A fluorescent light ballast regulates the flow of electrical current, preventing it from rising to destructive levels once the lamp ignites. Fluorescent lamps have a negative resistance characteristic, meaning current increases uncontrollably without regulation. Ballasts are typically removed when they fail and need replacement, or when upgrading the fixture to modern, energy-efficient LED tube technology.
Essential Safety and Preparation
Work involving electrical components requires strict adherence to safety procedures. The process must always begin at the main electrical panel, where the circuit breaker supplying power to the fixture should be switched off entirely. Simply turning off the wall switch is inadequate because residual current may still be present in the fixture wiring.
After the breaker is secured, use a non-contact voltage tester to confirm that no electrical potential remains at the fixture terminals or supply wires. This mandatory check ensures the circuit is fully de-energized before physical contact. Gather necessary tools beforehand, including wire cutters, strippers, screwdrivers, and safety equipment like gloves and eye protection.
Physical Removal of the Ballast
Accessing the ballast requires removing the fluorescent tubes and any protective diffuser or lens covering the fixture interior. The ballast is typically housed within the metal channel, often secured beneath a separate cover plate. Removing this plate exposes the internal wiring compartment, revealing the ballast and its associated harness.
The ballast wiring harness includes input wires connecting to the main power supply and output wires connecting to the lamp holders (tombstones). Disconnecting these wires is the next step. This is done either by cutting them close to the ballast body or by releasing them from quick-connect terminals. Cutting the wires is the preferred method for a complete ballast bypass, as it leaves conductor length for subsequent modifications.
Once all electrical connections are severed, the ballast unit can be physically detached from the fixture chassis. Ballasts are commonly secured by mounting screws or a simple clip system. After removing the fasteners, the unit can be lifted out of the metal channel.
Handling the Wiring After Removal
After the ballast is extracted, the fixture’s internal wiring must be modified to accommodate the new lighting plan. If installing a replacement fluorescent ballast, connect the supply wires to the new unit following the provided diagram. The cut output wires should be stripped and connected to the corresponding lamp holder wires. Any unused wires must be individually capped with wire nuts and properly labeled.
Ballast Bypass for LED Tubes
A ballast bypass is a more complex modification that involves wiring the main line voltage directly to the lamp holders for use with direct-wire LED tubes. This requires determining the type of socket present: shunted or non-shunted. Shunted sockets, where the two contacts are electrically connected internally, are common in fixtures that used instant-start fluorescent ballasts.
Non-shunted sockets are necessary for many single-end powered LED tubes, as they require separate pathways for the line and neutral conductors. If the existing sockets are shunted, they must be replaced with non-shunted versions. Alternatively, a double-ended powered LED tube can be used, which typically accommodates either socket type. The final step involves splicing the fixture’s main power supply (line and neutral) to the wires leading to the appropriate lamp holders.
Proper Disposal of the Old Ballast
Disposing of the removed ballast unit requires attention to environmental regulations, especially for older models. Ballasts manufactured through 1979 may contain Polychlorinated Biphenyls (PCBs), which are toxic industrial chemicals. Any ballast without a clear “No PCBs” label, particularly if manufactured before 1978, must be handled as hazardous waste.
PCBs pose a hazard to the environment and human health, meaning these components should never be placed in standard household trash. The EPA requires that PCB-containing ballasts be disposed of according to specific federal regulations, often involving incineration at approved facilities. Modern electronic ballasts are typically PCB-free but still contain materials like heavy metals that should be recycled. Check with local municipal waste management or a specialized hazardous waste collection center for proper disposal.