I'm posting here in the hope that I can get some guidance on how to add
an electric start feature to a cheap inverter generator cursed by the
traditional recoil pull starter (the Devil's invention, imho). Apologies
beforehand for what is a rather long initial post but I thought it best
to appraise you of my thoughts and what I know of the problems involved
in my proposed electronic add-on starter solution.
Not too long after purchasing a Parkside PGI 1200 B2 inverter genset
from Lidl (UK) for the miserly sum of 99 quid about two months ago (third
time lucky), I was wishing for an electric start feature to relegate
its accursed recoil starter to that of 'emergency only' status.
Now an obvious way to 'electric start' such ICE powered kit cursed by
the infamous 'recoil starter', is to use a cordless electric drill with a
socket wrench on a longish extension mounted in the chuck to crank the
engine into life via the retaining bolt head on the exposed end of the
engine shaft. In the case of that PGI 1200 B2, this isn't an option since
the inverter module blocks such access.
Having already viewed the innards of this model of suitcase generator, I
knew that buying an add-on electric starter motor option was, well, not
an option. I did briefly entertain the notion of a Heath Robinson
electric drive attachment to the starting rope handle or even something
that would turn it into a less obnoxious 'kick start' mechanism before it
occurred to me that the damn thing was already possessed of the necessary
starter motor essentials - it just lacked the required BLDC motor drive
module circuitry was all.
What had inspired me were several youtube videos I'd come across several
months earlier, demonstrating the use of car and truck alternators as BLDC
motors using R/C brushless ESC modules (a radio controlled (BLDC motor)
Electronic Speed Controller). In particular, this video at:-
where a purpose made electric scooter BLDC module had been used rather
than a cheaper R/C brushless ESC .
In this case he'd used a 1500W rated module. I'm obviously not going to
want to push more than double the alternator's 5 or 6 amps maximum rating
through its windings so I reckon something like a 40 dollar
SPD-3648350BLDC module would more than suffice with its 18A maximum
current limiting feature. However, if I'm going to use such low voltage
modules, I'll obviously have to add a high voltage isolating relay
(probably a solid state one for speed and reliability) to protect it
against the 350/400 voltage once the engine has fired up.
It turns out that I'm not the first to ponder the possibility of
doubling up the utility of the three phase multi-pole PM 170/340v
alternator that's used to supply the inverter module with the required
175 to 200/350 to 400vdc (120v 60Hz/240v 50Hz gensets), by adding a
suitable BLDC motor drive module along with a 12v battery and a converter
to produce the required 48 vdc to crank the engine at 400 to 500 rpm
(just 10 to 12 percent of its normal running speed, circa 3900 to 4600
rpm). A google search took me to the "allaboutcircuits" forum where a
member had posed the exact same question way back in February 2011
He had pretty much the right idea although his thoughts about using a
170v converter to power a modified R/C brushless ESC and a cranking speed
of only 100rpm were rather at odds with each other (never mind that such
controllers typically max out at 6 cell's worth of LiPo battery pack
voltage (22.2 to 25.2 volts) and 100rpm would most likely be far too slow
to generate sufficient voltage to initialise the inverter and ignition
module(s). Unfortunately, he didn't receive any helpful replies.
In the case of the 120v 60Hz inverter gensets, a repurposed cheap
commodity R/C brushless ESC probably would suffice - sadly for me, not so
in the case of the 230/240v 50Hz inverter gensets. :-(
I figured that a minimum cranking speed of 400rpm would be needed,
necessitating at least ten percent of the 350 to 400 peak voltage
generated at 4000 rpm to power the BLDC motor module which equates to a
40 to 50 volt requirement for a cranking speed of 4 to 5 hundred rpm.
I might be able to get away with half that voltage (and cranking speed)
if I can use the starter battery to power the ignition module.
Unfortunately, I don't have a workshop manual with schematic diagram(s)
for my specific generator to check out the viability of such a
Considering just how old that forum posting is (over 7 years old!), I'm
surprised at the absence of such an electric starting option in the
inverter modules used in current designs of commodity inverter suitcase
generators available today. After all, the extra components could quite
easily be integrated into the inverter module since they're essentially
just an extra bit of Silicon 'real estate'.
