What does hard wired mean? Hardwired exit signs means they are physically connected into your buildings electrical power supply. There is no plug to plug into an outlet. A certified electrician can wire the exit sign and determine what voltage to use, either 120 or 277 volts. This will depend on the voltage coming into the building. LED hardwired exits signs use around four watts of power to operate. Exit Sign typical with have NiCad battery. The purpose of the battery is only to illuminate the exit sign for a minimum of 90 minutes. The battery is rechargeable and should last any where from 2-5 years. No hard-wired exit signs will operate on a battery solely. It is used a back up.
Corded exit signs are an option. They tend to have a10’ cord that plugs directly into a 120-volt outlet. They meet the same criteria as above. They have a 90 Minute battery back up and will recharge once plugged in. The corded exit signs are a simple option but in most cases it will VOID the UL listed warranty. Traditional they are meant to be hard wired. The other downside of the corded exit sign is that it can be accidently unplugged. It this happens the battery would not be fully recharged. In the event of an emergency the battery would be dead or not function at all.
Photoluminescent Exit Signs (Glow in the dark exit signs)
These require no AC power to operate. So how do they function? Glow in the Dark Exit Signs aka photoluminescent exit signs absorb ambient light. This can be light can be from anywhere in the building but it must be 5 ft. candles. Five-foot candles can be of fluorescent, LED 4000K or higher, metal halide or mercury vapor light to charge the material for a minimum of 60 minutes. Out door rated photoluminescent exit signs can be charged with sunlight, Glow in the Dark exit signs have a life span from 15-25 years. They do not need to be recycled at the end of their life span
Tritium self Luminous exit signs – (Nuclear Exit Signs)
Tritium exit signs illuminate with a low-level tritium isotope – They have a shelf life of 10 or 20 years. They require no maintenance and do not consume any electricity. All tritium signs are registered with the NRC. (Nuclear Regulatory Commission.) At the end of their lifespan they will need to be recycled
Both signs have pro and cons
Photo luminescent Exit Signs have a lower cost, non radioactive. Do not need to be recycled.