How does a genny work?

[County4x4]

I think I'd suggest having a visit to the Navitron forum and asking a few questions on there. There are lots of off-grid enthusiasts and electrical engineers and the like hanging around the place. Some of them use an entirely different language to us mere mortals, but I've found they are a helpful and knowledgeable bunch!

 

Navitron Renewable Energy and Sustainability Forum - Index

 

Andy

[Justme]

I am on the Navi forum (and others) already.

 

I am getting a good mix of replies from them all.

[County4x4]

@Justme - tell me you're not on the Transit forum as well 'cos if you are I may start thinking I'm being stalked:laugh1:

 

Andy

[gensetsteve]

I wont say too much unless you ask me for an opinion.

 

I will say the unit you have imo is the best you can get for £2000 if you spend

6k you may not get much better.

 

I dont work for the manufacturer but have sold this exact unit to many standby customers.

 

The manufacturers seem to be a good out fit you may be better appealing to their better nature.

 

I wont say these units are not up to the job but i dont sell them to prime power users either.

 

a 1500 rpm lister flat top with top quality alternator may be more suitable for you but then you are looking at £6000 +.

 

I am suprised about the amount of problems over a £6 capacitor I feel there may be more to this.

[Justme]

No Andy I'm not on the tranny forum.

 

Thanks for your comments gensetsteve.

 

I have been very happy with the genny (and recommended it to lots of people) so far & was not even that miffed when it failed still in the warranty period. How I will feel about that company in the future will depend on the repair cost & how they treat me.

 

I would have gone down the lister road but need to keep the noise down as we have a complaining neighbour.

 

I wont say too much unless you ask me for an opinion.

 

 

I am suprised about the amount of problems over a £6 capacitor I feel there may be more to this.

 

Please do give me your honest opinion.

 

Thats what I dont get either. Even with a pallet cost each way we are not talking much.

 

I might know more once I get their quote for fixing it.

Edited December 3, 2009 by Justme

[gensetsteve]

When you get the unit back I would make sure you stay under 4kw and service it every 50 hrs or once a week if running 8 hrs a day. They only have 1.5 litres of oil in them. Yanmar quote 2400 hrs for a strip and overhaul the most hrs I have seen on one is 4000 . When the warranty is up I would look into getting a spare Alt . I think you bought the best 5.9 kva on te market if you have the

p6000s. Good luck with it I will watch with interest.

[Justme]

Thanks for the comments.

 

Yep its the P6000s.

 

Lovely & quiet. Runs smooth starts on the button every time.

Has some good design features (like the oil drain pipe, Fuel filler & level indicator, single lifting hook, elec & pull start, not that its been needed yet). The wheel kit is ok but does add to the noise so needs a bit of padding to stop handle shaking.

 

I would highly recommend the genny, but so far cant recommend the UK agent. The dealer has been ok too.

 

(had it failed out side the warrranty I would have done more tests on it my self & would have found the fault & fixed it for less than a tenner & if I could not find it a local genny place would have done it for a reasonable fee, in fact last time I have work done (sorting out the elec motor on a hydraulic sausage stuffer) I paid him in fresh meat from our own on farm butchers shop)

 

I want to add remote start & stop to it (but not auto mains fail start) so in winter I dont have to go outside in the rain to opperate it & I also have a bat SOC (thats state of charge) meter that can activate a set of contacts at a pre programmed V or SOC to trigger the remote start & then hold it till the bats are full & had an EQ charge.

 

I can also do the same with the inverter & solar charge controller as they too have controllable relays.

 

I had a genny before this one that had auto start on mains fail. I just used the on & off switch on that to trigger it as the mains was not passed through the ports just turning it on would start the genny. In fact I still have it but would need to sort the wiring out to add it to this one.

 

Service oil change is in the book at 200 hours I have been doing it at 100. But if you think its best to do it at 50 I will up it (oil condition/feel/ colour seems ok still at 100 hours). Its not a huge cost. My tractor "looses" more than that in a week or so.

 

It runs for between 6 & 12 hours every 3 to four days. So about 12-20 hours per week max.

 

Just checked that & my usage this year has been

 

Month Hours

JAN 88

FEB 80

MAR 88

APR 86

MAY 88

Had less solar panels in Jan to May as I added 50% more in Jun/Jul

JUN 33 (just for power tools)

JUL 0 KWh made from genny (only started recording from here)

AUG 25 24 (just for power tools)

SEP 29 56

OCT 65 113

NOV 68 112

DEC ?