Anyhow, those are my thoughts on the modern day version of the Dynastart
(tm) system as used with a small two cylinder four stroke marine gasoline
engine (auxiliary propulsion and battery charging in a 30 foot sailing
sloop) where a specially designed dynamo was also used to provide
starting torque via a pair of V belts wrapped around a 50cm or so
diameter engine flywheel grooved to accept said drive belts.
My main problem is more to do with sourcing suitable hardware as well as
trying not to re-invent the wheel if I can avoid it. For all I know,
purpose made for inverter generator 'electric starter kits' may already
be available (it is 2018 after all!).
 The 1st one ran just long enough to prove it was immune from the
dreaded capacitive loading induced overvolting effect that ordinary
petrol (gasoline) generators are afflicted with (the real reason why
they're unsuited as backup power for UPS protected computer kit), before
it dislodged the alternator connection to the inverter module and kicked
out with an overload signal.
The 2nd unit failed to start until I disconnected the low oil level
sensor wire. The engine vibrations unstuck the jammed oil level sensor
float but since I'd initially assumed it was a low oil *pressure* switch,
I was reluctant to keep hold of it so it too went back to Lidl for a
By the time I'd discovered the true nature of these show stopping faults
(and the ease by which they could be fixed), the original store had run
out of stock. However, to my surprise, another local Lidl store turned
out to still have three left so I bought two to reduce the risk of them
being out of stock should my next one also need to be swapped out. Both
proved to work ok so I chose what I thought was the better example and
returned the 'spare' for a refund.
The problem with these Parkside inverter generators was less to do with
Parkside's quality control and more to do with Lidl's oddball stock
control whereby unsold stock *has* to make way for "The Next Week's
Offers" since the shop floor is also the store's only warehousing space,
resulting in these generators accumulating hundreds, if not thousands, of
road miles over the UK's motorway network, being shunted from store to
store or main depot. It's no wonder that oil sensor floats get jammed or
connectors dislodged (BTW, both trivial to fix issues once you're aware
As inverter generators go, they seem nothing short of perfection
compared to other commodity inverter gensets in this market segment. It's
true they're not as quiet as the Honda inverter generators but, until
very recently, Honda were in a class of their own in this regard.
 This was after guestimating the power strokes per second rate I could
achieve with the recoil starter (ignition off whilst re-priming the fuel
line and float chamber) from which I could calculate a cranking rpm
figure. It sounded about 5 such cycles per second, making it 10 revs per
second or 600rpm.
My gut feeling is that 4 to 5 hundred rpm should suffice. However, I
could well be over-estimating the cranking speed requirement so it might
pay me to simply buy (or better yet, borrow) a cheapish 6 cell rated R/C
brushless ESC module to do some initial tests with a pair of 12v SLAs,
with the spark plug removed and then fitted but ignition disabled before
worrying about protecting the module from the 350/400 volts when the
engine fires up. There's little point in worrying about adding a
disconnect relay if this 'Proof of concept' testing fails to deliver any
encouragement to proceed further.
Johnny B Good
Posted by Jeff Liebermann●July 10, 2018
On Wed, 11 Jul 2018 01:20:32 GMT, Johnny B Good
> I'm posting here in the hope that I can get some guidance on how to add
>an electric start feature to a cheap inverter generator cursed by the
>traditional recoil pull starter (the Devil's invention, imho).
I did indeed! I guess that's one good reason not to try and explain
*everything* in one huge post (all too easy for such detail to get lost
in the 'noise'). :-(
I did check out the links on the off chance there were some that did
*not* involve access to the nut on the end of the crankshaft. Believe me,
if I'd had access to the crankshaft end, I'd have gone for that option in
a heartbeat. I'm all for a pragmatic solution, talking of which, I'm
considering the use of a cheap(ish) R/C brushless ESC module (6 cell LiPo
version) with a couple of 12v SLAs just to test the viability of the
whole "Turn the alternator into a starter motor" concept.
