LEPA G 500 W Power Supply Review

[nextpage title=”Introduction”]

LEPA is a newcomer in the power supply market, established by Ecomaster, the official distributor for Enermax power supplies. The LEPA G series is comprised with 500 W, 700 W, and 900 W models, with 80 Plus Gold certification. Let’s see how the 500 W model fared in our tests.

LEPA power supplies are manufactured by Enermax, and their G series are simply Enermax MODU87+ models renamed. Can someone explain us why a distributor sells the same power supplies under two different brand names?

Figure 1: LEPA G 500 W power supply

Figure 2: LEPA G 500 W power supply

The LEPA G 500 W is 6.3” (160 mm) deep, with a 140 mm twister bearing fan (Enermax-branded Power Cooler PD142512W-OAB) on its bottom part.

The new LEPA G 500 W has a modular cabling system with seven connectors, two red for video card power cables and five black for SATA/peripheral power cables. The main motherboard cable and the ATX12V/EPS12V cable are permanently attached to the power supply. The power supply comes with the following cables:

• Main motherboard cable with a 20/24-pin connector, 23.2” (59 cm) long, permanently attached to the power supply
• One cable with two ATX12V connectors that together form an EPS12V connector, 23.2” (59 cm) long, permanently attached to the power supply
• Two cables with one six/eight-pin connectors for video cards each, attached to a single connector on the power supply side, 19.7” (50 cm) long, modular cabling system
• One cable with four SATA power connectors, 18.5” (47 cm) to the first connector, 5.9” (15 cm) between connectors, modular cabling system
• One cable with two SATA power connectors and two standard peripheral power connectors, 18.5” (47 cm) to the first connector, 5.9” (15 cm) between connectors, modular cabling system
• One cable with four standard peripheral power connectors and one floppy disk drive power connector, 17.7” (45 cm) to the first connector, 5.9” (15 cm) between connectors, modular cabling system

All wires are 18 AWG, which is the minimum recommended gauge, except the +12 V, +5 V and +3.3 V on the main motherboard cable, which are thicker (16 AWG).

The number of cables and connectors is simply fantastic for a 500 W product. Also, if you pay attention, even if you use all cables that come with this power supply, you still have one red and two black connectors available, so you can buy extra cables from Enermax (since they follow the same standard used by all Enermax power supplies with modular cabling system) if you need more connectors – including a cable with two extra video card power connectors!

Figure 3: Cables

Let’s now take an in-depth look inside this power supply.

[nextpage title=”A Look Inside The LEPA G 500 W”]

We decided to disassemble this power supply to see what it looks like inside, how it is designed, and what components are used. Please read our Anatomy of Switching Power Supplies tutorial to understand how a power supply works and to compare this power supply to others.

On this page we will have an overall look, and then in the following pages we will discuss in detail the quality and ratings of the components used. As already explained, the LEPA G 500 W is a renamed Enermax MODU87+ 500 W.

Figure 4: Top view

Figure 5: Front quarter view

Figure 6: Rear quarter view

Figure 7: Printed circuit board

[nextpage title=”Transient Filtering Stage”]

As we have mentioned in other articles and reviews, the first place we look when opening a power supply for a hint about its quality, is its filtering stage. The recommended components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components, usually removing the MOV and the first coil. 

The transient filtering stage of the LEPA G 500 W is impeccable, coming with all required components plus two extra Y capacitors, one extra ferrite coil, and one X capacitor after the rectification bridge.

Figure 8: Transient filtering stage (part 1)

Figure 9: Transient filtering stage (part 2)

In the next page we will have a more detailed discussion about the components used in the LEPA G 500 W.

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the primary stage of the LEPA G 500 W. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one GBU10J rectifying bridge in its primary, attached to an individual heatsink. This bridge supports up to 10 A at 100° C so, in theory, you would be able to pull up to 1,150 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 920 W without burning itself out. Of course, we are only talking about this
component, and the real limit will depend on all the other components in this power supply. The Enermax MODU87+ 700 W uses a more powerful bridge here (20 A).

Figure 10: Rectifying bridge

The active PFC circuit uses two SiHG20N50C MOSFETs, which are capable of delivering up to 20 A at 25° C or up to 11 A at 100° C (note the difference temperature makes) in continuous mode, or up to 80 A in pulse mode at 25° C, each. These transistors present a 225 mΩ resistance when turned on, a characteristic called RDS(on). The lower this number the better, meaning that the transistors will waste less power and the power supply will achieve a higher efficiency. It is interesting to note that the Enermax MODU87+ 700 W uses different transistors here, but with the same specs.

Figure 11: Active PFC transistors and diode

The active PFC circuit is controlled by a CM6502 PFC controller.

Figure 12: Active PFC controller

The capacitor used to filter the output of the active PFC circuit is Japanese, from Matsushita (Panasonic), and labeled at 105° C.

