Portfolio Lighting Model 999928302: Transformer Specs, Wiring, and Setup Guide

What Is the Portfolio 999928302 Transformer?

The Portfolio 999928302 is a current-generation multi-tap digital landscape lighting transformer — the model that represents the upgrade path from older Portfolio EE-series, SL-series, and magnetic-core transformers. It is referenced in the Portfolio transformer master guide as a recommended modern replacement for aging Portfolio equipment. Homeowners searching this model number are typically either troubleshooting a recently purchased unit or researching it as a replacement for a failing older transformer.

The 999928302 incorporates a toroidal core design that improves efficiency and reduces acoustic hum compared to older E-I core magnetic transformers. It meets the Department of Energy mandatory efficiency requirements (Rating VI) that older Portfolio models do not meet. For the full comparison across Portfolio transformer generations see the transformer master guide. For sizing methodology see the transformer sizing guide.

Key Specifications

999928302 Wiring and Multi-Tap Setup

The 999928302 wiring follows the standard Portfolio multi-tap approach documented in the transformer wiring diagram guide. The full wiring methodology including hub vs T-wiring approaches is covered in the landscape lighting wiring guide.

Mounting and Primary Side Connection

Mount the 999928302 on an exterior wall within cord reach of an outdoor GFCI-protected outlet. Mount at least 12 inches above finished grade. Provide adequate ventilation clearance on all sides — the transformer housing warms during operation and requires airflow for heat dissipation. Full mounting requirements are in the transformer mounting code requirements guide. The GFCI outlet must comply with NEC 2026 Article 210.8 — see the outdoor GFCI requirements guide. For the licensing and permit context of outlet installation see the contractor licensing requirements guide.

Secondary Side — Low-Voltage Terminal Block

Open the housing to access the dual output terminal block. Strip 3/4 inch of insulation from each wire end. Insert firmly and tighten the terminal screw — the wire must not pull free. Connect separate lighting zones to separate terminal pairs. For zone planning strategy see the low-voltage zones guide and the system diagram. The landscape lighting connectors guide covers the connector types used to extend wire runs to individual fixtures.

Voltage Tap Selection

The dual tap allows selection of different output voltages to compensate for voltage drop on long wire runs. Use the voltage tap calculator and the voltage drop guide to determine the correct tap setting for each zone. The voltage drop calculator provides numerical verification. For wire gauge selection see the wire gauge guide and the wire gauge ampacity database.

999928302 Timer Programming

The 999928302 uses the standard Portfolio current-generation digital timer interface. The Portfolio low-voltage timer guide covers the full programming procedure. The landscape lighting timer settings guide covers scheduling strategy.

Setting the Clock and On/Off Times

1. After first power-on or after a power outage the display will show 12:00 or flash. Press clock-set and use navigation buttons to set current time. Confirm.
2. Press the on-time button. Set desired activation time. Confirm.
3. Press the off-time button. Set desired shutoff time. Confirm.

The photocell sensor prevents activation during daylight regardless of the timer setting. If the system is not activating at the correct time verify the photocell is not blocked and that the clock is correctly set. See the photocell troubleshooting guide and the Portfolio photocell guide for photocell-specific diagnosis.

999928302 Troubleshooting

Start with the Portfolio transformer troubleshooting guide for the full diagnostic sequence.

System Not Activating

Verify the GFCI outlet has not tripped. Verify photocell is not obstructed. Verify clock and on-time are correctly set. Switch to manual mode to test transformer output independently. See the transformer not working guide and the transformer not powering lights guide.

System Activates Then Shuts Off

Thermal protection cycling indicates overheating from excess load or poor ventilation. Calculate total fixture wattage vs rated capacity. Verify ventilation clearance. See the transformer getting hot guide and the transformer reset guide.

Transformer Buzzing

The 999928302 toroidal core produces less hum than older magnetic transformers. Noticeable buzzing typically indicates a loose internal mounting or a connected load creating harmonic feedback. See the landscape transformer buzzing guide.

Lights Dim at End of Long Runs

Adjust voltage tap to a higher setting. Verify wire gauge using the wire gauge database. Check the Portfolio lighting too dim guide.

Why the 999928302 Is the Right Upgrade From Older Portfolio Transformers

The 999928302 improves on older Portfolio models in three meaningful ways. The toroidal core design reduces heat and improves efficiency — more power reaches fixtures. DOE Rating VI compliance means lower standby consumption. And the improved driver design works better with modern LED fixtures that have different load characteristics than the halogen fixtures older transformers were designed around.

Existing low-voltage wire runs, connectors, and fixtures connect directly to the 999928302 output terminals without modification — only the transformer is replaced. The transformer replacement guide covers the step-by-step replacement procedure. The transformer alternatives guide covers the full landscape of current replacement options. For smart control integration see the AI outdoor lighting guide and the legacy transformer retrofitting guide.