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Difference between revisions of "Uninterrupted power supply"

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'''Question:''' Hi Mario, I would like to purchase back-up power supplies.Ā  Our buildingĀ  Ā  Ā  power went out the other night 20 minutes after finishing a human biopsy trial!!Ā  While we escaped a disaster this one time, I would hate to think what could happen in the future...these are trialsĀ  Ā  Ā  are obviously expensive and hard to organize.Ā  I see there areĀ  Ā  Ā  many different types of back-up power supplies available (forĀ  Ā  Ā  example, here:Ā  http://www.apc.com/products/category.cfm?id=13) Could you let me know what features the UPS (uninterrupted powerĀ  Ā  Ā  supply) should possess?Ā  Voltage, current, etc, etc.Ā  I believe IĀ  Ā  Ā  know based on the specs of the oxygraphs, but would like to verify first.
{{MitoPedia
|abbr=UPS
|description=A back-up power supply may be required to secure '''uninterrupted power supply'''.
|info=[[O2k-Main Unit]]
}}
{{MitoPedia concepts}}
{{MitoPedia methods}}
{{MitoPedia O2k and high-resolution respirometry
|mitopedia O2k and high-resolution respirometry=O2k hardware
}}
{{MitoPedia topics}}


'''Answer:'''


Hi Chris, I fear there is not far much more then the specs to go by. I work fromĀ  home today so can`t access the serialĀ  number of your O2ks but I think this linkĀ  [http://www.oroboros.at/index.php?id=o2k-series_e-features @OROBOROS] should be helpful anyway, because old and new values are compared. Of course the typical power ratings are only useful if you assume that you already reached thermal equilibrium. Some other considerations: * switching time: In our case we use notebooks for computers, so DatLabĀ  will run some time anyway. However, once a O2k is switched off and onĀ  again WITHOUT getting any contradicting instructions from DatLab it willĀ  try to go to a hardware default temperature of 25 Ā°C. Therefore, onceĀ  there was an interruption in the power supply it is necessary toĀ  re-connect (new file) with DatLab to the O2k as soon as possible afterĀ  the power is back (switched to the alternative source).
__TOC__


A different approach would be to contact the people who have experiences with power supplies for O2k's on expeditions, starting with Erich himself but a.) Erich is in the Everest Base camp (presumable fighting with the power supply ) right now and b.) I think these are realy rather different questions. [[User:Fasching Mario|Fasching Mario]] 16:53, 20 March 2013 (CET)
{{Technical support integrated}}


=== UPS functional type ===


Dear Mario and Chris, Ā 
Online UPS means, that the output-power ist constantly generated from the battery while the battery becomes constantly loaded from the mains power. This concept ensures uninterrupted output-power even in the moment of mains powerfailure.
Ā 
my apologies, we don't have any experience with UPS systems onĀ  expeditions. Though power stability (and even oscillations thereof) canĀ  be a real drag, as they also influence POS signal stability.
So far, we have just reconnected as Mario described in the WikiĀ  after the power came back on. If it's only a short power cut, not tooĀ  many data points are lost (depending on the experiment, of course).
I have heard of UPS systems that connect between power socket andĀ  consumer, they consist of a kind of constantly recharging battery. OnceĀ  there is a power cut, the oxygraph would be directly connected to itsĀ  battery part without having to switch, so youĀ  wouldn't have to restart and data loss could be excluded.
I'd go for something like thisā€¦. Ā 
Cheers
Felix


Other concepts deliver mainspower and start generation from battery only in case of powerfailure. The startup of generation may take some (short) time. So the output-power can have dips or other deformations in the moment of powerfailure, which could cause the "load" instruments to stop working.Ā 




{{#set: Technical service=Main unit}}
Choose a high-quality UPS with "online"-generation.


__SHOWFACTBOX__
{{Troubleshooting}}
Ā 
=== UPS output voltage ===
Ā 
The waveform should be sinewave or stepped approximation to sinewave.
Ā 
The voltage should meet the O2k requirements which are 110 or 230V at 50 or 60 Hz with Series A-D according to the setting at the O2k mains input. O2k Series E and higher accept nominal voltages from 100 to 240 V 47 - 63 Hz. With accepted tolerances of +/- 10% the maximum range covers 90 - 264 V.
Ā 
For the waveform of any UPS is only "close" to a sinewave its always a good idea to stay securely within these ranges and not to explore the boundaries. The type of "rectangle"-output UPS and most cheap UPS come with the risk of interference with the loads electronics.
Ā 
Ā 
=== UPS Output maximum current ===
Ā 
The instruments powered by the UPS draw different currents at startup, at running with full load or in normal operation. The UPS needs to limit the current to prevent its internal electronics from damage. This limitation may cause problems with the "load" instruments especially at startup when they need to switch on transformers or to load capacitors, thus drawing inrush-currents.
Ā 
Therefore an UPS with inrush capability is preferable.
Ā 
Ā 
=== UPS Output thermal current ===
Ā 
The output current will warm up the internal electronics of the UPS, which is designed for a certain maximum of continuous current.
Ā 
All "load"-Instruments together may not reach this value during an experiment.
Ā 
So the rated UPS output continuous current has to be higher then the sum of continuous current of all connected instruments, including Oxygraphs, computers, monitors.
Ā 
=== UPS power failure buffering time ===
Ā 
The battery of the UPS in normal operation is fully charged by the mains supply, the batteries capacity becomes only relevant in case of mains powerfail. From fail on the battery has to deliver all the energy used by the load. The longer an experiment should be continued without mains power the bigger batteries must be used.
Ā 
Ā 
Calculate more power failure buffering time than you ever plan to use. The battery will loose capacity during lifetime and the convenient use will increase the number of "load" instruments.
Ā 
Ā 
* Oxygraph power-consumption Serie E-H:
# Nominal mains input: 100 - 240 VĀ  47 - 63 Hz
# Maximum mains range: 90 - 264 V
# Inrush-current: depends on the mains power net impedance, at WGT-Labs we measured maximum 45 A for 5 Āµs. With limited current the inrush becomes lower in current but takes more time. We measured 8 A for 50 Āµs.
# Maximum current: At ambient temperature 25 Ā°C with O2k-chamber temperature set to 0Ā° the O2k consumes full Peltier-power. Additionally the stirrers and the TIP2k moving will add to a maximum of 110 W and 0,5 A at 50 Hz.Ā 
Ā 
* Normal operation
# 25 Ā°C ambient and 37 Ā°C O2k-chamber lead to app. -11% Peltier-power thus consuming 40 W from mains power.
# 25 Ā°C ambient and 5 Ā°C O2k-chamber lead to ca. -66% peltier-power thus consuming 75 W from mains power.
Ā 
Ā 
* Definition: "Load" instrument refers to all electric equipment connected to the UPS.
# Even a cheap UPS may work properly.
# Even the most luxury UPS still can cause some complications with certain load-situations.
# We can not guarantee functionality of UPS-powering of the O2k.

