Answer: There are several potential causes for this problem.
1. The battery is disconnected: Per Department of Transportation regulations, APC ships all of their UPSs with one battery
lead disconnected. APC's newer Back-Ups models will either not turn on or flash their replace battery light, followed by a single
beep in 3sec intervals. The older 2G Back-UPS and Powercell models will turn on with the battery disconnected. You would not know
that it is disconnected until the unit went to battery at which point the unit would turn off and drop the connected equipment.
Consult your User's Guide for battery connection instructions.
2. The UPS is overloaded: Each UPS is limited in the amount of equipment that can be plugged into it. The number in the model
number of the UPS tells you the Volt-Amp (VA) limit of your specific model. (The exact model number can be found on a white bar-code
sticker on the rear of the unit.) For example, a BX1500 is capable of handling 1500 Volt Amps being plugged into the Battery + Surge
side of the UPS. To determine if your UPS is capable of handling the amount of equipment you've plugged into the Battery side, visit
APC's sizing guide at www.apcc.com/sizing If the UPS is severely overloaded, the UPS may shutdown and/or the unit's resettable
circuit breaker will trip. The unit must do this in order to protect it's internal circuitry. This will cause all the equipment
connected to the battery side of the UPS to power off. If the circuit breaker is tripped (it will stick out about a quarter of an
inch to a half inch), turn the unit off and push the breaker back in with your finger. Reduce the load and power back up. Ensure that
you only have "data-sensitive" equipment plugged into the Battery side of the UPS. Peripheral devices, such as printers, copiers, fax
machines, and table lamps, should be connected to the Surge-Only side of the UPS to prevent unnecessary loading of the UPS.
3. Equipment is plugged into the wrong outlets: Many of APC's UPS's have a "Multi-Path" design where some outlets on the unit
are for Surge Protection only. In other words, some outlets are not battery backed up. So any equipment plugged into these outlets
will lose power anytime the UPS goes to battery. Ensure that all "data-sensitive" equipment is plugged into the battery outlets on
the UPS. The outlets are labeled as being Battery + Surge outlets or surge-only outlets.
4. The UPS exhausted its available battery power: The UPS can only supply battery power for a limited time before the unit
must shutdown to protect itself from totally discharging. In some cases, depending on the size of the load and the size of the UPS's
batteries, the UPS may only have a few minutes of battery power. If the UPS didn't shutdown when it reached a low battery condition,
the unit would become incapable of recharging its batteries. Try to determine if the UPS had been on battery shortly before the load
shutdown. Keep in mind that while normal power may seem to exist, many power problems are transparent or invisible to a user. These
unforeseen power problems, such as voltage waveshape distortion, Harmonic Distortion, and frequency variances, will cause the UPS to
go to battery. You may have found that your UPS has been going to battery but only for a very short amount of time. So, what may be
happening is that it is going to battery frequently enough that the unit has not had enough time to recharge. Eventually, then, the
UPS will shutdown (and drops your load). Try letting the unit recharge by leaving it plugged into the wall and turned on (with no
load attached) for 6-8 hours or so.
5. The connected equipment does not accept a stepped-approximated sine wave: APC's Back-UPS models, all output a "stepped-
approximated" sine wave when the unit is On Battery. While this kind of waveform is ideal for computers and computer-related
equipment, it may not be compatible for other types of loads like motor loads. If you are using non-computer loads with one of the
above mentioned UPSs, consult the manufacturer's specifications to determine if the equipment can run off of a "stepped wave". If it
can't, then it will require a UPS which outputs a pure sine wave when On Battery. APC UPS models which do output a Pure Sine Wave
include: Smart-UPS 700va and above, Matrix-UPS, and the Symmetra Power Array.
6. The power supply in your equipment is faulty and incapable of handling the transfer time of the UPS: Depending on the model
of the UPS, the transfer time (time it takes for the unit to transfer from On Line to On Battery) can vary anywhere from 2
milliseconds to 8 milliseconds. Modern computer and computer-related power supplies can "ride through" power outages as long as 10-20
milliseconds. Many, in fact, can last through a 50 millisecond gap in power. If the equipment is rebooting when the UPS transfers to
On Battery operation, this may be the problem. Try to recreate the problem by connecting another device, pull the plug on the UPS
(puts it on battery) to see if the new device stays up and running when the UPS goes to Battery. If it does, then its more likely
that there is a problem with the power supply of the original piece of equipment.
