There's a lot of attentions on the HSTNS-PL11 with its small size but hefty 100A 12V output. As I've just put together an electronic 'wattmeter' (see image) using an AliExpress bought module, I might as well measure how these supplies perform on standby and idle. The following are my findings.
The no load wattage shown are in the range of 42~44W for PL11, double checked with several PL11 power supplies. What it means is the power supply is consuming 44W with 12V but no load attached. This figure seems exceptionally high and unreasonable compares to different models of server power supply.
It would be helpful if anyone with a HSTNS-PL11 and wattmeter can either confirm or rebute the figure using other makes of wattmeter.
If it turns out to be correct, then it is definitely not a good choice if your application is mostly placing the supply on standby or very lightly loaded. However, its efficiency is still very good when loaded.
The C7000 supply shows the best result. Before you even consider to go out and buy a C7000 power supply, be warned that there is no trim POT inside the power supply for output voltage trimming and access to circuitry is severely blocked by large components. Unless you are contented with 12.2V output, there is'nt any mention of voltage increase modification or OVP mod anywhere on the whole internet.
Test Results: Server Power Supply Measurement
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Measured with electronic wattmeter module
AC mains voltage = 243V
Test Conditions:
AC ON: Supply +12V output disabled
DC ON: Supply +12V output available, no Load
Loaded: Supply +12V output loaded
1. 2450W Blade C7000 Power supply
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AC On: 3.9W
DC On: 14.6W
Loaded: 12.2V 60.5A =738W
Wattmeter: 790W, PF=1
Efficiency: 738/790 = 93.4%
2. HSTNS-PL11 1200W supply
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AC On: 8.12W
DC On:
42.3W Loaded: 12.3V 60A =738W
Wattmeter: 787W, PF=1
Efficiency: 738/787 = 93.8%
3. DPS-650EB 665W
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AC On: 9.7W
DC On: 18.32W
Loaded: 12.13V 59.3A =719W (overloaded, max 54A)
Wattmeter: 823W, PF=1
Efficiency: 719/823 = 87.4%