Despite my misgivings about the limited cranking speed (200 rpm or so in
this case), it might still prove sufficient - I've had the damn thing
'kick back' when I've hit the compression point too soon to have built up
enough speed due to not feeling my way just past compression (ignition
off) to give myself a run up via the subsequent exhaust/induction/
As I've said before, it's all too easy to over-think the problem and end
up over-engineering a solution. The need to save a 24v rated ESC module
from getting fried by the resulting 350 to 400 volts when the engine
fires up shouts "Over-engineered!" loudly enough as things stand already.
My gut feeling is that the alternator can provide enough starting torque
when run off a suitable BLDC motor controller module but I do wonder
whether, in over 7 years, it's already been considered (after all, it
*does* seem to be such a "No-Brainer" electric starting option) and
discounted for the lack of the necessary 'grunt'.
TBH, if you're going to give this option *any* thought at all, you'd
consider using the microprocessor controller in the BLDC motor drive
module to do something a little more sophisticated than merely emulate a
dumb electric starter motor designed to brute force its way past the
The key obstacle here is the torque required to overcome compression
without any run up to recruit the flywheel inertia. I'm pretty sure
there'll be more than ample cranking torque once the initial resistance
to compression has been overcome and the engine starts turning.
A blindingly obvious way to overcome this problem is to have the BLDC
module crank the engine backwards until it hits and detects the
compression loading before reversing the direction using the compression
to bounce the shaft into rotating in the right direction with a whole 630
degrees or so's worth of 'run up' to build up the necessary speed to
carry through the next compression stroke without risk of 'kick back'.
It's not as if the BLDC modules are lacking the 'Smarts' required to run
such an algorithm - "Work smarter, not harder!" would the obvious
solution in this case. :-)
Assuming such an electric start system using the inverter genset's own
built in three phase PM alternator for the 'grunt work' is viable (and I
rather think it is), then there would seem to be a small window of
opportunity for a cheeky startup to go into mass production of add-on
electric start modules for the many thousands of commodity priced pull
start inverter gensets already sold.
I say "small window of opportunity" since such extra circuitry can so
readily be incorporated into the inverter modules (where it's best
implemented in the first place) of later production inverter gensets once
the manufacturers realise they've 'missed a trick' by allowing a cheeky
upstart company the opportunity to take advantage of their oversight.
The manufacturers can charge a premium for the luxury electric start
'feature' at little more than the cost of a lightweight 6 cell Li-ion
battery pack and a few extra inches of wiring and an ignition/starter
keyswitch. They can still charge a premium for generators that are merely
"Electric start capable", requiring a battery and ignition switch upgrade
kit bought from the manufacturer who will make a nice profit at the
expense of any such cheeky upstart company.
It's not as if any of this tech is costly to produce, so where the hell
are all the "Inverter genset electric start upgrade packs"? :-)
Johnny B Good
Posted by ●July 11, 2018
On Wednesday, 11 July 2018 02:20:36 UTC+1, Johnny B Good wrote:
> I'm posting here in the hope that I can get some guidance on how to add
> an electric start feature to a cheap inverter generator cursed by the
> traditional recoil pull starter (the Devil's invention, imho). Apologies
> beforehand for what is a rather long initial post but I thought it best
You do realise that cheap gennies have very short operational lives, making
extensive work on them pointless. If you want something worth tinkering with get a
Listeroid from some 3rd world country. Tinkering is not optional & they will run for
a lifetime, day in day out, once fully built. Listeroids also use a fraction as much
fuel as modern junkboxes.
> Looking again, I find:
> The operator was able to start it in one easy pull. However, this
> appears to be a different version of the generator, where the pull
> starter is on a plastic panel that presumably could be removed. That
> would have been too easy. Here's the manual for the INVERTER GENERATOR
> PGI 1200 A1:
> The OP states that he has a B2, not A1 model. Oh well.
> This is the B2 model with the recoil starter between the engine and the
> front panel:
> <https://www.youtube.com/watch?v=JTTGvjbY8_s> (19:50)
> Starting at 13:40, getting the B2 going took 13 pulls. Yep, doesn't
> start very easily. Removing the recoil starter assembly and drilling an
> access hole in the front panel might aesthetically disgusting, but would
> do the job. So much for new and improved.
