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Pharmacy Fridge UPS Applications

Pharmacy Fridge

Why use a UPS on a Pharmacy Fridge?

Unlike applications where sudden power loss causes data loss or other operational issues, power loss to a pharmacy fridge is not such of an issue since the internal temperature is well controlled. In the event of a power cut a solution is simply not to open the fridge. A typical fridge will maintain the internal temperature for around 4 hours in the event of a power cut – provided the door is unopened. However note if the fridge cannot be opened then no medicine in the fridge can be retrieved.

Many laboratory or pharmacy fridges have alarm contacts which can alert to the fact that power has failed and as a result warn users not to open the door. However, a power fail alarm will have to be operated on a secondary power system, such as a battery, due to the obvious fact that a mains powered system would also be rendered inactive during a power outage. Having a battery system, will also require the battery to be maintained in a state of charge. These added complications mean that such alarms are rarely, if ever, implemented.

A pharmacy fridge will be used to house items, typically vaccines, diluents, immunoglobulins and other medicines with temperature requirements. The costs of these medicines can be quite substantial and if the temperature inside the fridge should rise to over +8°C, then, according to the NHS Green Book, the “cold chain” has been broken and these medicines may need to be destroyed. If not destroyed, then a time-consuming process needs to be instigated to determine the effect on the medicine which most likely will include a reduction in the expiry date.

Clearly, protection against sustained power outages has operational and financial benefits.

Fridge Power Consumption

Instead of giving power ratings of the Pharmacy Fridge, the manufacturers specify the energy consumption in KW for a 24 hour period. The method I found for doing this is here: ENERGY STAR® Program Requirements Product Specification for Laboratory Grade Refrigerators and Freezers, and Ultra-Low Temperature Freezers. This value varies from product to product and depends upon a number of factors, including capacity, the type of doors (glass or solid etc.) and the configuration (bench top, under counter etc.). Typically these figures are around 1KW/24 hour for a typical small system in a typical pharmacy. See Note 1.

The test schedule includes opening the fridge door for a period of 15 seconds (plus an additional 4 seconds for opening and closing), 3 times an hour each hour for 8 consecutive hours. This is useful as it allows us to specify a UPS runtime that will allow a degree of use of the fridge during an extended outage.

A typical fridge compressor has a power draw of around 200W, and will require a sine-wave inverter to ensure correct operation.

UPS Selection

In the table below I’ve created a lookup for the number of hours of runtime you could expect (and remember this includes periodically opening the door) given the energy rating of the pharmacy fridge.

The PF-S-Li products are units ideal for Pharma Fridge applications. The units contain an internal high capacity Lithium Ion battery offering long runtimes, long life and low weight. The PF1200S-Li has a continuous power rating of 1200W, but with a surge rating of 2400W. This allows it to easily deal with the inrush current generated by the compressors of the fridges.

Achievable Runtime in hours:

Energy Rating
(KWhr/24hr)
Equivalent
Watts
PF1200Li
Expected Runtime
0.521>24 hrs
0.753221 hrs
14216 hrs
1.56310 hrs
2848hrs
2.51056hrs
31255hrs
3.51464hrs
41674hrs
4.51883hrs
52093hrs

Contact us to enquire about UPS for Pharma Fridge Applications.


The PF1200S-Li has superb surge rating of twice its capacity for 5 seconds allowing it to cope with the inrush demands of high performance refrigeration units. It also has the benefit of fast recharge and can be connected to a solar panel array. Connectivity is via 4xUK socket outlets and it even boasts a wireless charging pad, USB A and USB C outlets. In addition to powering the fridge it can also provide battery backed power for ancillary devices.


Note 1: I’ve used what manufacturers are displaying on their spec sheets in order to avoid confusion, however the correct term should in fact be kilowatt hours per 24 hour period eg. kWh/24

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New Product for FTTP – the iPower-DC2

Power Inspired launch the iPower-DC2 – a DC UPS designed to provide long runtimes on telecommunications equipment. Not only will this keep equipment going in mission critical applications following a power outage – it allows FTTP (Fibre To The Premises) companies to have compliance with OFCOM guidance on providing telephony services for an hour following a power outage. 1

The Power Inspired existing iPower-H is a fantastic solution for this, and indeed is used in many thousands of installations for that very purpose, however with the increased power demands of routers and hubs the need for a more powerful and higher runtime unit became apparent.

