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Lidl (UK) has Parkside inverter generator on offer next Thursday 31st May 2018

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Posted by Johnny B Good on May 26, 2018, 3:24 pm
 
 Seeing as how quiet this news group is of late, I thought I'd post a  
copy of the above titled thread originally posted in uk.d-i-y on the off  
chance that there may be UK based subscribers still monitoring  
alt.energy.homepower.

 However, since Lidl have expanded their operations into the USA in  
recent years, this may prove of interest to the wider US centric group  
monitoring from the sidelines so, if nothing else, here's my take on the  
'Latest Offering' in inverter gensets from Lidl in the hope that it will  
help relieve the boredom of monitoring this NG, an "activity" that's  
perhaps best described as the business of "Watching Paint *Peel*". :-(

=========================================================================

/START-QUOTE/

 The XYL returned from a quick shopping foray this afternoon with the
latest magazine showing next week's offers which included a "Golden Oldie"
first seen two years back. Said Golden Oldie (the PGI 1200 A1), presumably
being priced for nostalgic reasons, is on 'offer' at the original 129 quid
price (their version of "Rollback Pricing" I'm guessing).

 Although remarkably cheap for an inverter genset even at the 30 quid
higher asking price than the later PGI 1200 B2 "Suitcase" generators they
were selling in the 2nd week of April this year, it has even more going
against it than the 99 quid B2 model which I'd assumed to be its
replacement and thus rendering the A1 model totally obsolete.

 After checking out this video review on youtube:

<

 and taken another look at this one on the B2 model:

<

 which is worth checking out simply for the extremely informative
comments made by dean handley from ten months ago which would have saved
me so many return trips to finally track down a working PGI 1200 B2 some
seven weeks back, I have come to the conclusion that unless you want to
strip out the guts of the A1 and transplant them into a properly designed
enclosure of your own (whether portable "suitcase" or just a small brick
outhouse), or you simply want to use it for spares[1], I wouldn't bother
unless you're really desperate to get hold of a 1KVA pure sine wave
inverter generator having just missed out on April's bargain of the decade
in cheap inverter genset technology.

 Having said that, it's still superior to a cheap open frame genset. Yes,
it may be almost as noisy but at least its 1KW of pure sine wave power can
be safely used with electronic kit and even old fashioned sine wave UPSes,
unlike normal generators using 'sophisticated' AVR control which will
grossly over-volt at the drop of a hat (leading current loads from a few
microfarad's worth of capacitance generally being all that's needed ime to
send a 2.8KVA 230vac generator going north of the 270vac mark!).

 If you're looking for a cheap alternative to buying a few hundred quid's
worth of SLAs to boost the autonomy of a 1.5KVA or higher rated UPS by a
couple of hours, this could prove a more cost effective alternative,
especially as you can get a good 3 to 5 hours worth out of each gallon of
unleaded petroleum/gasoline you care to pour into its tank (5 to 7 hours
in the case of the PGI 1200 B2).

 The only downside, of course, being the noise pollution if you don't
already have a suitable brick outhouse to minimise this and both secure
and run it safe from the CO poisoning and fire hazard risks presented by
such generators. In this regard, it's very little different to the 99 quid
PGI 1200 B2 Lidl were selling just a mere 7 weeks ago. For static use, the
only downside is that extra 30 quid hit on your bank balance.

 Even so, it's a remarkably cheap way to buy into a 1KW standby source of
pure sine wave 50Hz 230vac power. Now that I've replaced all the GLS lamps
(bar the set of four 35W 12v halogen downlighters in the shower room) with
LED lamps, I can keep all the lights on along with the fridge,
the freezer, the 4K smart TV, my IT kit and the CH with a mere 1KW of
standby power. Admittedly, only at a pinch and by careful power management
but if ever the need for sustained emergency power ever arises, this is
just exactly what anyone running off emergency power would be having to do
anyway.

