Powervar Security II UPM vs TX Series


A factual comparison of the key technical differences between the Powervar Security II UPM and the Power Inspired TX Series UPS System.

FeatureSecurity II UPMTX SeriesComment
N-E BondedYesNo➀ To Bond or Not to Bond
Isolation TransformerOn outputOn input➁ Transformer on input or output?
TechnologyLine Interactive
Online Double Conversion
➂ Quick explanation
Hot Swap BatteriesYesNo➃ Hot Swap Batteries
Extended RunNoYes➄ Extended Run

➀ To Bond or Not to Bond

Isolation transformers will negate the effectiveness of Residual Current Devices (RCDs). Where an RCD has been specified either for additional safety or due to poor earthing then this point needs to be considered.

The advantage of making a Neutral to Earth bond is that it removes any voltage between the Neutral and Earth conductors. This is what the Security II UPM does. However, as a result of this the output live conductor is now referenced to earth directly. This means that in a fault condition it is possible to receive an electric shock between the output phase conductor and earth. Any protective RCD put in place to protect against this will not trip.

Where no bond is made, the output voltage is now floating with respect to earth. This means that any phase to earth fault would not cause an electric shock as the fault would simply reference the phase to earth. Again, no RCD would trip but this is irrelevant as no hazard exists.

See this article on isolation transformers for further info.

➁ Transformer on Input or Output?

An issue with transformers is called “Regulation”. What this means is that the output voltage with no load will be higher than when the transformer is under full load. In line interactive topology such as the Security II UPM, the transformer on the input or the output does not make for much difference except when the unit is running from inverter. The problem is that the output voltage can be quite high under no-load conditions to being quite low under full load conditions. If the load is fluctuating this can cause the output voltage to be varying quite substantially.

This is also problematic where certain loads may have high start up currents, such as those with motors or pumps. The initial current surge causes the output voltage to fall resulting in under-voltage protections operating on the load.

In online units, such as the TX series, the load is powered from the inverter and hence is extremely stable. A transformer on the output would negate this benefit. The transformer on the input will still be subject to regulation issues however the UPS inverter will correct for any voltage variations. This means the output with online technology is fixed and unwavering – even with high start up current loads.

➂ UPS Technology

A line interactive UPS allows the input power to pass through to the output. If the voltage rises too much that the output voltage would become out of tolerance, then the UPS enters a “buck” mode to reduce the voltage by a fixed percentage.

The reverse is also true. If the input voltage is to become too low to remain in tolerance, then the UPS enters a “boost” mode to raise the voltage by a fixed percentage.

Such technology is referred to as “Voltage Independent” or VI. However in normal operation the output voltage is in fact passed straight through so the voltage regulation is somewhat minimal. Any distortions on the input power will also be passed through to the load.

The Powervar Security II UPM is a line interactive UPS.

Online double conversion units supply power to the load from the inverter at all times. This means the output voltage is fixed and of high purity. In fact, the TX series, being an online unit is capable of having an adjustable output voltage, or even frequency.

This feature of online UPS means this technology is referred to as “Voltage Frequency Independent” or VFI. In that the output voltage and frequency are in fact, independent of the input. However, note that it is common practice for online units to be in synch with the input frequency in case a revert to bypass is necessary. So technically, the frequency isn’t always independent.

➃ Hot Swappable Batteries

Hot swappable is a term coined to describe that the batteries in the UPS can be replaced with the unit still powered up and connected. The important point is that this should be safe and be able to be performed without the use of a tool. It is advantageous in that it allows the replacement of batteries by unskilled persons and without powering down the load. If the UPS requires a service however, then this benefit is largely removed.

➄ Extended Run

Extended run units allow for the connection of additional battery packs in order to extend runtime if required. Such units should have a higher capacity battery charger in order to recharge this larger battery bank. The TX series is an extended run unit with an adjustable battery charge current of up to 4Amps.

This Is The Age Of The Lithium UPS

This Is The Age Of The Lithium UPS

Introducing the new range of KR-RM-LI series UPS, true online double conversion UPS Systems with internal Lithium Ion batteries. Welcome to the new age for UPS.

UPS have traditionally used valve regulated sealed lead acid batteries for energy storage. They are relatively cheap, easy to install and maintain and have a reasonably good energy density. They’ve been the technology of choice for decades now.