Latest revision as of 08:32, 27 October 2020


high-resolution terminology - matching measurements at high-resolution


Uninterrupted power supply

Description

A back-up power supply may be required to secure uninterrupted power supply.

Abbreviation: UPS

Reference: O2k-Main Unit





MitoPedia O2k and high-resolution respirometry: O2k hardware 





Template NextGen-O2k.jpg


MitoPedia O2k and high-resolution respirometry: O2k-Open Support 



UPS functional type

Online UPS means, that the output-power ist constantly generated from the battery while the battery becomes constantly loaded from the mains power. This concept ensures uninterrupted output-power even in the moment of mains powerfailure.

Other concepts deliver mainspower and start generation from battery only in case of powerfailure. The startup of generation may take some (short) time. So the output-power can have dips or other deformations in the moment of powerfailure, which could cause the "load" instruments to stop working.


Choose a high-quality UPS with "online"-generation.


UPS output voltage

The waveform should be sinewave or stepped approximation to sinewave.

The voltage should meet the O2k requirements which are 110 or 230V at 50 or 60 Hz with Series A-D according to the setting at the O2k mains input. O2k Series E and higher accept nominal voltages from 100 to 240 V 47 - 63 Hz. With accepted tolerances of +/- 10% the maximum range covers 90 - 264 V.


For the waveform of any UPS is only "close" to a sinewave its always a good idea to stay securely within these ranges and not to explore the boundaries. The type of "rectangle"-output UPS and most cheap UPS come with the risk of interference with the loads electronics.


UPS Output maximum current

The instruments powered by the UPS draw different currents at startup, at running with full load or in normal operation. The UPS needs to limit the current to prevent its internal electronics from damage. This limitation may cause problems with the "load" instruments especially at startup when they need to switch on transformers or to load capacitors, thus drawing inrush-currents.

Therefore an UPS with inrush capability is preferable.


UPS Output thermal current

The output current will warm up the internal electronics of the UPS, which is designed for a certain maximum of continuous current.

All "load"-Instruments together may not reach this value during an experiment.

So the rated UPS output continuous current has to be higher then the sum of continuous current of all connected instruments, including Oxygraphs, computers, monitors.


UPS power failure buffering time

The battery of the UPS in normal operation is fully charged by the mains supply, the batteries capacity becomes only relevant in case of mains powerfail. From fail on the battery has to deliver all the energy used by the load. The longer an experiment should be continued without mains power the bigger batteries must be used.


Calculate more power failure buffering time than you ever plan to use. The battery will loose capacity during lifetime and the convenient use will increase the number of "load" instruments.


  • Oxygraph power-consumption Serie E-H:
  1. Nominal mains input: 100 - 240 V 47 - 63 Hz
  2. Maximum mains range: 90 - 264 V
  3. Inrush-current: depends on the mains power net impedance, at WGT-Labs we measured maximum 45 A for 5 Āµs. With limited current the inrush becomes lower in current but takes more time. We measured 8 A for 50 Āµs.
  4. Maximum current: At ambient temperature 25 Ā°C with O2k-chamber temperature set to 0Ā° the O2k consumes full Peltier-power. Additionally the stirrers and the TIP2k moving will add to a maximum of 110 W and 0,5 A at 50 Hz.
  • Normal operation
  1. 25 Ā°C ambient and 37 Ā°C O2k-chamber lead to app. -11% Peltier-power thus consuming 40 W from mains power.
  2. 25 Ā°C ambient and 5 Ā°C O2k-chamber lead to ca. -66% peltier-power thus consuming 75 W from mains power.


  • Definition: "Load" instrument refers to all electric equipment connected to the UPS.
  1. Even a cheap UPS may work properly.
  2. Even the most luxury UPS still can cause some complications with certain load-situations.
  3. We can not guarantee functionality of UPS-powering of the O2k.