Initial power to PSU causes UPS to trip

[Levent]

Hi,

 

I had to swap my home servers VS450 into a different machine and in turn I replaced it with an RM850e.

 

Machine in question hardly draws past 150-200w and mostly sits at 80w.

 

My online UPS is a rebrand but of a decent manufacturer (I don’t remember the name) and I haven’t had a single issue since I put it in.

it’s rated for 1kva and has 2x9ah lead acid batteries and handles up to 900ws just fine before it complains about draw 

 

Problem:

 

I am having trouble with sleeping so I have started turning off every single device that has a fan in my room.

 

When UPS is turned off (by unplugging it from the wall and clicking off button. Upon waking up in the morning and plugging the UPS in and turning it on results in my pcs turning on immediately as I want them. However occasionally when rm850e gets turned on, UPS immediately turns it off (it has an very loud relay)

 

this doesn’t happen every time or duration of the devices being turned off has any effect.

 

Any ideas? I got GX650 from Seasonic also connected to same UPS which has been dandy the whole time.

[mariushm]

The Corsair psu has big capacitors inside and a high inrush current as they charge up at cold power on - power supplies reduce this inrush current by placing a resistor in series with the input that lowers the resistance as it heats up from the current passing through it, and after a few seconds a mechanical relay in the power supply shorts out (removes it from circuit) that resistor to increase the power supply efficiency and reduce heat produced.

 

The draw at startup can be significantly higher with simulated sine wave or square wave outputs (if the USP provides the power from internal batteries through an inverter)

 

The UPS may see that high inrush current as too high power draw and turn off to protect itself.

 

Fix ... other than replacing that resistor inside the psu with a bigger one to slow the startup, I don't see what you could do...

[Levent]

2 minutes ago, mariushm said:

The Corsair psu has big capacitors inside and a high inrush current as they charge up at cold power on - power supplies reduce this inrush current by placing a resistor in series with the input that lowers the resistance as it heats up from the current passing through it, and after a few seconds a mechanical relay in the power supply shorts out (removes it from circuit) that resistor to increase the power supply efficiency and reduce heat produced.

 

The draw at startup can be significantly higher with simulated sine wave or square wave outputs (if the USP provides the power from internal batteries through an inverter)

 

The UPS may see that high inrush current as too high power draw and turn off to protect itself.

 

Fix ... other than replacing that resistor inside the psu with a bigger one to slow the startup, I don't see what you could do...

I guess other than swapping the new PSU again, only option is to never turn it off. Yeah UPS powers devices from battery all the time. 
 

Thanks, other than this minor annoyance I suspect this is just fine? PSU won’t get powered on until inrush capacitors are fully charged right? I don’t have to worry about 30 hdds turning on and off within half a second?

 

 

Seasonic Gx650 probably also has a similar setup so I wonder if I can stagger startup sequence of my computers