Telecom Generator

Re: Telecom Generator

TheBackRoads wrote: »

Hey all,

Saw on the news this last week the following generator in a story about storm damage. I looked it up as it looks like a Honda EU3000iS but with "Alpha" tags on it. Google search found it. It's apparently a converted 3000iS but for 36/48V output for telecom. What's everyone's thought on this? Would it be worth it to find one, and use a secondary charge controller for running this genny for off-grid charging?


Generator Link

The ALPHAGEN DCX3000 is not a converted Eu300is but a completely different D.C product, Alpha Technologies Co-engineered this product with Honda using the Eu3000 product as the starting platform. You should go to the alpha technologies generator http://alpha.com/outside-plant-power/generators. Solarvic mentions in this thread that he has 2 of these but powered by Kohler. Those would be ALPHAGEN 5K or 7.5K curbside stationary generators, LPG /Natural gas powered. the ALPHAGEN DCX3000 is a gasoline powered portable, D.C 36/48VDC (switchable). The Alpha website has manuals you can download for further info. I can provide more technical information if you need.


NOTE: The poster works for Alpha.

I just bought one and have been using it for a couple of days now because my family was visiting and solar couldn't keep up.  This thing is a champ.  I ran it 9 or 10 hours per night (one of our party had asthma-like conditions and running a dehumidifier really helped).  Huge fuel tank would last a couple of nights.  The unit is extremely quiet like its cousin the eu3000i.  It got rained on one night with no visible ill effects.


If left on indefinitely it would probably charge your batteries up to the roughly 90% SOC range and the last few percent would be painfully slow so it is not a "charger".  I spoke with the Alphagen guys and they confirmed that the design is aimed at being able to drop one of these off the truck at a remote site, plug it into the battery bank, and leave it running for many hours without overcharging the batteries, and that they did not build in any smarts beyond that.  They picked a voltage (52.5 volts) that would keep the batteries relatively happy sort of towards the upper end of their range of SOC.  It does respond to the increasing voltage of the batteries by throttling back.  I have it on now and I noticed it gradually decrease power over several seconds.  Turns out the sun came out and the panels are now doing most of the work.  You can hear it suddenly throttle up when the reefer or microwave comes on.  If you were to unplug it the speed drops to an eco-idle speed.    The specs say it has a permanent magnet generator so I figure that means voltage is linked to rpm.  Other changes with load are merely throttle changes not speed changes as far as I can tell so it seems not to have an eco setting beyond dropping to idle when no power at all is needed.  The Alphagen tech said it's like a lawnmower in that you must manually start and stop it.  I asked whether the output voltage could be adjusted and he said no, although he may have been instructed to dissuade customers from fiddling with the controls.


All in all it's great and I can't imagine why anybody with a 36 or 48 volt system wouldn't snap one up.  Let your solar panels do the fancy charging.  This will keep your batteries 90% of fat dumb and happy overnight or through periods of no sun.

It does have some quirks.  There is a battery interface cable with leads about 3 ft long that attach to the poles of the batteries on one end and have a grey Anderson SPE80 connecter on the other end.  There is also an output interface cable with a red SPE on the end that plugs into the generator and a grey SPE80 that connects with the one on the end of the battery interface cable.  There are three lengths for the output interface cable, 10', 30', and 50'.  All conductors are #6 gage.  I was initially glad to have received the 50' cable since it seemed most versatile and since it was undoubtedly expensive I felt like I had scored somehow.  However my calculations show that the voltage drop through 100' of #6 wire at 55 amps is 2.2 volts!  So even when running in the middle of the range at 25 amps the generator is actually delivering 1 volt less than it thinks it is.  The penalty is significant because as the current through the cables increases the battery bank sees less and less voltage coming from the generator.  The battery bank must discharge down to whatever voltage is actually getting through at the battery end and until it does the generator is only carrying part of the load and of course as the battery voltage goes down the current from the generator goes up, further aggravating the condition.  Later after the loads decrease the generator slowly replaces what came out of the battery but I find it all very unsatisfying.  My Morningstar charge controller increases the absorption period if the voltage drops below 50 volts overnight, and I was seeing 50.4 volts at the batteries even though the generator was producing 51.6 volts at its end.  The voltage would have to be under 50 before the generator was fully loaded.  In short the response of the generator to load increases is somewhat muted.  This phenomenon must be greater when using a 50' pair of #6 than when using say a 10' pair of #2/0.  Also this is on top of the fact that I seem to be getting only 51.6 volts at the generator output rather than the 52.5 the generator is labeled for.  I alluded to the possibility that there was a voltage output adjustment somewhere or somehow.  The fact that the tech told me no does not completely deter me.  He would undoubtedly keep such info from the un-initiated.  Another possibility is that there may be a connection where voltage sense wires from the output terminals are landed to let the control board know what the output voltage is.  If there is and I can find it I can just add a twisted pair of light gage wire to the output cable and land them on the battery terminals.  Then I could keep the cable 50' long and it would only cost me a little gas, but the batteries would be held at a steady voltage.


It seems my options are:

1. Live with it.  It works pretty good as is.

2. Cut cables way short.  Get larger conductors or double up using multiple lengths of the #6.  Eliminate the grey SBE80 connectors and terminate directly onto the batteries.  Betcha that would count as a few feet of #6.

3. Find the pot that adjusts output voltage and turn it up.  There must be a control circuit for this.  I now think that I hear subtle speed changes as the generator increases throttle to maintain the output voltage at higher load.  This would be necessary to compensate for losses in the windings.  The question is whether there is a manual adjustment and whether I can find it.

4. Find where on the control board the output voltage is landed, assuming it is something that can be isolated, and detach it from the output.  By adding conductors to the output cable, sense the battery voltage  at the battery posts rather than at the generator output.

5. While I'm at it, increase the size of all wiring in my battery string as well as too and from it.  The APC SmartUPS 3000 I am using came with a 100 amp fuse.  I had a supply of #4 stranded.  That's what I used everywhere.  I don't think it will burn up before the 100 amp fuse does but it turns out that my system is very sensitive to voltage drop given the limitations of the DCX3000.

Which has more resistance, a 100 amp fuse or a 100 amp breaker?

I was hoping you might have insight newPV2.  In the spirit of looking a gift horse in the mouth though, does the DCX3000 have an inverter?  Are you thinking of the additional parts that the eu3000i has?

Looking for more information and possibly pictures on how to modify these alphagen dcx3000 generators.  I will begin the teardown of one of my generators if there are people that can assist.  The goal being to produce amps from one of these for direct charging and not load sensitive even if the load at idle can be increased to produce more amps.

I would like to charge with them at around 60-80amps and need a solution.