Question Confused over PSU safety features including SIP ?

[Mikk_UA_]

Hello, little question about PSU safety features. Choosing new PSU with bigger capacity I got a bit confused.
My choices around pretty popular mid-range+ 850W\1000 variants, few examples:

• Seasonic FOCUS GX FOCUS GX-850 850W
• MSI MPG PCIE5 A850G PCIE5 850W
• MSI MAG PCIE5 A850GL 850W
• be quiet! Pure Power 12 M 850W

All of them have protection futures like :

• OVP – Over Voltage Protection
• OPP – Over Power Protection
• OCP – Over Current Protection
• SCP – Short Circuit Protection
• OTP – Over Temperature Protection
• UVP – Under Voltage Protection

But when I looked for my current old budget PSU Chieftec 600W Proton, and their newer variants Chieftec 1000W Proton & Chieftec Polaris PPS-850FC(80+ Gold) , they have all of the above protection features plus SIP – Surge and Inrush Protection.
Why this more budget friendly PSU have all of this protection features but not Seasonic or be quiet! ?* Or this is just by default ?* 😵 Or i`m missing something and SIP not a big deal?

 

[bill001g]

It might be related to the watt rating. That feature is related to the large power spike that can occur when you first turn on the power supply and it charges the capacitors. It is used to prevent you tripping the power breaker in your house. Most breakers can tolerate a small surge something like the motor on a refrigerator or wall AC units likely causes more surge.

The higher the watt rating the larger the capacitors so the more surge it has. All the protection feature would be is something to limit how fast the capacitors can charge.

 

[Mikk_UA_]

It might be related to the watt rating. That feature is related to the large power spike that can occur when you first turn on the power supply and it charges the capacitors. It is used to prevent you tripping the power breaker in your house. Most breakers can tolerate a small surge something like the motor on a refrigerator or wall AC units likely causes more surge.

The higher the watt rating the larger the capacitors so the more surge it has. All the protection feature would be is something to limit how fast the capacitors can charge.

Watt rating - but SIP Protection have all line-ups of Chieftec from 500 to 1000W.
Also, I think it's MSI PSU, on the startup have 115-150W+ inrush surge, which isn't ok?* (could be wrong)

"tripping the power breaker in your house" so it's more protection of house power breakers, not pc system ? it's "180" from what I thought. 😶

 

[Misgar]

Why this more budget friendly PSU have all of this protection features but not Seasonic or be quiet!

Just because a PSU manufacturer fails to include a long list of protection features in their spec, doesn't mean these functions are not included. When you buy a modern car, you tend to assume that air bags and seat belts will be included, even if they're not specifically mentioned.

I'd be very surprised if Seasonic and bequiet! do not include multiple protection features in their designs. Really cheap PSUs (sub $25) omit some of these safety features, because they cost money to implement.

I think it's MSI PSU, on the startup have 115-150W+ inrush surge, which isn't ok?

Inrush surges into ATX PSUs are usually specified in Amps, not Watts.

In a test (see link below) on a Gigabyte UD1000GM PG5, the inrush current for a 115V AC supply is 31.54A and for a 230V supply it's 87.60A. Values between 15A and 100A are quite normal in Tom's Hardware PSU test results.
https://www.tomshardware.com/reviews/how-we-test-psu,4042-7.html

Good quality PSUs include an NTC (Negative Temperature Coefficient) thermistor to reduce the initial inrush, but high currents still flow briefly despite using this component.
https://www.tomshardware.com/reviews/power-supplies-101,4193-9.html

To quote from the article "The resistance of a "cold" thermistor is usually 6 to 12 Ohms, and after the PSU is started up, the thermistor heats up and lowers its resistance to approximately 0.5 to 1 ohm."

"tripping the power breaker in your house" so it's more protection of house power breakers

The use of an NTC thermistor in a PSU, reduces the chance of house power breakers tripping unnecessarily.

Miniature Circuit Breakers (MCB) come with a number of different trip curves, depending where they're used.
https://www.electricalclassroom.com/b-c-d-k-and-z-mcb-trip-curves/

The graph below shows an MCB can support a relatively high inrush current for several seconds before tripping, e.g. 3 to 5 times the rated current for up to 3 seconds, but it might trip earlier if the current spike is higher.

If your MCB has a fast acting trip curve and your ATX PSU generates a 100A spike, the breaker could trip out in less than 3 seconds.

The graph also shows this particular MCB will not trip even if the current spike is very high (up to 40 times the breaker's rated current) if the duration is less than 0.01 seconds (10 milliseconds).