Connect the permanent AC supply first and route the hot conductor from the unswitched lighting circuit to the unit input. Most emergency egress indicators operate on 120 V or 277 V building power and require a constant feed so the internal battery remains charged. The neutral conductor returns directly to the fixture terminal, while the equipment ground attaches to the metal housing or marked grounding screw.
Battery backup modules inside these safety luminaires typically use sealed nickel-cadmium or lithium cells rated for about 90 minutes of illumination during a power outage. The charger circuit remains active whenever building power is present. A small push-button test switch interrupts the incoming line for a few seconds and forces the unit to run from the battery pack, allowing quick verification during routine inspections.
During installation, confirm conductor identification before connecting leads inside the canopy or junction box. Black or brown usually carries line voltage, white or gray returns neutral, and green or bare copper bonds the metal body. Many modern egress indicators include quick-connect terminals or color-coded leads that match the branch circuit conductors. Secure the housing to the wall or ceiling box, tuck the cable splices neatly inside, and check that the illumination panel lights after power restoration.
Exit Sign Wiring Diagram With Battery Backup and AC Power Connection Layout
Connect the permanent branch circuit first. Route an unswitched 120 V or 277 V line conductor from the lighting circuit into the emergency egress indicator housing and terminate it at the marked input lead. Attach the neutral conductor to the return terminal and bond the green or bare copper grounding conductor to the metal chassis. Continuous supply keeps the internal charger active.
Most illuminated egress panels contain a compact battery pack rated for about 3.6 V to 9.6 V depending on the LED driver design. Nickel-cadmium or lithium cells remain on charge while building power is present. During a blackout, the control module automatically switches to stored energy and powers the LED array for roughly 90 minutes, matching typical safety code requirements.
AC Supply and Internal Power Routing
Inside the fixture body, the incoming hot lead connects to the charger board. From that board, low-voltage conductors feed the battery pack and LED driver module. Neutral connects directly to the charger circuit. Many units use quick push-in terminals or color-coded leads such as black for line voltage, white for neutral, and green for grounding.
Install the unit on a standard junction box mounted in the wall or ceiling grid. Leave about 15–20 cm of conductor length inside the box so splices remain accessible. Secure connections with approved wire connectors, fold the cables toward the back of the box, and attach the canopy plate using the supplied mounting screws.
Battery Backup and Test Circuit Connection
A small test push button interrupts the incoming line conductor through the control board. Pressing this switch temporarily removes building power from the charger circuit, forcing the fixture to operate on the battery pack. The illumination panel should remain lit during this test. If the light dims immediately, the battery module may require replacement.
Many installations include a pilot LED that shows charging status. A steady indicator means the charger circuit is active. Flashing patterns often signal battery faults or disconnected cells. Check the manufacturer wiring layout printed inside the housing door for the exact meaning of each indicator code.
After completing conductor connections, restore the breaker and verify operation. The panel should illuminate within a few seconds while the charge indicator activates. Press the test switch for at least 30 seconds and confirm that the illumination continues without AC supply.
How to Connect Line Neutral and Ground Wires in an Exit Sign
Turn off the branch circuit breaker and verify zero voltage with a multimeter before touching any conductors. Emergency egress indicators normally connect to an unswitched lighting circuit rated at 120 V or 277 V so the internal charger receives constant power.
Identify the three conductors entering the junction box. Standard color coding in many buildings follows this pattern:
- Black or brown – live conductor carrying building voltage
- White or gray – neutral return path
- Green or bare copper – equipment grounding conductor
Attach the live conductor from the building circuit to the fixture input lead marked for AC supply. Use an approved twist connector or push-in terminal supplied with the unit. Leave about 10–15 cm of conductor length so the housing can be removed later for inspection or battery service.
Connect the neutral conductor directly to the return lead from the illumination panel and charger board. The connection normally sits inside the canopy or mounting plate. Many fixtures provide color-matched leads:
- Black fixture lead joins the building live conductor
- White fixture lead joins the neutral conductor
- Green lead attaches to the grounding screw on the metal frame
Secure the grounding conductor tightly under the marked ground screw or bonding clip inside the metal housing. This bond directs fault current safely to the panel and reduces shock risk if insulation fails inside the luminaire.