 I'd have preferred a 2KW inverter genset but not only are the cheapest
alternatives some four or five times as pricey, they'll burn through
emergency fuel reserves faster as well even when only providing the same
amount of power as the smaller genset. Limited emergency power is better
than no emergency power at all and even if I do push the boat out on a
quieter 2KVA inverter genset at a later date, at just 99 quid, I can
afford hang onto the Lidl genset as an emergency backup to the 2KVA
emergency backup genset. You can never have too many emergency gensets
when the price is *so* right.  

 TBH, I'm quite amazed at the cheek of Lidl in trying to sell an inferior
version of the PGI 1200 B2 less than two months later and at an extra 30
quid to boot! Perhaps they're thinking that its "Retro Chic" cheap two
stroke portable genset looks are deserving of the extra 50 or 40 quid over
a more appropriate (IMHO) 80 or 90 quid price point.  

 Major points of difference between the A1 and the B2 models are:

 The A1 uses a top mounted 4.2l pressed steel gravity feed tank prone to
leaking fuel during transportation. Fuel consumption rating at 2/3 power
output is 0.88l/hour from its 2.85hp 53.5cc engine (4.77 hours run time on
a tank of fuel). Considering the use of a gravity feed fuel system,
there's a surprising absence of a carburettor float bowl priming plunger
to assist cold starting.

 The B2 uses a plastic (presumably shatter-proof) 4.5l side tank (which
reduces sloshing of its contents) feeding an engine vacuum powered fuel
lift pump[2]. Fuel consumption rating at 2/3 power output is 0.68l/hour
from its 2.04hp 53.5cc engine (6 1/2 hours run time on a tank of fuel).

The A1 is 200g lighter than the B2 (13Kg). Both produce the same total
sound power of 95dBW but the B2 claims to be 1.3dB quieter at the 1 metre
SPL test distance (80.2dBA).

 Now that I have an actual class 2 SPL meter to test with, I'll be able
to confirm just how optimistic a claim this is for myself (give or take
1.5dB of metering error along with other environmental factors that make
such tests so less than 'scientific'). At least I'll be able to get base
line figures by which to gauge any attempts to quieten it.
  
  
[1] Afaict from pictures - unlike the potted inverter module in the B2,
two cermet trimmers do actually poke up out of the hard and shiny black
potting compound in the one used by the A1 making it amenable to adjusting
for manufacturer's calibration errors[3], assuming they haven't switched
over to using the same inverter part used by the B2 (probably not since
the A1 shown still only uses two LEDs to show status using blink codes for
normal/slight overload/full overload condition and "Goodnight Vienna"
whilst the B2 uses three LEDs).

[2] The only downside of using a fuel lift pump, aside from the extra
complexity over that of a simple gravity feed setup, is the need to spin
the engine over several times on the starter cord just to prime the fuel
line and the carburettor float bowl when starting from "Dry" (initial
commissioning run or else after a long lay up after letting the carb run
dry to minimise the risk of fuel gumming up the carburettor's jets during
periods of protracted storage).

 In this case, it's best to crank the engine over leisurely 4 or 5 times
after turning the fuel feed on with the ignition still off and closing the
choke for the penultimate pull before turning the ignition on for a full
on pull of the cord to actually fire it up without needlessly wasting
energy on premature attempts to fire it up before there's even any fuel in
the carburettor float chamber.

 Where more regular use (say every weekend) precludes any need to run the
carb float bowl dry, this won't be an issue. A single priming yank before
turning the ignition on and setting the choke should get it running on the
next pull of the starter cord.

[3] I discovered when testing with a 900W toaster and a bunch of 150W
incandescent lamps and a few other ses lamps of various wattages that the
inverter signals overloading at the 980W mark according to my digital watt
meter. I was a little disappointed at discovering this, especially in view
of the fact that it would cheerfully run a 1200W test load not for the
mere 5 seconds claimed but a full half minute every time before shutting
the inverter down.

 I realise it's just possible that it's been calibrated to detect
overload at exactly 1001 watts and my watt meter is merely under reading
by 2% of the +/-3% allowance of its rated measurement tolerance. Still,
I'd have hoped they would have erred a little more on the positive side of
the tolerance range with their overload setting point, say 1050W before
sensing an overloaded state.