In the switching section, two 2SK4107 MOSFET transistors are used, each one supporting up to 15 A at 25° C in continuous mode (unfortunately the manufacturer doesn’t say the limit at 100° C), and up to 60 A at 25° C in pulse mode, with an RDS(on) of 330 mΩ. The Enermax MODU87+ 700 W uses more powerful transistors here (20 A).

Figure 13: Switching transistors

The switching transistors are connected using a design called LLC resonant, being controlled by a CM6901 integrated circuit, which operated under PWM (Pulse Width Modulation) mode when the power supply is operating under light load, but under FM (Frequency Modulation) mode under other loads.

Figure 14: LLC resonant controller

Now let’s take a look at the secondary of this power supply.

[nextpage title=”Secondary Analysis”]

This power supply uses a DC-DC converter design in its secondary, meaning that it is basically a +12 V power supply where the +5 V and +3.3 V outputs are produced by two separated power supplies connected to the +12 V line. This design is proving to be the best solution for achieving high efficiency. On top of that, the +12 V power supply uses a synchronous design. On this kind of design the rectifiers are replaced by transistors (MOSFETs) for higher efficiency.

The +12 V output is produced by four IRFB3206 MOSFETs, two for the direct rectification and two for the “freewheeling” part of the rectification. Each transistor has a maximum RDS(on) of only 2.5 mΩ and can deliver up to 270 A at 25° C or up to 190 A at 100° C in continuous mode, or up to 1,080 A at 25° C in pulse mode. Good Lord! This would give us a maximum theoretical current of 266 A for the whole +12 V bus; if all this current would be pulled from the +12 V outputs, this unit would be able to deliver up to 3,192 W! Of course other parts of this power supply would burn way before we could be even close to this theoretical value.

Figure 15: +12 V transistors (the diode on the right is used for the +5VSB output)

Like other all members of the MODU87+ family, the filtering stage of the +12 V line uses a mix of solid capacitors and Japanese caps, from Chemi-Con, installed on small printed circuit boards attached to the main power supply board.

Figure 16: Filtering circuit

The +5 V and +3.3 V outputs are produced by two separated DC-DC modules, which are connected to the main +12 V line to produce these two voltages. Each module uses three APM2556 MOSFETs, controlled by an APW7073 integrated circuit, and only solid caps.

Figure 17: One of the DC-DC modules

Figure 18: One of the DC-DC modules

The secondary is monitored by a PS231S integrated circuit, which supports over voltage protection (OVP), under voltage protection (UVP) and over current protection (OCP). This integrated circuit has five OCP channels (+3.3 V, +5V and three +12 V), correctly matching the number of +12 V rails advertised by the manufacturer.

Figure 19: Monitoring circuit

The secondary of the LEPA G 500 W (Enermax MODU87+ 500 W) is identical to the secondary of the 700 W model (Enermax MODU87+ 700 W).

[nextpage title=”Power Distribution”]

In Figure 20, you can see the power supply label containing all the power specs.

Figure 20: Power supply label

According to the manufacturer, this unit has three +12 V rails, and we could confirm this by the presence of three shunts (current sensors, see Figure 21) and also by the presence of a monitoring integrated circuit that really supports three +12 V OCP channels. Click here for a better explanation.

Figure 21: Shunts

The three +12 V rails are distributed like this:

• +12V1: Main motherboard and ATX12V/EPS12V cables
• +12V2: Half of the two red connectors for video cards
• +12V3: The other half of the two red connectors for video cards, SATA and peripheral power connectors

This distribution is perfect, as it separates the CPU and the video cards, which are the main components connected to the +12 V output, in different rails. Also, since the half of the red connector is fed by a different rail, the two six/eight-pin video card connectors that come with this power supply are installed on separate rails.

Let’s now see if this power supply can really deliver 500 W.

[nextpage title=”Load Tests”]

We conducted several tests with this power supply, as described in the article Hardware Secrets Power Supply Test Methodology.  

First we tested this power supply with five different load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching the behavior of the reviewed unit under each load. In the table below, we list the load patterns we used and the results for each load.

If you add all the powers listed for each test, you may find a different value than what is posted under “Total” below. Since each output can have a slight variation (e.g., the +5 V output working at +5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. In the “Total” row, we are using the real amount of power being delivered, as measured by our load tester.

The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During our tests, the +12VA and +12VB input were connected to the power supply +12V1 and +12V3 rails, while the +12VB input was connected to the power supply +12V1 rail.

