Most read and commented posting (About Generators)

To be honest, as you may recall, I asked only for this blog not to be a dry as the dryer lint blog.  (which seems to have disappeared like that lost sock)

So its sort of surprising, that so many people turn to this Blog.  And what most people want according to Google statistics, at least on this blog, is facts about Generations and UPSes

So while I prepare a treatise on this this subject for my 150th Blog post coming out next week... let review what I have said so far....
http://webobups.blogspot.com/2010/10/when-you-need-online-upses.html
http://webobups.blogspot.com/2010/09/dream-rack-visualized.html
http://webobups.blogspot.com/2009/10/dumptruck-of-batteries-or-generator.html
http://webobups.blogspot.com/2009/05/5000-upsgenerator-solution-for-server.html
http://webobups.blogspot.com/2009/05/upses-and-generators.html

Best Posts of 2011

So you think its too early to a Best Of ... post.
Well I have been in rare form and want to highlight some of these better posts.

3phase UPS Systems - Design Ideas and Considerations
He is a Swell Wink, even if his Glitches give me Saggy Bumps  (about Power Quality)
What does "refurbished" really mean
Sizing a UPS for Non Computer loads
Our dedicated Symmeta site.. SymmUPS.com

Quick Buying Guide and Thoughts

We'll wait until March to revisit our popular blog series "Best UPS for a Desert Island", but for now lets do a quick update based on recent requests.

Best Unit for Imaging Machines ... the SUA3000 - 300b
You need the 3000va for the startups

Best 3000va Value ... the DL3000RM3U - 303b
The best model, made black, now for less

Really stupid purchase ... SUA3000RMXL3U - 333b
More money than the Double conversion version 313g3

Best unit for relay racks ... SU14000RMXLB3U - 413b
Extend-able runtime, good base battery system

Best 5kva version ... DL5000RMT5U - 595b
5U for lots of runtime, Extendable runtime feature, black face plates

Best 8kva system .. SU7500RMXLT - 796g3
take 500va less and save $300 over the 896g3

Inflation on UPS units

The Fed says consumer prices have remained near flat over the last 12months, however prices have changed here at GreenlightUPS.

Like any inventory-scarce business, prices change to reflect demand.  So as frequent customers know, certain items have had big price increases.

Biggest Price Change and 2nd biggest seller  - SU3000RMXL3U - 313B

from $399 in 2008 to $589 in 2011
Why...
More and more people want black units and want the ability to add runtime in the future.  Curiously, less than 10% actually buy the extended run packs at the time of sale.






Biggest Seller Price Change -  SU3000RM3U - 303

from $379 in 2008 to $409 in 2011

Why...

As the SU3000RM3U turns 10 years old, most people are wanting the newer models, keeping the price low.

Our 3rd biggest seller price change - SUA3000RM2U - 302b

from $389 in 2008 to $469 in 2011

Why...

As you all know, I hate this unit.  Its poor quality, but people keep demanding it.  The price change reflects the extra refurbishment work required to make these work

More Sizing UPS challenges

Here is another case of nameplate sizing of equipment.  
I got a request for a UPS to power a fridge that uses 7.5amps that will last 4 hours.

7.5amps times 120volt is 900volt amps or va.   But thats not the whole story.....

Step one is to understand the amperage value and its meaning for the size of the UPS.   There are 4 "types" of amperages

• FLA or full load amps or nameplate amperage  (this is usually on the equipment by the manufacturer)  It is used to size the circuitry.   That amperage never happens in real life.
• SLA or starting load amps or the peak load that occurs just briefly during startup (depending on the motor, this can be 2 to 10 times the FLA)
• RLA or running load amps  (this is the average amperage during operation)
• RMS Amps or Observed amps  (this is when someone actually measures the amperage during the equipment's operation)

So,  7.5amps  is probably the FLA and the SLA on a new high efficiency equipment is about 15amps. (15a x 120v = 1800va).  So any 3000va UPS will work 

Step two is to understand the actual load over the 4 hour outage period.  Fridges cycle on and off, so getting an observed amperage is critical.  Factoring in the duty cycle of on and off over a 4hour period suggests the RLA is about 4.5amps.  Converting to wattage, suggests this fridge uses 430 watts.

Bottomline, left to his devices he might of gotten a 900va UPS with a trunk of batteries, but by understanding is real load meant he got what he needed for about half the price.

