Thanks very much. This allows me to assess the pros and cons.
My thinking is not to install a UPS since power cuts are very infrequent here (all supply wiring underground). Also, I have a dedicated radial circuit for the computer and all circuits have individual RCBOs so a fault inside the property should not affect the supply to the computer. I'm not doing anything very out of the ordinary and Windows 10 generally seems to recover well.
I apologise for my dismissive tone earlier - instinctively I knew it was a small number but no way anyone else might assume that.
And in this case, the problem of frequent power cuts is a bigger issue to me.
I know this has been discussed before, but can you please give a link to a resource for doing this (for those A{C units that support it)?
I have three APC units here, and I'd be interested in doing it. My batteries last 3-4 years depending on the unit.
It's fine. We all send stuff in a rush - that's the nature of social media.
My impression is that power cuts are far more common in areas with overhead cabling than in urban areas where the cabling is underground and old. My brother used to live in a village and regularly had power cuts. I'm in a 100 year old flat where power cuts are very rare. Certainly, in your position I would adopt your approach.
Thanks! I remember seeing some instructions a while ago, but time to *do* something...!
Yeah, it did for me, and I didn?t watch the other link to old Steptoes either.
I see Andy has already provided a link to a useful website. Bear in mind that the Back-UPS series generally didn't cater at all for such external monitoring and control. The Back-UPS Pro and the Smart-UPS models are equipped with the proprietary wired DB9 serial port (later models used a USB interface) required to support remote monitoring and control.
APC provide software called PowerChute. I see I have a copy of PowerChutePersonalEdition which I downloaded (presumably for free after registering on line) from APC's support site way back in Nov 2008. I've also got a copy of winapcupsd-3.14.4.exe I downloaded a few days later which is an open source APC power monitoring daemon for windows (I note that the latest version is now at 3.14.14).
You can google for details on how to wire up the UPS end of a basic 3 wire serial interface cable once you're ready to try the remote access feature of a suitably equipped APC UPS.
Having browsed through most of the many circuit diagrams for APC's earlier UPSes (circa 1995 to 2004 that I'd downloaded from a Russian website back in 2008) to track down the diagrams for that tiny BackUPS500 I mentioned earlier to verify the battery charging circuit that I'd had to repair just 12 months or so after purchasing it from a radioham rally trader (unused and in its original packaging for just 25 quid). I see that the analogue regulator IC that I'd had to replace must have been a
7815 (at least originally) rather than a 7812 as I'd misremembered it.It's highly likely that I'd simply substituted the 7815 with a 7812 and a resistor network to lift the common pin by the required 3 volts. The details of this repair are now marked up on a printed out circuit diagram packed away in the original box which is now stored in the attic for safe keeping so I can't be any more precise about the details of the repair than that.
The 12v battery charging circuit was as crude as can be, relying on the
1.4v drop of a couple of 1N4005 diodes in series to drop the 15v regulator output to approximately 13.6v - however, the diodes did serve the secondary function of preventing the battery from back feeding into the output of the 7815 chip, rather neatly fulfilling two separate functions in the circuit. I think it was just a matter of dumb luck that the float charge voltage ended up being 13.5 rather 13.8 volts in this case.Having looked at so many of APC's circuit diagrams, I have to say that I've never seen so shitely laid out circuit diagrams in all my life as those (and that's even going by the crap standards of 1960s American electronic "Schematic diagram" practice!).
I even spotted a few totally illogical wire ups of CMOS 4000 series logic gates including one case where the output of a dual input gate was wired to Vcc at 12v. I suppose I could have worked out what "IC2" actually was if ICBA but life's too short to waste on satisfying mere idle curiosity.
The one thing about all of these diagrams is that most of the ICs and discrete semiconductors were simply labelled with an IC or U number with no BoM listing in sight. However, in many cases I'd spot voltage and current ratings for diodes and transistors marked against these components even to the extent of indication Rds values of 0.028 ohms and
50v for the power FETs used in the inverter sections which, to my mind, could only be BUZ11s (or their equivalent).If you're trying to repair one of these older UPSes using these diagrams as a guide, you can usually identify the mystery components on the diagram by locating the actual components as fitted to the PCB(s) anyway, so these diagrams aren't entirely useless in this regard (just bloody difficult to follow and make sense of).