7. Optional UPS shutdown software is shutting down the UPS: Some of APC's UPSs have an RS-232 serial port. The Serial port is
to be used with the management software provided with the UPS. In the event of a sustained power outage, the management software will
gracefully shutdown the computer's operating system. Once the operating system has confirmed it's shutdown, the UPS will shut itself
down. If you are using the optional software, check for the possibility that the software performed a shutdown of your system and
UPS. Users of PowerChute plus or PowerChute Business Edition, can check the Event Log to determine if this occurred. In certain
situations, the software can put the UPS to "sleep" whereby it turns off the output (so load turns off). When the unit is in this
state, the front LED lights will flash alternately in a particular pattern (Online and Overload Lights). If there is sufficient input
power, you can "wake-up" the UPS by pressing the ON button. Once it wakes up, the UPS will return power to the output and boot up any
connected equipment.
8. An RS-232 serial cable is connected to the UPS, although no UPS shutdown software is installed: APC's non-USB Back-Ups,
require an RS-232 connetion to communicate with the attached computer. It is important to not connect the supplied serial cable,
between the ups and the computer's interface port, without also installing the optional UPS shutdown software. If the software is not
installed and running, its possible for a random dc voltage pulse to be sent to the UPS causing it to shutdown or reboot.
9. The incorrect serial cable is connected when using APC's optional shutdown software: Only APC serial cables can be used
with non-USB models. The proper cable and software comes bundled with all USB and non-USB Back-Ups models. Use of other RS-232 cables
can result in unpredictable UPS behavior including dropping the load. Consult the software User's Guide to know which specific cable
should be used for your UPS.
10. The UPS may be faulty: In order to receive advanced troubleshooting assistance in the United States and Canada, contact
APC Technical Support at 800-800-4272. When calling, please be near the UPS in question. For support outside North America please
refer to their worldwide contact page at www.apcc.com/support/contact/#worldwide to find the support location nearest to you.
Answer: When installing an APC UPS or any electrical device, it is important to keep in mind the capacity of the circuit into
which it is connected. Per National Electric Code which is developed by the National Fire Protection Association, a circuit must be
derated to 80% its capacity.
Users often have questions regarding the amperage draw of the load versus what the circuit is capable of supplying. According to
National Electric Code, continuous loads (like an UPS operating continuously longer than three hours per day) must not exceed 80
percent of the branch-circuit overcurrent device (e.g. fuse or circuit breaker) rating. The following is taken directly from Article
210-23 of the 1995 National Electric Code Handbook (7th Edition):
Free, restricted access to the 2005 NEC
online (Must register with the NFPA to access this document.)
Description: Your PowerNet SNMP adapter (v. 3.0.0 and v3.0.1) is sending warm boot alarms to your NMS. One reason why this is
happening is because your adapter might be located on a part of your network that has low network traffic. If ARP (Address Resolution
Protocol) requests are not received by your adapter every 7 minutes, then the adapter will reboot to check that its networking
components are working.
Solution: In order to stop your adapter from rebooting:
1. Verify that all SNMP adapters are version 3.0.0 or 3.0.1
2. Confirm that the adapters are warm booting through telnet. This can be done by viewing the agent uptime on the main console.
Confirm that this uptime matches the time indicated by the last warm boot trap received by the NMS. (If the time does not match, it
could be a problem with the compilation of the MIB.)
3. Perform a set to disable the NetSafe feature. Set the sysName OID with the following string exactly: *NeTsAfEOFF. This will should
not alter the sysName setting of the adapter. If the sysName is changed, the set failed and it should be attempted again. Make sure
the string being used is correct.
4. With the NetSafe feature disabled, the adapter will not reboot.
5. If you do not have an NMS to set the system OID. Obtain the serial number of the device and obtain the debug password by
contacting APC Technical Support by going to support.apcc.com.
6. Use the debug password to log into the device. Use apc as the user name. The Debug menu will appear.
7. Select option #15 to disable the feature. Exit out of the debug menu.
Answer: The Different Types of UPS Systems White Paper
There is much confusion in the marketplace about the different types of UPS systems and their characteristics. Each of these UPS
types is defined, practical applications of each are discussed, and advantages and disadvantages are listed. With this information,
an educated decision can be made as to the appropriate UPS topology for a given need.