Most DC based IT products are 12V, however a proportion are 9V powered and some even 24V. Furthermore, more essential equipment is being powered via USB. In addition several separate boxes can be required in an installation requiring several connections. The iPower-DC2 encompasses all these scenarios with adjustable 9V, 12V or 24V operation, a 2A USB port and 5 DC jack outlets. An adapter can also be used for affixing to a DIN rail on the wall or in a cabinet.

Runtime is impressive with a 10,000mAh Lithium Ion battery pack delivering over an hours runtime at 25W. Full safety is ensured by using UN38.3 certified cells, and with full battery protection circuitry – the battery pack is monitored for overcharge, over-discharge and over-current.

iPower DC2 Rear Panel Connections

Operation is simple. Set the Voltage Selector switch to the nominal voltage of your power supply and plug in. The iPower-DC2 will start automatically and provide continuous power to the connected loads. If the DC power is unavailable the iPower-DC2 can be cold started – to basically act as a power bank.

To save needless expense and waste, the iPower-DC2 is intended to be used with the AC/DC adapter that comes with the equipment to be protected. However it can be provided with a suitable AC adapter within the same box and any additional leads required. It comes as standard with two 30cm DC-DC leads with sprung connectors suitable for 2.1 or 2.5mm input jacks.

For further information see iPower DC UPS or contact us.

iPower DC2 UPS
Power Inspired iPower-DC2
Notes

1 “Providers should have at least one solution available that enables access to emergency organisations for a minimum of one hour in the event of a power outage in the premises.” From Protecting access to emergency organisations when there is a power cut at the customer’s premises Guidance on General Condition A3.2(b)

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Lead Acid Battery Life

Valve Regulated Lead Acid Battery Design Life.

Battery Life or “design life” of a battery is based on average use at room temperature (20-25°C) operation. For a modest UPS System, the design life is typically 5 years. Since, UPS applications are standby applications, the batteries are float charged, and the life is also referred to as “float life”.

The moist gel interior of VRLA batteries dries up over time, gradually reducing the effectiveness until the battery capacity is no longer viable for the application. This is why batteries will wear out regardless of how well they are maintained.

Typically, you have around 200 charge/discharge cycles in a 5 year design life battery. This is because the charge and discharge process involves a chemical reaction and this causes corrosion within the battery itself.

As this limit is approached the battery capacity starts to tail off, and can become very low very quickly. You can see that if a battery is used daily for example, the life expectancy is lower than one year.

Battery Life in relation to depth of discharge
Note how cycle life can be extended significantly by reducing the battery depth of discharge

Sulphation

If the battery is allowed to stand unused for a prolonged period of time, lead sulphate crystals form- blocking recharge. If this happens the UPS charger is usually incapable of recharging these batteries. It is possible to sometimes recover such batteries using high charging voltages that break down the sulphate but also having a current limited charger. Temperature monitoring is also required and as such, this is beyond the scope of most UPS built in chargers.

Sulphation occurs mainly when batteries are allowed to stand in an uncharged state. This is why it is important to have your UPS charged as soon as possible after an outage.

Heat

The float life of batteries is rapidly reduced with heat, and I mean rapidly.

HIGH TEMPERATURE will reduce battery service life often quite dramatically, and in extreme cases can cause Thermal Runaway, resulting in high oxygen/hydrogen gas production and battery swelling. Batteries are irrecoverable from this condition and should be replaced.

Yuasa Little Red Book of Batteries
Temperature (°C)20°25°30°35°40°45°50°
% Expected Float Life100%100%80%60%40%20%10%

Based on this, if the batteries are locked in a cupboard with little ventilation and temperatures allowed to build, for example to 50°C, then a 5 year float life battery would be expected to last no more than 6 months, regardless of how it has been used.

