LD Series

LD provides two specified arrow modes within one 12-inch module. The catalog identifies Yellow/Green and Yellow/Yellow configurations, rather than arbitrary red/yellow/green combinations. TSL-12BM-LD-A1 is the Yellow/Green model; TSL-12YYBM-LD-A1 is the Yellow/Yellow model. Specify the exact indication combination and orientation in the signal plan instead of ordering a generic two-color arrow.

Specifications & documents
LD Series 12” Yellow Green & Yellow Yellow Arrows Traffic Signal Spec Sheet · LD Series Traffic Signal Module – Bi-Modal Arrow

Both listed LD models operate at 80–135Vac. The Yellow/Green table lists 7W for yellow and 6.2W for green; the Yellow/Yellow model lists 6.2W for each mode. Use the actual energized mode and operating duration for energy calculations. Do not add every mode as if continuously illuminated, and do not extend DC ratings from IL6-P3 to this separate LD order table.

Specifications & documents
LD Series 12” Yellow Green & Yellow Yellow Arrows Traffic Signal Spec Sheet

A bi-modal face may suit a specifically designed signal arrangement, but it is not an automatic two-face consolidation. LD changes how the indications are presented within a 12-inch opening, while controller outputs, wiring, arrow orientation and the approved signal sequence still have to match. Keep the indication and circuit drawing with the exact LD model; approval of another arrow module does not approve the revised arrangement.

Specifications & documents
LD Series 12” Yellow Green & Yellow Yellow Arrows Traffic Signal Spec Sheet

Further reading
Traffic Signal Approval: ITE, ETL and DOT Lists

The LD sheet identifies a fail-state impedance design, alongside constant-current output. It does not publish a universal compatibility result for every cabinet or monitor. Compare the ordered model and the manufacturer’s installation/wiring information with the actual cabinet acceptance procedure. Verify the energized, de-energized and monitored states without treating the feature name as proof that an existing monitoring threshold is correct.

Specifications & documents
LD Series 12” Yellow Green & Yellow Yellow Arrows Traffic Signal Spec Sheet

The published LD table gives response under 75ms and turn-off voltage above 35Vac, with THD below 20%. During the agency’s test, record the commanded modes, transitions, off-state behavior and monitor response for the actual circuit. Retain the accepted model and orientation so future replacements reproduce the same indication. Those module characteristics should be checked against the controller implementation, not used to invent a new timing sequence.

Specifications & documents
LD Series 12” Yellow Green & Yellow Yellow Arrows Traffic Signal Spec Sheet

LD uses complete O-ring sealing, a hard-coated UV-stabilized polycarbonate lens and a constant-current source. The published operating range is −40°C to +74°C. Maintain the complete housing seal and installed termination according to the installation information. A weather-resistant module does not make an incorrectly sealed signal head or damaged cable entry weatherproof.

Specifications & documents
LD Series 12” Yellow Green & Yellow Yellow Arrows Traffic Signal Spec Sheet

The LD sheet lists a five-year limited warranty and 70% initial intensity after 100,000 operating hours. The latter is a light-output claim, not a 100,000-hour full-system warranty or a guaranteed maintenance-free interval. Keep warranty terms, failure records and maintenance costs separate in lifecycle comparisons, especially where field visits and traffic control cost more than the module itself.

Specifications & documents
LD Series 12” Yellow Green & Yellow Yellow Arrows Traffic Signal Spec Sheet

Further reading
Long-Life LED Traffic Signals: Replacement Cost and ROI

Identify Yellow/Green versus Yellow/Yellow, exact model, orientation, 12-inch housing, 80–135Vac circuit and termination. The LD table lists ITE 2007 for the Yellow/Green entry and a different FHWA reference for Yellow/Yellow; retain the matching approval evidence. A common shelf label such as “12-inch arrow” omits the details that distinguish a correct bi-modal replacement.

Specifications & documents
LD Series 12” Yellow Green & Yellow Yellow Arrows Traffic Signal Spec Sheet · LD Series Traffic Signal Module – Bi-Modal Arrow

Further reading
Traffic Signal Approval: ITE, ETL and DOT Lists