That's probably it - a pair of 33kV lines come into our village and it's probably those that are the problem.
I'm currently looking at the Riello Sentinel Pro series:
Look quite nice - need to see if I can find any reviews now...
Auto selecting online or line-interactive modes, low noise, high efficiency, sine wave.
Protections Overcurrent - short-circuit - overvoltage - undervoltage - temperature - excessive low battery
OS support: Windows, Linux, VMware ESXi, MacOSX and more.
Ticks the boxes on paper at least.
My Smart UPS 700 needed a hardware hack and poking some values into the firmware via the serial port and the units "debug" mode. I have a sneaky feeling that I don't have any documenation about what I did but may well have posted details in here around Mar 2014.
I can satisfy your curiosity about that for three APC models of UPS if that's any help. The SmartUPS2000 draws 32 to 35 watts depending on the actual mains voltage I suppose. The much smaller SmartUPS700 draws a whopping 20 watts for its miserly 450W/700VA's worth of protection and the tiny BackUPS500 takes a mere 2.7W for its 'quasi-sine wave'
350W/500VA's worth of protection (also, it only uses a *single* 7AH 12v SLA).These "maintainance" consumption figures exclude battery charging activity (i.e. the figures are for when the battery packs are well and truly charged up and drawing less than a milliamp of charging current).
The UPS manufacturers rarely, if ever, mention the "Maintainance" consumption figure in their specifications. All UPSes consume some power whilst in service ready to switch over to their battery powered inverter supply in the event of a mains outage.
That tiny BackUPS500 was the only one that consumed what I'd hoped all similarly rated UPSes in the sub 500W class would be specced for. A 3W or less maintainance figure for a 350W/500VA unit is a not unreasonable energy cost but discovering that the 450W/700VA rated SmartUPS700 was taking 20W regardless of whether or not its fully charged battery pack was connected was a rather shocking surprise.
Scaling that up threefold to the SmartUPS2000's level of 1500W/2000VA protection would equate to a 60W maintainance figure which is what made the SmartUPS2000's 32 to 35 watts figure look so economic by comparison. However, despite the better maintainance consumption to protection ratio, that's still a significant running expense added onto a household's annual electricity bill.
At one time I had a total of five UPSes in service, adding some 80 watts to my background consumption when each watt of 24/7 consumption approximated to a pound a year's worth of electricity. I've now cut that down to about 35 watts which now works out to about a quid's worth of electricity a week which seems a reasonable premium to pay for protection against any unplanned outages.
Of course, these are all 20 years or older models and one might hope for lower standby consumption figures with more current models. However, I wouldn't bank on that being true unless the manufacturer is prepared to publish this figure of merit in the specifications.
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I suspect that figure is for the DC to AC conversion efficiency of the sine wave inverter. However, assuming they've expressed the ratio of maintainance consumption to maximum power output as an 'efficiency' percentage (I'm guessing the 1000 is the VA rating making the wattage rating 750W on the assumption of a PF figure of 75% for the VA rating being used), that would imply a standby power consumption circa 22.5 watts (or 24 watts for 800W at a less generous 80% PF rating).
Using the same basis to calculate the SmartUPS700 'efficiency rating' would give a figure of 96% and for the SmartUPS2000, a figure of 97.7%. I somehow don't think that 97% efficiency figure relates to what you think it does.
The only other type of UPS where such an efficiency figure would be significant is the no-break type where power to the protected load is provided from the inverter at all times. I'm pretty certain the SmartUPS1000 is just another line interactive UPS just like the SmartUPS700 and SmartUPS2000 models.
If that 3% energy loss is for when the SmartUPS1000 is passing mains power through to a load at the maximum rating, you can't apply a linear efficiency calculation for fractional loadings since it must include the fixed maintainance consumption leading to an efficiency figure of just
30% or so for a 10W load (or just 1% for a 1W load). The real concern is down to the cost of just keeping it plugged into the mains without any load connected or switched on. I think you need to determine exactly what APC mean by "An efficiency of 97%" before you try working out such TCO figures. :-)
That feels about right for the warmth of the case of mine, I used to run a switched APC PDU on the output of the UPS, so I could remotely control
8x IEC sockets with various IT kit, but that ate a similar amount of power to the UPS, and I eventually decided it wasn't worth it.I just have the SU2200 in use (but I have a spare SU2200 and SU1400).
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