  

Rumble in the Rack II - APC 302b versus Liebert lp312

Its been a busy sales week for APC SUA3000RM2U units.  Despite having disparaging remarks about it on my webpage, its still sells out.  ... but can it stand up to the Liebert

$469 - APC SUA3000RM2U (302b) 

versus 

$515 - Liebert PS3000RT3-120XR (lp312)

 v. 

Both units have

• 3000va, 2700watts, 120volt line interactive power architecture
• 2U frame size with 480vah battery capacity

APC has

• Cheaper price

Liebert has

• Separate controllable receptacle banks
• Extended Run feature which allows for adding more batteries to increase runtime
• Can be either rack or tower and comes with free rack rails
• Network surge suppression
• Separate twistlock receptacle on dongle cord for ease of connection

WINNER:  Liebert... not even close

Random APC Part of the month VI

Here is a RAPM that I use... the NetworkAir PA1000 Air Cooled Self Contained  system (AP7003).  Believe it or not, Cooling is a major sector of APC.  On big systems, like Lieberts, the ACs are more than the UPSes

I bought mine to run on my generator during the Hurricane sagas we had going on a few years ago.  During Wilma, this baby managed to cool my bedroom down to about 81.9 degrees at night.

So while its not going to replace your central air, it does work nicely to supplement existing AC systems.  At about $300 its a good price point.
Read more about APC's religion of cooling here, especially their Hot and Cold zone fetish

Sizing UPSes for non computer loads

Sometimes, we get a request to suggest a UPS based on model numbers.  Other times we get specs or competing bids.  Then occasionally we get someone that knows just enough to be dangerous....

This guy wanted a UPS for his two computer controlled lathes.  The nameplate on each lathe motor was 9.5amps at 208volt.  So he asked for our APC 5000va UPS since the total VA or volt-amps was 3952.  Fortunately he shared his purpose before we shipped it to him.  Why?

a ) 19amp x 208volts is indeed 3952 volt amps, but that is based on FLA or full load amps.  Lathes have motors and have a startup amperage of 2-5 times the FLA that must be considered in the UPS
b)  the computer lathe had other components, not just the main motor.  Displays, servos, etc, dont take up too much power, but must be included in load calcs
c)  both motors could be starting at the same time, so its possible to have extended startup amperage.
d)  VA isnt the same as wattage. On non computer loads is very important to understand the factors that influence wattage.

So, I am pretty sure the 5000va unit would not have met his needs, because each unit probably demands 20amps to start, meaning 40amps potentially.

Our solution, was to a) get the real startup amperage using a MinMax multimeter {peak 14.6a}  b) sell him two 3000va ups units so as to limit the chance of dual startup and c) switch to Powerware UPS system since they often can handle 125% of load for a brief period.

Bottomline,  even if you have been told about a certain UPS, feel free to ask for our opinion.  We want you happy and your equipment working well.

All plugs are created equal and have certain inalienable rights....

I got this question today... and freaked out!

We upgraded our server wiring from 120volt to 208volt.  I want to buy a 208volt UPS.  But, since I didnt change all the plugs, I wondered if you can put a L530P on the 208volt UPS?

L5xx is a NEMA designation for 125volt circuitry.  As I mentioned before, NEMA plug designations allow people to look at a device and know the voltage for it.

So, when someone asks me to put a L530R (Locking - 3wire 125volt - 30amp - Receptacle) on a their new 208volt system, I freak out.  L5 is a 125volt, L6 is for 250volt.

True on the L5 and L6.... the wire, prongs, cord, etc are all rated for 250volt, so its not going melt.
But, if you sell or move that unit, someone will be able to plug that 208volt unit into a 120volt L530R outlet and be disappointed.

I know plugs, devices, and electricians are expensive, but put the proper class of plugs on a unit.

Website for just Symmetras

As followers of this blog know, WeBobUPS has many websites selling the exact same things.

Our new website is SymmUPS.com as in APC Symmetra UPS

This site will focus on selling the Symmetra systems.  It has the same prices as GreenlightUPS.com and others, but it will have the whole line of units, even if I dont have that product in stock.

It also will have a Symmetra Buyback page, so partners can track the value of certain parts

Are you some type of L530P preacher

A potential customer called me out on a what he saw was an obsession with the L530 Nema designation. (just talked about NEMA plugs a few days ago here)

He noticed that nearly every 2200va UPS has a recommended L530P as the input plug on my website.

As a possible member of the dreaded Plug Police, he reminded me that it was illegal to put a 30amp plug (which is what a L530P is) on a UPS rated for 20amps.  And that no manufacturer recommends this. Even though he called before 8am, I tried to politely reminded him of the tag at the bottom of every listing.

