# LED drivers explained: 120 V vs 240 V, real watts, and Mean Well vs Inventronics vs Sosen

> The LED driver decides how many watts reach the diodes. Most drivers are slightly less efficient at 120 V than 240 V (Mean Well HLG-600H about 94.7% vs 96.5%), derate at low input voltage and high temperature, and only give full power inside a set voltage or current window. In the founder's experience, many budget panels deliver about 80% of their advertised watts. Datasheets from Mean Well, Inventronics and Sosen show real trade-offs in efficiency, surge protection, life rating and warranty; no-name drivers can't be checked.

- Canonical: https://genetixbay.com/knowledge/equipment/led-drivers-explained.html
- Category: Equipment · Level: Intermediate
- Evidence: Supported · Status: Draft: awaiting expert review (some figures are being checked)
- Stage: Any stage · Systems: Any system
- Updated: 2026-11-01 · Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay Knowledge Base (genetixbay.com/knowledge)"

## Questions and answers

**Why does 120 V vs 240 V matter for an [LED](https://genetixbay.com/knowledge/glossary/led.md) driver?** LED drivers are usually specified at 230 VAC, and most run slightly less efficiently on 115–120 VAC. A Mean Well HLG-600H runs about 94.7% efficient at 115 V versus 96.5% at 230 V, and an XLG-320 about 92% versus 95%. Some drivers also cut their maximum load or ambient temperature rating at low input voltage. Read the efficiency curve and the static characteristic on the datasheet.

**How do I check how many watts my LED light really uses?** Plug the fixture into a plug-in power meter (or use a clamp meter on 240 V circuits), let it warm up 30 minutes at full power, and read the watts. Compare that with the advertised watts and the driver's rated output. GenetixBay's founder says many budget panels deliver only about 80% of their claimed wattage to the diodes once driver losses and limits are counted.

**Which LED driver brand is best for grow lights?** There's no single best. From their datasheets, Mean Well's HLG series has the highest published efficiency (about 94.7% at 115 V, 96.5% at 230 V) and UL type HL listings; Inventronics' EUD-600S has higher surge immunity (10 kV), a 90,000-hour life rating at 70 °C and a 7-year warranty; Sosen publishes 10 kV surge and 5-year warranties. A no-name driver with no datasheet can't be checked at all.

**Short answer, in plain words.** The driver is the box that feeds the LEDs. It decides how many watts actually reach the diodes, how long the light lasts, and how much of your wall power turns into wasted heat before it ever makes light. Most North American home growers run on 120 V, and most drivers are a little less efficient there than at 240 V. Read the driver's datasheet, not the light's box: in the founder's experience you often get only about 80% of the advertised watts once you do the math.

**The deeper version.** Mean Well's HLG-600H runs about 94.7% efficient at 115 V versus 96.5% at 230 V; the XLG-320 about 92% versus 95% [1][2]. Drivers also derate at low input voltage and high temperature, and constant-current or constant-power drivers only deliver their full rating inside a set voltage or current window [1][2]. The brand comparison below is from the makers' own datasheets.

> **Part of the series: LED grow lights, properly.** 1. [LED vs HPS: the heat and power-bill myth](https://genetixbay.com/knowledge/equipment/led-vs-hps-hype-and-buyer-beware.md) · 2. [Samsung LM301B vs LM301H, bins and fake chips](https://genetixbay.com/knowledge/equipment/led-buyer-beware-samsung-bins-fakes.md) · 3. [LED drivers explained](https://genetixbay.com/knowledge/equipment/led-drivers-explained.md) · 4. [How much grow light your space needs](https://genetixbay.com/knowledge/equipment/calc-lighting-sizing.md)

## Why are advertised watts not real watts?

**Founder's field experience:** advertised watts and real delivered power often differ; you typically get about **80%** of the claim once you do the math or read the driver datasheet's fine print [3]. Common forms: a model number that sounds like a wattage ("1000"), wattage quoted as "[HPS](https://genetixbay.com/knowledge/glossary/hps.md) equivalent", or the sum of the diodes' maximum ratings rather than what the driver delivers [3]. We found no public dataset measuring this across fixtures; the worked example below shows how to check your own.

