Support - FAQ's
- What is a UPS and how does it work?
- What is the difference between on-line and
off-line?
- What is a bypass function?
- What does kVA mean? VA mean?
- What is the wattage and VA relationship?
- Is an on-line UPS better?
- How do I size a UPS for my application?
- Can a single UPS support more than one
workstation or server?
- Can we change, or have the electrician change the
voltage taps inside the UPS module to change the input voltage
wiring?
- How does CPT calculate battery run time?
- What is "MTBF"?
- What is the difference between the UPS
technologies: off-line (or stand-by), line interactive and
on-line?
- How much battery run-time do I need?
- How do I figure out how much battery backup time
I have at less than 100% capacity?
- How do I select the proper size unit?
- What is "SNMP"?
- Why do I need a UPS?
- When do I need new batteries?
- I have a number of workstations in one location,
do I need to buy multiple UPS's?
- A UPS is sized by VA - what is "VA"?
- Do I need software to run my UPS?
- How can I get the cover off of my micro-FERRUPS
(500-3.1KVA)?
- Where can I find the Serial Number?
- Can I change the batteries in my UPS while it is
running?
- How often should I change my batteries?
- Why won't my unit run on generator power?
- Why is the runtime displayed on my unit
different from the actual runtime?
- What should I do if I find that I have a circuit
reading 88 VAC?
- How often does my unit need preventive
maintenance?
- Can I use a 208VAC with a Make-Before-Break
Bypass Switch?
- Can you monitor and control UPS(s) remotely?
- Explain gel batteries vs. SLA batteries
- Explain battery ratings and how they are used?
- What is a battery cycle?
- What are deep cycle batteries?
- How does overcharging damage batteries?
- List the types of batteries
- Can UPS Battery Life be extended?
1. What is a UPS and how does is
work?
An Uninterruptible Power Supply is a device that sits between a
power supply (e.g. a wall outlet) and a device (e.g. a computer) to
prevent undesired features of the power source (outages, sags,
surges, bad harmonics, etc.) from the supply from adversely
affecting the performance of the device.
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2. What is the difference
between on-line and off-line?
On-line UPS implies that an electronic inverter is constantly
supplying AC power to the load under all modes of operation.
Off-line UPS supply input utility to the load during normal
operation and revert to a battery-powered inverter during utility
failures.
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3. What is a bypass function?
In a UPS scenario, a bypass feature is in essence, a switch between
the input and output of the device. It allows the routing or
transfer of incoming power to the output bypassing any internal
circuitry. The bypass function uses the A/C supply power as its
standby source of power. This feature allows power to continue to
flow to connected equipment if the UPS system encounters an internal
error or overload condition. The UPS system will automatically
transfer to the by-pass quickly to ensure that the connected
equipment continues to operate.
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4. What does kVA mean? VA mean?
The output of a UPS or Power Conditioning product is measured in
volt-amperes or VA (output voltage x output current). The term kVA
refers to kilo-volt-amperes or VA x 1000.
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5. What is the wattage and VA
relationship?
Put simply, real power (watts)/apparent power (VA) = power factor.
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6. Is an on-line UPS better?
On-line UPS units provide better overall power protection to the
load than off-line. This protection includes power conditioning,
regulated voltage and frequency, and zero translation time to
battery during a utility failure.
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7. How do I size a UPS for my
application?
Multiply the voltage rating of the equipment by the current rating
of the equipment to obtain a VA rating. The UPS must be rated to
deliver at least this VA rating. See the "How to Size a UPS" section
of our web site for more info.
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8. Can a single UPS support more
than one workstation or server?
Yes, if the UPS is sized large enough for the application.
Maintaining close proximity of the hardware to be supported is
preferred to long distance electrical runs, which can cause unwanted
ground current imbalances. Our technical staff is available to
assist in the design of the electrical distribution.
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9. Can we change, or have the
electrician change the voltage taps inside the UPS module to change
the input voltage wiring?
Lugs inside the UPS module should only be changed by a qualified CPT
Services Field Engineer.
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10. How does CPT calculate
battery run time?
Battery run times are calculated based watts per battery
measurements referred to in our product technical specifications per
manufacturer.
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11. What is "MTBF"?