 This is how I came to discover the complete absence of any means to
adjust the output voltage setting or the current overload point to correct
such a parsimonious setting. I guess I'll have to do some cross checking
with my other "Kill-A-Watt" meter and the analogue watt meter before
deciding whether to buy another PGI 1200 B2 the next time they're on offer
from Lidl to do a "Pick 'n' Mix" swap out to get the inverter genset I so
richly deserve.

/END-QUOTE/

==========================================================================

 For the benefit of American readers, here in the UK we rarely experience  
summertime heatwaves longer than a week so very few homes are equipped  
with AC - it's simply not worth the investment unless it's part of a heat  
pump based heating package. Most urban UK homes rely upon NG powered  
central heating and domestic hot water systems which require less than 50  
or 60 watts to maintain the controller panel, a zone valve or two, a  
circulating pump and perhaps a small boiler flue purging fan.

 The biggest compressor motor load in a UK home is likely to be a chest  
freezer or fridge/freezer, typically less than 800W peak load, well  
within the 1200W max (5 or 30 seconds) rating of the Parkside inverter  
gensets mentioned above.

 Also worth noting is the fact that urban mains voltage supplies which  
serve over 80% of the UK's population, are largely laid underground and  
have annual 'up times' in excess of 99.99%. The rest of the population in  
the UK countryside (farmers and well paid city workers who commute or  
otherwise telecommute or simply work from home) do have to endure the  
problems of mains power carried over rural lines and so are generally a  
little better prepared for outages typically measured in hours rather  
than days. As per usual, some are better prepared than others.

 Interest in backup emergency power is now increasing in proportion to  
the increasing levels of Government incompetence in the provision of  
winter time energy supply security, largely as a result of the folly of  
'Green Power' investments made as a sop to those idiot 'Greens' who  
believe that a few windmills and solar cells will provide all the energy  
we'll need in preference to the only sane (and truly green) nuclear power  
option.

 All that and the fact that Honda no longer have a monopoly in inverter  
genset technology means that we are seeing competitively priced inverter  
gensets appearing in the market to serve the modest needs of homes with  
electricity demands largely centred on sensitive electronic devices which  
are not only susceptible to the poor quality of standard genset supplies  
to begin with but which will also trigger such gensets into producing  
destructive overvolting events. IOW, there's already an existing market  
for mass produced cheap inverter gensets right here and right now.

 I can only see those 2 and 3 KVA gensets with their "fancy" AVR going  
the way of the Dodo as they prove themselves deadly to the task they were  
designed for (they were never a good idea - the simple induction motor  
converted to a "Poor Man's generator" with a dozen or so microfarad's  
worth of run caps across the output were a safer bet for this application  
anyway).

 I can already see a situation where using such a conventional generator  
won't even be a safe option just to literally keep the lights on in a  
modern home full of cheap LED GLS lamps using simple capacitive dropper  
ballasts for fear of over-volting to the capacitive load of the lighting  
circuits alone! :-)

 Even if for no other reason than this, the future for emergency gensets  
depends on the use of inverter technology. It might be a relatively  
expensive solution right now but, given the manufacturing cost reductions  
of mass produced electronic hardware, it won't be too long before it  
becomes cheaper to make an inverter genset than a 'standard' conventional  
one.

 Not only that but I can foresee the day when the recoil pull starter  
will be relegated to backup emergency use only in favour of electric  
start courtesy of a small 12v 7AH SLA (or more likely its more compact  
and lighter Li-ion equivalent) and a brushless motor drive module  
(ideally, a function built into the inverter module) to run the PM  
alternator as a starter motor (no need for the extra weight and  
mechanical complexity of a seperate starter motor when you can apply the  
"Dynastart" principle in modern day brushless motor form).