## How do you read an LED driver datasheet?

The driver turns wall power into the DC power the diodes run on, and its datasheet tells you how much power the diodes can actually get. Read five things: the rated power and how the driver regulates (constant current, constant voltage or constant power), efficiency at **your** input voltage, the static characteristic (input-voltage derating), load versus temperature, and life expectancy. Mean Well's HLG and XLG series are good examples [1][2][4].

### Constant current, constant voltage, constant power

- **Constant current (CC):** the driver holds the current steady; power = string voltage × current. On an HLG-600H-48, the CC region runs 24–48 V at a rated 12.5 A [1]. If the diode string sits at 44 V, the diodes get **44 × 12.5 = 550 W**, not 600 W.
- **Constant voltage (CV):** the driver holds voltage steady, and the board's own circuitry sets the current. Common on boards with built-in resistors or secondary drivers [1].
- **Constant power:** the XLG-320-H delivers its full **312 W** only when the current sits in its "full power" window, **5.57–7.42 A**, which means a string voltage of about 42–56 V [2]. Below that window the current is capped at 7.42 A, so a 36 V string gets only **36 × 7.42 ≈ 267 W (86%)**.

### Efficiency depends on input voltage

Most North American home growers run their lights on 120 V household circuits, while driver datasheets are measured at **230 VAC** unless stated otherwise [1][2][4].

| Driver | Efficiency at 115–120 VAC | Efficiency at 230 VAC | Source |
|---|---|---|---|
| Mean Well HLG-600H-48 (full load, Tcase 80 °C) | about 94.7% (115 V curve) | about 96.5% (curve); 96% typ. in table | [1] |
| Mean Well XLG-320-L (full load, Tcase 85 °C) | about 92% (120 V curve) | about 95% (curve); 93.5–94.5% typ. in table | [2] |
| Mean Well HLG-480H | not tabled; see curve | 94–95% typ. | [4] |

Curve values are read from the published graphs and are approximate.

The difference is modest on a good driver: a 600 W HLG-600H load draws about 634 W at 115 V versus 622 W at 230 V, about **12 W (41 BTU/h)** more heat [5][1]. Budget drivers with no published curve may do worse (founder's field experience) [3].

**Chart: Driver efficiency at 120 V vs 230–240 V.** Every driver here is a little less efficient on 115–120 V than on 220–240 V: Mean Well HLG-600H about 94.7% vs 96.5%, XLG-320 about 92% vs 95%, Inventronics EUD-600S about 92% vs 94%, and Sosen's 200 W SS-200EP 88% vs 91%.

| Driver | 115–120 V (%) | 220–240 V (%) |
|---|---|---|
| Mean Well HLG-600H | 94.7 | 96.5 |
| Mean Well XLG-320 | 92.0 | 95.0 |
| Inventronics EUD-600S | 92.0 | 94.0 |
| Sosen SS-200EP (200 W) | 88.0 | 91.0 |

Mean Well values read from the published curves; Inventronics values are mid-range typicals across models.

Source: Datasheets [1][2][6][7].

### Read the derating curves

- **Static characteristic (input voltage):** the HLG-600H keeps 100% load from **115 V** up, but derates toward **80% at 90 V** [1]. The XLG-320 keeps 100% from **120 V** and falls toward **80% at 100 V** [2]. A sagging 120 V circuit (long extension cords, a loaded circuit) can push a driver into its derating zone.
- **Load vs ambient temperature:** on 120 VAC the XLG-320 holds full load only to about **35 °C (95 °F)** ambient, versus about **45 °C (113 °F)** on 230 VAC [2]. A driver mounted inside a hot tent may be running past its full-power rating.
- **Life expectancy:** stated at a case temperature, for example above 62,000 h at a Tcase of about 75 °C or less for the HLG-600H and HLG-480H [1][4], and above 50,000 h at 75 °C or less for the XLG-320 [2].