Input plugs changed at no charge

So 1) Its not an obsession, more like a  compulsive preoccupation to have all server rooms use dedicated 30amp outlets for the UPSes.

If I give you a L530P plug on your UPS that means you will need to have a 30amp receptacle to use it.  And a 30amp receptacle is a good thing because: the presence of a 30amp outlet in your server room means your probably have a modern and safe electrical system.  Thats because if you have a 30amp receptacle you specifically asked for it.  Its not ever put in voluntarily by a low bid contractor. And when he put it in it didn't get spliced from another circuit, since there isnt any 30amp 120volt circuits wandering around.  And 30amp outlets typically weren't installed 20 years ago, which means the outlet will be modern and safe and probably up to code.

And 2) Its not illegal... maybe it is in Russia... This isnt Russia?

Ahh, Danny, this isn't Russia. Is this Russia? This isn't Russia, is it?

Amperage designations and related circuit breaker protection is what must be followed.  A 30amp outlet must have #10 wire supplying the receptacle.  A 30amp cord cap (L530P) must have #10 wire on the cord.  True, putting a 30amp cord cap on #12 wire is bad, but if the UPS has a 20amp input circuit breaker on it, it doesn't really matter

Bottomline, I like to put L530s or everything to make it easier.  Your IT rooms are complicated enough.  If everything is 30amp your wont have to keep changing 520s, L520s, and L530s around as you change and upgrade equipment.

L5, L6, L7, EL-Libre... plug designations

In order to prevent us electricians from using terms like "the outlet with a t socket,"  "a monkey face," or "Looser head", the. National Electrical Manufacturers Association created a hierarchy of devices with number designations.  Every device has a name that designates its wiring style, amperage, and type of device.
 

Your typical home outlet is called a 5-15R.  5 - meaning 125v 3wire L+N+G (line, neutral and ground) - 15 meaning - 15amp - Receptacle.  Adding an L to the terminology, means that it is a locking or "Twist Lok" device.  L5-30P means Locking - 125v, 3 wire L+N+G - 30amp - Plug.  There are 20 or so wiring styles and many combinations thereof.

What helps us electricians is that each designation has different contact blade widths, shapes, orientation, and dimensions that are unique to that  particular voltage, current capacity, and grounding system.(1)

So a L5-20P cant fit into a L6-30R.  Being that one is 125 volt and the other 250 volt, thats a good thing.

The other benefit is that we can look at the equipment's plug and quickly determine the voltage.  

Bottomline, you dont need to learn all the NEMA subclassifications to discuss your UPS power needs, just know that I will always refer to devices not by crazy descriptive name, but by their NEMA name.  And my most common Nema devices are here

KnowUPS - Getting More from your UPS: Issue 2 - Switched Load Management

A common feature desired by many IT users from UPSes is the ability to switch On and Off various loads remotely on the UPS.  Such as during an outage, having UPS plug X shut off to conserve power.
While Powerware and Tripplite have had this feature, APC just recently added it in their 5th generation systems.

Switched Load Management is described as

By using new APC Smart-UPS with switched outlet groups and PowerChute Business Edition 9.0, users can configure the exact sequence by which equipment shuts down and restarts so that more critical servers stay online longer. Users can also power off less critical equipment under certain conditions to conserve runtime. This increased flexibility means greater availability for mission critical equipment.

Look for this SLM in our 5gen APC units: 200v, 300v and in most of our newer Powerware (p9212v), Tripplite (to313) and Liebert Units (lp312).

Split Phase UPS Units... the UPS to power your subpanel

Awhile back I wrote about a customer looking for a split phase UPS.
"75mins saved hims 75%"

In that post, I mentioned how in many cases the need for a 4 wire or "split phase" UPS is unnecessary if all you need is 120volt outlets.  (Better to buy a step down transformer or re-evaluate your low voltage needs)

The only application where a split phase UPS is useful is when connecting to a panel.  Your electrical panel, either 120/240 or 120/208v is a 4 wire system.  Two wires carrying current called "hots", a ground, and a neutral.  But nearly every UPS is a 3 wire system (2 hots +G), which causes a problem

The solution in most cases, is to add a transformer (xf5iso) that outputs a fixed neutral creating 4 wires (2 hots + N + G).

However, a more expensive option is to buy a UPS that has the separate neutral system built in to its 3U frame.  These Smart UPS RTD-P units take in 4 wires and output 4 wires.

We finally have our first one and while it is still expensive, its just a bit more than buying the transformer separately.  The 693p3.