GB2380620A

GB2380620A - Automatic emergency lamp testing unit

Info

Publication number: GB2380620A
Application number: GB0215716A
Authority: GB
Inventors: Paul Alexander Breen
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-07-07
Filing date: 2002-07-08
Publication date: 2003-04-09
Also published as: GB0215716D0; GB0116655D0

Abstract

A testing unit T for installation to an emergency lighting unit E, comprises means 20,22 for periodically interrupting the mains supply to the emergency lighting unit in automatic manner, and means 24,26 for monitoring the current flowing from the battery supply 16, of the emergency lighting unit and testing the value of said current. A light sensor 28 may also be provided to test the output of the lamp 12.

Description

TESTING EMERGENCY LIGHTING UNITS The present invention relates to a unit for testing emergency lighting units.

It is a requirement for emergency lighting units to be tested periodically. Usually this requires the emergency lighting unit to be tested manually, tripping a switch to interrupt the mains supply to the unit and observing whether the battery of the unit effectively energises the emergency light. Such a manual testing procedure is time-consuming, especially in premises where there are a large number of emergency lighting units to test.

I have now devised a testing unit which may be installed to the various different types of emergency lighting unit which are in use, and which serves to test these emergency lighting units automatically.

Thus, in accordance with the present invention, there is provided a testing unit for installation to an emergency lighting unit which comprises a battery supply and means for detecting any interruption of the mains supply to connect the battery supply to an emergency light, the testing unit comprising means for periodically interrupting the mains supply to the emergency lighting unit, in automatic manner, and means for monitoring the current flowing from the battery supply of the emergency lighting unit and testing the value of said current.

Preferably a processing unit of the testing unit initiates an alarm if the monitored current from the battery supply of the emergency lighting unit is below a predetermined value, indicating that the emergency light is defective or the emergency lighting unit fails to switch, as it should, to the battery supply.

Preferably the processing unit compares the value of the current flowing at two different instants, following interruption of the mains supply and before restoring it. The processing unit initiates an alarm if the current values at these two different instants differ by more than a predetermined amount.

Preferably the testing unit includes a light sensor, arranged to receive light from the emergency light when energised. Preferably the processing unit initiates an alarm if this light sensor receives no light or light of less than a predetermined intensity, indicating failure of the emergency light.

Between successive tests, preferably the current monitoring means of the testing unit monitor the charging current flowing into the battery, from the battery charger of the emergency lighting unit. Preferably the processing unit initiates an alarm if the sensed charging current exceeds an upper threshold level, and/or if it falls below a lower threshold level.

Preferably the testing unit is arranged to provide a visual indication that its emergency lighting unit has passed the preceding test. Preferably this visual indication also indicates the number of preceding tests which have been passed in succession. For example, the testing unit may include a number of different lights (e. g. differently coloured lights) which are energised in accordance with a predetermined code which indicates the number of preceding tests which have been passed in succession. Preferably the indicator lights are arranged to flash periodically, the selected lights which flash, and the rapidity at which the respective lights flash, each time, collectively indicating the number of the preceding tests which have been passed in succession.

An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: FIGURE 1 is a schematic diagram of a conventional emergency lighting unit; FIGURE 2 is a schematic diagram of the emergency lighting unit provided with a testing unit in accordance with the present invention; and FIGURE 3 is a table showing the code applicable to indicator lights of the testing unit.

Referring to Figure 1, there is shown a conventional

emergency lighting unit E which comprises a control module 10 and a discharge tube 12. A mains electricity supply is provided to the control module 10 via a connector 14, and a battery supply 16 is also provided. The control module 10 is arranged to detect any interruption in the mains supply, in order to connect in the battery supply, to energise the emergency light 12.

Referring to Figure 2, the emergency lighting unit E of Figure 1 is provided with a testing unit T in accordance with the invention, typically installed within the emergency lighting unit. It will be noted that the testing unit T is connected into the mains supply leads L, N between the connector 14 and the emergency lighting unit E and also into the battery supply leads LI, L2. The testing unit T includes a timer 20 which controls a switch 22 to periodically interrupt the mains supply to the emergency lighting unit E. The testing unit T further comprises a current monitor 24, coupled to the leads carrying the battery current, and a processing unit 26: power for the circuitry of the testing unit T is provided by a battery 27.

