HLG-240H A, B or AB? Specify Dimming Before Ordering
Your project calls for a 24 V LED supply, and the lighting schedule says the brightness must change. That is not enough to order an HLG-240H. The last letters of the MEAN WELL part number decide whether someone adjusts the output at the driver, an external control signal changes the light level, or both. Agree on that control method before a contractor orders dozens of supplies.
The choice in one minute
For the HLG-240H series, A has internal voltage and current adjustment; B accepts an external three-way dimming input; AB has both. MEAN WELL lists A and AB as IP65, and B as IP67. Those are ratings of the driver enclosure, not a promise that the complete installation is weatherproof. The blank suffix has fixed output and no external dimming input. This comparison applies to HLG-240H: another HLG wattage may have different adjustment details.
If the brief says “set it once during installation,” ask what voltage or current setting actually needs changing and whether an A model is appropriate. If a wall control or automation system must change brightness during use, first check the signal it delivers and whether a B or AB model fits. Do not buy B simply because the word “dimmable” appears in the catalogue.
What the external input actually expects
On HLG-240H B and AB, the manufacturer's three-in-one input uses either 1–10 V DC, a 10 V PWM signal, or resistance between the dedicated DIM+ and DIM− wires. PWM here is the low-voltage control signal into the driver, not a licence to connect a strip controller's LED output to those wires. The datasheet describes adjustment of output current level; it does not by itself prove that every 24 V strip and controller combination will dim as the designer expects. Ask for a test using the intended load and control device.
The manufacturer's dimming graph begins at roughly 10% output at a 1 V input. A project that needs a definite “off” state should specify how mains power is switched and verify that behaviour in the sample. Do not assume that the dimming input alone turns the lighting fully off. The datasheet also warns against connecting DIM− directly to the driver's −V output; the wiring detail belongs in the electrician's approved drawing.
What belongs on a repeat-order specification
Write down the full output version, not just “HLG 240 W.” MEAN WELL publishes a 24 V member of this series, but the exact output load, cable length, mounting position, AC supply, control signal and destination market still matter. A and AB have internal trim access and IP65 on the datasheet; B's IP67 marking does not make an exposed splice or control cable weatherproof. If the driver sits outdoors, include the location and connection method in the quotation request.
For a repeat order, test one driver with the actual light and intended control. Record the full suffix on its label, the control wiring, the lowest useful light level and the off behaviour. This gives every installation team the same reference and catches a wrong suffix before the whole batch arrives.
Ask LIKELIGHT for an exact-version quote
See the LIKELIGHT HLG driver family. Send the light's 24 V load and total quantity, the control device or signal, and a photo or drawing of the driver location. Ask LIKELIGHT to identify the complete HLG-240H part number available for quotation, the applicable manufacturer datasheet and a representative compatibility test. Availability, approvals and delivery terms must be confirmed for that exact version.