Introduction The varied types of UPSs and their attributes often cause confusion in the data center industry. For example, it
is widely believed that there are only two types of UPS systems, namely standby UPS and on-line UPS. These two commonly used terms do
not correctly describe many of the UPS systems available. Many misunderstandings about UPS systems are cleared up when the different
types of UPS topologies are properly identified.
Common design approaches are reviewed here, including brief explanations about how each topology works. This will help you to
properly identify and compare systems.
UPS types A variety of design approaches are used to implement UPS systems, each with distinct performance characteristics.
The most common design approaches are as follows:
• Standby
• Line Interactive
• Standby on-line hybrid
• Standby-Ferro
• Double Conversion On-Line
• Delta Conversion On-Line
Standby UPS The Standby UPS is the most common type used for Personal Computers. In the block diagram illustrated in Figure 1,
the transfer switch is set to choose the filtered AC input as the primary power source (solid line path), and switches to the battery
/ inverter as the backup source should the primary source fail. When that happens, the transfer switch must operate to switch the
load over to the battery / inverter backup power source (dashed path). The inverter only starts when the power fails, hence the name
"Standby."
Line Interactive UPS The Line Interactive UPS, illustrated in Figure 2, is the most common design used for small business,
Web, and departmental servers. In this design, the battery-to-AC power converter (inverter) is always connected to the output of the
UPS. Operating the inverter in reverse during times when the input AC power is normal provides battery charging.
When the input power fails, the transfer switch opens and the power flows from the battery to the UPS output. With the inverter
always on and connected to the output, this design provides additional filtering and yields reduced switching transients when
compared with the Standby UPS topology.
In addition, the Line Interactive design usually incorporates a tap-changing transformer. This adds voltage regulation by adjusting
transformer taps as the input voltage varies. Voltage regulation is an important feature when low voltage conditions exist, otherwise
the UPS would transfer to battery and then eventually down the load. This more frequent battery usage can cause premature battery
failure. However, the inverter can also be designed such that its failure will still permit power flow from the AC input to the
output, which eliminates the potential of single point failure and effectively provides for two independent power paths. This
topology is inherently very efficient which leads to high reliability while at the same time providing superior power protection.
Standby On-Line Hybrid UPS The Standby On-Line Hybrid UPS is the topology used for many of the UPS under 10kVA which are
labeled "on-line." The standby DC to DC converter from the battery is switched on when an AC power failure is detected, just like in
a standby UPS. The battery charger is also small, as in the standby UPS. Due to capacitors in the DC combiner, the UPS will exhibit
no transfer time during an AC power failure. This design is sometimes fitted with an additional transfer switch for bypass during a
malfunction or overload. Figure 3 illustrates this topology.
Standby-Ferro UPS The Standby-Ferro UPS was once the dominant form of UPS in the 3-15kVA range. This design depends on a
special saturating transformer that has three windings (power connections). The primary power path is from AC input, through a
transfer switch, through the transformer, and to the output. In the case of a power failure, the transfer switch is opened, and the
inverter picks up the output load.
In the Standby-Ferro design, the inverter is in the standby mode, and is energized when the input power fails and the transfer switch
is opened. The transformer has a special "Ferro-resonant" capability, which provides limited voltage regulation and output waveform
"shaping". The isolation from AC power transients provided by the Ferro transformer is as good or better than any filter available.
But the Ferro transformer itself creates severe output voltage distortion and transients, which can be worse than a poor AC
connection. Even though it is a standby UPS by design, the Standby-Ferro generates a great deal of heat because the Ferro-resonant
transformer is inherently inefficient. These transformers are also large relative to regular isolation transformers; so standby-Ferro
UPS are generally quite large and heavy.
Standby-Ferro UPS systems are frequently represented as On-Line units, even though they have a transfer switch, the inverter operates
in the standby mode, and they exhibit a transfer characteristic during an AC power failure. Figure 4 illustrates this Standby-Ferro
topology.