Results of over thermal runaway on batteries exposed to excessive heat
Thermal runaway results on VRLA battery

Battery Life Conclusions

  • A battery cannot be expected to last in excess of its design life so schedule a replacement before this.
  • Regular cycling of the battery will diminish its performance. If your application is for regular charge/discharge cycles then the life expectancy reduction needs to be considered.
  • Avoid heat build up. Ensure the UPS and batteries are well ventilated with adequate air flow though the air intakes. Ensure vents are free from a build up of dust and the UPS is not in direct sunlight.
  • Always recharge the batteries as soon as possible after an outage to prevent the possibility of sulphation.
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UPS CCTV Application

UPS Install

Our client runs a campus environment and has been suffering from regular outages on his CCTV equipment. Throughout the campus the CCTV cameras get their power directly from the street lights. This meant that a UPS solution would not have to power just the CCTV, but the lights as well.

Another problem is that space is a real issue. A competitor had visited this site and had proposed a UPS solution that would fit in a pre-fabricated cabinet outside the comms room, and this would keep the system up and running for a good 12 hours or so. Hmm, this seemed real overkill and a more cost effective solution would be to fit a small UPS within the comms cabinet and use a generator outside. This was a better solution, but not what the client wanted to pursue. Discussing this with the client it became apparent that having the system up and running for 12 hours was more of a wish list than a real requirement. In fact about an hour to 90 minutes would be acceptable. What else can we do?

The site has the street lights split into three zones, each powered from a single phase. This necessitated the use of a three phase UPS System, although the entire power consumption was in the region of 3000W or so. Our standard 10KVA 3phase UPS, the VFI33-10KT would provide around 20 minutes runtime. Not long enough.

Fitting a battery pack comprising a +/-120V strings with 36Ah capacity did the job exactly with a calculated 102 mins of runtime. There’s the solution, now where’s it going to go?

The comms room was a bit of a squeeze. And calling it a comms room is also a bit misleading. It was more of an out-house than anything. The UPS could possibly fit, but then getting in would be a challenge. As luck would have it another outhouse was nearby that we could wire the UPS to. Bring on the electricians.

UPS CCTV Application

A schematic was made up, discussed with the site electrician and a plan put in place to minimise downtime. Phase 1, the electrician would run cables to the outhouse and fit the UPS input and output breaker panels. Phase 2, UPS installation, leaving it in bypass mode. Phase 3 involved unavoidable downtime where the power feeds to the cameras needed to be diverted to the UPS.

Once this was completed, the UPS internal bypass made sure that power was still being presented to the CCTV. All that was left was for Power Inspired to come back to site and commission the UPS System. Take it out of bypass and switch it online. All completed without any downtime.

Happy days, over 90minutes autonomy for a CCTV UPS application from a 10KVA 3phase UPS System with additional battery cab.

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Demand v Generation

Pi Pylon

It was an August Friday, there was a sense of urgency prior to the blackout: people skipping around starting their weekend or at least the endorphins were being released with the anticipation that R&R was imminent for those that had the weekend off.

This Friday was different, just before 5pm trains halted and traffic lights glitched in central London- there was a metaphoric handbrake placed on everyone’s journeys. A blanket of darkness swept over parts of England & Wales on the late afternoon of 9 Aug. 2019. Chaos engulfed the regular journey home for many London commuters whether they were sat in their cars or were wading through busy mainline stations.

Walking through Cardiff around the same time you’d hear masses of security alarms going off like a Mission Impossible movie. Newcastle homes and businesses were affected and the local airport announced flight cancellations. Not all of the power outages on that day can be attributed to the causes discussed herein, the recorded blackouts are visible in the map below.

Source: https://www.dailymail.co.uk/news/article-7343681/Government-launches-probe-mysterious-power-cut.html
Power cuts registered on 9-8-19

You might be thinking ‘how can a train problem in London Euston simultaneously affect traffic lights in Bradford but have no significant power disturbances in between?’ Diverse areas of England and Wales, in terms of proximity, and with disparate tenures were affected that Friday. I was in Oxford and had no inkling, no horror movie like lights out or quietness as my fridge cutout conveying powerlines downing. The question may not bother you longer than a few seconds, because you know about the National Grid, right. You may have mapped out a plan that if it ever happened you’d start walking home and if it went on for hours you’d be forced into eating the contents of your fridge before they spoiled.

