Navitron Renewable Energy and Sustainability Forum

Energy/Electricity Storage and Use/Grid Connection => Off-Grid, Batteries & Inverters => Topic started by: Eleanor on January 02, 2013, 06:53:41 PM



Title: Change Frequency of Generator AC Output - Possible?
Post by: Eleanor on January 02, 2013, 06:53:41 PM
We have a small back up petrol generator which worked quite happily for a year charging batteries via the Victron MultiPlus. A couple of months ago the Victron started ignoring the generator output and refused to charge. Having fiddled about I found that the frequency was outside the range the Victron will accept ie > 65Hz. I've enabled "Accept wide input frequency range (45-65 Hz)" in VE configure but I can't see any way of getting it to accept more than 65Hz. So, to the question : can I do anything to reduce the frequency by a few Hz? It must have been lower in the beginning for it to have worked. Thanks.  tumble:


Title: Re: Change Frequency of Generator AC Output - Possible?
Post by: guydewdney on January 02, 2013, 07:08:59 PM
Tweak the spring that holds the throttle open, inthink they will generally need shortening to lower the rpm


Title: Re: Change Frequency of Generator AC Output - Possible?
Post by: marshman on January 02, 2013, 09:43:35 PM
Before doing anything check that your generator doesn't have a lever on it somewhere which sets the frequency. My old Honda 650W genny has a level to set it to either 50 or 60Hz. Basically it just speeds the engine up 20% to give 60Hz. If it has it is possible that it has got knocked over to the 60Hz position.

If not then as guy says try shortening the spring on the throttle or bending the governor lever.

Roger


Title: Re: Change Frequency of Generator AC Output - Possible?
Post by: johnrae on January 02, 2013, 10:29:51 PM
If the governor is driven by air from the cooling fan then check there isn't debris interfering with the air flow.  Low flow of air is the equivalent of the engine running slow, hence the governor opens up which increases speed and therefore frequency.   If you can beg or borrow a hand-held tacho unit you could check engine speed.  For 50hz it will be either 1500 or 3000 RPM.


Title: Re: Change Frequency of Generator AC Output - Possible?
Post by: Eleanor on January 02, 2013, 11:04:20 PM
Thanks, a few things to go on there and it sounds like it can be sorted out.
I'll look at air flows - I've already cleaned the filter but there could be something lurking somewhere else horror: and then go for the tweaking :genuflect


Title: Re: Change Frequency of Generator AC Output - Possible?
Post by: billi on January 02, 2013, 11:43:47 PM
I know  ::)..... perhaps its not the solution (longterm), in my case it worked fine to apply a second load to the second outlet/socket of the generator to get him "loaded " first and push down the Volt towards something the Victron will accept ..... it seems to me , that once accepted by the Victron it works better and voltage of the generator does not climb up towards out of range

My wife was not sure that everything was alright with me , those days , when i went out at night  to the generator shed with her hairdryer  whistle



Other scenario i know very well , is Victron allows to connect the Genny , but Voltage fluctuates too much cause internal charger of the Victron draw too much or too quick  and kicks him (her?) out and back in , then i switch on the hairdryer  in the house (just on low power) , that balances the Genny , until the Victron finds his balance as well, to keep the Genny running  more smooth , for charging


Sure if the Genny worked before , there can be some other problems ,   but Generators and Billi  have a long affair , and will probably not marry in a lifetime  whistle

Regards Billi


Title: Re: Change Frequency of Generator AC Output - Possible?
Post by: Eleanor on January 03, 2013, 12:10:09 AM

My wife was not sure that everything was alright with me , those days , when i went out at night  to the generator shed with her hairdryer  whistle

Regards Billi

At least I'm not the only weirdo in town as that's what I did to try and slow it down. Great minds think alike  ;D


Title: Re: Change Frequency of Generator AC Output - Possible?
Post by: Eleanor on January 03, 2013, 12:21:59 AM
On a more serious note I'm fairly convinced that the frequency is the problem as the Victron doesn't even try to connect although the voltage is within limits. I expect the Victron is objecting to being connected to a cheapo generator and would prefer a Lister  ;D