Dock Traffic Light Systems for Loading Bays and Parkades

What a dock traffic light actually does

A dock traffic light is a red/green LED signal mounted at a loading bay door or parkade entry. Red tells the driver to stay clear; green means the door is fully open and the dock is clear to approach. The light replaces hand signals, radio chatter, and the guesswork that gets forklifts hit and trailers damaged.

Where they mount and why placement matters

The standard mounting point is the header above the overhead door, centered so the driver sees it in the side mirror on approach. In a parkade, the light sits at the entry portal, visible before the driver commits to the ramp.

Two-light sets — one inside, one outside — are the norm for loading docks. The interior unit faces the forklift operator; the exterior unit faces the truck driver. Both wire to the same controller so they never show conflicting signals.

Single units work for parkade entries where traffic flows one way at a time, or for drive-thru windows where the signal only needs to face the queue.

Power options: 120 VAC versus 24 VDC

Manaras-Opera supplies both voltages in the same housing profile.

120 VAC (TRAFFIC036A / TRAFFIC046A)

Wire it to the building lighting circuit or a dedicated receptacle at the header. No transformer needed. Draw is 0.10 A on the 036 series, 30 mA on the 046 series. Practical when you have power at the door and want the simplest install.

24 VDC (TRAFFIC037A / TRAFFIC047A)

Runs off the door operator’s low-voltage supply or a separate class-2 transformer. Draw is 0.13 A (037) or 70 mA (047). Choose this when the operator cabinet already has a 24 VDC bus, or when code requires low-voltage wiring at the dock face.

Both voltages use the same LED arrays. Brightness does not change with input voltage.

Housing series: 036/037 versus 046/047

Feature	036/037 series	046/047 series
Lens diameter	4.25 in	3.75 in
Overall dimensions	6.5 × 11.5 × 3.75 in	5 × 10 × 2.5 in
Sun visor	Eyebrow style, deeper	Low-profile, ultra-bright LEDs
Conduit entry	Mounting holes only	Two knockouts for conduit
Housing	Single-piece polypropylene	Two-piece, UV-rated, weatherproof
Casing colours	Yellow or black	Yellow or black
Operating range	-29 °C to 54 °C	-29 °C to 54 °C
Rating	IP54, cULus	IP54, cULus
LED warranty	3-year limited	3-year limited

The 046/047 series is shallower — 2.5 in versus 3.75 in — so it clears tighter header spaces and takes less impact risk from high loads. Its knockouts make conduit runs cleaner. The 036/037 series has a larger lens and deeper visor, which some operators prefer for long straight approaches where glare is the main enemy.

Wiring into the door control circuit

The light does not decide when to change. The door operator or a separate controller does that.

Typical logic:

• Door fully open limit switch made → green
• Door not at open limit (moving, closed, or faulted) → red
• Optional: photo-eye or loop detector confirms dock clear before green

On a Manaras OPH/OMH jackshaft or LiftMaster MAXUM operator, the open-limit contact is a dry pair in the control box. Run 18/2 from there to the traffic light’s control input. If the operator lacks a spare contact, add a 24 VDC relay coil across the motor run winding — but only if you know the schematic. Wrong tap and you back-feed the logic board.

For parkades, the signal often ties to the gate controller’s “gate open” output. Same principle: the light follows the authority that owns the clearance decision.

Environmental reality in the Lower Mainland

Rain, salt air, and the occasional forklift tap are the real test.

• IP54 means water splashing from any direction won’t enter. It is not submersion rated. Mount the unit with the lens facing down or vertical — never up — so water sheds off the visor.
• Polypropylene casing (036/037) resists salt corrosion better than painted steel. The 046/047 two-piece housing uses a UV-stabilized polymer that holds colour through years of south-facing exposure.
• Temperature range (-29 °C to 54 °C) covers every Vancouver winter and rooftop summer. LEDs do not dim in cold; they actually run more efficiently.
• Shallow depth on the 046/047 (2.5 in) reduces the target profile. A forklift carrying a wide load clips the header first; a protruding light becomes the sacrificial part. Replacing a $200 light beats straightening a header.

Common miswires and how to avoid them

1. Powering the light from the motor circuit — motor start surge drops voltage, LEDs flicker, driver sees amber. Use a dedicated 120 VAC feed or the operator’s low-voltage bus.

2. Reversing red/green wires — green means go. If you wire it backwards, the driver sees green on a closed door. Label the tails at both ends.

3. No interlock — light shows green because the limit switch made, but the dock leveler is still deployed or a pedestrian gate is open. Wire the leveler stored limit and gate contact in series with the door open limit.

4. Single unit on a two-way dock — interior forklift operator sees red while the trucker sees green. Install the paired set.

Maintenance that actually gets done

• Quarterly: wipe the lens with a damp rag. Road film cuts output 30% in six months.
• Annually: verify red/green switch-over at the door open limit. Confirm the interlock chain (leveler, gate, door) still holds.
• After any impact: check housing cracks, conduit seal, and lens integrity. A hairline crack lets water into the LED board — corrosion kills it in one wet season.

When to replace versus repair

The LED arrays are not field-serviceable. If one colour fails, the unit is done. Three-year LED defect warranty covers premature failure; after that, replace the head. Wiring, conduit, and mounting hardware stay.

How to specify for a new dock or parkade

1. Count the approaches that need a signal (truck side, forklift side, parkade entry, exit).

2. Choose voltage based on available power at each header.

3. Pick housing series: 046/047 for tight headers or conduit runs; 036/037 for long approaches where larger lens helps.

4. Define the control logic — which limit switches, which interlocks — before the electrician prices the run.

5. Order paired sets for docks; singles for parkade entries.

Closing

A dock traffic light is the cheapest safety device on a loading bay. It prevents the confusion that bends roll-up doors, cracks dock levelers, and puts forklifts into trailers. Wire it to the door’s open limit, interlock the leveler, and wipe the lens once a quarter. That is the whole system.

INTERNAL_LINKS:

• [Loading dock door repair and maintenance] -> loading-dock-door-repair-vancouver
• [Commercial door safety devices explained] -> commercial-door-safety-devices-guide
• [Commercial garage door operators — types and specs] -> commercial-door-operators
• [Vehicle impact and structural repair for docks] -> vehicle-impact-garage-door-repair-insurance-claim

FACTS_USED:

• Manaras-Opera TRAFFIC036A/037A/046A/047A specifications (voltage, amperage, dimensions, temperature range, IP rating, warranty, housing materials, lens sizes, visor types, conduit knockouts, cULus listing) -> MANUFACTURER SPEC EXTRACTS
• CCGDS serves loading docks and parkade buildings -> Business focus
• CCGDS works with Manaras commercial operators -> Business focus

If the diagnosis points past what you can safely check yourself, Custom Commercial Garage Doors services this equipment across Metro Vancouver — call (604) 206-5727.