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History:
In 2000, I purchased a Honda EU3000is inverter generator for use with
my new 2001 Airstream Bambi 19ft trailer, intending to run the Bambi's
11kBTU Dometic airconditioner, Sanyo microwave and other loads.
I decided to find a way to mount the genset in a weatherproof cover onto
the trailer tongue, and to provide remote start and dual-fuel capability.
I had purchased the Honda Shop manual for this generator to have reference
information.
Mechanical Arrangement:
I started by modifying the trailer A-frame to mount the genset between
dual 30lb propane tanks and the body of the Bambi. This included modification
for Blue Ox weight distributing hitch model BX2004, with dual action spring
rising through battery box. The EU3000 genset, battery and gas can for
genset were mounted on two 1.5in x 1.5in x 0.25in steel angles, using stainless
mounting hardware and stainless sheet for weather protection, atop the
A-frame. The dual propane tanks were moved forward four inches by notching
the tank tray, and this allowed the jack to be fully enclosed by the Airstream
propane tank cover. The original hand jack was replaced by an electric
H&H power jack, which fits between the two tanks and the forward part
of the tank enclosure nicely.
EU3000 Modifications:
The EU3000is genset was modified to accomodate a remote electric start,
while retaining all the original functions and ability to manually pull
start. This involved adding wiring to parallel the existing electric start
switch, connecting the genset to a new trailer harness with waterproof
connectors, and building a remote control panel.
EU3000 Choke:
In addition, since the EU3000 always requires a short duration of full
choke to start, an electric choke system was designed and built. No off
the shelf system could be identified with the required electrical, mechanical
and tension characteristics. Using a 12volt solenoid, fabricating a bracket
to add to the choke mount, and modifying the Honda choke cable retainer
assembly, a new electric choke system was fabricated to allow both the
existing manual cable choke and the new solenoid electric choke to act
on the choke lever arm. Thus the manual choke will work if the EU3000 genset
battery is dead.
EU3000 Remote Start:
The remote panel inside the trailer includes two rocker switches and
an indicator light, and has room for expansion. The generator is started
and stopped by the 3-position DPDT switch for START-RUN-STOP (momentary
on-off-momentary on). The choke is controlled by the 2-position SPST
switch mounted beside the start switch (momentary on-off). The indicator
light shows generator output and is powered from the +12V output of the
genset. To start the genset, simply depress both the START and CHOKE rocker
switches for 1 to 3 seconds.
EU3000 Front Panel Modifications:
The genset front panel has been modified to install a 2 in round 12volt
DC runtime hourmeter, allowing tracking of maintenance due by hours run.
The hourmeter is actually wired directly in parallel with the genset 12VDC
output. I removed the rectangular 12VDC circuit breaker/outlet combination,
punched out the hole to 2-1/8 diameter for the hourmeter and then installed
the meter there. I added two banana jacks for the DC output on the front
face of the control panel to the lower right of the twistlock L5-30 panel
jack, enabling the 12VDC to be accessible to the outside. This is used
for providing the 12VDC power to the propane valve while running.
Dual-fuel Modifications:
In 2001 the EU3000 genset was modified to allow dual fuel (gasoline/vapor
propane). I purchased a propane conversion kit for dual-fuel operation
of a generator from carbturbo.com. This kit comes with a propane carburetor
adapter, Garretson load-sensing demand regulator and associated hardware.
Also purchased a 12volt DC fuel shutoff valve to ensure complete propane
shutoff.
The propane carburetor adapter required some extensive machining alteration to fit in the required position on the EU3000, and to provide for the internal vacuum ports of the existing Honda genset gasoline carburetor. Several milling, boring, lapping and finishing steps were to shorten the body by 8 mm and complete the vacuum port extensions.
Modification to the existing Honda air cleaner cover were necessary to allow the EU3000 access door to close properly. This consisted of using a 300C heat gun to soften the thermoplastic case, deform it to the required shape, and then plastic weld the resulting shape for strength. The completed air cleaner end housing still fits, albeit tightly, and the air cleaner has no resulting air restrictions.
The EU3000is electrical system was again upgraded to provide for 12-v output to the propane shutoff valve. The valve is open when voltage is applied. The voltage is provided either (1) from the genset battery when the starter is engaged, or (2) from the +12v output of the genset when the unit is running. A bypass valve around the solenoid was added to allow for manual operation if required.
The propane flow from the dual tanks comes to the propane shutoff switch/bypass valve, then to a two-stage regulator, bringing the propane vapor pressure down to 0.5 psi. Flexible rubber propane vapor-qualified tubing comes from this first regulator to the genset. The connection is made with a quick disconnect fitting with positive closure on both sides of the connection, to close off the line from outside air. Inside the genset the tubing goes to the inlet side of a Garretson SD demand regulator. The output of this regulator has a needle valve threaded on the outlet port to adjust the engine demand. The needle valve outlet connects to the propane carburetor adapter with a short length of rubber propane vapor tubing. The overall length of the demand regulator to the propane carburetor adapter has been kept as short as possible to allow for quick and reliable response to changing engine speeds. This is desirable, since unlike many gensets, the EU3000is changes engine speed according to load when in "ecothrottle" mode.
Genset Weather Enclosure:
I designed and constructed stainless-steel enclosure to help protect
the EU3000, using stainless sheet, stainless angle and all stainless hardware.
This was designed to provide reasonable protection from direct rain and
snow, as well as roadspray while allowing air flow. The enclosure
protects the bottom and all sides, except for the back exhaust side.
Sufficient clearance is provided for ventilation air to be drawn from the
rear. The stainless sheet was spot-welded to the angle to provide
rigidity, and backing retaining nuts were spot welded to the angle, allowing
the stainless front plate to be bolted on to the enclosure. Marine
screw-down hatches were installed to access the fuel fill, the manual start
and the front panel. The enclosure bottom fits snugly at the
base of the genset and is bolted to the frame at several points with stainless
hardware. Dampening has been added to reduce noise and vibration.
The genset has been run all day in ambient temperatures of over 90 F degrees
and has sufficient air flow to stay below 130 F degrees internally behind
the control panel (from remote thermometer measurements).
Results:
Combined results have been excellent. The remote start modifications
have been a great convenience from inside the trailer. With the genset
is running on propane, I was worried that it wouldn't have the same load-handling
ability, but the testing I have done indicates the EU3000 handles startup
and operation of heavy loads, including the Dometic airconditioner, a 3000
watt resistive dummy load, and a large Porter-Cable worm-drive circular
saw drawing 18 amps the same with propane as it does with gasoline. The
genset starts up as easily on propane as it did on gas. The load behavior
and easy starting have exceeded my expectations. With the EU3000
running on propane, the oil stays cleaner, and the fumes are much less
obnoxious.
I don't have to use a choke when on propane, but I did leave the complete choke system intact to allow me to easily run on gas when necessary. In fact, I have been able to "hotswap" between fuels with the engine running, with a little attention paid to avoiding "propane flooding" when transitioning from propane to gas.
The EU3000 cannot reliably handle the microwave or the toaster (an 800 watt Sharp Carousel) while powering the airconditioner (an 11kBTU Dometic) with the compressor engaged. I have started the microwave on low power, which simply cycles the microwave tube power some percentage of the time, and at 50% power the genset can handle it, while running the airconditioner on full blast in 85 deg F outside conditions.
Previous detailed info on my experience with this genset can be found
by going to the site www.irv2.com, choosing
the FORUM, and searching for postings with the criteria of:
Containing Text: "EU3000"
Author Name: "mswartz".
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