The principal reason why Standby-Ferro UPS systems are no longer commonly used is that they can be fundamentally unstable when
operating a modern computer power supply load. All large servers and routers use "Power Factor Corrected" power supplies which
present a negative input resistance over some frequency range; when coupled with the relatively high and resonant impedance of the
Ferro transformer, this can give rise to spontaneous and damaging oscillations.
Double Conversion On-Line UPS This is the most common type of UPS above 10kVA. The block diagram of the Double Conversion On-
Line UPS, illustrated in Figure 5, is the same as the Standby, except that the primary power path is the inverter instead of the AC
main.
Wear on the power components reduces reliability over other designs and the energy consumed by the electrical power inefficiency is a
significant part of the life-cycle cost of the UPS. Also, the input power drawn by the large battery charger is often non-linear and
can interfere with building power wiring or cause problems with standby generators.
In the Double Conversion On-Line design, failure of the input AC does not cause activation of the transfer switch, because the input
AC is NOT the primary source, but is rather the backup source. Therefore, during an input AC power failure, on-line operation results
in no transfer time.
The on-line mode of operation exhibits a transfer time when the power from the primary battery charger / battery / inverter power
path fails. This can occur when any of the blocks in this power path fail. The inverter power can also drop out briefly, causing a
transfer, if the inverter is subjected to sudden load changes or internal control problems.
Double Conversion On-Line UPS systems do exhibit a transfer time, but under different conditions than a standby or line interactive
UPS. While a Standby and Line Interactive UPS will exhibit a transfer time when a blackout occurs, a double conversion on-line UPS
will exhibit a transfer time when there is a large load step or inrush current. This transfer time is the result of transferring the
load from the UPS inverter to the bypass line. Generally, this bypass line is built with dual Silicon Controlled Rectifiers (SCRs).
These solid state switches are very fast, so similar to the Standby and Line Interactive UPS, the transfer time is very brief,
usually 4-6 milliseconds.
Both the battery charger and the inverter convert the entire load power flow in this design, which causes reduced efficiency and
increased heat generation.
The Delta Conversion On-Line UPS This UPS design, illustrated in Figure 6, is a new technology introduced to eliminate the
drawbacks of the Double Conversion On-Line design and is available in the range of 5kVA to 1 MW. Similar to the Double Conversion On
-Line design, the Delta Conversion On-Line UPS always has the inverter supplying the load voltage. However, the additional Delta
Converter also contributes power to the inverter output. Under conditions of AC failure or disturbances, this design exhibits
behavior identical to the Double Conversion On-Line.
A simple way to understand the energy efficiency of the delta conversion topology is to consider the energy required to deliver a
package from the 4th floor to the 5th floor of a building as shown in Figure 7. Delta Conversion technology saves energy by carrying
the package only the difference (delta) between the starting and ending points. The Double Conversion On-Line UPS converts the power
to the battery and back again whereas the Delta Converter moves components of the power from input to the output.
Figure 7: Analogy of Double Conversion vs. Delta Conversion
In the Delta Conversion On-Line design, the Delta Converter acts with dual purposes. The first is to control the input power
characteristics. This active front end draws power in a sinusoidal manner, minimizing harmonics reflected onto the utility. This
ensures optimal conditions for utility lines and generator systems and reduces heating and system wear in the power distribution
system. The second function of the Delta Converter is to charge the battery of the UPS by drawing power and converting it to the
appropriate DC charging voltage.
The Delta Conversion On-Line UPS provides the same output characteristics as the Double Conversion On-Line design. However, the input
characteristics are extremely different. With full Power Factor Correction, the delta conversion on-line design provides both input
power control and output power control. The most important benefit is a significant reduction in energy losses. The input power
control also makes the UPS compatible with all generator sets and reduces the need for wiring and generator oversizing. Delta
Conversion On-Line technology is the only core UPS technology today protected by patents and is therefore not likely to be available
from a broad range of UPS suppliers.
Summary of UPS types The following table shows some of the characteristics of the various UPS types. Some attributes of a UPS,
like efficiency, are dictated by the choice of UPS type. Since implementation and manufactured quality more strongly impact
characteristics such as reliability, these factors must be evaluated in addition to these design attributes.