 From this, I can also foresee an integrated battery/inverter genset UPS  
module to optimise the whole UPS with standby genset backup power  
paradigm (the presence of battery backup would allow for improved stall-
free "eco-throttle" performance as an additional bonus). Since the PM  
three phase alternators[1] generate either a nominal 200vdc for 120vac or  
400vdc for 230/240vac inverter gensets, you'd either use 200 or 400 volt  
battery packs in the genset/UPS combo or else use 12/24/36/48 volt  
battery packs with a high efficiency DC-DC converter to provide the two  
or four hundred volts required and accept the additional 1 or 2 percent  
loss this would involve.

[1] Essentially a PM multi-pole rotor three phase high voltage version of  
an automobile/truck alternator where the magnets are mounted on an outer  
rotor which allows the alternator to be keyed onto the engine shaft to do  
double duty as the engine's flywheel, thus neatly saving unnecessary  
weight and space. It's the reason why they can be made so lightweight and  
compact. The inverter module is effectively a pair of back to back class  
D power amplifiers, designed to be powered off a 200 or 400 volt DC rail,  
driven from a 50 or 60 Hz pure sine tone reference and using the much  
lower sampling rate of circa 5KHz to improve efficiency beyond the  
typical Hi-Fi sampling rate of 48KHz used in standard class D audio amps.

 The 200/400 dc voltage from the alternator is controlled by engine speed  
alone via stepper motor control of the carburettor throttle mediated by  
the microprocessor in the inverter module which compensates for varying  
electrical demand on the inverter's output terminals both for volt drop  
due to resistance in the alternator windings and to vary the throttle to  
control engine torque according to the current demanded by the electrical  
load. All that's required by way of alternator voltage control is that it  
stays within the relatively wide range of 350 to 420vdc in the case of a  
240vac inverter output (or half of those voltages for a 120vac inverter  
case).

 Given enough time between now and Armageddon, I've no doubt we'll see  
water cooled fuel injected engine modules being used in the later more  
compact, quieter and even more fuel efficient portable inverter gensets  
with built in Li-ion battery backup and automatic electric start. :-)

--  
Johnny B Good

Posted by Johnny B Good on June 1, 2018, 9:59 pm
 
 Well, did anyone here in the UK check these out at their local Lidl  
store? :-)

--  
Johnny B Good

Posted by dolmen on June 2, 2018, 9:32 am
 On Saturday, May 26, 2018 at 4:24:17 PM UTC+1, Johnny B Good wrote:

Hi there I watched the vids, thanks for the links and decided against the A1 and am waiting in the chance that the B2 option will come up again. It certainly seems like a much better option all things considered.

Posted by Johnny B Good on June 3, 2018, 2:32 am
 On Sat, 02 Jun 2018 02:32:51 -0700, dolmen wrote:


====snip====

=========================================================================

=====snippage of my take on the merits of inverter gensets====


 Thanks for the follow up. I was beginning to think I was the only UK  
citizen still subbed to this NG. :-)

 The only problem with doing that is you could be left waiting for quite  
a long time before the B2 gets put back "On Offer" (or it might reappear  
next month - who can tell with Lidl's (and, for that matter, Aldi's)  
kakamaimee retailing strategy?) so you might start regretting that  
decision some six months down the line.

 It's worth keeping in mind just how much more expensive the alternatives  
available in this segment of the UK inverter genset market are. A quick  
search using duckduckgo located this open frame HortiPower 1800/2000W  
inverter genset at Amazon, currently on sale for a mere £249.00  

<https://preview.tinyurl.com/yce6fbct>  

 That's an unusually cheap price for a 1.8KW rated inverter generator but  
I've no idea what their quality is like. They quote the 7 metre SPL  
rating which makes it around 16dB quieter compared to the 1 metre SPL  
figure quoted by Parkside inverter gensets. Once you've added that  
missing 16 dB this gets you an 81dBA SPL@1mtr to directly compare the  
two. Considering the absence of cosmetic panels, this rather highlights  
what the reviewer was saying about the A1.

 If you're looking for a less marginally specified output power genset,  
this could be a better alternative (but you'd be spending an extra 120  
quid on a machine that burns a litre of fuel an hour when loaded to 70%  
(1260W) versus 0.88 litre per hour at 75% of load (750W) for the A1 or  
0.68 litre an hour in the case of the B2) and you'd be dealing with a  
company based out of Peterborough in Cambridgeshire run by a person of,  
it would appear, Polish extraction.

