surge protection not working on Smart-UPS SRT 5000s - why?

[jerryku7]

My company uses the Smart-UPS SRT 5000 to protect network equipment. Recently, at three different buildings, we have seen thousands of dollars worth of equipment be destroyed by power surges. The equipment was supposed to have been protected by the UPSs but was not.  Can APC/Schneider support explain why?

To elaborate...   each building has network equipment cabinets with two 220V AC outlets, two SRT 5000s, ,two APC PDUs, and three network switches (each switch has two power supply units aka PSUs).

Each SRT 5000 plugs into one of the AC outlets.

Each PDU is plugged into one of the UPSs.

For each network switch, one PSU is plugged into one of the PDUs, and the other PSU is plugged into the other PDU.

Each building was fully shut down.  Main utility and backup generator power were completely turned off.

All UPS devices in the network cabinets were fully unplugged from the 220V AC outlets mentioned above.

Then, when main utility and backup generator power was restored, the UPS devices were reconnected to the 220V AC outlets.

For all three buildings, some network equipment was destroyed, presumably by power surges. The devices do not boot up anymore and must be RMA'ed or thrown away. Any theories as to why the destruction occurred at all?

From reading this post: https://community.se.com/t5/APC-UPS-for-Home-and-Office-Forum/Why-is-my-apc-Ups-Joules-rating-so-low...

BillP said:

"Our products are designed to redirect the surge back to ground instead of absorbing it and incorporate a let through voltage, which is the maximum transient voltage the attached equipment will be subjected to above the normal RMS voltage. Any remaining voltage is redirected to ground."

So why did equipment still get destroyed?

also..

1) Reading Rau_APC's posts in https://community.se.com/t5/APC-UPS-for-Home-and-Office-Forum/UPS-surge-protection-status/m-p/328775 ...the UPSs do not have a way to report that the surge protection is no longer working.  But does my company have to worry about the MOVs inside the UPSs depleting? And becoming too old to be functional?

In other words, for the UPSs involved in the three cases mentioned above, is the surge protection now no longer working for these units since a surge event (probably) happened?

2) Our UPSs do not have their chassis ground screws grounded to anything. I assume this does not matter in regards to the network equipment being destroyed. But is that correct? I assume that the chassis ground screws are to protect people from being electrocuted when touching the metal surface of the UPS, if a wiring fault occurs within the UPS. So it would have nothing to do with surge damage..

[BillP]

@jerryku7 

We cannot explain what may have happened with out an investigation. Your UPSs are covered by the equipment protection policy https://www.apc.com/us/en/support/equipment-protection-policy/ 

You should contact local support and they will be happy to assist you. 

Local support contact information will be found at this link.

https://www.apc.com/us/en/support/contact-us/index.jsp

You may need to change the region in the upper left of the contact us web page. 

[jerryku7]

Our UPSs are 208V so i don't think we're covered