 

June July & Aug was mainly running it for power tools.

 

I check the oil every time I start it. When new it used lots of oil for the first 50 odd hours & then slowed down & is now hardly using any.

 

We dont use it much in spring & summer as the solar will provide nearly all our needs. Just the odd day running power tools ect.

 

 

Our standard max load is less than 4000w with every thing on & the longer its on the more it goes down due to the bats taking less from the charger. The biggest single load would be my welder. But that only ever used on its own at low settings & is plugged in via the 15amp breaker so cant draw more than 3600watts ish & I dont use it often. I am however looking at a bigger genny (poss PTO as its more mobile & can be used as a back up if the main one fails again) for it as I cant turn it up to max for thick stuff.

 

They have point blank refused to do it under warranty. Even after my selling dealer tried to convince them. The dealer has just passed on the costs with no mark up.

 

The repair bill is

 

courier both ways £90.70 (which is cheap for a 200kg plus pallet on next day)

capacitor £4.50

Labour £54.67 (just to test & fit cap)

VAT £19.14 (already added in above costs)

Total £146.75

 

(the thing is I would have been liable for the courier any way & had it been a warranty item I would have had the dealer service as well, so all it would have cost them is the £4.50 cap & 30 seconds to fit it)

 

Thats the min to fix.

 

They also wanted to do a service for about £100 but I said no.

So they would have got more money out of me doing it as a warranty item.

 

But I did buy a service kit for £37.63 inc vat that contains

 

1x air filter

 

1x oil filter

 

1x gauze fuel filter

 

1x paper fuel filter

 

2 x 1 litre bottles of oil

(did try to not have the oil as I buy that in bulk but its part of the "pack")

 

The thing is that have now fixed it (due back on Monday) & I assume tested it WITHOUT DOING THE SERVICE that they say caused the failure.

 

It will be interesting to measure the RPM when it returns to see if it really is slow & if it changes after fitting the new filters.

[Justme]

I can even if needed set the inverter to Assist Mode. So if the power need hits the limit set for the available power from the genny (which I set for 1 or 2 amps below max) it will sync with the genny & add in the extra power needed. It also has a UPS mode where the switching is extra fast (but the standard setting does it quick enough for tv, lights & computers any way)

 

A full strip every 2400 hours is about every 3 years for me.

 

What is it likely to need?

 

a, a clean up

b, full recon

 

 

At the min I am borrowing a cheapy import petrol 2000w genny. Its coping with all our standard loads apart from the inverter drops the charging when the freezer starts (due to hertz going down to 47/48, at 52 off load), but once started it starts charging again so is coping with the load just not the starting load.

Edited December 5, 2009 by Justme
add stuff

[Justme]

Well its arrived back.

 

So I refilled it with oil & started her up. Was running smooth (remember this is with no load & before the service).

 

I then connected it up to my system to see what it was doing with a very small load & a larger load.

I then fitted the service parts & repeated the test.

 

I was hoping to be able to show a difference in the before & the after shots but they were the SAME.

 

This is small load

 

 

This is a larger load

 

 

 

UMains = incoming mains voltage

IMain = incoming current

UOut = voltage entering the domestic meter

IOut = current being used via the domestic meter

Udc = battery bank voltage

Udc = ripple is battery bank voltage variation

Idc = charging current going into the battery bank

Freq Out = Hertz at domestic meter

Freq In = hertz from genny

 

The first pic shows a 0.3 amp load on mains & no charger (the other 0.1 amp is the system load) so 0.4amps from genny.

The second pic shows a 9 amp total load on genny with the same 0.3 amps to the mains meter & the charger using the rest to charge at 106 amps.

 

As you can see the herts (so engine speed) is high at 54 hertz with virtually no load & still slightly high at 52 hertz with the largest load we can apply.

 

It is also interesting to see that the £200 AVR module seems to not be working very well as the genny voltage alters from 226v no load to 219v under half load.

[gensetsteve]

The strip at 2400 is a Yanmar idea. I would change oil 50-100 hrs run till 4000 hrs and sell at auction for £550. Buy a new one start again, a new engine is £1200 - £1500. Starter motor on its own is £250 trade. Just my opinion not a recommendation.