Practical Power Range (kVA)
Voltage Conditioning
Cost per VA
Efficiency
Inverter always operating
Standby
0 -0.5
Low
Low
Very High
No
Line Interactive
0.5 -3
Design Dependent
Medium
Very High
Design Dependent
Standby On-Line Hybrid
0.5 -5
High
High
Low
Partially
Standby Ferro
3 -15
High
High
Low
No
Double Conversion On-Line
5 -5000
High
Medium
Low
Yes
Delta Conversion On-Line
5 -5000
High
Medium
High
Yes
Use of UPS types in the industry The current UPS industry product offering has evolved over time to include many of these designs.
The different UPS types have attributes that make them more or less suitable for different applications and the APC product line
reflects this diversity as shown in the table below:
Use in APC products
Benefits
APCs Findings
Limitations
Standby
Smart-UPS, Back-UPS Pro, and Matrix
High reliabilty, High efficiency, Good voltage conditioning
Impractical over 5kVA
Most popular UPS type in existence due to high reliabilty, ideal for rack or distributed servers and/ or harsh power
environments
Standby On-Line Hybrid
not used by APC
Excellent voltage conditioning Low efficiency, Low reliabilty, High cost
Available UPS Output VA
Line Interactive provides better reliability and similar conditioning at a better value
Standby Ferro
not used by APC
Excellent voltage Conditioning, High reliability
Low efficiency, unstable in combination with some loads and generators
Limitied application because low efficiency and instability issues are a problem, and N+ 1 On-Line design offers even better
reliability
Double Conversion On-Line
Symmetra
Excellent voltage conditioning, ease of paralleling
Low efficiency, Expensive under 5kVA
Well suited for N+ 1 designs
Delta Conversion On-Line
Silcon, Symmetra M series
Excellent voltage conditioning, High efficiency
Impractical under 5kVA
High efficiency reduces the substancial life-cycle cost of energy in large installations
Different UPS types are appropriate for different applications, and that there is no single UPS type that is ideal for all
applications. With the variety of UPS topologies on the market today, these guidelines will help clear confusion about how each
topology operates and the advantages and disadvantages of each. There are significant differences in UPS design between available
products on the market, with theoretical and practical advantages for different approaches. Nevertheless, the basic quality of design
implementation and manufactured quality are often dominant in determining the ultimate performance achieved in the customer
application.
Answer: APC does not recommend that you daisy-chain two or more UPSs together. Each unit should be plugged directly into a
properly grounded wall outlet for optimum surge protection.
We do not recommend this configuration for the following reasons:
1: It is not UL tested. Therefore, should something go wrong and damages be caused to your connected equipment, APC would not honor
the claim. (Underwriters Laboratories Inc. [UL] is an independent, not-for-profit product safety testing and certification
organization)
2: This configuration does not provide any extra surge protection. The UPS is designed to remove any possibility of a surge reaching
the output recepticles. If a surge, strong enough to damage equipment was received, the first UPS in the chain would sacrifice itself
to protect it's load. This would mean that power would be removed from the 2nd UPS in the chain and force it to battery.
3: Whenever connecting a 2nd UPS into a 1st UPS, the chance of Overloading the 1st UPS is greatly increased. The amount of
receptacles in a UPS are restricted. This is due to the power limitations of the UPS itself. Although, the amount of receptacles has
been increased, the overall Watt capacity of the 1st UPS remains the same. The capability of the 2nd UPS, will be inversely affected
by that of the 1st UPS. Therefore, the overall Watt capacity of the configuration is no greater than that of the 1st UPS in line.
4: In most cases, daisy-chaining UPSs does not allow for extra run time. If you are using a UPS that outputs a step-approximated sine
wave when on battery, as soon as the fist UPS goes on battery, the second UPS will also go on battery because it will see the step-
approximated sine wave as distorted or bad power. Both units will discharge together, and will not provide any extra run-time to the
load.
If you are looking for extra run-time, we recommend one of our Smart-UPS XL products, which have the capability of adding extra,
external battery packs.
Introduction: This note helps explain the differences between Watts and VA and explains how the terms are correctly and
incorrectly used in specifying power protection equipment. Many people are confused about the distinction between the Watt and Volt-
Amp (V-A) measures for UPS load sizing.
Background: The power drawn by computing equipment is expressed in Watts or Volt-Amps (VA). The power in Watts is the real
power drawn by the equipment. Volt-Amps is called the "apparent power" and is the product of the voltage applied to the equipment
times the current drawn by the equipment.