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12VA	4 A (48 W)	7.5 A (90 W)	11 A (132 W)	14 A (168 W)	17.5 A (210 W)
+12VB	3 A (36 W)	7 A (84 W)	10.5 A (126 W)	14 A (168 W)	17.5 A (210 W)
+5V	1 A (5 W)	2 A (10 W)	4 A (20 W)	6 A (30 W)	8 A (40 W)
+3.3 V	1 A (3.3 W)	2 A (6.6 W)	4 A (13.2 W)	6 A (19.8 W)	8 A (26.4 W)
+5VSB	1 A (5 W)	1 A (5 W)	1.5 A (7.5 W)	2 A (10 W)	2.5 A (12.5 W)
-12 V	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)
Total	104.7 W	204.1 W	307.8 W	404.7 W	502.2 W
% Max Load	20.9%	40.8%	61.6%	80.9%	100.4%
Room Temp.	45.6° C	44.4° C	44.2° C	44.6° C	46.8° C
PSU Temp.	51.3° C	51.2° C	51.0° C	51.2° C	52.2° C
Voltage Regulation	Pass	Pass	Pass	Pass	Pass
Ripple and Noise	Pass	Pass	Pass	Pass	Pass
AC Power	118.5 W	224.6 W	340.2 W	456.3 W	573.7 W
Efficiency	88.4%	90.9%	90.5%	88.7%	87.5%
AC Voltage	118.6 V	117.5 V	116.7 V	115.9 V	114.5 V
Power Factor	0.978	0.98	0.988	0.993	0.995
Final Result	Pass	Pass	Pass	Pass	Pass

The LEPA G 500 W passed our test with flying colors, being able to deliver its labeled wattage at high temperatures.

Efficiency was outstanding, between 87.5% and 90.9%, completely fulfilling the 80 Plus Gold requirements (87% minimum at light and full loads, 90% minimum at typical load).

Voltage regulation was excellent, with all positive voltages within 3% of their nominal values (the -12 V output was outside this tighter regulation, but still inside the proper range). The ATX12V specification allows voltages to be up to 5% from their nominal values (10% for the -12 V output). Therefore this power supply presents voltages closer to their nominal values than necessary all the time.

Noise and ripple levels were always extremely low. Below you can see the results for the power supply outputs during test number five. The maximum allowed is 120 mV for the +12 V and -12 V outputs, and 50 mV for the +5 V, +3.3 V, and +5VSB outputs. All values are peak-to-peak figures.

Figure 22: +12VA input from load tester during test five at 502.2 W (37.4 mV)

Figure 23: +12VB input from load tester during test five at 502.2 W (37.6 mV)

Figure 24: +5V rail during test five at 502.2 W (13 mV)

Figure 25: +3.3 V rail during test five at 502.2 W (15.2 mV)

Let’s see if we can pull even more from the LEPA G 500 W.

[nextpage title=”Overload Tests”]

Below you can see the maximum we could pull from this power supply. We couldn’t pull more than that because the power supply shut down, showing that its protections are working just fine.

Input	Overload Test
+12VA	23 A (276 W)
+12VB	23 A (276 W)
+5V	10 A (50 W)
+3.3 V	10 A (33 W)
+5VSB	2.5 A (12.5 W)
-12 V	0.5 A (6 W)
Total	612.1 W
% Max Load	122.4%
Room Temp.	45.5° C
PSU Temp.	52.3° C
AC Power	714 W
Efficiency	85.7%
AC Voltage	113.5 V
Power Factor	0.996

[nextpage title=”Main Specifications”]

The specs of the LEPA G 500 W include:

• Standards: NA
• Nominal labeled power: 500 W
• Measured maximum power: 612.1 W at 45.5° C ambient
• Labeled efficiency: Up to 93%, 80 Plus Gold certification
• Measured efficiency: Between 87.5% and 90.9% at 115 V (nominal, see complete results for actual voltage)
• Active PFC: Yes
• Modular Cabling System: Yes
• Motherboard Power Connectors: One 20/24-pin connector and two ATX12V connectors that together form an EPS12V connector, permanently attached to the power supply
• Video Card Power Connectors: Two six/eight-pin connectors on separate cables, two extra six/eight-pin connectors if optional cable is bought
• SATA Power Connectors: Six on two cables
• Peripheral Power Connectors: Six on two cables
• Floppy Disk Drive Power Connectors: One
• Protections (as listed by the manufacturer): Over power (OPP), over voltage (OVP), over current (OCP), and short-circuit (SCP)
• Are the above protections really available? Yes, under voltage protection (UVP) present but not listed by the manufacturer
• Warranty: NA
• Real Model: Enermax MODU87+ 500 W
• More Information: https://www.lepatek.com
• Average Price in the US: The product will arrive on the market around USD 110-120

[nextpage title=”Conclusions”]

The LEPA G 500 W is a flawless power supply targeted to users that demand only the best in class. It presents ultra-high efficiency (between 87.5% and 90.9% in our tests), voltages within a tighter 3% regulation, and very low noise and ripple levels. It comes with an appropriate number of cables and connectors for a 500 W product, but as an added bonus you can buy extra cables to use the unused connectors of the modular cabling system – allowing you, for example, to have four video card power connectors.

The main drawback with this power supply is, of course, its price, especially compared to regular 500 W power supplies. Of course, if you want “the best,” you will have to pay for it. The LEPA G 500 W should arrive on the market costing between USD 110 and USD 120, but at this price range we have the Seasonic X-Series 560 W, which has similar performance and officially gives you extra 60 W.

As final note, we repeat that we don’t understand the strategy of a distributor that offers two identical power supply series with different names (LEPA G and Enermax MODU87+).