Honda Generators - running on boat

[sigbear]

So, on a boat like Robs catalina 30, how big of a generator would you need to run marine AC, refridgeration and lights?

Sigbear

 

[Hermit Scott]

So, on a boat like Robs catalina 30, how big of a generator would you need to run marine AC, refridgeration and lights?

Sigbear

If you are running all that at the same time, you need a 4000 watt behemoth. If you run one thing at a time a Honda 2000 will probably work fine unless he has an AC like mine, which is 16,000 BTUs. The compressor start up is what will be the problem, maybe, depending on the AC unit.

 

[Chuckbear]

So, on a boat like Robs catalina 30, how big of a generator would you need to run marine AC, refridgeration and lights?

Sigbear

Size of the boat has nothing to do with power needs, it is the size of the load that needs to be calculated. Chuck

 

[Sumner]

The Honda 160 is rated at 4.8 hp or 3.6 kw or 3600 watts, divide that by 14.2 volts and you get just over 250 amps.

Ross in theory the above might work on paper, but in the real world a 5 hp gas engine isn't going to do the same work as a 5 hp electric and you can't replace the 5 hp electric with a 5 hp gas....

http://cr4.globalspec.com/thread/55905/Gas-Motor-vs-Electric-Motor-Equal-HP

If you read .........

http://homepower.com/files/webextras/mark8.pdf

..... the article at the link above they have the following recommendations ..

A 35 Ampere alternator can be driven by a 3 hp engine. A 100 Ampere alternator
needs at least a 5 hp engine. For alternators between 100 and 200 Amperes use the 8–12 hp engine. See Access at the end of this article for a source of small gasoline engines.​

I agree with them and feel anything much over 100 amps and my 5 HP would be struggling to start and run.

If

Above is my wiring diagram. If you don't turn the switch off while starting it is pretty hard to start and will pull the Honda down to the point where it struggles to pick up RPM. Also if you don't turn the switch off after charging the battery will drain back through the alternator and discharge (a proper diode would probably save you, but you still need the switch to start the Honda.

I used 8 gauge wire for the positive and negative from the stern to the batteries. We just bought an electric start Tohatsu, so I'm going to use the two 8 gauge wires for the negative side and use a 4 gauge from the stern up to the batteries, so that I'm sure I don't have a voltage drop to the outboard when starting.

Here is.......................

http://theepicenter.com/tow02077.html

........ another resource I used when I built mine, but the other one is better.....

Your results might be different ,

Sum

 

[Ross]

Ross in theory the above might work on paper, but in the real world a 5 hp gas engine isn't going to do the same work as a 5 hp electric and you can't replace the 5 hp electric with a 5 hp gas....

http://cr4.globalspec.com/thread/55905/Gas-Motor-vs-Electric-Motor-Equal-HP

If you read .........

http://homepower.com/files/webextras/mark8.pdf

..... the article at the link above they have the following recommendations

I agree with them and feel anything much over 100 amps and my 5 HP would be struggling to start and run.

If

Above is my wiring diagram. If you don't turn the switch off while starting it is pretty hard to start and will pull the Honda down to the point where it struggles to pick up RPM. Also if you don't turn the switch off after charging the battery will drain back through the alternator and discharge (a proper diode would probably save you, but you still need the switch to start the Honda.

I used 8 gauge wire for the positive and negative from the stern to the batteries. We just bought an electric start Tohatsu, so I'm going to use the two 8 gauge wires for the negative side and use a 4 gauge from the stern up to the batteries, so that I'm sure I don't have a voltage drop to the outboard when starting.

Here is.......................

http://theepicenter.com/tow02077.html

........ another resource I used when I built mine, but the other one is better.....

Your results might be different ,

Sum

http://www.honda-engines.com/engines/gx160.htm

read it and weep.

 

[Sumner]

http://www.honda-engines.com/engines/gx160.htm

read it and weep.

Sorry, but I'm not weeping, I'll do that when you take a 5 HP gas engine and show me an amp meter putting out over 200 amps with the gas engine turning an alternator or alternators .

I have the GC160 that is "3.4kW (4.6HP) at 3,600 rpm" according to their specs, so slightly less than the gx160 and there is no way it is going to run an alternator putting out 3.4 kW of electricity. The reason is power losses in doing so.