However, they do have drawbacks. Probably the biggest of which is heat. The expected life from a lead acid battery diminishes once the temperature exceeds 25°C and this deterioration becomes much more rapid above 30°C.

Damaged Battery

Secondly, like all rechargeable batteries, they have only so many charge/discharge cycles in them. Typically this is 200-300. This is usually more than enough for average use. However if the batteries are called into use daily, then you will find that the batteries are shot in under a year.

Thirdly, they only have a fixed life in any case. This is referred to as the “design life”, and is normally quoted as 5-year or 10-year. However this is assuming the batteries are subject to perfect environment, hardly cycled and continuously float charged. Usually you can expect battery life to be 2-3 years in good conditions and less if the environment becomes warm.

Lastly, although the energy density is reasonable, they are in fact quite heavy. A typical UPS battery block of 12V 9Ah weighs 2.5kg. For a typical 3KVA UPS with a 72V string, this is 18kg of weight just for the battery.

Introducing the New Age of Lithium UPS

Lithium Ion batteries are now ubiquitous in our world. They power everything from smart phones to laptop computers and now even cars. Although there has been a few scares with safety, given the sheer number of batteries out there, the problems have been in fact an extremely small percentage. Notwithstanding that, the safety protocols that are required to be in place now mitigate many of these issues. 

Lithium Ion Battery in UPS

Each battery pack is made up of an number of individual cells. Each cell is produced to high quality standards, and electronic circuits monitor the pack to ensure balance in both charge and recharge in each cell. Signs of thermal runaway cause the pack to be disconnected from source power before any external damage can be caused.

So why use Lithium in UPS

Lithium offers some very compelling advantages over lead acid.

Temperature. Lithium is not affected by temperature in the same way as lead acid.  In fact, our UPS can operate in environments up to 60°C without damage to the lithium battery. This is a clear advantage for Lithium UPS where warm environments may be experienced.

Power Density. Did you know Lithium is the lightest metal? It is item number 3 in the Periodic Table of Elements after Hydrogen and Helium. As a result we can cram in  more battery capacity into our KR-RM-LI Lithium UPS than we could possible hope to achieve with lead acid. Each of our models, 1,2 and 3KVA contain 10Ah batteries of 24V, 48V and 72V and provide 11 minutes of runtime at full load. All in a 2U chassis, and not only that – our 3KVA model weighs only 16Kg. To put into perspective the equivalent 3KVA lead acid provides 3minutes of runtime and weighs 32kg! If you wanted to match the Lithium UPS you would need to add a battery pack making a 4U solution weighing 75kg!

Battery Life. The Lithium battery is good for well over 1000 cycles, meaning that you can charge and discharge it every day for about 3 years before you started to see a degradation in performance. It’s service life is 8years with a typical 10 year life.


Lithium UPS, with the higher power density, gives more runtime in a smaller footprint than the lead acid. This may be a good reason to elect for Lithium, however, if you have the room you could opt for additional battery packs with lead acid. However, when you consider you can get three times the runtime for a third of the weight and rackspace than with lead acid, then the Lithium case again starts to become compelling.

The Lithium UPS is of course more expensive than lead acid, but that is just the up-front cost. Taking a whole-life-cost approach you will find, as some of our customers will testify, the Lithium UPS makes financial sense when protecting an investment which has to last 5 years or more. Being fully guaranteed -including the battery – means there is no need to be concerned with scheduling in a battery replacement midway – or even several times – throughout the equipment life span.

If warm temperatures are expected, perhaps due to restricted ventilation- not just hot summer days- then Lithium really is your only option unless you’re happy to swap out the buckled lead acid blocks. If you’re bundling UPS with equipment to go on a customer site, then Lithium will ensure that you won’t have battery problems down the line.


Finally, there’s a lot of misconceptions about being able to ship Lithium units by air. There are certain guidelines you need to have, and all our units are correctly labelled to allow to be sent by air, so there is no need to discount Lithium for transportation reasons.

Christmas Shutdown

Christmas Holly

Christmas Shutdown 2018

We will be closing for Christmas on Friday 21 December and reopening on Wednesday 2 January 2019.

Any orders received during Christmas will be processed immediately upon our return.

Emails will be monitored for any urgent requirements. Please email:

For technical queries:


For sales enquiries or orders:


Merry Christmas and Happy New Year!