Both Watt and VA ratings have a use and purpose. The Watt rating determines the actual power purchased from the utility company and
the heat loading generated by the equipment. The VA rating is used for sizing wiring and circuit breakers.
The VA and Watt ratings for some types of electrical loads, like incandescent light bulbs, are identical. However, for computer
equipment the Watt and VA ratings can differ significantly, with the VA rating always being equal to or larger than the Watt rating.
The ratio of the Watt to VA rating is called the "Power Factor" and is expressed either as a number (i.e. 0.7) or a percentage (i.e.
70%).
The power rating of the UPS: UPS have both Watt ratings and VA ratings. Neither the Watt nor the VA rating of a UPS may be
exceeded. In most cases, UPS manufacturers only publish the VA rating of the UPS. However, it is a standard in the industry that the
Watt rating is approximately 60% of the VA rating, this being the typical power factor of common loads. Therefore, it is safe to
assume that the Watt rating of the UPS is 60% of the published VA rating.
How to avoid sizing errors: Equipment nameplate ratings are often in VA, which makes it difficult to know the Watt ratings. If
using equipment nameplate ratings for sizing, a user might configure a system which appears to be correctly sized based on VA ratings
but actually exceeds the UPS Watt rating.
By sizing the VA rating of a load to be no greater than 60% of the VA rating of the UPS, it is impossible to exceed the Watt rating
of the UPS. Therefore, unless you have high certainty of the Watt ratings of the loads, the safest approach is to keep the sum of the
load nameplate ratings below 60% of the UPS VA rating. Note that this conservative sizing approach will typically give rise to an
oversized UPS and a larger run time than expected. If optimization of the system and an accurate run time are required, discuss your
requirements with RefurbUPS Power protection representative, for product recommedations to meet your needs.
Conclusion: Power consumption information on computer loads is often not specified in a way that allows simple sizing of a
UPS. It is possible to configure systems that appear to be correctly sized but actually overload the UPS. By slightly over sizing the
UPS compared with the nameplate ratings of the equipment, proper operation of the system is ensured. Over sizing also provides the
side benefit of providing additional UPS backup time.
Answer: This document applies to all APC product families that produce a stepped approximated sine wave (a.k.a. quasi wave)
when operating on-battery. When these units are on-line, they pass through the sine wave coming from the utility power.
Note: This discussion is a result of the fact that a Non-True RMS meter will read anywhere from 80 - 90 Vac from the output of a 120
Vac APC UPS (or 170 - 180 Vac from the output of a 230 Vac APC UPS) producing a stepped approximated sine wave while operating on-
battery. This is not an issue when the UPS is operating on-line.
Smart-UPS (SU700 or higher), Matrix-UPS, Symmetra and Silcon product families produce a pure sine when operating on battery.
There are generally two types of meters: "Average responding" and "True RMS" meters. Average responding meters are more commonly
used. True RMS meters tend to be more expensive. If the meter does not have "TRUE RMS" written right on the front, it is most likely
NOT a True RMS meter.
The issue that arises with a non-True RMS or average responding meter is whether it is measuring the output from a linear load or a
nonlinear load.
Linear loads include but are not limited to devices such as light bulbs, incandescent lamps and resistive heaters. Nonlinear loads
include devices like computers. When measuring the output of nonlinear loads, the average responding meter will typically read LOW.
True-RMS meters are most effective when measuring environments with harmonics. When a waveform is distorted from a standard sine wave
("the fundamental"), an average responding meter may produce readings that are misleadingly incorrect. A stepped approximated sine
wave appears distorted when compared to a true sine wave; therefore, a reading will produce incorrect results.
When an average responding meter is measuring the stepped approximated output from an APC UPS while operating on battery, this meter
will also read low. The wave shape generated is similar to what the meter would see from a nonlinear load, hence the averaging
calculation that the meter makes will be miscalculated.
Answer: The following is a list of APC Accessories that may be upgraded. However, certain accessories may need to be serviced
by APC due to safety issues.
