Restaurant Lighting Systems That Support Dining Experience and Operational Flow

When is a slip fitter the correct mount choice for an area light?

Choose a slip fitter when the fixture is intended to sit on top of a pole (tenon/top-of-pole interface) and the site needs predictable area distribution with minimal aiming. Slip fitters work best when the pole top diameter matches the fixture’s fitter range and the application does not require aggressive tilt to reach the target plane.

What field measurements should be confirmed before specifying a slip fitter?

Confirm the pole top outside diameter (OD), the tenon configuration (if present), and whether the pole is round or square with an adapter. Also verify the fixture’s fitter clamp range and the allowable tilt adjustment. A slip fitter that “almost fits” typically results in loose clamping, rotation, or premature mechanical wear.

What are the most common slip fitter installation failures?

The most common issues are incorrect pole top diameter, insufficient clamp engagement, and excessive tilt used to compensate for the wrong optic distribution. Over-tilting an area light can increase glare, raise uplight, and reduce uniformity at the far side of the coverage area.

When is a trunnion mount the better option than a slip fitter?

Use a trunnion when the lighting intent is directional and the fixture must be aimed—such as perimeter coverage, wall-to-yard throws, loading zones, or sign illumination. Trunnions are designed for surface mounting and controlled tilt, which is not the core strength of a top-mounted slip fitter.

What is the main mechanical advantage of a trunnion mount?

A trunnion provides a defined pivot point and locking hardware to hold an aiming angle against wind and vibration loads. This makes it suitable for flood-style distributions where the fixture must maintain its aim over time instead of relying on a limited-slip fitter adjustment.

When should an arm mount be specified instead of top-of-pole mounting?

Specify an arm mount when the fixture needs offset geometry to move the luminous center away from the pole, improve spacing, or control where the peak intensity lands on the pavement. Arm mounts are common for parking lots and roadways where the distribution must project forward rather than radiate symmetrically from the pole centerline.

How does mounting height affect mount selection and aiming tolerance?

As mounting height increases, small aiming errors translate into large shifts in where light lands at the task plane. At higher heights, mounts that hold aim reliably and maintain fixture alignment under wind load become more critical. If a site requires tilt to reach the design area, the mount and optic selection must be evaluated together.

How do round vs. square poles change compatibility for these mounts?

Slip fitters and arms are commonly designed around round pole interfaces, while square poles often require adapters or specific bracket patterns. The critical check is not the pole shape alone but the interface dimensions and the bolt/tenon geometry needed to prevent rotation and maintain a fixed aiming reference.

Do these mounts change photometric results, or only how the fixture attaches?

They can change results. A mount that shifts the fixture position (arm offset) or requires tilt changes the distribution relative to the site geometry. If a mount change alters height, setback, or aiming angle, photometrics should be re-run using the as-installed mounting condition.

When should a mounting change trigger a re-run of the photometric plan?

Re-run photometrics if the mount changes the fixture’s setback from the pole, the aiming angle, the mounting height, or the fixture orientation (for example, rotating a Type III distribution off the intended direction). Small geometry changes can materially affect minimum foot-candles and uniformity at edges and corners.

What site conditions most often force a trunnion mount in the field?

Trunnions are frequently used when the installation surface is a wall, parapet, canopy fascia, or a non-standard pole condition that prevents a correct top-of-pole interface. They are also common when the project requires aimable light to avoid spill into adjacent properties or to keep intensity off building elevations.

What is the most common mistake when using an arm mount on parking lots?

The common error is selecting an arm length or orientation that does not match the optic distribution, causing light to peak too close to the pole or overshoot into unwanted zones. Arm offset, distribution type, and pole spacing must be coordinated; otherwise, uniformity degrades and glare complaints increase.