PHOTOBIO CX 2125 LED 850W 100/277V S4 (10′ 277V L7-20P Cord)

The PHOTOBIO CX 2125 LED 850W 100/277V S4 is a compact, high-output full-spectrum LED top light designed for horticultural professionals. It delivers 2125 umol/s photon flux at 277V and 2.5 umol/J efficacy — making it a direct 1:1 replacement for 1000W DE HPS fixtures while drawing less power and generating less heat. This listing includes the 10-foot 277V L7-20P power cord.

PHOTOBIO CX 2125 LED Specifications

All values sourced from the PHOTOBIO CX 2125 100/277V S4 canonical product data and manufacturer documentation.

Specification	Value
Wattage	850W
Photon Flux (PPF) @ 277V	2125 umol/s
PPF (rated)	2087 umol/s
Efficacy	2.5 umol/J
Spectrum	S4 Full Spectrum (Osram/Seoul diodes; enhanced red, far-red, and blue)
Input Voltage	100–277V AC
Dimensions (L x W x H)	24.1 x 14.2 x 2.6 inches
Weight	22.7 lbs
Ingress Protection	IP66
Cooling	Passive heat-dissipating fins (fanless)
Power Cord (included)	10 ft, 277V, L7-20P plug
Control	iLOC push-button interface with digital screen; 0-10V dimming via PHOTO•LOC cable
Warranty	5 years
Supplier SKU	PTB8850LS44

Why Choose the PHOTOBIO CX 2125 LED

The CX 2125 is PHOTOBIO’s highest photon-output fixture. At 2125 umol/s photon flux (measured at 277V) and a 2.5 umol/J efficacy rating, it outperforms the 1000W DE HPS fixtures it replaces while drawing the same or less power. The efficiency gain translates to lower operating costs and reduced heat load in the grow room — two factors that matter when scaling to a commercial footprint.

The 2.6-inch slim vertical profile is a deliberate engineering choice. In rooms where vertical space is at a premium — stacked racks, low-ceiling warehouses, or multi-tier setups — a fixture under three inches tall recovers real estate that a full-size DE reflector would otherwise consume. Passive cooling fins remove heat without fans, which eliminates fan-noise, motor-failure risk, and another maintenance item from the checklist.

The iLOC (Integrated Light Output Control) push-button interface lets growers step photon output up or down at the fixture itself, with a digital screen confirming the active output level. When networked through the 0-10V PHOTO•LOC control cable, up to 500 fixtures can be managed per zone through compatible Autopilot PX Controllers — a practical ceiling for most large commercial operations. The S4 full-spectrum diode array (Osram and Seoul Semiconductor) is tuned with additional red, far-red, and blue energy to support both vegetative vigor and flower development across the full crop cycle. IP66 ingress protection means the fixture tolerates high-humidity grow environments and periodic washdowns without voiding the 5-year warranty.

This variant includes the 10-foot 277V L7-20P twist-lock cord, which is the appropriate power connection for 277V commercial branch circuits. Growers on 120V or with different plug configurations should verify their panel’s outlet standard before ordering.

Best Uses for the PHOTOBIO CX 2125 LED

Direct HPS replacement in established grow rooms. The CX 2125 occupies a footprint comparable to a standard 1000W DE HPS fixture, so operators can swap fixtures one-for-one without reconfiguring hangers, rails, or canopy spacing. Higher photon output per watt means the same electrical service delivers more light to the crop.

High-density commercial flowering rooms. The 850W power draw and passive cooling design work well in tightly packed flowering rooms where heat management is critical. No fan means no additional airflow load from the fixture itself, and the slim profile keeps the fixture well above the canopy even in rooms with eight-foot ceiling heights.

Multi-zone operations using centralized dimming control. Facilities running Autopilot PX Controllers can network up to 500 CX fixtures per zone and adjust output levels remotely via 0-10V signals. This setup suits operations that run multiple crop stages simultaneously and need to dial light levels per room without walking each fixture individually. For growers pairing this with a timer or environmental controller, also see the Gavita Pro 1700e LED as an alternative high-output LED option to compare specifications before committing to a fixture line.

PHOTOBIO CX 2125 vs 1000W DE HPS

The canonical comparison PHOTOBIO makes for the CX 2125 is a direct 1:1 replacement for 1000W double-ended HPS fixtures. The practical differences a grower will encounter are summarized below.

Output and efficacy. A typical 1000W DE HPS system produces photon flux in the range of 1,700–1,900 umol/s depending on the reflector and lamp condition. The CX 2125 delivers 2087–2125 umol/s at the same or lower wattage draw, at 2.5 umol/J — a meaningful gain in photons delivered per watt consumed.

Spectrum. DE HPS produces a broad yellow-orange spectrum with a characteristic sodium emission peak. The CX 2125 S4 spectrum uses Osram and Seoul Semiconductor diodes to provide a more balanced full-spectrum output with deliberate enhancement in red, far-red, and blue bands. Far-red in particular accelerates the shade-avoidance response and supports flower initiation under certain photoperiod protocols — a capability absent from standard HPS.

