portable generator low voltage

toolmaker312

Hello. I recently bought a new generac 3300i generator to hook up to my shore power cord. When I check the on board voltage meter coming in it is below 70 volts.The purpose of generator was to use the onboard battery charger to keep the batteries charged through out the year. I tried two different cords, and tried the 30 amp receptacle and 20 amp receptacle.
Thanks for looking.
I hope you had a Merry Christmas and have a Happy New Year

MH342

If your measuring voltage just using the meter on the panel, those can be pretty inaccurate. I would suggest using a multimeter to measure the outlet at the generator and in an outlet on the boat. 

PickleRick

The generac 3300i is a POS.   The 3000i was actually an amazing unit, I had one for over a year with zero issues and would run a 12.5btu marine ac plus two battery chargers, 24" box fan and TV/DVD player.  The 3300i would only run the AC with everything else off.


The issue is faulty inverter.  This inverter controls the rpms as well as voltage output.  If it's not under warranty the inverter costs as much as the generato(I'm taking dealer pricing)

I can buy/sell generac generators at dealer costs but to become a "dealer" for warranty I must pay nearly 800 bucks.   The closest supposed warranty repair center to me is northern tool.  Good luck having warranty done there.

PickleRick

I most add, despite being a dealer for generac portable generators I can usually order them from Amazon or eBay for less than dealer costs.   My dealer rep was chewed out up one side and down the other from my personal experience and lack of support on a brand new gp3300i.  I now only sell Honda. Screw generac.  I now run a remote electric start wen and it's a much better generator.  Same support as generac but at half the cost and it's some 4400 watt at the same weight and longer run time my almost 50%.  

toolmaker312

Thanks for the info. I will check output from gen and boat.Not revving was concerning. I wont see the boat for about a month. It is shrink wrapped and was very difficult to get the plug in position. ( should have just cut out a window around shore power outlet). I am now thinking I maybe bent a leg. The wen does look interesting but I was liking the generac made in Wisconsin.Probably to late to return. I will let you Know

LaRea

Measure voltage at the shore power cord (the end that plugs into the boat).  If you get 120v there but 70v inside the boat, the two likely causes are both dangerous fire hazards.  One is a failed shore power receptacle (look for charring or melting).  The other is a failed PowerPole connector somewhere in the system (details HERE).  

PickleRick

Only some of the generac generators/engines are made in USA. It's likely limited to most of their large home backup style generators.

 I don't think any of their ohv engines are built in the USA.  I highly doubt any of their electronics, especially the inverter, are made in the USA as most of these components are sourced from China.   This is the case for most portable generators. 

I suck at anything AC power wise so my test was to compare performance of my 3000i and my 3300i side by side.   I have the ability to stick probes of my multimeter into the outlet to verify 110v.  This, however doesn't test amps.   There is a load tester specifically for generator for amps but not something I've found a reason to invest in.  

MH342

Just another thought … if there is no load on the generator, is it possible it produces 70v until it senses a load and rev’s up and increases voltage?  Have you tried measuring it with a load?  The best type of load would be a resistance load like a heater (stovetop, water heater, etc) since they don’t care about low voltage.  I had a large (non-inverter) portable generator which had a power saving mode and it behaved like this.  The power savings mode was more for a job site application, where as soon as you pulled the trigger on a circ saw it would spool up. The instructions warned against using that feature when powering electronics because it might not draw enough to spool up and then would just supply low voltage continuously.

I also have a Honda inverter and this is NOT how operates. An inverter generator should always supply steady 120 regardless of load. So if this is an inverter gen and is still behaving this way under very small loads, then it is defective. 

Lake_Bum

Not sure if this would be related or not to your problem.  I recently bought a class A diesel pusher, and it has a inverter/charger that is a smart charger.  I have used my Yamaha ef2000is generator to charge batteries on several different RV's but my new one, wouldn't even recognize that it was plugged in at ALL.  A simple ground neutral plug for $20 bucks solved my problem.   It just plugs in the generator on a spare outlet, and my RV would then "see" the correct current on the smart charger to power it up.  