From new, pretty well all of these engine vacuum driven fuel pumped
carburettors needed several pulls on the starter cord to finally prime
the float bowl so, since this was effectively an unboxing video (but with
very little actual unboxing shots), 13 pulls doesn't seem excessive in
The priming procedure when the generator has been allowed to run the
fuel line dry (float bowl and fuel pump and the line in between and the
one to the fuel shut off valve) prior to being put into storage isn't
quite so protracted (about five leisurely pulls with the ignition off to
eliminate the recoil starter's nasty surprise of 'Kickback'). Thus
primed, it usually starts on the next pull or two.
I know some pull start inverter generators incorporate a 'Priming Bulb'
to provide pulses of suck 'n' blow to operate the fuel pump independently
of the engine but, like the piece of shit Workzone 1800/2000W inverter
genset sold by Aldi a week ago that I sampled three of before concluding
they were utter shite, this one isn't so blessed.
A fuel priming lever would have removed a lot of the effort required to
start it after its been retrieved from 'dry' storage. I could probably
add a priming squeeze bulb without compromising the warranty but I'll
wait and see how my electric starter project goes before I look to adding
that enhancement (it won't matter so much with electric start but it's
one hell of a bonus when your only option is that accursed recoil starter
For that, you'll need to track down a workshop manual and they're rather
thin on the ground for the cheaper commodity generators.
> My next step would be to tear off the various plastic panels and let's
> see what's inside.
I'd already done that when I was delving into the 2nd unit which had
suffered a stuck oil level float switch. The job would have been a lot
easier if I hadn't been concerned about voiding the warranty by having to
work around a bolt protected by a sticker obviously intended as an anti-
tamper label by bending the plastic side panel aside to gain minimal
access to other fixing bolts and screws.
The air intake vent at the front, opposite the rear end where the
silencer and ventilation exhausts live, is straddled by the inverter
module which blocks access to the recoil starter mechanism (the usual
access to the flywheel retention bolt).
I could probably replace the recoil starter mechanism with such a
pancake motor, replete with a planetary reduction gearbox and free-wheel
coupling, but I'd lose the emergency recoil starter option unless I can
extend the case to refit it ahead of the pancake starter motor assembly.
Considering what my options are with regard to relegating the pull cord
to 'emergency use only', you can perhaps understand why I'm considering
using the alternator as a BLDC starter motor.
If it's at all viable, this completely eliminates any sort of
complicated mechanical modification, reducing the job to a much easier to
implement installation of a suitable BLDC motor drive module and a high
voltage solid state isolation relay (unless I can get hold of a BLDC
motor drive module designed to tolerate the expected 350 to 400v output
when the BLDC motor starts operating as a high voltage alternator).
Thinking about it, I don't really need turn on resistances as low as 7mΩ
in a low voltage BLDC controller module since the alternator stator coil
resistance is likely to be around an ohm per winding so a higher motor
voltage BLDC controller with turn on values measured in tens of mΩ rather
than mΩ should nicely suffice in this case so I'm still floundering
around looking for the best way to implement a practical and cost
effective electric starter solution.
If I can get enough cranking speed using just 24v, I can simply use a
pair of 12v SLAs (or possibly a 6 cell Li-ion battery pack). If I need to
use 40 to 50 volts, it would make more sense to stick with a 12v SLA and
use a DC-DC boost converter module to generate the higher voltage. I'll
probably need an 8A rated 48v converter module for this task (assuming a
brute force approach to the task of overcoming compression resistance).
In the meantime, I'll keep searching for suitable BLDC motor controllers
and keep an eye on this thread for any further advice that might appear
from those with more knowledge and experience in this field than my own.
 I haven't actually measured the stator windings resistance yet so
this is just an educated guess. Furthermore for obvious reasons, the
windings will most likely be connected in star (wye) rather than delta
form with no access to the neutral point so regardless of the actual
arrangement, I'll only be able to measure phase to phase anyway. However,
that will at least inform me of the maximum possible stall current for
any given BLDC motor controller supply voltage.