This guy explains it better than I do...

In a perfect alternator one horsepower would deliver 746 watts. But, alternators are only about 40% efficient. So, if you have a 14 volts, 100 amp alternator, you're putting out about 1.8 horsepower electrical wise, which means at 40% efficiency. it takes about 4.5 horsepower to put out maximum current. Most alternators never put out nearly max. The easy answer is that 1 horsepower from the engine will get you about 300 watts from the alternator

I agree with that and with what these.....

http://homepower.com/files/webextras/mark8.pdf

...guys are saying and they have built lots of these over the years.

OK, I'm done on this one ,

Sum

 

[Ross]

Then you are putting out 60 percent of the energy in as heat. that is about 1100 watts. The alternator would be red hot at two HP output.

 

[Hermit Scott]

http://www.hayesequipment.com/eu2000i.htm
the honda 2000 is a 3.5 hp engine and it puts out 2000 watts max and 1600 continuous. There IS a way to configure an engine that puts out 4.6hp to continuously produce 2000 watts. I am sure it would have to be started with no load, but it must be possible.

 

[Ross]

You always start an auxillary power plant at no load and bring the engine up to operating speed and then connect to the load. Just as you don't start a car in high gear with the clutch engaged.

 

[paulj]

Rob19574
Are you going to connect the Honda generator to your existing 110-120v ac circut system on the boat?

 

[Ross]

The spec's for a Honda EU2000. It uses a GX100 rated at 2.1 KW and 2.8 hp.



Dealer sets actual selling price.
FeaturesSpecificationsOptions

• 2000 watts (16.7 A) of Honda Inverter 120V AC Power
• Super quiet - 53 to 59 dB(A)
• Lightweight (less than 47 lbs.)
• Eco-Throttle - runs up to 9.6 hr on 1.1 gal. of fuel
• Advanced inverter technology provides reliable power to computers and other sensitive equipment
• 12v - 8.0A DC output
• Parallel with another EU2000i for additional power
• Protected by Oil Alert®
• Power for microwave, refrigerators, hair dryer, and small AC units
• USDA-qualifed spark arrestor/muffler
• 3 year residential and commercial warranty

EU2000iSpecificationsEngine Honda GX100 javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl02$lbtnSpec','')Displacement 98.5cc javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl03$lbtnSpec','')AC Output 120V 2000W max. (16.7A) 1600W rated (13.3A) javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl04$lbtnSpec','')Receptacles 20A 125V Duplex javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl05$lbtnSpec','')DC Output 12V, 96W (8A) javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl06$lbtnSpec','')Starting System Recoil javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl07$lbtnSpec','')Fuel Tank Capacity 1.1 gal javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl08$lbtnSpec','')Run Time per Tankful 4hrs. @ rated load, 9.6 hrs. @ 1/4 load javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl09$lbtnSpec','')Dimensions (L x W x H) 20.1" x 11.4" x 16.7" javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl10$lbtnSpec','')Noise Level 59 dB @ rated load 53dB @ 1/4 load javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl11$lbtnSpec','')Dry Weight 46.3 lbs. javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl12$lbtnSpec','')Residential Warranty 3 Years javascript:__doPostBack('ctl00$ctl0...il$Tabs$tabSpecs$gvwSpecs$ctl13$lbtnSpec','')Commercial Warranty

 

[Hermit Scott]

Ross in all that info you have I don't see HP anywhere? If you derived that somehow, check the math.


2,000 watts max.
1,600 watts rated
Engine: 3.5 HP, 4 stroke, Single cylinder, overhead cam, air cooled
Starter: Recoil
Noise level: 53-59 dB (1/4 load & Rated load) 60dB is normal speech!
Weight: 46.3 lbs. Dry
tank size: 1.0 gallons
Run time: 15.0/4.0 hrs. (1/4 load & Rated load)
DC output (Requires optional cable)
20" x 11.4" x 16.7" Dimensions (LxWxH)
Eco-Throttle - Engine RPM adjusts to amperage draw. (Scroll Down for More Information)
Low oil shut down
Ac and DC breaker
Honda inverter technology provides a pure sine wave allowing computers and other sensitive testing equipment to be run with confidence (Scroll Down for More Information)
Parallel operation with optional connector and second EU2000i doubles available power

 

[Ross]

Ross in all that info you have I don't see HP anywhere? If you derived that somehow, check the math.