PickleRick

It is weird how inventer generator have a floating ground.   I've heard of them having issues in RVs,  usually setting off the reverse polarity light.  I've not heard of it in a boat but most of my customers are not using them in boats.    Although I do wish wakeboard boats would tie them off to their speakers towers then throw the genny off the boat at full speed.   The lake would be so much more peaceful if I didn't have to listen to their country bro rap from 8 coves over 


Update on the genny im running.  I gave the wen to my dad, it was too heavy to pick up and over the transom solo.   I could do it but I'd get yelled at by the admiral for it.  It also took up too much space on the transom making the ladder useless 


I'm running the genkins 3800 with remote electric start.

It's almost as nice as having an in board genny.  I hit a little button and it fires right up.   669 plus tax and free shipping on eBay, I've seen it as low as 549. 


I ran a generac 3300i, my genkins 3800 and Honda eu2200 all side by side.  

At idle the eu2200 was most quiet by a very flawed ear test between 3 small engine mechanics. 

With a 7000 btu portable ac running the genkins was most quiet, it was also the highest rated so it didn't have to run full rpm to produce the power needed for the AC amp draw

davidbrooks

if you do hook up a load to the generator make sure it is something that is fairly cheap to replace.  Low voltage will burn something up faster than high voltage will. It does sound like a bad inverter or what i would of called a regulator.  Even on my built in generator that went out and i was only getting 20v output.  I want to say that was a ~$600 part.  i have a Generac house backup generator.  Old, propane generator that is no longer automatic but i can still get it running when needed.  Only i can though.  Power ever goes out if i am away from home and my wife is SOL.

LaRea

@Lake_Bum-- what you wrote makes total sense to me (after I spent a couple hours this week studying how my own charger-inverter works). 

In any AC system, the safety ground must be connected to the neutral wire, and that connection must be made only at the AC source -- wherever the source is.  

When a smart charger-inverter is generating AC current, it makes the ground/neutral connection at the inverter.  However, it automatically breaks the connection when you hook up shore power.  That's because shore power connects ground to neutral on land, at the source.  

If you try to run a smart charger-inverter from a floating neutral generator, the safety ground would not be connected to anything at all, so the charger-inverter will not operate.  But a bonding plug makes the ground/neutral connection at the genny, and then the charger-inverter will operate. 

rasbury

You all don't know how much I wish I had barely a clue what your talking about...

raybo3

@LaRea Keep in mind most shore power connections are considered  sub panels where the grounding conductor needs to be isolated from the grounded conductor. If not you would have the potential for a ground loop....... Just say'n 

Lake_Bum

When in doubt, stick a fork in it. Or a penny!  *kidding* 

LaRea

@raybo3 - good point, I guess there's some ambiguity about where on shore the connection gets made.  Maybe through a ground stake at the panel for the pier?  In any case, when using shore power, the connection can't get made on the boat.  

toolmaker312

I have a small update. We recently moved to shore power(still on land) and the 2 cords I tried prior, both produce the 120 volts. Once I am in the water I will try the generator again to see if there is a difference

PickleRick

I wouldn't be shocked if the gp3300i was the issue.  I'd recommend borrowing another generator from a friend/family member to give a try. 

I've ran the portable generators on two boats now.  Generac gp2300i, gp3000i, gp3300i (all generac models)  wen and now the genkens.  The 3300i is the only one I had issues with.

The only issue I've found thus far on my other portable generators has been running the reverse cycle heat.  It  runs perfectly for one cycle.  Then when the compressor kicks on the second time it trips the breaker.   It apparently demands more than 20 amps to kick off a second time in reverse.  Ac has worked flawlessly all night thermostat set 70 degrees 12 hrs a night in our south Carolina summer heat.   

Now I run the reverse cycle heat to get to desired temp then cut on a small portable electric space heater.   I don't boat past mid October.