Mean Well LRS vs. RSP Series: When Should You Upgrade to a PFC Power Supply?

If you are sourcing a power supply for your next project, you’ve likely narrowed your search down to two of Mean Well’s most popular lines: the LRS Series and the RSP Series.

At first glance, they may look similar—both are enclosed switching power supplies known for high reliability. However, there is a significant price gap between them. The question is: Is the RSP series worth the extra investment, or can you get away with the budget-friendly LRS?

The answer usually comes down to one technical feature: Power Factor Correction (PFC).

What is the Mean Well LRS Series?

The LRS (Low Profile) Series is the industry’s "no-frills" champion. It was designed to provide the highest possible efficiency at the lowest possible price point.

Key Advantages:

• Ultra-Low Profile: With a height of only 30mm (1U), these fit into the tightest industrial cabinets.

• High Efficiency: These units often reach up to 90% efficiency, meaning less wasted heat.

• Cost-Effective: By removing complex circuitry like Active PFC, Mean Well has made the LRS the most affordable high-quality PSU on the market.

Best for: 3D printers, DIY hobbyist projects, basic LED signage, and standalone machinery where cost-optimization is the priority.

What is the Mean Well RSP Series?

The RSP Series is Mean Well’s premium industrial line. While it performs the same basic task as the LRS, it is built with more "intelligence" under the hood.

Key Advantages:

• Active PFC (Power Factor Correction): This is the biggest differentiator. The RSP series includes circuitry that aligns the current wave with the voltage wave, making the power usage much cleaner.

• Global Compliance: Many regions (specifically Europe) have strict regulations (like EN61000-3-2) that require equipment over 75W to have PFC.

• Remote Functions: Many RSP models include remote ON/OFF control and sense functions, allowing for more complex automation setups.

Best for: Telecommunications, data centers, industrial automation for export, and high-wattage systems where electrical noise must be minimized.

When Should You Pay More for the RSP?

It can be tempting to always choose the LRS to save on project costs. However, you should upgrade to the RSP if any of the following apply:

1. You are exporting to Europe or International Markets

If you are an OEM building a machine to be sold in the EU, your product must comply with harmonic current regulations. The LRS (at higher wattages) often won't pass these certifications, whereas the RSP is built specifically to meet them.

2. You are running multiple units on one circuit

Non-PFC power supplies draw current in short, high-intensity bursts. If you have ten LRS-350 units on a single circuit, those "harmonic spikes" can overheat your neutral wires and trip breakers. The RSP draws power smoothly, allowing you to put more units on a single line.

3. You need Universal AC Input

Most LRS models require you to manually flip a red switch between 115V (USA) and 230V (International). If you forget to flip this switch, you can destroy the unit. The RSP series features Universal Input, meaning it automatically detects and adjusts to any voltage worldwide.

Final Verdict

• Choose the Mean Well LRS if you need a reliable, compact, and extremely affordable power supply for a domestic project or a standalone machine.

• Choose the Mean Well RSP if you are building professional-grade industrial equipment, require global regulatory compliance, or need the cleanest power delivery possible.