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Our FAQs Portal host a vast amount information related to Sales, Batteries, SNMP Management and UPSs.

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Our Manual Library hosts Manuals for UPS equipment and accessories for a large selection of products.

If you can't find the answers you are looking for there, feel free to call us at (845) 357-6911, email us at support.refurbups.com.


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You can login to your ACccount to check and track the status.


Certain UPS require the battery to be disconnected for shipment in compliance with Department of Transportation (DOT) regulations. See the battery connection instructions included with unit


Our UPS are shipped with the standard maurfacturer input plugs. Many of these units are made for data center facilities which use twist lock outlets. This prevented the UPS from being accidentally unplugged. Plug type can easily be changed and plugs can be purchased from any local hardware and/or electrical supply store. If there is a specific plug type you need, just let us know in the comments section of the order form when placing your order. Please note that SmartUPS 3000's Rack Mount come with an 30A Twist-Lock plug. This can only be changed to a 20A twist-lock plug if needed.


We have the 940-0024C SmartUPS signaling cables available in our Accessories section. Please note that this cable is available for use with "SmartUPS" only!


We carry a broad line of proprietary Signaling Cables for APC UPS systems. To view our current line please visit our UPS – Network Management section. The most commonly used APC UPS Signaling Cables are available online, if you have a special need please contact us for other available Signaling Cables.


When loads exceed the UPS's rated VA(volt-amp) or Watt capacity, the overload LED will illuminate and the UPS will emit a continuous tone. The alarm remains on until the overload is removed.

Disconnect nonessential load equipment from the UPS to eliminate the overload.

If the overload is severe, the input circuit breaker may trip (the resettable center plunger of the circuit breaker pops out). Disconnect nonessential load equipment from the UPS to eliminate the overload and press the plunger back in.

If there is AC power and the overload is not so severe as to trip the UPS circuit breaker, then the loads will still be powered. If the circuit breaker trips or the UPS attempts to transfer to battery in an overload condition, the load's power will be shut off. Turn the UPS off then back on to power the loads.

If the Overload LED remains illuminated even without any load plugged into the UPS, the UPS has most likely sustained a surge or fault, and will need to be replaced. Contact RefurbUPS Technical Support to resolve the problem.


The equipment attached to a Smart-UPS can be dropped or caused to reboot due to any of the following reasons:

  1. Battery connection is loose or disconnected - If the battery connection is not secure the battery power will be unreliable. Verify that the internal battery connections are secure.
  2. Unit 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 SU420NET is capable of handling 420 Volt Amps being plugged into the UPS. Determine if your UPS is capable of handling the amount of equipment you have plugged into it.

    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 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 UPS. Peripheral devices, such as printers, copiers, fax machines, and table lamps, ought to be connected to a separate APC surge strip. This will help to prevent unnecessary loading of the UPS.

  3. 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 4-6 hours or so.
  4. The incorrect serial cable is connected when using APC's optional shutdown software - The serial cable attached to the Computer Interface (COM) Port on the back of the Smart-UPS is not the correct cable. To verify this, the part number is located on the connector end of the cable that attaches into the UPS COM port.
    Note: Unix, Novell, OS/2, Windows NT, Windows 95, and Windows 98 all use the 940-0024C serial cable to communicate with PowerChute Plus in Smart signaling. AS/400 uses the 940-0006A cable with the native AS/400 shutdown.
  5. An RS-232 serial cable is connected to the UPS, although no UPS shutdown software is installed - Check to see if the serial cable is attached to the Server/Workstation communications port without PowerChute plus installed or running and configured correctly. If PowerChute plus is installed and not configured properly or running, any activity at the Server/Workstation communications port could send a false signal to the Smart-UPS thus causing it to shutdown and reboot.

Smart-UPS protect data by supplying network-grade battery backup when power fails. Computer hardware is protected and system life extended through superior full-time multistage surge suppression and noise filtering. The Smart-UPS can switch to on-battery operation as a result of power disturbances or software initiated commands. There is a common misperception that a Smart-UPS will use its battery based only on voltage fluctuations. The following list provides the possible causes for a Smart-UPS switching to battery operation, along with a brief definition of each.

No Voltage (Blackout): A total loss of utility power.

Low Voltage (Brownout): A decrease in voltage levels.

High Voltage (Over Voltage): A surge is a short-term increase in voltage. A spike is an instantaneous dramatic increase in voltage.

Total Harmonic Distortion (THD): Periodic distortion of the sine wave. Harmonics add to the fundamental frequency in magnitude.

Change in Voltage (dv/dt): Rapidly changing voltage. If the voltage increases or decreases rapidly, the Smart-UPS will transfer to battery because the Smart-UPS does not know how high or how low the voltage will go.

Frequency Changes (Hz): Deviation from the nominal 60Hz in North America.

Before concluding that the Smart-UPS is malfunctioning merely because it is operating on battery, be sure to consider all of the above possibilities.


Yes, it is. You can safely turn off your computer equipment and APC unit when you're not using them. As long as your equipment is correctly connected to an APC UPS or APC SurgeArrest/SurgeStation, your equipment will be protected from physical hardware damage caused by surges and spikes.


The Site Wiring Fault LED light is only present on 120V UPS 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.

RefurbUPS 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:

  1. Overloaded neutral wire.
  2. Reversed polarity (hot and neutral wires are reversed).
  3. Missing ground wire.

If the outlet that the APC UPS unit is plugged into is not properly grounded or properly wired, the surge protection capability of the unit may be diminished. Therefore, please 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.