First question: Are Backup UPS considered relocatable taps?
Second question: Can extension cords and power strips that are plugged into Backup UPS be considered daisy chaining?
does your UPS have a breaker panel? i'm thinking that might make a difference. another question might be whether it is portable or not.
The UPS is plugged into a 120VAC outlet and can be moved around as needed. I have found an eight outlet UPS with a power strip with ten devices plugged into each of the outlets and another power strip that has a fan plugged in it same UPS. So that 11 devices in one UPS that was should only support eight devices. There are six open outlets on the UPS the person believe they can use for other devices. Eight of the devices are electronic load for battery charging and discharging tests, and two chart recorders.
UPSs can be designed in a number of ways. i am aware of a couple of them, which would likely affect the decision. a UPS can pass power from the outlet into which it is plugged directly into the loads, with the energy storage being trickle-charged (usually with a battery-specific charge profile) so long as the input has power, switching to the energy storage when the criteria for power fail has been met, or it can charge the energy-storage *and* power the load at the same time. if i'm not mistaken, most of them follow the former course, because it's more efficient and less wear on the battery, but the latter scheme, which usually has multiple batteries in parallel, never has to switch over from input to storage, so there are no switch-over glitches.
if the load is usually connected to the incoming power, switching only when the incoming power fails, i would think that it would be considered a relocatable tap, and the extension cords would be daisy-chaining. if the devices are being run off the battery, OTOH, they would not be daisy-chaining. i have yet to see much in the way of design information imparted by the manuals and instruction sheets for UPSs, so without clear information about its operation, i think i would err on the side of caution and call it a relocatable tap with daisy-chaining.
finally, this brought a question to my mind. if the UPS outlets and the cables plugged into them were inaccessible, perhaps in a locked box of some kind, so that the devices were in essence hard-wired (plugs could not be relocated without a key to the box), and the power-use of the devices on each outlet did not exceed wiring limits of the UPS outlets, would that clear up the daisy-chaining issue? i suspect that it would not, because a person with the key could then deliberately (because of ignorance) overload the wiring. just curious.
Thank you for your response. I talked with management and they agreed to have one or both UPS hard wired. In the next NFPA 70, NFPA 70E and National Electrical Code add your recommendations for UPS being hardware and the devices were in essence hard-wired so plugs could not be relocated without a key to the box, and the power-use of the devices on each outlet did not exceed wiring limits of the UPS outlets, would that clear up the daisy-chaining issue.
I went to a few UPS vendor sites and they do state "Do not use extension cords, adapter plugs, or surge strips" in their manuals. APC even provides a little background why not by Schneider Electric, which recommends against the use of any surge protector, power strip or extension cord being plugged into the output of any APC Back-UPS and Smart-UPS products. See link: http://www.apc.com/us/en/faqs/FA158852/
Thank you again for response and assistance. Ted
Retrieving data ...