If you want to understand a little bit more about your electricity supply and get an insight into what is keeping the WiFi signal alive here’s a high level intro to the events of that evening.

Along your read there is a bit of technical knowledge needed regarding AC power network. Where power demand is greater than power generated then the frequency falls. If the generated power is greater than the demand then the frequency will rise. Once the frequency fluctuates to a level outside the set tolerance 50Hz +/-1% any service or appliance connected to the grid will experience instability and/or damage. Hence, frequency changes are monitored and balanced meticulously by controlling demand and total generation. There’s a website here if you want to see what is happening right now.

Watt happened then?

1.1m customers experienced a problem, blackouts on this scale are rare. Even the energy watchdog Ofgem demanded a report. It was released a couple of weeks ago and some of the findings are mentioned here.

Key Connected Personnel

Did the fact that it was 5pm on a Friday and certain connected people had started their weekend have anything to do with it? Only in terms of operational communications. There’s a protocol stating a sequence of communications must be released. Owing to the incident being on a Friday it is believed that certain key members were not readily available however it’s a red herring to believe this had an impact on the nationwide extent of the powercut. The important decisions were left to the Electricity System Operator (ESO) control office that manages the response in such situations.do trains stop during a electricitytrains stop

Electricity demand

The ESO had forecast demand, expecting it to be the same as the previous Friday. Post-event analysis whereby the demand profiles for the two days were mapped shows almost identical dips and rises. Nothing to point the finger at here. It’s not like Love Island airing and causing a surge in demand like earlier on in 2019. That particular increase in demand caused the grid to switch onto coal-powered generation after the longest stint of fossil-free power generation. (Like we needed a reason to dislike that program.) Incidentally, that record still stands at 18 days, 6 hours and 10 minutes. To date this year, we have prevented 5m tonnes of carbon dioxide(source = Guardian) being released into the atmosphere. Greta would be pleased to know.

The electric generation for the day was as expected, humans are creatures of habit so consumption was predictable, and it was known that neither wind nor solar was going to break any records. The generation mix was as per any regular day in August.

The Weather

Did the weather have to do with it? The ESO control room is provided with lightning strike forecasts. It comes from the Meteogroup in the form of geographical region stating the likelihood of a strike, represented on a scale of 1 to 5. A few minutes prior to the strike, the details sent across were ‘1’ signifying that the highest risk of lightning was predicted practically everywhere in England. Within the two hours prior to 5pm the main land UK had 2,160 strikes. So when the lightning strike on the transmission circuit occurred hitting a pylon near St Neots, it wasn’t a surprise.

Lightning strikes are routinely managed as part of everyday system operations. The eventuality is factored in by the ESO. The Protection System detected the fault and operated as expected within the 20 seconds time-limit, as specified by the grid code. The embedded generation which was part of the response to the strike, had a small issue on the distribution system. A 500MW in reduction of generated electricity was recorded. The monitoring system calculated the frequency, on the grid, which was in tolerance and any voltage disturbances were within industry standard, the Loss of Mains protection that was triggered was on cue. The ESO state this was all handled as expected in the response to the lightning event, and the incident was handled to restore the network to its pre-event condition.

The catalyst to the wide scale power problems was the unrelated independent problems that occurred at two separate sites just minutes later. Not one but two disparate power plants had a problem at nigh on the same time.

An off-shore wind farm (Hornsea) and a gas power station (Little Barford) meant the National Grid lost a combined 1691MW, as these two sites started under generating. (For the record these losses are attributed to the consequences of the lightning strike but the industry is asking the question of compliance, nothing is clarified yet). These generators fell off the grid and the frequency fell. As demand was now greater than the electricity generated the frequency fell below the tolerance value. To correct the frequency, the ESO did its job by prioritising disconnection of major load, it had to reduce demand by 1000MW. This equated to 5% of the consumption at that time, hopefully you were in the protected 95% that was kept powered !

