Connecting 1 UPS to two PDUs with C19/C20 cables, best practice?

[jb_dk]

Dear forum,

At work we have an APC UPS for our servers, currently it feeds (via a manual transfer switch, MTS) a small horizontal managed PDU.  Power delivery from UPS to MTS to PDU is via standard C19/C20 "cordset" cables.  Now I am looking to design an expansion to have two such PDUs, but the MTS only has a single J (C19) outlet and the question is what is the *correct* way to split the output between 2 PDU C20 inlets here in the EU (230V mains, EU LV directive wiring).

Options that seem clear are: A. A C19/C20 Y-cable (seems to be offered by some vendors for the US market, unsure of EU certification).  B. A C13 to C20 cordset if available between an unused C14/F outlet on the MTS (relying on the MTS breaker to limit current to 10A worst case)  C. Purchasing an entirely new unmanaged C19/J PDU to go between the MTS and the managed PDUs.

Entire rack setup is multivendor, but the UPS and fixed installation is Schneider/APC products.

One fact was removed because the forum software declared it "banned", even in "Home and Office forum".

[Teken]

I would suggest you sit down pen to paper and determine the following. As knowing these important facts will dictate what the next steps are:

Load: The UPS must not exceed 80% of its rated capacity.

Runtime: The extra connected loads will impact the operational runtime. As such you better validate all the servers / VM have enough time to complete their grace full shutdown.

Current: This goes hand in hand with the load and must not exceed the 80% threshold. It’s imperative that you measure the inrush current for all new devices.

Failure to do so will result in the UPS shutting down / dropping the load.

Temperature: If the system is not in a climate controlled and managed environment. You risk shorter battery life and possible shutdown due to elevated internal temperature.

Questions Ask . . . 👍

[jb_dk]

The 80% rule is a known oddity of the US National Electric Code, not applicable in the rest of the world.  I don't think it is a misfeature of APC UPSes sold in Europe.

The total load is always something to watch and is currently way below 50%, including a temporary PDU solution for most of the devices that will use the second standard PDU.   Temperature regulation is also installed and watched.

And once again, the censorship software installed on this forum refuses a completely meaningful sentence that I then had to remove.

Now please return to the question asked about wiring up the power cables under EU, not US, rules.

[jb_dk]

Teken's answer is entirely off topic and also seems specific to US electrical code not relevant here in the EU.

[Teken]

The 80% rule is not an oddity of North America.

It’s a well established and fundamental understanding of electricity, safety, and operational standards acknowledged world wide! ☝️

You don’t have to take my word for it you can refer to this APC FAQ or any electrical code in the world:

https://www.se.com/us/en/faqs/FAQ000268376/

My initial reply to you are the most basic things that must be considered along with many others.

It’s quite obvious to me you’re well past your depth as it relates to these basic concepts. 🤦‍♂️

Your fixation on wiring vs performing an energy audit clearly indicates this task be given to someone else with more basic understanding of power management, electrical codes, and conformance with established standards.

Feel free to load that UPS to 100% and let me know what the outcome is. 😂