automatically actuated for a plurality of predetermined time periods at predetermined intervals of time.

3. Apparatus according to claim 1 or claim 2, in which the timer means is electrically operated with a back-up supply.

4. Apparatus according to claim 2, in which the back-up supply comprises a battery.

5. Apparatus according to any of the preceding claims, in which the light source is of the type required to operate upon power failure to further lighting equipment, and is connected in parallel to the same power source.

6. Apparatus according to claim 5 when dependent on claim 2, in which the timer means is connected to the power source for the light source only, such that the power to the latter is disconllected during the predetermined time periods whereby to enable actuation of the light source without disconnecting the further lighting.

7. Apparatus according to any of the preceding claims, in which the indicating means comprises a light.

8. Apparatus according to any of the preceding claims, in which the indicating means comprises an audible alarm.

9. Apparatus according to any of the preceding claims, in which the predetermined light intensity is substantially 2200 lux.

10. Apparatus according to any of claims 3 to 9 when dependent on claim 2, in which delay means is incorporated in the timer means such that the sensor does not measure the light intensity until after a predetermined delay subsequent to the commencement of the predetermined period of time.

11. Apparatus according to any of the preceding claims, in which the light sensor includes a fibre optic cable substantially directed towards the light source to be tested and connected to a photo-detector.

12. Apparatus according to any of the preceding claims, in which the apparatus comprises a plurality of light sensors, means for mounting each sensor adjacent a respective one of a plurality of light sources to be tested, and means for connecting the light sensors to the timing means.

13. Apparatus according to claim 12, in which a monitor is provided which gives an indication of the status of each individual light source.

14. Light testing apparatus substantially as hereinbefore described with reference to the accompanying drawing.

15. Any novel subject matter or combination including novel subject mattcr herein disclosed in the foregoing specification or claims arid/or shown in the drawings, whether or not within the scope of or relating to the same invention as any of the preceding claims.