Testing & Troubleshooting Emergency Lighting
The same safety regulations that require the installation of Emergency Lighting also require regular testing of those lights, to insure that they will function in the case of an emergency involving loss of power. These test requirements include both monthly and annual tests. Emergency Lights are typically manufactured with integral test buttons, which interrupt power to the emergency light, to facilitate testing.
Records must be kept of your testing program, testing dates and test results for all emergency lights in your facility.
The monthly test consists of:
- Press & hold the test button for 30 seconds, verifying the lamps turn on
- Visually check each light for physical damage
- Check alignment of beams and readjust if necessary
- Verify that there is live AC power connected to the lamp
- Charge battery if necessary
In addition to the items on the monthly checklist, the annual test consists of:
- Check battery and connections for corrosion
- Disconnect battery; verify voltage levels of battery and charging circuit
- Adjust lamp beam alignment
- Clean unit and lamp lenses
- 90 minute power disconnect, to verify that the lamp stays illuminated for that length of time
All emergency lights feature a simple push button for easy testing of the battery backup system. OSHA requries monthly and yearly tests.
Troubleshooting Inoperative Emergency Lights:
If, in the course of your testing, you find an emergency lamp that doesn’t function, these are the steps to determine which component of the unit is non-functional. You will need a standard multi-meter and a screwdriver to compete these steps. One minor note for those who have never used a multi-meter. You must touch the leads of the meter to the metal contacts, touching connector bodies or the wire’s insulating covering won’t tell you anything.
- If your light works properly, except that the lamps do not stay illuminated for the full 90 minutes of your annual test, your battery is bad and needs to be replaced.
- If only one bulb on a two-bulb unit is not lighting, the unit is probably fine and the problem is with the bulb.
- First verify that the non-working bulb is mounted all the way into the socket
- Verify that the contacts on the bulb are not corroded and that the socket is not corroded. If they are corroded, you can clean light corrosion off of contacts with an ordinary pencil eraser. Heavy corrosion requires cleaning with a stiff nylon brush. Do not use a metal wire brush, as it can short out the contacts.
- Bulbs can be tested with the multi-meter on an ohms scale. Touch the two leads to the contacts on the bulb (on some bulbs, where there is only one contact at the bottom, the metal outside of the base is the other contact). A good bulb should read about 0 ohms; a defective one will read infinite ohms.
- Check voltage to the bulb with the multi-meter on a low DC voltage scale. Touch the two leads to the contacts in the socket and read the voltage on the meter. This reading should approximately equal the voltage rating of the battery; 6 VDC, 12 VDC or 24 VDC.
- If neither bulb lights, the problem is probably internal to the unit. Open the case and disconnect the battery. Set the multi-meter to DC voltage and check the voltage at the two wires or contacts that connect to the battery.
- If you have voltage here, but the bulbs don’t light, check the bulbs, as mentioned above.
- If the bulbs are good, check the wiring to the bulbs, and voltage at the sockets.
- If your voltage is good at the bulb sockets, your battery is probably bad, replace it.
- If you don’t have voltage at the battery leads, you need to check the transformer. To check the transformer, set the multi-meter to the lowest AC voltage scale that the meter has. Touch the leads of the meter to the connections where the two leads of the transformer connect to the circuit card. Your voltage reading should be approximately that of the battery rating.
- If you have voltage here, then your circuit board is bad.
- If you don’t have voltage here, you need to check the AC power coming into the unit.
- The AC power should connect only to the transformer. It is probably connected by wire nuts, so you will need to carefully remove them, keeping in mind that you are now working with a live 120 volt circuit. Don’t shock yourself! Change the range on your multi-meter to a higher AC voltage, at least 120 volts. Touch the two leads of the power wire entering the unit.
- If you have voltage here, but didn’t have it at where the wires from the transformer connected to the circuit board, your transformer is bad.
- If you don’t have voltage here, there’s nothing wrong with your emergency light. Verify that the circuit breaker supplying power to the light is turned on. If it is, call an electrician.
By Evan Delaporte+