**What can cut a driver's output.** Input voltage: Below ~115 V: down to 80% at 90 V → Ambient temperature: XLG-320 full load to ~35 °C on 120 V → Output window: Constant power only between 42 and 56 V → Case temperature: Life rated at ~75 °C or less → Watts to the diodes. Source: [1][2]

### Mean Well vs Inventronics vs Sosen vs no-name drivers

The three brands below publish full datasheets, so you can check them. Figures are typical values from each maker's datasheet for the model named; sizes differ, so compare like with like. *Supported (manufacturer datasheets).*

| | Mean Well HLG-600H (600 W) | Mean Well XLG-320 (315 W) | Inventronics EUD-600SxxxDV (600 W) | Sosen SS-200EP-56B (200 W) | Generic no-name |
|---|---|---|---|---|---|
| Efficiency at 115–120 VAC | ~94.7% (48 V model, curve) [1] | ~92% (curve) [2] | 91–93% typ. by model [6] | 88% [7] | Usually unpublished |
| Efficiency at 220–240 VAC | ~96.5% (curve); 92–96% typ. by model [1] | ~95% (curve); 92.5–94.5% typ. [2] | 93–95% typ. by model [6] | 91% [7] | Usually unpublished |
| Low-voltage derating | 100% from 115 V; 80% at 90 V [1] | 100% from 120 V; 80% at 100 V [2] | 100% from 115 V; 80% at 90 V [6] | Derating curve referenced [7] | Unknown |
| Rated life | >62,000 h at Tcase about 75 °C or less [1] | >50,000 h at Tcase 75 °C or less [2] | 90,000 h at 70 °C case (220 V, 80% load); about 120,000 h at 65 °C or less on the curve [6] | 62,000 h at Tc 72 °C [7] | Unknown |
| Warranty | 7 years for HLG made from 2015 on [8] | 5 years in reseller listings | 7 years, at the warranty case temperature [6] | 5 years [7] | Often short or none (founder's field experience) [3] |
| Surge immunity | 4 kV line–earth, 2 kV line–line [1] | 6 kV line–earth, 4 kV line–line [2] | 10 kV common mode, 6 kV differential [6] | 10 kV CM, 6 kV [DM](https://genetixbay.com/knowledge/glossary/downy-mildew.md) [7] | Unknown |
| Dimming | 0–10 V, PWM or resistance (B type) [1] | 0–10 V, PWM, resistance (AB type) [2] | 0–10 V, PWM, timer modes; programmable current [6] | 1–10 V, PWM, resistor [7] | Often a crude potentiometer |
| Safety listing and IP | UL 8750 (type HL), CSA C22.2 No. 250.13; IP65/IP67 [1] | UL 8750 (type HL), CSA; IP67 [2] | This variant lists ENEC, CE, CB and others; check the North American variant for UL [6] | UL/cUL 8750; IP rating per model [7] | Often none, or a printed logo with no file number |

**Fair pros and cons.**

- **Mean Well:** highest published efficiency of the group, easy-to-find datasheets with curves at 115, 230 and 277 V, UL "type HL" listings for damp locations. But its HLG surge rating is lower on paper than Inventronics or Sosen, and the life figure is quoted at 75 °C, so it can't be compared directly with a figure quoted at 70 °C.
- **Inventronics:** high surge immunity, a long published life curve, a 7-year warranty and programmable current. But 120 V efficiency is a little lower than the Mean Well HLG, and you must check that your exact suffix is the UL-listed variant.
- **Sosen:** high surge immunity, UL 8750, a 5-year warranty and a 62,000 h rating. But the datasheet we could find covers a 200 W model with lower published efficiency (88% at 120 V); we found no public Sosen 600 W datasheet to compare.
- **No-name drivers:** cheap, and sometimes fine. But there's no datasheet, so there's no way to know efficiency at 120 V, the life at your temperature, surge protection or listing (founder's field experience) [3].

**How drivers usually die.** Heat ages the electrolytic capacitors, roughly halving life for every 10 °C hotter [9]; all four makers rate life against case temperature for that reason [1][2][6][7]. Power surges kill drivers with low surge immunity. Water gets into drivers without an adequate IP rating. Drivers run near or past their derating limits (low input voltage, hot tent) fail early. A driver hung outside the tent runs cooler and keeps its heat out of the canopy.