 That's just fine and dandy if you happen to live in and around  
Peterborough but a bit of a pain for the rest of us who have to wait on  
delivery by Amazon or, worse still, deal with returning faulty goods,  
guarantee or no guarantee.

 I only mentioned that HortiPower unit because it's the first time I've  
seen an alternative 1 to 2 KVA rated inverter genset in the UK below the  
300 quid mark. The prices for inverter gensets available from walk in  
stores such as MachineMart, Toolstation and Screwfix typically start at  
£190 for a 700/780W rated inverter genset <https://tinyurl.com/ycfm8vjo>  
and carry on upwards of 280 quid for a 1.2/1.5KW Impax and 400 quid for  
the 2.2/2.5KW Impax inverter gensets (Screwfix prices). What the extra  
money might buy you in this case is maybe a 2dB reduction in noise  
pollution levels (Oh, and a 12v charging lead and shorter run times on a  
tank of petroleum/gasoline).

 My derogatory remarks about the A1 were made from a position of great  
strength. I'd already acquired the slightly superior version at the  
bargain of the decade price of 99 quid. :-) It won't matter so much to me  
if the B2 models never reappear but if and when they do, I'll get my  
chance to compare the overload set points and swap out the inverter  
module if the second unit is on a more generous overload trip point  
setting.

 With the exception of the B2 model, compared to every other 1000/1200W  
inverter genset model currently available in the UK, there's nothing  
anywhere near as cheap, even at that elevated £129.00 price point.

 There's a massive price premium on truly quiet suitcase inverter gensets  
(12 to 18dB quieter) suitable for use on camp sites. The Honda units  
typically adding an extra 800 quid onto the price of the Parkside units.  
Those other Impax models mentioned above are, at best, just another 2 or  
3dB quieter and this is typical of most of the competing models in the  
two to four hundred quid price bracket.

 BTW, talking about SPL figures, I took the opportunity yesterday  
afternoon to run another test of mine using a 240v 900W toaster as a 780W  
(230v) test load to get some SPL readings. This time I took the trouble  
to mentally take note of the actual readings at the 1 metre mark for idle  
at eco and normal settings as well as on a 780W load.

 I'd stood the generator on a hard concrete surface alongside of the  
patio table (so no benefit from soft grassy soil to knock a dB or two off  
the 'hard standing' readings) where I had the toaster and a couple of  
plug-in energy monitors[1] plugged into a short 4 way mains extension  
lead set up to toast a couple of slices for my 7 year old twin  
granddaughters to sample the delights of "Generator Toast".

 From the starboard side panel, I got readings of 79 and 88 dBA  
respectively for eco idle and 780W loaded (whether in eco-idle mode or  
not) whilst the figures for the exhaust (stern) end were, as expected,  
about another 2 or 3 dB higher. I didn't bother stepping back another 20  
feet to get 7 metre SPL figures since there was too much 'clutter' to get  
any meaningful 'free space' readings.

 I was a little surprised that the 780W load didn't boost the non eco-
idle speed since earlier tests with 960 to 1200 watt loads had  
demonstrated a slight but definite speed increase. I guess the 780W load  
wasn't quite enough to justify any further speed increase, merely a wider  
(and louder) throttle setting to increase the engine torque required to  
balance the alternator drag. I'd expect the SPL to go up another dB on  
the 780W load figure when generating the full 1KW's worth of maximum  
sustainable output (in my case, 980W[2] just before it starts the 30  
second timer[3] to 'overload shutdown')

 Since the Parkside generator specs included a tolerance error (K factor)  
of 1.2dB for their claimed 1 metre SPL dBA figures and my class 2 SPL  
meter could be out by +/- another 1.5dB anyway, those readings seem an  
entirely reasonable match to the specifications which I had naturally  
assumed to have been determined with the generator running in its  
quietest mode, unloaded eco-idle enabled.