"MTBF" stands for "Mean Time Between Failures". To calculate MTBF:
8760 hours (= 1 year)
--------------------------------------------
No. of power disturbances in 1 year
MTBF, for most UPS systems, is 25,000 hours and higher. When
deciding whether to use one facility UPS or multiple smaller systems
keep in mind the following: If one UPS has an MTBF of 25,000, then
two UPSs will have a combined MTBF of 12,500 hours. Extending this
logic to a medium size data center with 10 UPSs, they will have a
combined MTBF of 2,500 hours (or 2 months) between failures. The
failure may only become apparent when utility power is lost and the
supported system crashes.
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12. What is the difference
between the UPS technologies: off-line (or stand-by), line
interactive and on-line?
Please refer to the UPS Topology
section.
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13. How much battery run-time
do I need?
This can vary greatly depending on the critical load. Do you need
just enough time to save files and shut down the computer, or is
this a 24/7 site where no downtime is acceptable? For a typical PC
or workstation, you need at least 5-10 minutes of battery backup to
complete any work in process and gracefully shut down your system
during extended power failure. For more mission-critical systems,
extended run-time batteries or emergency generators are required. A
JT Packard representative can help you determine the correct
solution for your unique application.
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14. How much battery run-time
do I need?
Battery backup time is a non-linear function dependent on the
battery type, battery age and the load. There are two ways to
determine the actual time:
1)Contact CPT with the battery and load information. We
have detailed battery discharge curves for most battery systems to
provide the calculated hold-up time. Keep in mind that a UPS
battery, like any battery, is a consumable and weakens with age.
You may have considerably less hold-up time with a three year old
battery system than when new.
2) Perform a discharge test. Call
CPT for the procedures or to arrange for a battery service
professional to perform this test for you.
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15. How do I select the proper
size unit?
Sizing a UPS for a PC or workstation can be simple. As with any
electrical device, a computer has a rating plate that will give the
power consumption, usually listed as "amps".
A UPS is sized by VA, or Volt Amps. To determine the VA, multiply
the amps by the 120 (volts) to determine the VA (Volts x Amps = VA).
Be sure to allow for at least a 20% growth factor.
Configuring a larger UPS is more complex with many more variables
such as interaction between devices, different voltages, growth
planning, and distribution. Contact a power professional at CPT for
assistance.
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16. What is "SNMP"?
Simple Network Management Protocol (SNMP) is a family of protocols
that provide a means for monitoring and controlling networked
devices. Computer vendors have built into some network devices,
including some UPS models, network management capabilities so that
you can query their status remotely, as well as allow the sending of
alerts when a certain type of event occurs. These devices are
usually referred to as "smart" devices.
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17. Why do I need a UPS?
A UPS is the life support system for your computer installation. It
protects against the combined risks of data loss and hardware damage
resulting from daily power fluctuations and losses. These events are
routine and uncontrollable, and without a UPS will affect your
operations and bottom-line costs.
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18. When do I need new batteries?
UPS batteries are typically rated for 5 years or 200 complete
full-load discharge cycles. This assumes that the batteries have
been maintained within specifications. The only true way to
determine remaining capacity is to perform a battery discharge test.
CPT can provide this service or provide
you with the information if you wish to perform it yourself.
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19. I have a number of
workstations in one location, do I need to buy multiple UPS's?
In most cases, it is more cost efficient to simply buy one, larger
UPS to back up your critical load (see FAQ answer #11).
As UPS systems get larger, the per kVA purchase and maintenance
costs go down significantly.
Additionally, larger "data center" systems will typically provide
a higher level of protection against power anomalies, as well as
support more sophisticated monitoring capabilities.
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20. A UPS is sized by VA - what is
"VA"?
VA is short for "volt amps". This is a measurement of the power
consumed by any given piece of equipment. For larger installations,
you will see the term kVA (kilo volt amps). One kVA is equal to 1000
VA. For example, a computer that draws 5 amps from a 120 volt source
is using 600 VA of power (120 V x 5 A = 600 VA).
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21. Do I need software to run my
UPS?
For most UPS functions the answer is no. But remember, if a power
outage lasts longer than the battery hold-up time, the UPS is only
postponing the inevitable crash. For prolonged outages, a shutdown
utility must be installed on the protected computer. This utility
will communicate with the UPS and, after a set period of time which
you determine, take control of the computer and shut it down
gracefully, avoiding a system crash. Depending on the UPS and
manufacturer, these utilities can also perform a variety of
environmental monitoring and management tasks. Which UPS and
software package we recommend is based on your unique requirements
and environment.
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22. How can I get the cover off of
my micro-FERRUPS (500-3.1KVA)?