Johnny B Good
Posted by Jeff Liebermann●July 11, 2018
On Wed, 11 Jul 2018 22:27:07 GMT, Johnny B Good
>From new, pretty well all of these engine vacuum driven fuel pumped
>carburettors needed several pulls on the starter cord to finally prime
>the float bowl so, since this was effectively an unboxing video (but with
>very little actual unboxing shots), 13 pulls doesn't seem excessive in
Some motors have a primer bulb to manually pump gas into the carb.
Done correctly, I can start a small engine with one or two pulls of
the recoil starter. Of the saws I own or have serviced, the worst is
my Stihl MS180 (upper right)
which takes exactly 6 pulls when cold starting. However, once it runs
for a while, and the carb fills with gas, it will warm restart in one
I would consider 13 pulls to be rather excessive.
> The priming procedure when the generator has been allowed to run the
>fuel line dry (float bowl and fuel pump and the line in between and the
>one to the fuel shut off valve) prior to being put into storage isn't
>quite so protracted (about five leisurely pulls with the ignition off to
>eliminate the recoil starter's nasty surprise of 'Kickback'). Thus
>primed, it usually starts on the next pull or two.
Ok, that's normal. Five pulls is about right. I run my saws dry and
empty the tank in the fall, when I'm done using them (except for one
for emergencies where I put some Sta-Bil in the tank). I haven't had
to disassemble, clean, or rebuild any carburetors for a long time.
Yes, kickback sucks. It happens to me fairly often. I pull on the
starter rope normally a few times. Then, it acts like the starter
rope is stuck. I pull on the rope, which lifts the saw in the air,
while simultaneously aims my face into the saw. After a few close
calls, I'm VERY careful when starting a cold motor.
> I know some pull start inverter generators incorporate a 'Priming Bulb'
>to provide pulses of suck 'n' blow to operate the fuel pump independently
>of the engine but, like the piece of shit Workzone 1800/2000W inverter
>genset sold by Aldi a week ago that I sampled three of before concluding
>they were utter shite, this one isn't so blessed.
Ummm... I take it that you don't like this inverter generator, and by
implication also don't like the primer bulb concept? I don't want to
go into the pros and cons of primer bulbs. Let's just say they're a
necessary evil without which you would be draining the tank and carb
after every use and possibly removing crud from the carb.
>A fuel priming lever would have removed a lot of the effort required to
>start it after its been retrieved from 'dry' storage. I could probably
>add a priming squeeze bulb without compromising the warranty but I'll
>wait and see how my electric starter project goes before I look to adding
>that enhancement (it won't matter so much with electric start but it's
>one hell of a bonus when your only option is that accursed recoil starter
I think a fuel shutoff petcock and carb drain would be more useful.
You would have the option of leaving gas in the tank as long as
necessary. If it's been sitting for months, drain the carb, or flush
it with carb cleaner. Most larger gas generators, motorcycles, and
paint sprayers have this feature.
You're not going to preserve the warranty after installing a starter
motor unless you're VERY careful. Your decision. Electric start or
warranty. Pick one.
How many pulls does it take to cold start your generator? If 13, then
maybe you have a point. If 5, don't bother, and just get some more
>For that, you'll need to track down a workshop manual and they're rather
>thin on the ground for the cheaper commodity generators.
I think the term is "service manual". I have one for almost
everything I own (usually in PDF format). Unfortunately, many are in
foreign languages where Google Translate is nearly useless. I
couldn't find a Parkside PGI 1200 B2 Service Manual.
>> My next step would be to tear off the various plastic panels and let's
>> see what's inside.
> I'd already done that when I was delving into the 2nd unit which had
>suffered a stuck oil level float switch. The job would have been a lot
>easier if I hadn't been concerned about voiding the warranty by having to
>work around a bolt protected by a sticker obviously intended as an anti-
>tamper label by bending the plastic side panel aside to gain minimal
>access to other fixing bolts and screws.