2,000 watts max.
1,600 watts rated
Engine: 3.5 HP, 4 stroke, Single cylinder, overhead cam, air cooled
Starter: Recoil
Noise level: 53-59 dB (1/4 load & Rated load) 60dB is normal speech!
Weight: 46.3 lbs. Dry
tank size: 1.0 gallons
Run time: 15.0/4.0 hrs. (1/4 load & Rated load)
DC output (Requires optional cable)
20" x 11.4" x 16.7" Dimensions (LxWxH)
Eco-Throttle - Engine RPM adjusts to amperage draw. (Scroll Down for More Information)
Low oil shut down
Ac and DC breaker
Honda inverter technology provides a pure sine wave allowing computers and other sensitive testing equipment to be run with confidence (Scroll Down for More Information)
Parallel operation with optional connector and second EU2000i doubles available power

3rd line in the spec's

 

[Hermit Scott]

3rd line in the spec's

Ross those are the specs that I posted, I meant I don't see in YOUR specs that you posted where you got 2.8 hp.

 

[Ross]

EU2000iSpecificationsEngine Honda GX100

Click to enlargeFeatures
•Easy starting
•OHV horizontal-shaft mini 4-stroke engine

Applications: Edgers, pumps and concrete finishing equipment

View Specifications
View Performance Curve

Specifications Engine TypeAir-cooled, 4-Stroke, OHC, single cylinderBore x Stroke56 x 40 mm (2.2 x 1.6 in)Displacement98 cm3 (6.0 cu in)Compression Ratio8.5 : 1Net Horse Power Output*2.1kW (2.8HP) at 3,600 rpmLink:


http://www.honda-engines.com/engines/gx100.htm

 

[Hermit Scott]

http://www.hondapowerequipment.com/...tion=P2GG&modelname=EU2000i&modelid=EU2000IAN
That is interesting. The gx100 is rated at 2.8hp, but the honda eu2000 generator which has a gx100 in it is rated at 3.5hp.
what ever the deal is here I am fully confident that a small engine rated at 4.6hp will be able to produce 2000watts of power.

Sumner the electronic field controller looks simple enough. How big is your battery bank? I have two 125aH. I run the chart plotter, depth finder, fresh water pressure pump, and led cabin lights. I have a 4.5 w solar panel that is hooked up directly and when we are on the boat I run the engine at least 1 hour. If I don't leave the dock, I put it in gear and throttle it up for the hour. They are walmart batteries, $80 a piece. So I wouldn't be to distraught if I kill them with my unscientific method of charging them. I only have a 35 amp alternator as well. Really I have no idea what state of charge I leave them at. BUT I have a hand crank for my little diesel so, worst case scenario and we are still getting back into the marina. I never charge the batteries with the shore power, not that I am opposed I just haven't had the need yet.

 

[kloudie1]

Going to go out on a limb here because I can’t find the max allowable RPM that the GX-100 is allowed to go to in the generator application.. As a utility motor, I think there are regs that set 3600 as a prudent max RPM for blade tip speeds and constant running.. In the generator there would be no such regulated RPM and the smart throttle would be allowed to run it a good bit faster.. The performance curve that Ross listed shows that if the motor is allowed to run up to around 4500 RPM it will be making 3.5 HP or close to that.. This is an inverter type so it is not tied to 3600 RPM.. Honda has a long reputation for making engines that can turn lots of RPM’s .. That little engine should be able to go to 6000 or more without …uuhhhh… disassembling itself.. With some minor cam and/or carb changes, I don’t see a conflict in these two ratings for the same engine..

 

[Ross]

Hermit, Check the math, 746 watts/hp and 2000 watts equals 2.6 hp.

 

[Ross]

You have to click the specification tab for the generators and then go to the engines and the specification for the engine. Alernators have a speed limit above 10,000 rpm.

 

[kloudie1]

Found it.. The max set point of the ECO-Throttle is 5000 RPM..