Automatic Transfer Switch – The Power Inspired ATS-16A

Automatic Transfer Switch Diagram

This month’s product feature is our Automatic Transfer Switch – the ATS-16A.

What is an Automatic Transfer Switch?

An Automatic Transfer Switch, or ATS is a device that has two AC power inputs and one power output. One input is set to primary and the other secondary and the load is powered through the primary power source. Should the primary source fail, the unit automagically transfers power to the secondary source.

What is an ATS used for?

In many cases it is used to add resilience to an electrical network, or as a way of safely bypassing a UPS for maintenance work.

Can an ATS be used with generators?

Yes, in many cases this is the prime use of an ATS and coupled with a UPS can provide a fully power protected standby power system for critical loads.

What is the rating of the Power Inspired ATS?

Our ATS is designed for single phase rack mount systems and is rated at 16A. This makes it ideal to work in conjunction with any 3KVA UPS System.

What arrangements are possible for load resilience?

Automatic Transfer Switch DiagramWe will assume that Source A is set to primary and Source B is secondary, although in practice you can set either one. If source A is the output from your UPS and source B is raw mains, this allows you to easily bypass the UPS for maintenance, or provide a secondary backup should the UPS on source A fail.

If A is a generator and B is raw mains, then whenever the generator is powered up the output will be powered from that. This can also be used if the generator is an alternate source, for example a renewable energy supply. A UPS is advised on the output to protect the load and to cover for any breaks in supply.

ATS Resilient Arrangement

An extremely resilient supply however can be obtained by using two ATS. In the example above the UPS can be safely taken out of circuit without any loss of power. Source A can be generator and source B, raw mains. The UPS can be bypassed simply by turning it off or switching input on the right hand ATS.

Other FeaturesAutomatic Transfer Switch ATS-16A Front

The ATS-16A is a rack mountable unit occupying only 1U of height. The front panel has a membrane keypad for selecting the primary input source as well as displaying the current state of each input and the output. The unit can be connected to an attached computer via USB and RS232 to give real time status of source as well as voltages, frequencies and the power consumption. An Intelligent Slot is available to communicate this information via SNMP if required. The front panel switches also allow for the disconnection of loads connected to the PDU on the rear panel.

Automatic Transfer Switch - Rear Panel

The rear panel has both source inputs on 16A IEC leads. The output also couples as a Power Distribution Unit, or PDU. A single 16A outlet is available and is unswitched. Two further banks of 4 IEC10A connectors are available for supplementary loads. These can be switched from the front panel if required.

Furthermore a dry contact port is provided for communicating status to a remote alarm panel or Building Management System (BMS).

The Power Inspired Automatic Transfer Switch ATS-16A is currently on sale on our webstore: ATS-16A Store Page.

UPS Runtime API Released. Register Now.

UPS Runtime API Code

Our bespoke UPS Selector is an extremely useful tool in correctly selecting a UPS. In order to assist our customers in selecting the UPS within their quote tools we have opened up the UPS Runtime API (Application Programming Interface).  This is a powerful tool that can select a UPS meeting runtime criteria, or calculate the runtime for a particular UPS. The request can be filtered to only include certain model types, or to exclude certain model types or models. This allows the request to be dynamically filtered based on requirements. This is useful where only particular model types are offered or certain features are required. It also includes the new Lithium Battery UPS Systems.

The API can be added into a quote tool or website and requires JavaScript integration. The API is queried with a JavaScript Object Notation (JSON) request and a JSON object is returned containing the results of the query. Registration with Power Inspired is necessary as the calculation is performed on our servers. In order to comply with the requirements for Cross Origin Resource Sharing (CORS) guidelines the server will only accept requests from pre-approved domains.

UPDATE: We’ve also used the API for our own UPS Selector Tool.

There is a comprehensive readme file available and the example by the author.

Did you know we can also tailor the default request to your individual requirements? Just let us know which models you want the API to return and we can auto-filter it for you.

Request Access to the UPS Runtime API by Completing the following form:


AG1500S ReGen Hi-Fi World Review September 2018

HiFi World Sep2018 MAgazine Cover - includes AG1500S ReGen review

Just picked up the September issue of HI-FI WORLD Magazine that features a review of our AG1500S ReGen. When it comes to product reviews, Hi-Fi World state: “To ensure the upmost accuracy in our product reviews, Hi-Fi World has extremely comprehensive in-house test facilities, and our test equipment – from big names like Rohde & Schwarz and Hewlett Packard – is amongst the most advanced in the world… …No other UK hi-fi magazine has in-house testing, and none has access to such advanced tests across all types of equipment. That’s why you can depend on Hi-Fi World reviews“. So you can be sure that this is a properly conducted an independent review.

