UPS For Emergency lighting.

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R o y a l

Member
Gents,
I have been asked by a friend: if the use of UPS to power florescent fixture lights (small Business ) is a good option? or the use of emergency light (with battery) will be more better.? in case of black out .
when I checked through the internet I found that UPS's are used mostly for communication sector and few of them are used for supplying such load .
if the use of UPS is good option how can I calculate the right rate(UPS VA or KVA ) for this load (4 fixtures approximately 0.5 Amp EA )(120 volts) (0.5x4x120 =240 VA) for 60 Minutes.
Please if someone tried this option (UPS for emergency lighting ) give me his advice .

Thanks &best regards.

I'm here to learn from all of you:thumbsup:
 
weressl

weressl

Esteemed Member
Location
Texas by the Gulf, geat crab, great shrimp
R o y a l said:
Gents,
I have been asked by a friend: if the use of UPS to power florescent fixture lights (small Business ) is a good option? or the use of emergency light (with battery) will be more better.? in case of black out .
when I checked through the internet I found that UPS's are used mostly for communication sector and few of them are used for supplying such load .
if the use of UPS is good option how can I calculate the right rate(UPS VA or KVA ) for this load (4 fixtures approximately 0.5 Amp EA )(120 volts) (0.5x4x120 =240 VA) for 60 Minutes.
Please if someone tried this option (UPS for emergency lighting ) give me his advice .

Thanks &best regards.

I'm here to learn from all of you:thumbsup:
Click to expand...

UPS's are generally constructed to provide uninterrupted(less than 1/4 cycle transfer), regulated and clean sinusoidal wave power to sensitive electronic equipment, usually microprocessor based that would loose it's memory, interrupt the operation of systems that it controls. Obviously that quality of power supply far exceeds that supporting continuous emergency lighting that can tolerate lesser quality power with longer trasnfer times. The difference translates to $s.

I have used centralized, full AC voltage backup supplies for large and widely distributed emergency lighting. Their output were close to a square wave and employed mechanical contactors for normal/emergency transfer, resulting in longer transfer times. Even the longer transfer times did not cause HID lights to drop out, so it satisfied the purpose. Any of these systems rely on batteries and if long battery times are required, beyond 20-30 minutes, combining these with an emergency generator proved to be the economical choice.

One cource: http://www.controlledpwr.com/index.php

Good to remember that your battery string is the critical element in any of this type systems as a single battery failure makes the entire system inoperative, even if the electronics don't fail. You'll have a large number of series connected batteries. Dual battery banks and/or automatic monitoring the batteries could remedy this issue. The other trick is to use emergency lights with the lowest possible power consumption and I believe LED's would shine in these applications.

Remember to check the legal requirements for your system, such as length of backup time and separate wiring, required approval of components, etc.
 
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hurk27

Senior Member
Location
Portage, Indiana NEC: 2008
Emergency lights and signs are required to have a back up time of at least 90 Min's. see 700.12(E)

I should have said 700.12 require a UPS to follow 700.12(A) and (B) in which it will still be required to last 90 min's
 
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texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
Another thing to consider, aside from not complying with Art 700, is that most small/inexpensive UPS units brag about the VA capacity but the fine print says @.5 PF or so. So you have to be real careful in calculating the real watts.
 
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scotteng

Member
Location
Apollo Beach, FL
Occupation
Professional Engineer
You have three realistic options. First is to use wall mouted battery pack fixtures which cost about $30 each. Second is to have a battery ballast in each fluorescent fixture at a cost of about $100 each. Third option is a lighting inverter (UPS), which will cost more than the other two options and require dedicated wiring compliant to NEC 700.12. The UPS must be UL 924 listed for use as an emergency lighting system. Your application doesn't sound like one where I would use a lighting inverter as there are other options to do the needed task a whole lot easier and cheaper.
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
Another issue is the unit would have to be listed for emergency use.

There are emergency inverters for this purpose but they are very expensive.
 
rbalex

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Since most AC loads don?t actually need to be ?uninterruptable,? as a general rule, I avoid UPS unless the load must be AC AND it must be ?uninterruptable AND clean.?

?Uninterruptable? alone is usually best achieved making the loads DC and it?s usually more reliable.

?Clean? AC alone is usually best achieved with electrostatically shielded/isolation transformers. In fact, it?s usually ?cleaner? than most UPS.
 
O

Open Neutral

Senior Member
Location
Inside the Beltway
Occupation
Engineer
I'd think it crazy to run fluorescent lighting from a computer-style UPS. First off, they fail often.

Some of the LED lamps now sold for 120 VAC use will run off 48VDC. In a residence, client's SWMBO likes LED lighting, & I am looking at running them off 48V battery all the time. That way, they won't even blink when there's a line hit, including motor starts. In our case the 48V battery plant already exists for backup inverters, but I like the idea the lighting will run even if the inverters fail.