The timer 20 operates at one-monthly intervals to interrupt the mains supply to the emergency lighting unit E for a short period of time. This interruption is sensed within the unit E, in accordance with its normal operation, to switch in the battery supply to energise the emergency light 12. The current monitor 24 within the testing unit T monitors the current flow from the battery 16, firstly soon (e. g. 10 to 15 seconds) after the mains supply is interrupted, and again soon before the switch 22 restores the mains supply. The processing unit 26 compares the measured current value at these two instants, to initiate an alarm (e. g. a sound emitter or light emitter) if the two values differ by more than a predetermined amount, e. g. if the current value falls significantly, indicating a defective battery or a current leakage. The processing unit 26 also initiates the alarm if no current flow, or a current flow less than a predetermined value, is detected, indicating a defective emergency light or failure of the

emergency lighting unit to switch in its battery supply.

The test period (duration for which the mains supply is interrupted) may be of present duration according to local or national standards: typically the test period may be 10 minutes, but 180 minutes every 12 months and 60 minutes every intervening 6 months.

The testing unit further includes a light sensor 28 to receive light from the emergency light 12, when energised. The processing unit 26 is arranged to initiate an alarm if the light sensed by the sensor 28 is below a predetermined intensity.

The testing unit T includes a set of three LED indicator lights R, Y, G (red, yellow and green), which indicate that the emergency light unit has passed its latest test and further indicate the number of successive tests which have been passed. This indication is given for 3 seconds every minute. The code is shown in Figure 3. Thus, after the test is passed at the end of one month from installation of the testing unit, its red LED will flash rapidly during the 3 second indication period: after the month 2 test is passed, the red LED will flash slowly during this period; after the month 3 test is passed, the red LED will remain on during the 3 second indication period. After the month 4 test is passed, the yellow LED will flash rapidly during the indication period: after the month 5 test is passed, both the red and yellow LEDs will flash rapidly during the indication period; after the month 6 test is passed, the red LED will flash rapidly and the yellow LED will flash slowly during this period. The combinations for the following months will be noted from Figure 3, up to the test in month 48 being passed, after which all LEDs will flash slowing and continually to indicate the end of the units cycle.

It will accordingly be appreciated that the condition of the emergency light may be ascertained, when required, by visual inspection of the front panel of the testing unit T.

After month 48, the internal battery of the testing unit T is replaced and the unit reset.

It will be noted that the testing unit which has been described effectively tests the operation of the emergency lighting unit E, the emergency light 12 itself, the operation of the battery charger of the emergency lighting unit, and also the condition of the battery.

It will further be noted that, because the testing unit includes its own battery source, it is not dependent on the voltage or frequency of the mains supply. Testing units in accordance with the invention can therefore be fitted locally to the respective emergency lighting units already existing in a building (one testing unit for each emergency lighting unit).

Claims

CLAIMS 1) A testing unit for installation to an emergency lighting unit which comprises a battery supply and means for detecting any interruption of the mains supply to connect the battery supply to an emergency light, the testing unit comprising means for periodically interrupting the mains supply to the emergency lighting unit, in automatic manner, and means for monitoring the current flowing from the battery supply of the emergency lighting unit and testing the value of said current.
2) A testing unit as claimed in claim 1, arranged to compare the values of said current at two different instants of time, following interruption of the mains supply and before restoring it, and to initiate an alarm if the current values at said two instants of time differ by more than a predetermined amount.
3) A testing unit as claimed in claim 1 or 2, arranged to initiate an alarm if said monitored current is below a predetermined value.
4) A testing unit as claimed in any preceding claim, further comprising a light sensor for receiving light from the emergency light, the testing unit being arranged to initiate an alarm if said light sensor receives light of less than a predetermined intensity.
5) A testing unit as claimed in any preceding claim, in which said current monitoring means is arranged to monitor the charging current flowing into said battery supply, between successive said interruptions of said mains supply.
6) A testing unit as claimed in any preceding claim, arranged to provide a visual indication if the monitored current value passed the preceding test.

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7) A testing unit as claimed in claim 6, arranged so that said visual indication also indicates the number of the preceding tests which have been passed in succession.
8) A testing unit as claimed in claim 7, comprising a number of indicator lights which are energised in accordance with a predetermined code to provide said visual indication of the number of the preceding tests which have been passed in succession.
9) A testing unit as claimed in claim 8, in which said indicator lights are arranged to flash periodically, the selected lights which flash and the rapidity at which the respective lights flash, each time, collectively indicating the number of preceding tests which have been passed in succession.
10) A testing unit for installation to an emergency lighting unit, the testing unit being substantially as herein described with reference to Figure 2 of the accompanying drawings.