Cord Connected UPS - Additional Outlets Needed

[whiggins]

I've scoured the web for an answer to this question. I can't find a thing, except references to fire inspectors saying no.

We have a cord connected 800VA UPS. It does not have sufficient outlets. Can a relocatable power tap (non-surge type) be plugged into this UPS? I know relocatable power taps can not be plugged into other power taps; however, the UPS is not UL listed as a power tap. Could a UL listed as a PDU outlet strip be used? Somewhat the same thing, but a different UL listing.

Has anyone done the research on this? I'm not finding much.

 

[hbiss]

Not sure I've seen a "UL listed as a PDU outlet strip" in the flesh but I believe those are the ones that mount in a rack space. Also what I've used are Wiremold Plugmold strips up the inside of a rack, supplied with SO cord and a plug, plugged into the PDU in the front. No reason you couldn't do the same thing with a UPS in there someplace.

Check out these that I've used-

ETA ETAPD8A ETA-PD8A

Buy the ETA ETAPD8A, ETA-PD8A at Full Compass Systems. 0% Financing and Free Shipping on thousands of items!

www.fullcompass.com

It's usually cheaper to to make your own Wiremold Plugmold strips with a line cord then to buy them from Tripp Lite or others.

-Hal

 

[Little Bill]

I have one set up in my shop now, no problems. I know what the mfg says, but this is for myself and I was willing to take the chance. I think mostly its a CYA for the mfg for warranty and liability.

 

[hbiss]

I know what the mfg says, but this is for myself and I was willing to take the chance. I think mostly its a CYA for the mfg for warranty and liability.

Which mfg are you talking about?

-Hal

 

[Little Bill]

APC
I think most of them are the same from the ones I've installed.

 

[hbiss]

APC says you can't feed a PDU from their UPS receptacles?

-Hal

 

[winnie]

I have seen bad interactions when a surge suppression device was fed by a small UPS. Since many power strips include surge suppression, this is a problem to watch out for.

I've never seen a problem with simple multiple outlet taps, and I last encountered this problem perhaps 25 years ago.

Jon

 

[hbiss]

I have seen bad interactions when a surge suppression device was fed by a small UPS.

Of which that ETA PDU I recommended above is, unfortunately. Good point.

But there are others that do not include surge suppression.

-Hal

 

[zbang]

I have seen bad interactions when a surge suppression device was fed by a small UPS.

Possibly due to many small UPSs generating stepped square waves, with their attendant ringing and harmonics, instead of a nice clean sine. (I just discovered this site- https://www.hardwareinsights.com/database-of-ups-output-waveforms/4/, interesting scope photos. I wish I still had that Fluke 41B analyzer for researching this stuff.)

 

[whiggins]

My issues is with the local fire inspector. When they inspect the building they look for cord connected power strips. You can't plug them into each other. If they view the cord connected UPS as a power strip, then I'll get a ding for plugging a stirp into a strip. I'm looking for written justification that it is okay..

 

[zbang]

(That was a fun research project.)
You're not going to find much of an explicit permission since that's not how most of the codes work (that which isn't forbidden is allowed).

On the one hand, NFPA 1 (Fire Code)-- 11.1.4.2 "The relocatable power taps shall be directly connected to a permanently installed receptacle." OTOH 11.1.3.1 allows "multiplug adapters" (whatever that UL number is) in accordance with their listing. "Current taps" (aka "cube tap" UL 498) aren't mentioned at all, but I suspect that in context they're a multiplug adapter.

However it's all in the listing.... Relocatable power taps (plug strips) are UL 1363, but if the device you're using is under a different UL number, maybe UL 60950 (Information Technology Equipment) or UL 1449 (Surge Protective Devices), then they're not a relocatable power tap and the RPT rule wouldn't apply.

On the third hand, there's no arguing with some inspectors.

 

[retirede]

My issues is with the local fire inspector. When they inspect the building they look for cord connected power strips. You can't plug them into each other. If they view the cord connected UPS as a power strip, then I'll get a ding for plugging a stirp into a strip. I'm looking for written justification that it is okay..

I think the only answer you’re going to get that means anything will be from your inspection authority. Have you asked them?

 

[g-and-h_electric]

Just a thought here... How about a piece of "PLUGMOLD" with a piece of SO or SJO cord and a male plug to the UPS mounted in the rack (I am presuming this is a server rack). This could give you more receptacles, and eliminate the MOV issues, and hopefully keep the inspector happy.


Howard

 

[hbiss]

Just a thought here... How about a piece of "PLUGMOLD" with a piece of SO or SJO cord and a male plug to the UPS mounted in the rack (I am presuming this is a server rack). This could give you more receptacles, and eliminate the MOV issues, and hopefully keep the inspector happy.


Howard

Didn't I say that?

-Hal

 

[zbang]

Didn't I say that?

Yep. Unfotunately, one then runs the risk of some bright-eyes saying that it's not a listed device and can't be used at all. (And add the assembly time to the cost.)

 

[whiggins]

(That was a fun research project.)
You're not going to find much of an explicit permission since that's not how most of the codes work (that which isn't forbidden is allowed).

On the one hand, NFPA 1 (Fire Code)-- 11.1.4.2 "The relocatable power taps shall be directly connected to a permanently installed receptacle." OTOH 11.1.3.1 allows "multiplug adapters" (whatever that UL number is) in accordance with their listing. "Current taps" (aka "cube tap" UL 498) aren't mentioned at all, but I suspect that in context they're a multiplug adapter.

However it's all in the listing.... Relocatable power taps (plug strips) are UL 1363, but if the device you're using is under a different UL number, maybe UL 60950 (Information Technology Equipment) or UL 1449 (Surge Protective Devices), then they're not a relocatable power tap and the RPT rule wouldn't apply.

On the third hand, there's no arguing with some inspectors.

Exactly, it is a mess! That is why I gravitated towards the PDU device because it is listed under a different number. One of my volunteers (sound and video booth) just built a custom black box with a brown extension cord in, and the other end coming out with the plug. No grommets, no nothing, but some hot glue around the cords where they enter the box. LOL I specifically told him I didn't want anything in the cabinet that wasn't UL listed. Some people just don't get it. I told him no extension cords either, but I found one in the cabinet. Thank you all for your responses.

 

[hbiss]

Yep. Unfotunately, one then runs the risk of some bright-eyes saying that it's not a listed device and can't be used at all. (And add the assembly time to the cost.)

Well then, get one from TrippLite that already has the line cord and plug.

Actually, power distribution in a rack that is plug and cord connected to a receptacle isn't even covered by the NEC. But that's no excuse to cobble something together. There is plenty of equipment with which you can do the job properly.

-Hal