Part Number
Upgrade Information
SmartSlot Call-UPS II
AP9608
No upgrade available
SmartSlot Interface Expander
AP9607
No upgrade available
SmartSlot Measure-UPS II
AP9612
No upgrade available
SmartSlot Relay I/O Module
AP9610
No upgrade available
SmartSlot SNMP Adapter for 10Base-T
AP9605
No upgrade available
SmartSlot SNMP Adapter for Token Ring
AP9603
No upgrade available
SmartSlot Triple Chassis
AP9604
No upgrade available
SmartSlot Triple Chassis for Silcon
AP9604S AP904SR
No upgrade available
Web/SNMP Management Card
AP9606
Firmware upgrades are available under the Support section of www.apcc.com.
Network Management Card
AP9617, AP9618, AP9619
Firmware upgrades are available under the Support section of www.apcc.com
PowerView
AP9215
No upgrade available
Share-UPS
AP9207
No upgrade available
In order to contact APC for information, please call 1-800-555-2725.
Answer: Due to the large amount of power consumed by these devices, APC does not recommend protecting laser printers with a
UPS.
In most cases, surge protection is adequate for laser printers.
If you must use a UPS with a Laser Printer it is important to size your UPS appropriately. APC recommends a Smart-UPS series product
that is sized for the maximum power draw of the laser printer as defined by the manufacturer. This is typically a 1500va or larger
UPS. Even small laser printers can have very high maximum power draws due to the nature of the technology. We do not recommend the
use of Back-UPS products with a laser printer.
Answer: Although the Surge Arrest, Surge Station, Back-UPS, Back-UPS Pro, Smart-UPS, Smart-UPS V/S, and Matrix-UPS products
will appear to work properly without a ground, APC always recommends that these units are grounded properly. Grounding is not for
functionality, but rather for safety. Numerous issues are involved when there is no ground, including potential for electric shock,
signal attenuation, and unpredictable operation. Therefore, APC does not support using these products in any ungrounded application,
even with an earth leakage monitor or other such device in place to alarm in case of excess current or drop in resistance.
Background: Earth leakage monitors measure the resistance between phase (hot) and any current-carrying component to ensure
that resistance remains high. Leakage current is typically measured by breaking the ground connection back to the mains and inserting
a specific load that simulates a person interrupting the ground. Devices without a ground are highly insulated, and therefore the
missing ground is not an issue during normal operation. However, were the device to become energized due to a fault or failure, it
would look for a way to deflect the current to ground. Without a ground present, the current would take the path of least resistance.
This would be hazardous as the return path may be through the load itself, a data line, or even a person.
In 120 Vac environments, each electrical device must reference the same ground which originates at the main service panel.
Additionally, a properly grounded chassis acts as a filter against EMI/RFI interference. If this ground reference were missing, the
EMI/RFI interference may result in erratic behavior of the device.
Certain types of data communication systems require a reference to ground. Additionally, some data lines use the ground as a shield
against noise. RS-232, and other data cables, rely on ground to provide a return reference for the signal (although this is not the
case with isolated data systems such as Ethernet). Without a ground, the signal will attenuate.
Answer:
The Site Wiring Fault LED light is only present on 120V UPS and Surge products. On APC UPS products this indicator is typically on the rear panel. The purpose of this indicator light is to warn you that there are problems with your building wiring that may result in a shock hazard.
APC recommends that you have a qualified electrician inspect your wiring for one or more of the conditions listed below.
Reasons why the Site Wiring LED light will illuminate:
Overloaded neutral wire (>5vdc measured between Neutral and Ground).
Reversed polarity (hot and neutral wires are reversed).
Missing ground wire. (Note: this also includes using a 3 prong to 2 prong adapter)
If the outlet that the APC UPS unit is plugged into is not properly grounded or properly wired, the unit will attempt to absorb the excess voltage instead of redirect it to ground. It would be like attempting to catch a bullet with a catcher mit, where as if the light is not on it would be able to redirect the excess voltage to ground. Therefore, in order to maintain your warranty and protection under APC's Equipment Protection Policy, be sure that the APC unit is only plugged into a properly grounded outlet where the Site Wiring Fault Indicator (SWFI) light is not illuminated.
All of APC's UPSs with the exception of the Matrix-UPS and the Symmetra Power Array have a small red LED light that is called a SWFI. On some UPS models, this LED is referred to as the Building Wiring Fault Indicator. Both have the same function. On most UPS models, the light is located on the rear of the unit near where the output receptacles are located.
