"Full cutoff" is a photometric classification, not a housing shape. Two fixtures can look nearly identical on the wall and fall into different cutoff classes, because the class is set by how much light the fixture throws at and above the horizontal in a photometric test, not by how flat the housing looks. That distinction decides whether an install passes when a municipality, a property manager, or a neighboring landowner is the one signing off. This guide covers how to spec LED wall pack lighting the way a distributor does it: cutoff class first, then lumens, then mounting height, then controls.
What cutoff class actually measures
The Illuminating Engineering Society's cutoff classifications describe one thing: the share of a fixture's lumens emitted at or above two angles, 80° and 90° measured from straight down. 90° is the horizontal plane, so anything at or above it travels sideways and up, off the property and into the sky. The band between 80° and 90° is where most glare complaints come from, because that light arrives near eye level for anyone looking toward the building.
The four classic classes:
- Full cutoff: no light at or above 90°, and no more than 10 percent of lumens at or above 80°. This is the class most dark-sky ordinances name by wording.
- Cutoff: no more than 2.5 percent at or above 90°, no more than 10 percent at or above 80°.
- Semi-cutoff: no more than 5 percent at or above 90°, no more than 20 percent at or above 80°.
- Non-cutoff: no limit at either angle.
The IES has since replaced these four labels with the BUG rating (Backlight, Uplight, Glare), which scores the three separately instead of collapsing them into one word. Both systems are in circulation: newer ordinances cite BUG, older ones still say "full cutoff." Find out which your jurisdiction uses before you spec, because a fixture can satisfy one and miss the other.
Full cutoff vs semi-cutoff: what changes on the ground
Semi-cutoff allows a controlled amount of light above 80°, which is why a semi-cutoff fixture still lights the wall itself and throws out along the building face. That is what you want when the wall is the target: a loading dock face, a corridor between two buildings, a stairwell entrance where a lit wall surface reads as safer than a pool of light on the ground.
Full cutoff pushes everything down. It is the right call at a property line, next to a residential neighbor, or anywhere uplight is restricted outright. The tradeoff is that the wall above the fixture goes dark, and you may need tighter spacing to cover the same ground area.
NemaLED's Semi-Cutoff Wall Pack is classified by name and spec'd with a 55° by 105° beam, so it throws long along the wall rather than wide in every direction. The Traditional Slim Wall Pack is spec'd by viewing angle instead, at 110°, in a housing 2.2 in. deep. A low-profile housing is not automatically full cutoff, and this one carries no printed cutoff classification, so if an ordinance names full cutoff specifically, ask for the photometric file and confirm the classification rather than inferring it from the shape.
Sizing LED wall packs by wattage and lumens
Wattage is purchasing shorthand. Lumens are what lights the dock. Both fixtures publish the pairing on their own spec sheet:
- Semi-Cutoff Wall Pack: 28 W at 3,640 lm, 40 W at 5,200 lm, 60 W at 7,800 lm, 80 W at 10,400 lm, plus a field-selectable 75/60/45 W version at 9,750/7,800/5,850 lm. That works out to a flat 130 lm/W across the range.
- Traditional Slim Wall Pack: 20 W at 2,400 lm through 150 W at 18,000 lm in seven steps, with three field-selectable versions (60/40/20 W, 120/100/80 W, 150/120/100 W). A flat 120 lm/W across the range.
The selectable versions are worth a line on the spec. One part number covers three wattages set at install, which means a single SKU for a site with mixed conditions and headroom to dial output down later if a neighbor complains, or up if the lot gets extended.
Color rendering differs: CRI above 70 on the Semi-Cutoff, above 80 on the Traditional Slim. Both ship at 5000K, and both offer a selectable version covering 3000K, 4000K, and 5000K when a site standard calls for something warmer.
Mounting height and how much output you actually need
Wall packs typically mount between 8 and 20 ft, and the mounting height drives the wattage far more than the building's size does. A single man-door entry at 8 to 10 ft is usually served at the low end of either range. A loading dock face at 14 to 20 ft that also has to light the truck approach is where the higher wattages start to earn their cost.
Two things catch people here. First, a wall pack lights a fan-shaped area in front of the wall, not a circle, so the overlap between two fixtures depends on beam spread and wall length rather than a simple radius. Second, the target light level on the pavement is usually set by an insurer, a municipal bylaw, or a customer standard, not by preference. If the site is bigger than a couple of doors, send the dimensions through the photometric layout request and get fixture count and spacing calculated against the actual building instead of estimated.
Controls: photocell, sensor, and emergency backup
Three options show up on almost every wall pack quote, and each one changes the part number.