### Worked example: where does "650 W" go?

Here is the founder's "about 80%" in numbers. The two builds below are **illustrative**, not tests of any product.

| Step | Better build | Budget build | How to find it |
|---|---|---|---|
| Advertised power | 650 W | 650 W | Listing |
| Driver rating | 600 W (HLG-600H-48) | 600 W (unbranded) | Driver label and datasheet |
| String voltage × driver current | 44 V × 12.5 A = 550 W | 41.6 V × 12.5 A = 520 W | Board spec, or measure DC volts and amps |
| Driver efficiency at 120 V | ~94.7% [1] | ~89% (assumed; founder's field experience) [3] | Efficiency vs load curve |
| Wall watts (diode watts ÷ efficiency) | 550 ÷ 0.947 ≈ 581 W | 520 ÷ 0.89 ≈ 584 W | Plug-in power meter |
| Power to diodes as % of claim | 550 ÷ 650 ≈ **85%** | 520 ÷ 650 = **80%** | |
| Heat into room | 581 × 3.412 ≈ 1,982 BTU/h | 584 × 3.412 ≈ 1,993 BTU/h | [5] |

Same wall watts, same heat, and nearly the same power to the diodes. What differs is what the diodes do with it: bin, drive current, temperature and authenticity decide how many µmol/s come out.

**Where "650 W" goes.** 650 W: Advertised; 550 W (85%): Better build: to the diodes; 520 W (80%): Budget build: to the diodes; ~584 W: At the wall, both builds. Source: Worked example above; HLG-600H efficiency [1]; budget driver is founder's field experience [3].

**Plain-words version:** the number on the box is a wish. The number on your watt meter is the truth.

## Common mistakes

- Trusting the model name ("1000") instead of the driver label and a watt meter.
- Reading the 230 V efficiency when you run on 120 V [1][2].
- Mounting the driver inside a hot tent, past its full-load ambient rating [2].
- Running on a long 120 V extension cord that sags the input voltage into the derating zone [1].
- Buying a no-name driver with no datasheet, so nothing about it can be checked [3].

## Sources

1. MEAN WELL. HLG-600H series specification (file dated 2026-07-24): efficiency, static characteristic (input-voltage derating), efficiency vs load at 115/230/277 VAC, life expectancy note. https://www.meanwell.com/Upload/PDF/HLG-600H/HLG-600H-SPEC.PDF
2. MEAN WELL. XLG-320 series specification (file dated 2026-02-04): constant-power window, efficiency vs load at 120/230/277 VAC, output load vs ambient temperature by input voltage. https://www.meanwell.com/Upload/PDF/XLG-320/XLG-320-SPEC.PDF
3. GenetixBay founder. Field experience sourcing LED grow fixtures, diodes and drivers from Shenzhen suppliers (first-hand account; GenetixBay house position).
4. MEAN WELL. HLG-480H series specification (file dated 2026-02-04). https://www.meanwell.com/Upload/PDF/HLG-480H/HLG-480H-SPEC.PDF
5. Thompson A, Taylor BN. 2008. Guide for the Use of the International System of Units (SI). NIST Special Publication 811, Appendix B (1 Btu_IT/h = 0.293 071 1 W). National Institute of Standards and Technology. https://www.nist.gov/pml/special-publication-811
6. Inventronics. EUD-600SxxxDV 600W Programmable IP67 Driver datasheet, Rev. L: efficiency at 120/220/277 Vac, derating, lifetime vs case temperature, surge DM 6 kV/CM 10 kV, 7-year warranty. https://www.inventronicsglobal.com/am/wp-content/uploads/2017/12/DS-EUD-600SxxxDV_Rev.L.pdf
7. Sosen. SS-200EP-56B 200W LED driver datasheet, Rev. V02 (2021-09-02): efficiency 88% at 120 Vac, 91% at 220/277 Vac; lifetime 62,000 h at Tc 72 °C; surge CM 10 kV/DM 6 kV; UL/cUL 8750; 5-year warranty. https://lightbulbsurplus.com/content/SS-200EP-56B.pdf
8. MEAN WELL Australia. 7 years warranty: HLG series LED driver (HLG drivers manufactured from 1 January 2015 onwards). https://www.meanwellaustralia.com.au/blog/7-years-warranty-hlg-series-led-driver
9. Cornell Dubilier Electronics. Aluminum Electrolytic Capacitor Application Guide (life roughly doubles for each 10 °C cooler operation). https://www.cde.com/resources/technical-papers/AEappGuide.pdf