Remove the grounding screw on the top of the unit toward the rear,
then on the front of the unit, behind the BEST decal loosen the
captive screw by turning counterclockwise until you can hear a
clicking sound. Then slide the entire over off of the front until
completely removed.
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23. Where can I find the Serial
Number?
On the rear of the FERRUPS units, there will be a data plate with a
bar code and the serial number will be below the bar code. On 4.3KVA
and larger units, behind the locked door will also be a second data
plate containing the serial number.
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24. Can I change the batteries in
my UPS while it is running?
Several Best Power UPS's allow for hot-swappable battery
replacement: the FERRUPS 800 Series (2kVA to 7.5kVA); Fortress
tower, Fortress Rackmount and Fortress.TeleCom models (750VA to
2250VA); and Patriot Pro II (400VA to 1000VA). Hot-swappable battery
replacement results in reduced maintenance and service costs.
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25. How often should I change
my batteries?
You can expect to change your batteries in 3-5 years under ideal
circumstances. There are variables that could shorten the life
expectancy, such as bad site comercial power, hotter temperatues
where the batteries are stored and improper maintenance procedures.
There are more circumstances that could also lead to premature
battery failure; please contact Best Power for more information.
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26. Why won't my unit run on
generator power?
It may be possible that your unit needs to have a generator set-up
performed to make it less sensitive to fluctuations common to most
generators. If this is a problem, please contact Best Power for
information.
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27. Why is the runtime
displayed on my unit different from the actual runtime?
Runtime is only accurate when the unit is runnning on inverter power
and has been in that state for several minutes.
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28. What should I do if I find
that I have a circuit reading 88 VAC?
On FERRUPS units with hardwired outputs where the actual output
connections are made, you will find that one of the wires have been
fastened to a terminal that has 88VAC there (necessary if one of
your circuits are to be 208VAC Single-Phase) instead of one of the
120VAC terminals. Verify with a true RMS multimeter at the proper
terminal and reconnect the correct wire in accordance with your
Installation Manual.
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29. How often does my unit need
preventive maintenance?
At a minimum, Best Power recommends preventive maintenance once a
year to extend the life of your batteries, as well as to ensure
trouble-free operation. Contact Best Power for details including
some attractive maintenance contracts that can save you both money
and time.
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30. Can I use a 208VAC with a
Make-Before-Break Bypass Switch?
A FERRUPS or UNITY/I Single Phase installation using a
Make-Before-Break bypass switch will not work with a 208 VAC input.*
In this configuration, the phase angle difference between the
FERRUPS output and the bypass A/C circuit will cause equipment
damage if switching the bypass switch from the UPS to the LINE
position. It may cause the input breaker to trip, or possibly, weld
the switch contacts together permanently.
Recommendation: For all installations of a
Make-Before-Break bypass switch for which the input to the UPS is
208 VAC, a single-phase linear isolation transformer must be
installed to step the input voltage up to 240 VAC. The linear
isolation step-up transformer should have a kVA rating equal to or
greater than the UPS- rated kVA, with a 208 VAC primary winding and
a center tapped 120/240 VAC secondary winding. A Buck/Boost type
transformer is not compatible for this application.
*208 phase-to-phase has a 120-degree phase angle difference
derived from a Three-phase power source. The output of the FERRUPS
is a single-phase derived output with a 180-degree phase to phase
relationship. Since the neutral is bonded to ground on both
systems, the phase relationship is referred to as a common point,
therefore the phase difference will cause problems. This 60-degree
phase difference will cause a large current impulse through the
contacts of the bypass switch, leading to arcing and premature
failure of the switch.
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Can you monitor and control
UPS(s) remotely?
Yes, by using remote hardware, customers can monitor and view
remotely. This can also be done with a network management software
package, and network adapter products.
Explain gel batteries v.s. SLA
Gel or sealed lead acid batteries are basically the same chemistry
as a wet (flooded cell) battery. The batteries' electrolyte is in a
gelatin form and is absorbed into the plates and the battery is
sealed with epoxies. These batteries may be used in any position and
the batteries are exceptionally leak resistant. Battery uses are
UPS, emergency lights, and camcorders. These batteries are 2 volts
per cell so the common batteries are 4, 6, and 12 volt.
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Explain battery ratings and how
battery ratings are used?