No idea if such a scheme could meet Code in a commercial building.
 
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T.M.Haja Sahib

Guest
weressl said:
.......if long battery times are required, beyond 20-30 minutes, combining these with an emergency generator proved to be the economical choice.
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What about the other way around : minimizing the battery time to less than 10 minutes due to provision of an emergency generator?

Is it permitted by the code?

Thanks.
 
T

T.M.Haja Sahib

Guest
weressl said:
Yep, 10 minutes is less than 20-30, so the economics are even better.
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The UPS with a battery time of 5 minutes only and provided even with a standby generator is still more an economical option.I tried to provide one such in one of our company's computer installations,but could not,because ups with minimum battery back up time of 30 minutes only is available on Government Rate Contract for ups.

Is such ups available in the open market?Thanks.
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
A few points

If the lighting we are taking about is required egress lighting it must be supplied from a source that is identified and approved for that purpose.


700.5 Transfer Equipment.
(A) General. Transfer equipment, including automatic transfer
switches, shall be automatic, identified for emergency use,
and approved by the authority having jurisdiction.......
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A "UPS" contains transfer equipment.

If you have a generator that is designed for emergency use there is no requirement for the batteries at all.

If you have batteries and equipment that are designed for emergency use you will have at least 90 minutes run time and there would be no requirement for a generator.

700.12(A) Storage Battery. Storage batteries used as a source of
power for emergency systems shall be of suitable rating and
capacity to supply and maintain the total load for a minimum
period of 11⁄2 hours, without the voltage applied to the
load falling below 871⁄2 percent of normal.....
Click to expand...

700.12(B) Generator Set.
(1) Prime Mover-Driven. For a generator set driven by a
prime mover acceptable to the authority having jurisdiction.....
Click to expand...

700.12(C) Uninterruptible Power Supplies. Uninterruptible power
supplies used to provide power for emergency systems shall
comply with the applicable provisions of 700.12(A) and (B).
Click to expand...


Of course you can exceed the code and provide both batteries and generator but at least one or the other must be identified for the purpose and acceptable to the AHJ. We did a job in one area where the AHJ said both had to be identified for the purpose we did not agree but did comply.
 
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T.M.Haja Sahib

Guest
iwire said:
If you have batteries and equipment that are designed for emergency use you will have at least 90 minutes run time and there would be no requirement for a generator.
Click to expand...


Is it allowed to use a standby generator together with ups having backup time less than 90 minutes for emergency uses such as egress lighting?Thanks.
 
weressl

weressl

Esteemed Member
Location
Texas by the Gulf, geat crab, great shrimp
iwire said:
A few points

If the lighting we are taking about is required egress lighting it must be supplied from a source that is identified and approved for that purpose.

A "UPS" contains transfer equipment.

If you have a generator that is designed for emergency use there is no requirement for the batteries at all.

If you have batteries and equipment that are designed for emergency use you will have at least 90 minutes run time and there would be no requirement for a generator.

Of course you can exceed the code and provide both batteries and generator but at least one or the other must be identified for the purpose and acceptable to the AHJ. We did a job in one area where the AHJ said both had to be identified for the purpose we did not agree but did comply.
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The OP had not established that this is a legally required standby system or not, previous comments had reflected on that.

Standard UPSs actually are NOT labeled as approved for legally required life safety systems. Silly though as most of them are far exceed the requirements, but it's another test and another $.:D

If there is HID lighting, then there is restrike involved and the generator startup/stabilization length would leave the emergency lights off until the cooldown/restrike cycle, unless there is quartz standby installed within the HIDs. The Code is mute about what is an acceptable interruption time.
 
weressl

weressl

Esteemed Member
Location
Texas by the Gulf, geat crab, great shrimp
T.M.Haja Sahib said:
Please provide a 'yes' or 'no',as yourself used to insist.
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Yes, that maybe so, but you're asking questions to which the reply and answer is publicly available. In other words, you're not asking for advice, but asking people to do research for and instead of you, to provide links that you can also obtain easily. Not conducive to a friendly atmosphere that, beside all the needling and noodling, we all strive to maintain here.

This is no longer the British Empire with the Master/Servant relationship, nor is here a caste system.:lol:
 
R

R o y a l

Member
Thank you guys for your posts .
your posts were very helpful for me.

toady I found this :
:?
The Lifelight Mini-UPS is a true on-line system, providing 90 minutes of battery time for HID, fluorescent and incandescent lamp applications.
http://www.bigbeam.com/lifelight.html
and
I'm not sure if this can be true ."90 minutes":?
 
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