 The dBA SPL claims for all these gensets will always be for the quietest  
mode of operation and you can likewise expect a similar 10dB boost when  
running at maximum sustainable output (but don't forget the 16dB  
difference between 1 metre and 7 metre (23 feet) referenced SPL figures).

 Don't assign too much meaning to the expression "quiet" in the  
manufacturers' description copy, written by PR types educated in the fine  
art of "Lying by omission" where the justification for such a statement  
can be as slight as the product being a mere 1 or 2 dB quieter than a  
standard open frame generator of comparable output. Ignore such wishy  
washy statements as "Quiet", "Quieter", "Quietest yet" and take care of  
the 1 and 7 metre SPL standards' 16dB difference when looking at any  
actual numbers they may offer in their "Specification" sheet.

 Except for notably quiet exceptions from Honda (and a few other brands -  
Honda no longer hold a monopoly in "Very Quiet"), you can assume a 'ball  
park' 1 metre SPL figure of 96dBA safe in the knowledge that you're  
unlikely to be more than 2 or 3 dB out on the actual SPL figures.

[1] I was using one to monitor voltage and the other the load wattage.

[2] According to one of my plug-in energy monitors, the one that matches  
very closely my trusty Metrawatt analogue watt meter as opposed to the  
230vac version of a Kill-A-Watt meter which under-reads by comparison  
(and which I'd relegated to monitoring the voltage during this test).

[3] The specifications for both the A1 and the B2 models mention a 5  
seconds limit on the 1200W surge rating. However, it turns out that the B2  
model will sustain such an overload for a whole 30 seconds before  
tripping the inverter out, necessitating a reset which, unconscionably  
requires the engine to be stopped rather than by a reset button which  
would allow the engine to keep running to save the ritual of another pull  
start.

 Mind you, this is probably for the best since in practice this means the  
inverter will get a chance to cool down any thermally stressed parts  
before the user gets another chance to abuse it[4]. This can be a pain if  
you're running close to the limit without a UPS in line to protect more  
critical loads such as desktop PCs and NAS boxes which don't take kindly  
to having the rug pulled out from under them.

 Even with a UPS, there's still some pain since you have to nip out to  
attend the generator. However, that said, restarting is a doddle since it  
will be warm and primed ready to go on the first confident pull of the  
starter cord. even if you've left it half an hour it will still be nice  
and warm since the engine carries on running, leaving you to manually  
switch it off when you're ready to restart it (see note[4])

[4] Unless they stand ready to switch the engine off and then switch it  
back on just before it comes to a complete standstill which, if timed  
exactly right (it's quite critical is the timing!), will reduce the  
alternator output voltage sufficiently to initiate an inverter reset  
whilst there is still enough inertial energy to let the engine pick back  
up on turning the engine switch back on. No need to ask me how I know  
this, I'll tell you - I simply tried this trick a few times before I  
succeeded in resetting the inverter module without the engine stalling  
out. :-)

 It's a useful trick since it saves needless wear and tear on the starter  
cord and you can still give the inverter module time to recover by simply  
waiting a minute or two before cycling the engine switch. Incidentally,  
there's no need to unplug the load before firing it up unless you have  
loads with heavy startup current demands that can take it well beyond its  
1200W limit (or over its 1000W - 980W in my case) limit for more than 30  
seconds).

 The only item that didn't like the resulting soft start being the 230vac  
Kill-A-Watt meter which requires a more rapid voltage increase to reset  
itself - i.e being plugged into an already live socket or the socket  
switch turned from off to on. Apropos of which, other things that might  
not take kindly to a soft start could be fridge and freezer compressor  
motors.

 The freezer you'd only plug in once a day when the load will be  
minimised or even totally shed so as to chill the cabinet on the "Rapid  
Freeze" button to prepare it for its next round of doing without  
electricity for a bit. Freezers can keep their contents safely frozen  
during 24/48 hour power cuts if they aren't being accessed every half  
hour of the day so using the "Rapid Freeze" button to reduce the  
temperature below normal is an effective way to timeshare the generator's  
energy output to minimise overloading events.