Some of the common battery ratings are:
Amp-Hour battery rating: This is a common battery rating of
batteries. Amp-hour rating of battery capacity is calculated by
multiplying the current (in amperes) by time (in hours) the current
is drawn. Amp-hour battery rating is commonly used on sealed lead
acid batteries used in UPS systems, emergency lights and camcorders.
For example: A battery which delivers 2 amperes for 20 hours would
have a 40 amp-hour battery rating (2 * 20 = 40).
Cold Cranking Amperage
battery rating: CCA is the discharge load in amps which a battery
can sustain for 30 seconds at 0 degrees F. and not fall below 1.2
volts per cell (7.2V on 12V battery). This battery rating measures a
burst of energy that a car needs to start on a cold morning. This
rating is used mainly for rating batteries for engine starting
capacity and does not apply to NiCad batteries, NiMH batteries or
Alkaline batteries.
Reserve capacity battery rating: RC is
the number of minutes a new, fully charged battery at 80 degrees F.
will sustain a discharge load of 25 ahps to a cut-off voltage of
1.75 volts per cell (10.5V on 12V battery). This battery rating
measures more of a continuous load on the battery.
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What is a battery cycle?
Battery cycle: A cycle of a battery is a discharge plus a charge.
For example, if your battery is full charged and you apply load
(use) the battery and it discharges some (maybe completely) and then
recharge to full battery charge; that is one cycle. Cycle life is
the total number of cycles a battery yields. The cycle life is very
important in battery applications such as laptop batteries and
emergency light batteries. A Ni-cad battery has a cycle life of
500-1000 or more cycles.
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What are deep cycle batteries?
Deep-cycle batteries typically feature thick plates with a
high-density active material. The thick battery plates allow for
reserve energy to be stored deep within the battery plate and
released during slow discharge such as trolling or electronic
instrument use. The high-density active material remains within the
batteries' plate/grid structure longer, resisting the normal
degradation found in cycling conditions. They are typically used
where the battery is discharged to great extent and then recharged.
For example, a battery powered trolling motor on a fishing boat.
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How does overcharging damage
batteries?
Overcharging a battery occurs when the total capacity removed has
been replaced by recharging and the battery remains on charge. This
overcharging creates excessive heat which can cause the battery
plates within the cells to buckle and shed their active material.
The battery will react to the overcharge by producing an excessive
amount of hydrogen and oxygen. These gases are the result of the
breakdown of the water molecules within the electrolyte. The water
that has been displaced by overcharging can be replaced in a
serviceable (non-sealed) battery, but, in the maintenance-free
sealed batteries, permanent capacity loss will result.
Excessive discharging a battery can also damage a battery. The
amount of discharge a battery can have without damage depends upon
the chemistry of the battery, but in general a lead acid battery
will not tolerate as deep a discharge as a Ni-cad battery or Ni-mh
battery. Sealed lead acid batteries function best if they are
discharged to only about 85% of nominal voltage (10.2V on 12V
battery).
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List the types of batteries
A few types of batteries are: Sealed Lead Acid, Flooded Lead Acid,
Ni-Cad, Alkaline, Silver Oxide, Lithium, Mercury (not mfg in US any
more), Manganese-Dioxide, Zinc-Air, and Ni-MH.
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Can UPS Battery Life be
extended?
Any doctor will agree that exercise is the key to a long and
healthy life. Believe it or not , the same advice holds true for the
batteries in your UPS units. Before you go out and buy a "Thigh
Master" for your UPS
read on.
The batteries in the UPS are Sealed Lead Acid (SLA). The reaction
between the acid and the lead produce electricity that is used by
the UPS in the case of a power outage. However, there is a dark side
to this chemical reaction: Sulfation.
As time goes by, and the battery is not used, a white powdery
substance starts to adhere to the plates of lead in the battery.
This is called sulfation and is a by-product of the lead-acid
chemical reaction. If enough sulfation occurs the acid can no longer
make contact with the lead and the battery can no longer produce
electricity.
There is a way to prevent sulfation. You guessed it, exercise! If
the batteries are regularly exercised, the build-up of sulfates is
minimized and the battery life is extended. Here's what you do. Two
to four times a year (I suggest when you change your clocks), cut
the power to your UPS by simply pulling the plug. Make sure you are
not in the middle of any processing on your computer. Let the UPS
run on battery for about 3-5 minutes. As the battery heats up the
sulfates will release from the plates and fall to the bottom of the
battery case. Now the battery has clean lead for the acid to react
with, so as to obtain the maximum output. |