Heat and infrastructure. HPS fixtures generate substantial radiant and convective heat, requiring significant HVAC capacity and careful fixture height management. The CX 2125’s passive cooling fins dissipate operating heat without a fan, and the absence of radiant IR from the lamp reduces canopy-level heat stress. Growers transitioning from HPS typically find they can reduce HVAC load, though actual savings depend on room layout and climate systems.

Dimming and control. Most DE HPS ballasts offer limited dimming — typically 75% and 100% steps. The CX 2125 supports continuous 0-10V dimming via the PHOTO•LOC cable, which allows finer output adjustment across growth stages. For growers building a fully integrated lighting network, the Gavita Pro 1700e LED is a comparable large-commercial LED fixture worth reviewing for a side-by-side before purchase.

Compatibility

The CX 2125 operates on any voltage between 100V and 277V AC, making it compatible with both standard North American 120V household circuits and 208V/240V/277V commercial branch circuits. This listing ships with a 10-foot 277V L7-20P twist-lock plug — the standard commercial twist-lock configuration for 277V circuits. Growers on 120V or 208V should confirm plug type before ordering.

For network dimming, the fixture connects to a 0-10V control signal via the included 10-foot PHOTO•LOC control cable. The CX 2125 is compatible with Autopilot PX Controllers, supporting up to 500 fixtures per control zone. Any third-party 0-10V lighting controller with a compatible signal output can also drive the fixture, provided signal wiring is run correctly.

The IP66 ingress protection rating means the fixture is sealed against dust ingress and high-pressure water jets, making it suitable for greenhouse environments and rooms that undergo periodic pressure washing. Passive cooling requires no minimum airflow clearance for the cooling fins to function, though maintaining at least several inches of clearance above the fixture for ambient air circulation is advisable.

C clamps are included for hanging from standard overhead racking or bolt-down structures. Ratchet hangers or adjustable cables (sold separately) are commonly used alongside the C clamps to allow fixture height adjustment during the grow cycle. For propagation lighting that pairs with this fixture in a tiered setup, the T5 Designer 4ft 4-Tube Fixture with Bulbs is a common lower-intensity option for seedling and clone stages before transitioning to full LED top-light intensity.

Usage Guidelines

Mounting height and coverage. At 850W and 2125 umol/s, the CX 2125 is calibrated for high-intensity applications. PHOTOBIO publishes a photon distribution chart on their website; consult it to determine the appropriate hanging height and fixture spacing for your target PPFD. As a general reference, commercial single-canopy flowering rooms typically space high-output LED fixtures 12–18 inches above canopy and tile them to maintain uniform PPFD across the grow area, though the correct height depends on the specific PPFD targets and room dimensions.

iLOC dimming steps. The push-button iLOC interface steps output up or down in increments. The digital screen on the fixture confirms the current output level. During early vegetative stages or when introducing new cuttings to the room, dialing output down lets growers ramp light intensity gradually as the crop develops. This avoids photobleaching young tissue while still using the same fixture throughout the grow cycle.

0-10V network control. When using the PHOTO•LOC cable with an Autopilot PX Controller or compatible 0-10V controller, manual iLOC adjustments at the fixture are overridden by the network signal. Configure the controller schedule first, then confirm fixture response at the digital screen. Up to 500 fixtures can share a single control zone; for larger operations, use multiple zones and verify per-zone cable runs stay within the controller’s specified wire-length limits.

Photoperiod management. The far-red content of the S4 spectrum can interact with photoperiod-sensitive crops during light-off transitions. Growers running photoperiod-sensitive crops should consult PHOTOBIO’s published guidance on far-red and end-of-day protocols to ensure the lighting schedule does not inadvertently trigger early or late flowering.

How to Install the PHOTOBIO CX 2125 LED

1. Verify circuit compatibility. Confirm the branch circuit provides 277V AC and is fitted with an L7-20R receptacle to match the included L7-20P plug. Check that the circuit amperage is sufficient for the number of fixtures on the run (850W per fixture at 277V draws approximately 3.1A).
2. Attach C clamps. Thread the included C clamps onto the fixture’s hanging brackets. Tighten securely to the overhead structure — overhead rail, unistrut, or trellis netting support bar — ensuring the fixture is level and centered over the intended canopy area.
3. Set hanging height. Raise or lower the fixture to the target distance above canopy using ratchet hangers or adjustable cables. Refer to PHOTOBIO’s photon distribution data for the CX 2125 to select a starting height appropriate to your target PPFD.
4. Connect the power cord. Plug the 10-foot 277V L7-20P cord into the branch circuit receptacle. Ensure the twist-lock connection is fully seated and locked.
5. Connect the PHOTO•LOC control cable (if using network dimming). Run the included 10-foot 0-10V PHOTO•LOC cable from the fixture’s control port to the Autopilot PX Controller or 0-10V dimming controller. Daisy-chain additional fixtures in the zone if required, staying within the controller’s specified maximum cable run.
6. Power on and verify. Switch on the circuit and observe the digital iLOC screen on the fixture to confirm it is receiving power and displaying the output level. Adjust output via the iLOC push-button or through the network controller as needed.
7. Confirm output and monitor canopy response. Over the first several days, observe the canopy for signs of light stress (bleaching, leaf curl) or light deficiency. Adjust hanging height or output level as needed to reach target PPFD at the canopy surface.

Sources & Further Reading