 Modern fridge compressors, I believe, only use 35 to 60 watts when  
running although they may demand 3 to 6 times that for a few seconds when  
starting up. However, I haven't tested this with our own fridge so I  
can't verify this from actual experience.

 If you happen to have a really modern fridge/freezer using a linear  
compressor, you won't suffer the 'compressor startup surge' effect which  
simplifies the issue of running it from inverter generator power somewhat.

--  
Johnny B Good

Posted by Johnny B Good on June 9, 2018, 3:40 am
 On Sun, 03 Jun 2018 02:32:40 +0000, Johnny B Good wrote:

====snip====


 Following up on what I wrote above, I've since run a test with our under  
the counter larder fridge using the 2000MU-UK (the 230v version of the  
Kill-A-Watt, btw, both manufactured by Prodigit Electronics Co Ltd) and  
my Metrawatt analogue wattmeter for measuring the watts and volt amps  
consumption, both running, averaged and peak values.

 It's actually been several days since I ran the tests (I was hoping to  
use another follow response as a chance to include these test results,  
hence the delay). The on and off cycle times turned out to be hours  
rather than tens of minutes so on the 2nd day of monitoring, I set a  
camera up on a small tripod to video the meter readings so I could  
capture and replay the startup surge event.

 It turns out that my 3 to 6 times running wattage startup surge estimate  
was a little on the optimistic side. It peaked at a 1000 watts on the  
analogue meter (660W was the 2000MU-UK's best shot at registering this  
peak) which turns out to be some 14 times greater than the 65 to 72 watt  
steady state consumption of the compressor motor after it has been  
running for more than a minute, way higher than I was expecting. :-(

 The 2000MU-UK was showing a VA figure of around 135VA and a wattage  
reading some 7W higher than the more credible Metrawatt reading. The  
averaged over a 34 hour period power consumption, after correcting for  
the 7 watt over-read, proved to be 37 watts (324KWH per annum)[1]. The  
power factor figure btw, was 0.55 (55%) just about what you might expect  
of a domestic fridge compressor motor. The power factor at peak startup  
current will be a lot higher since most of the power under such an  
extreme surge condition will be resistive losses taking the PF somewhere  
around the 80% mark as a best guess.

 The only consolation of that assessment is that the 1KW peak isn't going  
to translate into a 1.8KVA (at 55% PF) load on the generator when  
attempting to power the fridge as the only load, more likely a 1250VA  
peak (which may still be enough to cause the generator to immediately  
shut down).

 Although the UPS's 2KVA 1500W rating will allow it to start the fridge  
compressor without tripping out, this relies upon the generator shutting  
down to effect the transfer to battery power and the UPS's much beefier  
inverter, so a far from ideal 'solution' since you'd have to reset/
restart the generator within a few minutes each time to avoid unnecessary  
depletion of the battery. You'd also have to limit the other loads to  
500W or less to avoid tripping out the UPS itself.

 The most practical way to make use of a 2KVA 1500W rated UPS in this  
circumstance would be to insert an automatic load shedding switch[2] with  
a reclosure time of ten seconds between the generator and the UPS set to  
immediately disconnect the generator before its own protection can  
respond with an immediate overload shutdown. You'd still need to limit  
the other loads to no more than 500W but at least you'd only lose  
generator power for a ten to fifteen second period each time once every 5  
hours or so.

 I haven't yet tested the chest freezer's load characteristics. The  
results from the fridge tests rather put a dent in my enthusiasm for  
trying to persuade such a weedy inverter genset to run it even with  
careful load management since I suspect its demands will be higher.  
However, now that I can see a way around this problem using the higher  
surge capacity of the UPS, I'm thinking that perhaps it's worth testing  
after all. It might not turn out to be as bad as I thought. In any case,  
it's always best to have some actual test results to work from rather  
than rely upon assumption alone. At least I'll know exactly where I stand  
in regard of my emergency power options.