Why wasn’t generation increased?

Reserves are already part of most plants, the solution would be to have more reserves available, right. Yes, but it is cheaper to just turn-off the load. It is also instantaneous, not too unlike having an overload on your UPS, you react by unplugging the load and then contemplate whether you need a higher capacity UPS. Not every power source can produce enough energy to stabilise the ‘demand-generation’ equation. Ramping up generation represents a significant outlay, sometimes the costs are inexact particularly when considering solar/wind plants due to forecast uncertainty and lest we forget every power plant is a business that needs to make money.

A note about renewable energy: the National Grid supply was originally set-up for fossil-fuel, the integration of renewable energy into the system is not simple. There are technical discussions relating to inertia, stability, ongoing compliance monitoring that needs to be addressed by policy makers and operators etc. before we see large scale deployment. 30% deployment seems to be the uptake globally on average in any country, more than this will require changes to system operations and market designs. Comforting to know that the National Grid is already being adapted and is expecting to be a carbon-free grid in the next 6 years.

Reducing demand

Each geographical region of the country is unique. The frequency recovery in different area is dependent on the transmission voltage, the transmission lines, energy generation and voltage support etc.  Routine maintenance is carried out on circuits and equipment rendering them out of service. Simply put, each region will react differently when the demand and generation is altered. The ESO is set up to manage faults and control demand. This is done in a predetermined manner based on knowledge about the limitations of all these region, those that lost power were scheduled to lose power.

Large users of electricity actually know the score when they connect to the grid. In these situations, the ESO will trigger the Distribution Network Operators (DNOs) to power-down companies who have contracts agreeing that they can have their energy cut-off to stabilise the grid i.e. balance the frequency. It doesn’t matter if it’s peak time in London’s Stations the agreement is to ‘pull the switch’ to non-essential supplies. The ESO signals to the DNO to stop powering those companies when it needs to control demand. The agreement is to cut-off for 30 minutes.

Further delays experienced by London’s commuters past this half an hour is reported to be the result of those companies having to restart their systems after the period of being cut-off. Certain new class of trains needed technicians to manually reboot approx. 80 trains on site and individually. On occasions the train companies had shifted supply to backup power but then when the grid was back the trains had complications switching onto grid power.

Companies would rather have the power cut than sustain long term equipment damage. Even so, it is unacceptable to the trainline operators and they did demand answers as the scale of disruption was phenomenal.

The report suggests that the ‘critical loads’ were affected for several hours because of their customers’ system’s shortcomings as the DNOs had only pulled the switch for 30 minutes. It also suggests that no critical infrastructure or service should be placed at risk of unnecessary disconnection by DNOs.

There are plans afoot to address the shortcomings highlighted by the report, we can only wait to see whether a powercut on this scale reoccurs. Modern technology can only facilitate improvements. Many of us have Smart Meters installed, the data these feedback will allow smart management. These would give the DNOs opportunity to improve reliability and switch-off only the non-critical loads when their network is being put under stress. Hey, you didn’t believe that those temperamental meters were just a freebie for you to cut-back usage and reduce your fuel bills, did you?

Sources: https://www.ofgem.gov.uk/system/files/docs/2019/08/incident_report_lfdd_-_summary_-_final.pdf

twitter #UK_coal

Ofgem

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UPS Runtime Calculator

UPS Runtime Calculator

How long will my UPS last for?

Need any idea how long your UPS will last for? Eg How much runtime will you get out of your UPS? Then this UPS Runtime Calculator is just what you need.

You’ll need to know how much power (in Watts) your UPS is delivering. Then you’ll need to know how many battery blocks and of what Ampere Hour capacity are in your UPS.

This calculator is based upon 12V blocks only and will only accept integer values. So, if you have one single 6V battery of 12Ah capacity, then you’ll need to say it’s a 12V 6Ah battery. If the spec of your battery is not in Ampere Hours but Watt Hours, then as a very rough guide divide the Wh rating by 4 to get the Ah. If you have 7.2Ah or 8.5Ah then if you round down this will give you a minimum, and round up will give you a maximum.

