Battery Backup Power (UPS) for a Fridge

Posted by admin 27/02/2017 0 Comment(s)

Looking to Provide Emergency Backup Power to a Vaccine Fridge in your Medial Centre?


There are circumstances when a need to provide power backup for a fridge (UPS for medical fridge, vaccine fridge) arises. An obvious solution is to use a generator, however, generators are typically very noisy, must be kept outdoors, produce exhaust gasses and need to be regularly maintained.


Consequently, in some situations an Uninterruptible Power Supply (UPS) might be the best option to provide power backup for a fridge. The beauty of a UPS System is that it can be used indoors, it is very quiet, and will switch on automatically when the main power fails. However, not every UPS is created equal and there are some considerations that need to be taken into account when selecting the right UPS to power your fridge.


Recommended Option Quick Overview:


This UPS comes in a “plug-and-play” configuration, which means that there is no specialised installation required. You simply plug the UPS into GPO (your electrical wall socket), turn it on and plug the fridge in the back of the UPS. The system is fully autonomous, it will switch to batteries automatically when there is a power failure (utility blackout) and switch back to normal as soon as the power is restored. There’s also very little maintenance required. It’s recommended to have the internal batteries replaced every 2-3 years.


Backup Time & Pricing Summary:


Battery backup time can be increased by adding External Battery Modules (EBMs) to the UPS. Each UPS can support up to 4 EBMs providing approximately 13 hours of backup time in total.

Recommended UPS: KSTAR Memopower 2000VA / 1800W Online UPS Tower

External Battery Module: KSTAR External Battery Pack for Memopower MPII UPS (72VDC)


Expected Backup Time (for a typical Vaccine Fridge such as Quirks Medisafe):


UPS alone…………………………………….          2 hours                         $1390.00 Ex GST                                 

UPS and 1 x EBM……………………………         5.5 hours                       $2468.00 Ex GST

UPS and 2 x EBM…………………………...          8.5 hours                      $3546.00 Ex GST

UPS and 3 x EBM……………………………         11 hours                        $4624.00 Ex GST

UPS and 4 x EBM……………………………         13 hours                        $5702.00 Ex GST

Note, the above backup times are approximations only and will vary depending on the type/size of the fridge as well as the operating conditions such as temperature, humidity, etc






Example of KSTAR UPS installation providing backup power to a Medisafe Vaccine Fridge

Example of KSTAR UPS installation providing backup power to a Medisafe Vaccine Fridge


1. Sinewave Output


Utility companies provide AC power that has a true sine wave. Although, most consumer electronics that utilise switch-mode power supplies (such as computers, TVs) do not require a true sine wave signal to function properly, some types of appliances and electrical devices run properly only on Pure Sinewave Signal. Any device that uses a control circuitry that senses the phase (for voltage / speed control) or instantaneous zero voltage crossing (for timing control) will not work properly from a voltage that has a modified sine wave-form. Also, as the modified sine wave is a form of square wave, it is comprised of multiple sine waves of odd harmonics (multiples) of the fundamental frequency of the modified sine wave.

An example of inrush current transients during capacitor bank energization. The peak inrush current transient rises as high as 28.4 kA.

For those applications that require sine wave power, UPS systems are also available with the sine wave output, also known as True or Pure Sine wave. These UPS systems are designed for electronics which have APFC power supplies, small AC motors (such as the compressor in your Fridge), laser and motor driven printers, variable speed drives (VLD), medical equipment, PLCs and any equipment deriving timing signals from the input require sine wave power to function properly.  

See our list of Pure Sine Wave UPS


2. In-rush current


Inrush current, input surge current or switch-on surge refers to the maximum, instantaneous input current drawn by an electrical device when first turned on. Alternating current electric motors and transformers may draw several times their normal full-load current when first energized, for a few cycles of the input waveform.

An example of inrush current transients during capacitor bank energization. The peak inrush current transient rises as high as 28.4 kA.

If your UPS will be supporting motors, variable-speed drives or laser printers, add more VA capacity to your requirements to account for the high power inrush that occurs when those devices startup.

Electric motors (such as fridge compressor) used in refrigerators have a start-up amperage requirement much higher than the normal power draw once they're going. On average refrigeration wattage needed is about 200 watts for running and 1200 watts starting. Therefore, the capacity (VA- or Watt-rating) of your UPS must be based on the maximum expected current.


3. Backup Time


A typical UPS battery provides five to 15 minutes of backup power. Applications that need more than that can use supplemental external battery modules or cabinets to add as much as several hours of emergency runtime at full load.

Therefore, it’s important to select a UPS that supports External Battery Modules.

UPS with External Battery Modules


4. Our Recommendation:


Power Backup Solutions recommends the following UPS for providing protection and power backup for Fridges, Incubators, Fish Tanks and other applications that use small electric motors.

KSTAR Memopower 2000VA / 1800W Online UPS Tower

Double-conversion design for superior power protection The UPS is constantly monitoring power conditions & €”regulating both voltage and frequency. Even when presented with the most severe power problems, this UPS's output remains within two percent of nominal voltage. With a wide input voltage range, the UPS does not depend on batteries to smooth out minor power fluctuations. Batteries are conserved for those times when utility power is highly unstable or completely out. If an outage occurs, the UPS transfers to battery with zero interruption in power, making this an ideal UPS for sensitive and critical equipment

Reasons for choosing KSTAR Memopower UPS are as follows:

     Pure Sinewave Voltage Waveform Output

     Double-conversion design for superior power protection The UPS is constantly monitoring power conditions & regulating both Voltage and Frequency.

     Zero Transfer Time when transferring from Mains Power to Battery - avoids any data loss or system corruption

     Extended runtime with up to four Extended Battery Modules (EBMs) per UPS.

     UPS Monitoring and Management with a bright LCD user interface, free, intuitive power management software and optional eNotify Remote Monitoring service

     Automatic Bypass Mode - transferring your equipment to utility power and ensuring RELIABILITY and CONTINUOUS supply.

     Backed by Worldwide Agency Approvals

     Australian Warranty and Technical Support

Disclaimer: This article should be used as a guide only. We advise seeking advice from a qualified person when making decisions. Power Backup Solutions holds no responsibility for material presented in this article.

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