We’ve had great feedback on our previous model of ReGens, the AG500 and AG1500, so were delighted when Hi-Fi World asked if they could take a look at one to get a truly independent viewpoint. However, this was just as the AG1500S was on the horizon so there was a little delay until we could get one of the very first production units to them.

So what did they say?

Hi-Fi World Summary of REview on the AG1500S ReGenWell I’m pleased to report that Noel Keywood did a pretty thorough job of putting the ReGen through it’s paces and gave it an “Excellent” marking. with the conclusion “It cleans the mains as claimed, to below 1% distortion and removes noise too, our measurements showed, usefully improving sound quality. It may look a bit industrial, but the AG1500S has massive ability at a good price.

For the full review please refer to Hi-Fi World to purchase the magazine.


39 Points at Team Meeting

Ken Bruce

Every morning at 10:30 we gather the team together for a morning meeting. It just so happens to coincide when PopMaster is on Radio2 so we generally listen to that instead of me. [Customers please note, we love your calls but we’d appreciate if you could wait until after the quiz.]

I’m delighted to report that this morning, for the first time ever, we gained a clean sweep of 39 points!!! We also got the 3 in 10 to boot!

Well done team!

I’m shocked to say I knew The Reynolds Girls would rather Jack than Fleetwood Mac and where did Sukhi dig out Midnight Oil from?

It’s not always gone so well. Sometimes despite our best efforts we can walk away with zero. Especially if the bonus is about Eurovision (which it seems to be an option quite often). So I’ve implemented a revised scoring system for such days. This involves

  • a point for guessing the same set of bonus questions as the contestant. Which of course we’ll get as we’ll make sure both options are chosen.
  • points for the same wrong answer.
  • double points for being one year out which is then doubled again if it is the same wrong answer.
  • bonus point for being over a decade out.
  • adding the points gained from both rounds together.

Our rules allow where there’s a multiple choice we all choose a different answer, to which we’re guaranteed to get it right but also have the benefit of same wrong answer bonus if the contestant gets it wrong. We’re also allowed to average the years shouted out to get the right answer.

There’s also bonus points of various amounts usually in the 30point+ mark awarded for giving a correct answer before the question, and for guessing a correct question on the bonus topic.

But we didn’t need it today – well done Team Power Inspired!

@BBCRadio2 @kenbruce #popmaster

New AC Power ReGenerator – AG1500S

AG1500S LCD Display

The AG1500S ReGenerator- What’s in a letter?

AG1500S AC Power ReGenerator

Due to be released in June the new AG1500S AC ReGenerator has built upon the success of the previous AG1500 model with some major upgrades. So what difference does that extra letter make?

Selectable Voltage

AG1500S LCD DisplayPrevious ReGenerator units have had a fixed output voltage and frequency. For those travelling to places which operated on a 60Hz frequency this required a factory adjustment. The unit was suitable for either 50 or 60Hz but not both.

The new AG1500S auto detects the frequency and adjusts itself automagically, allowing for the unit to be operated in any area.

As well as the frequency improvement, the output voltage can now be adjusted. The AG1500S can be set to output 208V, 220V, 230V or 240V, via the LCD panel, depending upon your requirements. Note as with the previous model the output voltage is fixed and unwavering.


Sine Wave

The earlier models were sine wave too of course with a Total Harmonic Distortion (THD) of under 3% and typically 2%. THD is simply a measure of how far away the output is from a pure sine wave, the lower the number the better. Anything lower than 8% can be called sine-wave.

The AG1500S has a THD of 2% and typically is 1%. This may seem a small change but it registers a substantial improvement in power quality. So much so, that our beta testers have said they thought the AG1500 was good, but the AG1500S is so much better.

Smart Fan Speed

fans spinning on ag1500s ac regeneratorFan speed is problematic of course as it generates noise. The standard way for fan speed control is to have the fan speed controlled by the amount of load the unit is delivering. However this leads to unnecessary increase in fan noise especially in audio environments where the load is not constant but rather has sharp peaks of demand. This is why we introduced a control mechanism in the original AG units, allowing you to set the fan speed depending upon your own set up and requirements. However, this can lead to the unit overheating and tripping out if set too low.