Note, the calculator is approximate. There are no assumptions made on standby current consumption and inverter efficiency. These will be different for different UPS and also different at different load levels. Please just use as a guide. For example if you have an AC load of 1000W, the calculator makes no allowance for DC to AC conversion losses. This allows you to add your own. For example if your system uses 5W in standby, and has an efficiency of 90% then for a 1000W AC load, use 1000 / 0.9 + 5 = 1116W.

If your load varies over time, you’ll need to estimate the average power consumption. You’ll need to size a UPS to meet the maximum power draw expected, but calculate the runtime based upon the average power consumption.

UPS Runtime Calculator

This needs a value. Enter an integer 10 to 100,000
This needs a value. Enter an integer value of the AmpereHour capacity of an individual battery block (2-1000)
This needs a value. Enter the number of battery blocks in the UPS (1-1000).

If you want to select a UPS to meet load and runtime calculators please use the UPS Selection Tool.

If you’ve used the UPS Runtime Calculator please leave a comment or drop us a line with any ideas.

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Residual Current Devices (RCD) and Isolated UPS Systems

Consumer Unit

Did you know BS7671:2018 Requirements for Electrical Installations, a.k.a. The IET Wiring Regulations 18th Edition states that any socket outlet 32A and under must be protected by a Residual Current Device (RCD)?

Section 4.11.3 is the Requirements for fault protection. Subclause 4.11.3.3 entitled “Additional requirements for socket outlets and for the supply of mobile equipment for use outdoors” states:

In AC systems, additional protection by means of an RCD with a rated residual operating current not exceeding 30mA shall be provided for:

(i) socket-outlets with a rated current not exceeding 32A

BS7671:2018 Section 4.11.3.3

In other words any socket outlet that you plug anything into (basically anything powered from a 13A outlet, or up to 8KVA Systems on Commandos) must have an RCD protecting that circuit. There are exceptions to this, dwellings excepted, but only following a documented risk assessment which clearly states why an RCD would not be necessary.

Purpose of RCDs.

An RCD works differently to a miniature circuit breaker (MCB) or fuse. An MCB renders devices safe in the event of an overload, or short circuit to earth. They are rated in Amps, generally in stages from 1-32A. RCDs work by tripping on an earth leakage fault typically of 30mA. This is a fault current of up to 1000 times smaller than the MCB! RCDs are useful as certain hazards can exist in the event of a fault that will not trip an MCB. Typically this involves applications that are, or may, come into contact with water.

Earth leakage is a small current that stems from phase conductors to earth. This causes an imbalance between live and neutral and it is this imbalance that RCDs detect. If the earth leakage is high enough on an appliance due to a fault or water contact then the equipment chassis can deliver a dangerous “touch current” if a user touches it. The RCD is there to protect against this scenario. If your application has water involved, then it is very difficult for a risk assessment to justify the omission of an RCD from the electrical infrastructure unless other safety measures are taken.

Isolation Transformer

An isolation transformer, by its very nature will stop RCDs from tripping – even in the event of an earth fault. See Isolation Transformers – what you need to know for further reference on this. However this isn’t a problem. In fact, the isolation transformer can make the installation more safe than with the RCD alone. Even a device with a fault can be touched by a user without any hazard occurring. Unless – and I can’t stress this point enough – the isolation transformer has the output Neutral and Earth bonded!

N-E bonds are not there for safety, but rather for noise rejection performance by establishing a zero volt neutral-earth voltage. Isolation transformers in conjunction with UPS Systems provide a very resilient power protection solution. However, in order to ensure the system is safe, then you should not bond the N-E. Our isolated UPS systems leave the system floating, providing true isolation and an inherently safe electrical environment. If you use a N-E bonded system and no risk assessment has been carried out to determine that no RCD is necessary then this contravenes the requirements of BS7671:2018.

Decision Flowchart

BS7671 RCD UPS Selection Flowchart

Start by asking if there is a documented Risk Assessment as to why there is no need for an RCD on a socket outlet. If there is, then you’re good to go and any UPS is good for this scenario. You can use isolated (floating or N-E bonded) or non-isolated depending upon your requirements.