You should have taken photos. These days, I don't work on anything
without taking photos of my work. It's mostly to help remember how
things go together, but also to show others what is involved.
Use some solvent to loosen the glue on the label. The solvent will
evaporate, but the glue will remain attached to the label. When
you're ready to re-attach the label, a little more solvent will soften
the glue again. This works on many labels, but not all of them. Some
labels use ink that is soluble in chlorinated hydrocarbon solvents
resulting in a destroyed label. On a plastic or painted case, your
choice of solvents may attack the plastic or paint. Start at the low
end of the scale with 70% isopropyl alcohol and work your way up to
stronger (and more toxic) solvents.
> The air intake vent at the front, opposite the rear end where the
>silencer and ventilation exhausts live, is straddled by the inverter
>module which blocks access to the recoil starter mechanism (the usual
>access to the flywheel retention bolt).
Ok. Drilling a hole in the inverter module is not going to work.
Can you remove the recoil starter, and attach a clutch and sprocket
gear to the drive shaft? If so, you can attach a bicycle chain to the
sprocket gear and hang the starter motor out to the side.
> I could probably replace the recoil starter mechanism with such a
>pancake motor, replete with a planetary reduction gearbox and free-wheel
>coupling, but I'd lose the emergency recoil starter option unless I can
>extend the case to refit it ahead of the pancake starter motor assembly.
Since the recoil starter and electric starter want to both occupy the
same space, you'll have to decide which one you want.
(I'm out of time...)
Jeff Liebermann firstname.lastname@example.org
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Posted by Johnny B Good●July 12, 2018
On Wed, 11 Jul 2018 06:44:02 -0700, tabbypurr wrote:
> On Wednesday, 11 July 2018 02:20:36 UTC+1, Johnny B Good wrote:
>> I'm posting here in the hope that I can get some guidance on how to add
>> an electric start feature to a cheap inverter generator cursed by the
>> traditional recoil pull starter (the Devil's invention, imho).
>> Apologies beforehand for what is a rather long initial post but I
>> thought it best
> You do realise that cheap gennies have very short operational lives,
> making extensive work on them pointless. If you want something worth
> tinkering with get a Listeroid from some 3rd world country. Tinkering is
> not optional & they will run for a lifetime, day in day out, once fully
> built. Listeroids also use a fraction as much fuel as modern junkboxes.
Not quite as small a fraction as you might think. However, they can be
run on duty free diesel for about half the cost of a petrol/gasoline
generator. Indeed they're not fussy about what fuel oil you choose to run
them on so you have a lot more fuelling options.
Thank you for that sage advice. I do appreciate what you're saying but
unfortunately, I'm not trying to live off grid and nor do I have the
space to install such venerable machinery. On top of which, the standard
generator heads typically fitted to these listeroids no longer suit
the needs of modern day lighting and computer loadings, particularly true
in the case of my venerable Smartups2000 with its 9.4μF's worth of
capacitive loading across its mains input which sends conventional single
phase AVR controlled 230vac 50Hz alternators into a massive over-volting
state as a result.
Lagging current loadings are merely the usual low power factor issue
without the overvolting effect on the standard AVR controlled single
phase alternators used in conventional generators but the slightest sniff
of excess leading current from just a single 3.3μF fluorescent lamp PFC
capacitor across the output of a 2.8KVA generator was enough to send its
nominal 230v north of the 275v mark. I'm sure you can appreciate the
problem caused by the Smartups2000 with its 9.4μF's worth across that
There is a very good reason why I blew a whole 99quid on that Parkside
PGI 1200 B2 inverter genset. Basically, it was because I knew the
inverter type lacked this overvolting defect in the face of capacitive
loads and so was the only viable backup option for my Smartups2000
battery backed 'protected supply'. I could have spent over a thousand
quid on SLAs to extend the autonomy of the UPS into the 8 to 12 hour
region but even if they were never to be called upon to provide emergency
backup power, I'd be lucky to see more than a decade's worth of service
life from them before having to blow yet another grand's worth on a
replacement battery pack.