[1] I hadn't been able to locate the model number rating plate when I  
first took a cursory look inside the fridge several days ago assuming it  
must have been stuck to the back of the fridge. It was only when I  
extricated it from its under the worktop location, just a few hours ago,  
that I discovered its absence from the back of the fridge, motivating me  
to get on my hands and knees to do a more thorough search of the interior  
which finally solved the mystery. I'd had to extract the 'crisper trays'  
from the bottom before it was revealed to be stuck to the right hand side  
just below the bottom shelf - a hands and knees job indeed, no wonder the  
cursory search had come up dry!

 This got me a model number (ART 417/G) and the electrical specification  
which, as is typical of most electrical specifications, a seeming work of  
fiction, apart from the voltage (220-240 V~) and frequency (50Hz - vital  
info in the case of induction motor driven appliances), leaving the  
fictional information that it had a consumption of 100W and that it was  
fused at 13A (this last was no doubt true despite the fact that a 5A fuse  
would have entirely adequate).

 The 100W is obviously intended to indicate the running wattage after the  
initial 1KW startup surge. It certainly would have passed through this  
wattage level a second or so after starting up but wouldn't have stayed  
within even +/-10% of that figure for more than another second or two  
before swiftly settling down to 75W from where it would eventually drop  
to 65W over the next two or three hours.

 Also included on the label was its energy rating in the form of  
0.6KWH/24h, corresponding to an annualised figure of just 219KWH which is  
how it's been more normally expressed for domestic fridges and freezers  
for at least a decade now. That was a bonus which proved useful since I  
couldn't find a free download of the owner's manual in English and the  
Dutch language version I perused showed no mention of this energy rating  
information.

 I can only surmise that my higher estimated 324KWH per annum figure was  
due to the summer like temperatures we had been enjoying when I had been  
running my tests, along with the fact that the back of the fridge had  
been long overdue a spring cleaning which I completed when I'd been  
searching for the rating plate information. Considering its age (some 15  
years or so, afaicr), it still seems to be doing well and as the door  
seals are still in good condition there's no urgent need to replace it  
just yet.

[2] I could homebrew such a switch using a current transformer with a  
transistor driven relay that can detect precisely when the current  
exceeds the 4.3A limit to operate[3] the relay to interrupt the line  
current for a ten seconds timeout interval, pre-empting the inverter  
genset's built in overload protection. This would allow the more robust  
UPS's inverter to deal with such brief overloads automatically without  
having to rely on the generator tripping out to effect the transfer to  
battery power and all that that entails.

 It's a work around solution to a problem most would consider best fixed  
with a simple generator upgrade. However, as 'obvious' a solution as that  
appears, it does rather overlook the expense, both capital and running  
costs, of providing excess capacity just to deal with a 4 or 5 second  
event once every 4 or 5 hours of run time.

 If it had been merely a choice between spending 280 quid on a 1.5KW  
genset and 400 quid on a 2.5KW one, spending the extra 43% choosing the  
higher output one (or even 143% if upgrading an existing 1.5KW genset)  
would have been the obvious choice. However, since for me, it amounts to  
spending an extra 400% to double up on my existing genset rating, such a  
work around solution has a very strong cost advantage.

 Admittedly, this work around solution does rather depend on my already  
having a 1500W/2KVA rated UPS conveniently to hand and one that I know  
from experience can handle such extreme surge loadings - the degaussing  
surge of a 19 inch colour monitor in point of fact.

[3] I want to disconnect by *operating* a relay rather than the more  
common release of a cut out relay typical of the more usual overload  
protection circuits. The rationale in this case being that when the  
generator is coping with the load. I don't want to be drawing any  
additional power holding a relay in its operated state to pass the power  
through to the UPS.

 It doesn't matter if the the circuit 'fails unsafe' (leaving the genset  
output connected) if the genset does trip out anyway since the end result  
remains the same - no power to the UPS in either event. When the overload  
shedding relay module successfully pre-empts the genset's built in  
overload protection, I'll have more genset power to spare than I'd know  
what to do with, which makes the few volt amps or watts of power needed  
to operate the relay to open its normally closed contacts a non-issue. :-)

--  
Johnny B Good

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