We’ve devised a novel way of controlling the fan speed with the speed adjusted automagically to the unit needs. If it’s getting hot the fans will speed up and slow down again when it cools. This way your ReGen won’t unexpectedly cut out and scream at you. Another feature we put in is that on power up the fans will ramp up to full speed for a few seconds and then revert to the appropriate setting. This way you can be confident that the fan circuitry is in good order – and if it isn’t the fans are defaulted to run at full speed so the unit can be used until a service can be arranged.

Super Cool

What’s more the unit efficiency has been improved to a remarkable 93% peak – which means the unit doesn’t generate as much heat in any case. In our lab tests, even running at a constant full load the fan noise was minimal. This high efficiency means the unit costs less to run as well as not pumping as much hot air into what may be an already warm environment.


AG1500S REar Panel


A big change from the AG1500 is the changeover to IEC socket outlets. Some liked the national socket outlet on the AG1500 but others found that this required the use of extension blocks as one socket wasn’t enough. So we’ve now got six of the IEC 10A socket outlets and one of the high current 16A outlets. The unit comes with a rewireable 16A plug allowing you to rewire your main cable. This of course means that there are no fuses in the output stages which we know is of importance to some users.

There’s also now a much smaller battery connection port to allow the connection of a separate battery pack. For those of you with existing ReGen battery packs please note the battery voltage is different and so they can not be interchanged (plus you would need to get a different cable adaptor).


We’re delighted with the performance of the AG1500S ReGenerator in our lab bench tests. The unit functionality, performance and robustness have all been put to the test and has come out with flying colours. We’ve had the unit out on test with a number of eager audiophiles who have reported extremely positive results using the AG1500S:

  •  “Overall it is a very well conceived unit and one that I certainly would recommend“,
  • This unit has made a significant difference, please put me on the list for a new one when released“,
  • So far I am confident the new unit is an improvement, it sounds cleaner at both ends of the spectrum, more dynamic and with a wider and deeper soundstage. The HF are smoother and more extended, the bass extends lower too and is tighter. Compared to my TX it is relatively close

We’ve currently got the demo unit out on review with a well known HiFi mag, so we’ll keep you updated with the results of that when it’s in.

Incidentally, the last comment above refers to our TX unit. Now this is not a ReGen but one of our isolated UPS Systems. The reviewer of the AG1500S said the TX was an improvement over the AG1500, but the AG1500S was close. Now the TX series is not quiet and not suitable for anything other than professional AV applications with a separate equipment room, so if you’re in this market the TX series may be an alternative for you.

The new AG1500S will have a retail price of £599 including VAT, delivered. I’ll let you into a secret though, since we’re 10 years old this year we’ve a promotion running  – get 10% off the AG1500S by using the discount code “10years” when asked in the order process. The code is valid until the end of August. Click for the AG1500S Webstore Page or to download the brochure.

10 Years!

Celebrating 10 years

Wow. I’m proud to say that Power Inspired Ltd is celebrating its 10th year in business! Did you know that only 30% of businesses make it to 10 years and that figure falls to only 9% for businesses with fewer than 20 employees?

It’s been a challenging decade with some highs and lows, but thankfully with more highs. I’d like to thank our team of dedicated staff both those who are still with us and those that helped us on our way, our responsive and willing suppliers who’ve helped us create novel and unique products and finally to our loyal customers, to without whom it could never have happened.

We’ve come a long way that we’re unrecognisable from our humble beginnings but one thing that hasn’t changed is the culture of our business. Our mission has always been to educate our customers to make the right power protection solution at the right price. We’ve always done that and will continue to do so.

Once again, thanks to you all.


Closed Today 2 March 2018

Snow on Motorway

For Health & Safety reasons we have closed the office today. The snow, ice and wind makes for dangerous travel conditions and so I have asked our staff to remain at home.

Please use our contact form or email us at support@powerinspired.com for technical enquiries, and sales@powerinspired.com for sales enquiries.

If you need to speak with somebody, contact us as above with your number, the nature of your enquiry and somebody will call you back.

Needless to say, no goods will be leaving our warehouse today, however we’ve been advised that many depots around the country are closed in any case.

According to the forecast we should be good to go again on Monday.