I don't expect to be running the generator for more than half a dozen
hours a year (monthly half hour test runs being the most likely
consumption of generator hours) but I like to be prepared against power
outages to maintain all the lighting, the CH/DHW (pump, controller and
zone valve), my IT kit (NAS box, desktop PC, a Gbit switch and a couple
of routers) along with the 4K smart TV in the living room to allow the
missus to watch her favourite soap operas without interruption.
At just 1000W continuous (actually 980W) with a 1200W 30 seconds surge
rating, it's a bit on the marginal side but surprisingly do-able
(upgrading the lighting to LED was what proved to be the key to this
unexpected result). I was tempted by Aldi's recent Workzone 1800/2000W
inverter gensets (three times no less before I gave up the whole idea of
a generator upgrade) but they proved to be quite frankly, pure
Unless we're due another unusually mild winter, the risk of power
outages due to the government's mishandling of the Nuclear power plant
construction programme that is now woefully years behind schedule, looms
ever larger so it seemed only timely to purchase a backup generator that
was compatible with modern day lighting loads and computer kit.
When Lidl put the latest B2 model on offer for just 99 quid two months
ago, it was such a 'bargain of the decade' I just had to buy one, even
though it was initially just to verify its compatibility with my
Smartups2000. It was some 30 quid cheaper than the A1 version which I
notice are still available in my local Lidl store (and rather
surprisingly, still at their original elevated price of 129 quid).
Needless to say, I wasn't in the least tempted. It wasn't just on
account of their higher price but also because of their retro 80's 'Cheap
two stroke petrol generator' looks complete with a gravity fed fuel
system from the classic top mounted steel fuel tank.
Don't be fooled by the side panels, they're just cosmetic coverings on
an otherwise open frame chassis. It's true enough that the plastic
carapace of the B2 model hardly improves its noise footprint over that of
its predecessor but at least it has a slightly larger capacity tank and a
more economic fuel consumption rating (0.68L/hour at 67% loading versus
the 0.88L/hour of the A1 model, also at 67% load).
TBH, those little PGI 1200 B2s are such a bargain at 99 quid that if
they ever become available again at that price, I'd snap up another two
just to keep one as a spare (never mind that if either or both prove to
have their first overload thresholds set above the nominal 1000W limit
rather than 2% below it as is the case with my current unit, I'll be
swapping inverter modules to correct the shortfall (unlike most inverter
modules, the one used here is completely devoid of trimpots), hopefully
leaving me with a pair of gensets both set above the 1000W limit for
their first stage overload state (where you have 30 seconds to remedy the
overload before the inverter module shuts down). The 1200W surge rating
is the upper limit which, if exceeded, will trigger an immediate shut
If only one or neither meets or exceeds the specified overload limit, it
just means I'll have to carry on the exchange/refund dance until I either
land up with two good units or else run out of exchange options.
Hopefully, my current inverter genset is the exception rather than the
rule over this business of being set 2% below rather than 2 to 5 percent
above the specified limit.
This time round, I'll know exactly how to deal with the two most common
stock faults that arise from their being mishandled in transit, stuck oil
level sensor floats and dislodged connectors in the wiring going to the
inverter module - both show stoppers yet trivial to fix. :-)
 Obviously, a permanent magnet three phase alternator wired to a high
voltage rectifier pack and geared to produce 420vdc on no load could be
used to power an inverter module (in essence a bridged pair of class D
amps driven from a 50Hz sinewave reference signal) to get round this
voltage instability impediment as well as improve on the best efficiency
of the standard single phase alternator typically used to directly
generate the required 50Hz 240vac voltage supply.
As long as the DC voltage feeding the inverter module doesn't dip below
340v, it will be able to sustain the 240vac right up to its maximum rated
current limit, assuming of course that this doesn't exceed the three
phase PM alternator's maximum ratings.
Johnny B Good
Communications/DSP Engineer (San Francisco, CA) Work with a small team of signal processing/communications engineers to develop and implement various radio functions (filtering, gain control, frequency tracking, digital upconversion/downconversion, linearization, timing and phase recovery, equalization, FEC, symbol mapping/demapping, framing, etc )