If there is no risk assessment in place then we check if there is an RCD fitted. If not, or unknown, then in order to provide the safest environment, the solution is a truly floating isolated UPS. Granted, if no RCD is in place, fitting any UPS does not make the situation less safe, it’s just that a floating isolated UPS does make it safe.

If there is an RCD fitted, and no risk assessment has been carried out, then you must not use any NE bonded system NOTE 1. This removes the safety aspect of the RCD.

Conclusion

According to the 2018 Wiring regulations there needs to be an RCD fitted on any sub 32A circuit. This will cause power to be removed if earth leakage of over 30mA is detected. Any standard UPS will not interfere with the operation of the RCD, however an isolated UPS will prevent the RCD from operating.

However, a floating isolated system, where Neutral and Earth are not connected provides a safe electrical environment. In situations where an RCD should be installed, for example there is water required by the application, and the electrical infrastructure is unknown (for example older installations to which RCD was not a mandatory requirement), floating isolated UPS provide the ideal solution.

An isolated UPS that is floating renders RCDs ineffective but provides enhanced safety by removing any touch current hazard.

On the other hand, a N-E bonded UPS system not only negates an RCD but does not make safe any scenario to which the RCD was required to protect against. There’s a reason for section 4.11.3.3 of BS7671 and this situation violates it.

An isolated UPS with a Neutral and Earth Bond renders RCDs ineffective and does not protect against hazards for which the RCD is intended.


NOTE 1: Unless a secondary RCD is fitted to the output of the UPS.

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BS8418:2015 UPS System Selector

BS8418 UPS Applications

Many moons ago we blogged about BS8418:2010 (Installation and remote monitoring of detector-activated CCTV systems, Code of Practice) and the requirements for UPS Systems. That standard stated:


Unless the mains power supply is supplemented with a stand-by generator, an uninterruptible power supply (UPS) must be able to power the CCTV control equipment and communications devices for a minimum of 4 hours after mains power failure. Where the mains power is supplemented by a stand-by generator, the UPS needs to be capable of providing stand-by power for a minimum of 30 minutes after mains power failure (for example if the stand-by generator does not start).


The 2015 revision relaxed this somewhat, allowing for a documented threat assessment and risk analysis to determine whether a UPS is required or not. That said, it is difficult to state how any threats or risks are mitigated against a loss of power without a UPS, so the requirement for UPS Systems is likely still to remain in BS8418:2015 installations.

If a UPS is used as the “alternative power source” then this has been changed from a 4 hour requirement to a 30minute requirement when supporting control equipment and data transmission devices. However the standby power capability for the detectors and semi-wired detectors remains at 4hours.

Find a UPS Solution

Enter in your load power and how long you need the UPS to provide backup power for. The UPS Selector will identify any UPS that meet your requirements.

You can filter the selection based upon required features, by clicking the checkbox. Many models are available to by online from our webstore but contact us using the form below for specific requirements or for other products not available to purchase online.

Watts

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Found Models

Errors or Warnings


Contact Us About This Solution

[contact-form-7 id=”1895″ title=”Contact Form UPS Selector”]

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Lithium-Ion UPS vs VRLA UPS

Lithium UPS

Our Lithium Ion UPS range is an impressive series of UPSs with internal Lithium Ion batteries, that make the units efficient, lightweight and more environment friendly. They also reduce the whole life costs of the UPSs. We have conducted some tests to show you how the Lithium-Ion UPS compares to the VRLA UPS in terms of runtime.

Each unit is connected to 1800W load. The Lithium UPS battery capacity is 48V 9.9Ah = 475VAh. The VRLA UPS battery capacity is 72V 9Ah = 648VAh. Although the Lithium UPS has only 75% of VRLA UPSs battery capacity, the runtime results are outstanding! See the video below:

We provide 5-year warranty on the Lithium-Ion UPS systems including the batteries.
Lithium-Ion UPS only from Power Inspired. Learn more at www.lithium-ups.com and register your interest.

Lithium-Ion UPS