Photocell. Dusk-to-dawn switching without a time clock or contactor. The Semi-Cutoff takes a built-in 12 V DC or external 120 V AC photocell; the Traditional Slim offers an on/off photocell.
Occupancy sensing. Both offer a built-in microwave sensor option, holding the fixture low and bringing it to full when something moves. On a perimeter that runs all night, that is where the energy savings come from, more than the wattage step itself.
Emergency backup. Both offer an emergency battery backup kit. If the wall pack is part of the egress path, confirm it early: it is a factory option, not a field add-on.
Both fixtures run AC120-277 V standard with AC120-347 V available, dim on 0-10 V, hold a power factor above 0.9, and are rated for a -30°C to 50°C ambient, which covers a Canadian exterior wall at the cold end. Both are listed by Intertek and carry a 5-year warranty. Neither spec sheet prints an IP number: both are marked suitable for wet location and dustproof, and wet location is the listing that governs an exterior wall mount.
When a wall pack is the wrong fixture
The area is classified. A wall pack is a general commercial fixture. If the wall sits inside or on the boundary of a classified area, a fuel island, a solvent storage bay, any Class I or Class II zone on the area-classification drawing, a standard wall pack is not code-legal there regardless of how well it is sealed. That is a hazardous location lighting selection, made against the printed Class and Division on the drawing, not a sealing question.
The target is pavement, not a wall. Once the area you need lit extends well past the apron in front of the building, a wall pack runs out of throw and a pole-mounted area light does the job better. The LED Area Light 8th Gen covers 100 W at 13,000 lm through 300 W at 39,000 lm with interchangeable Type II, III, IV, and V distributions, so the pattern gets matched to the lot rather than the wall. Type IV is the forward-throw distribution normally used where a pole sits close to the building. The rest of the commercial lighting line, canopy fixtures, vapor lights, and area lights, covers what a wall pack does not.
A short spec checklist
Before requesting a quote on LED wall pack lighting, have these five ready:
- Mounting height at the wall, and how far out from the wall you need lit.
- Cutoff requirement, if any: whether the jurisdiction names full cutoff, a BUG rating, or nothing at all.
- Target light level or wattage, with the surface it applies to (dock apron, entry, walkway).
- Controls: photocell, occupancy sensor, emergency backup, dimming, or a combination.
- Classification, if the wall borders a classified area on the drawing.
Send those five through the quote request and we'll come back with a fixture and a part number rather than a category.
Common questions
What is the difference between a full cutoff and a semi-cutoff wall pack? Cutoff class describes how much light a fixture emits at and above the horizontal. Full cutoff means zero lumens at or above 90° and no more than 10 percent at or above 80°. Semi-cutoff allows up to 5 percent at or above 90° and up to 20 percent at or above 80°. In practice, full cutoff sends everything down and leaves the wall above the fixture dark, while semi-cutoff still lights the wall face and throws further along the building.
How many watts does an LED wall pack need to be? It depends on mounting height and how far out from the wall you need light, not on the size of the building. A single entry door at 8 to 10 ft is usually served at the low end of the range; a loading dock face at 14 to 20 ft that also lights the truck approach needs considerably more output. Check the wattage against the target light level for that surface rather than picking a number by habit.
Do LED wall packs meet dark-sky requirements? Only if the specific fixture's photometric classification matches what the ordinance names, and ordinances differ. Older ones name the IES cutoff classes; newer ones name a BUG rating. A slim or flat housing is not proof of either. Ask for the photometric file and check it against the wording of the bylaw before ordering.
Can I use a wall pack in a hazardous location? Not a standard commercial one. If the wall sits inside or at the boundary of an area classified on your drawing, the fixture has to carry the matching certification for that Class and Division. Substituting a standard wall pack is a code problem, not a durability one, no matter how well sealed it is.
What does "wet location" mean on a wall pack spec sheet? It means the fixture is listed for locations where water can strike it directly or run down it, the normal condition for an exterior wall mount. It is a listing category, not an IP number, and the two are not interchangeable. If your specification calls for a particular IP rating, ask for it explicitly rather than assuming a wet-location listing covers it.
Is a photocell or an occupancy sensor the better option? They solve different problems and are often ordered together. A photocell handles on and off with daylight, so nobody maintains a time clock as the seasons shift. An occupancy sensor handles the hours the fixture is already on, holding output low until something moves.
Sources: Illuminating Engineering Society cutoff classifications and the TM-15 BUG rating system; NemaLED spec sheets for the fixtures referenced above.
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