Ham Radio Help Desk » generator

Field Day Power Topics

kx4o — Sun, 21 Jun 2009 04:05:38 +0000

Last year I made three posts about power in the generator category all related to issues we had with generators, UPS devices (why they don’t like some generators) and a thought about that dang fuel cap on the Honda EU2000.

If you are using generators at your Field Day please have a look at these posts for some previous lessons learned…

Generator Subject Posts

The Honda Inverter generators are, by far, the most fantastic generators ever to hit the market. Even with that fuel cap issue, they are still worth it. So very quite and such clean power… nice.

Ugly World of Generator Power

kx4o — Thu, 17 Jul 2008 04:27:47 +0000

It is well known many models of UPS units do not like the power from motor power portable generators. Indeed it is a difficult task to keep the sine wave pristine when you don’t have the benefit of hundreds of square miles of the power network feeding you an almost infinite about of energy. Here is an example of the waveform from a truck mounted generator delivering much less power than its rated output… about 100 watts from a 5,000 watt generator.

Waveform of 120 vac from truck engine mounted generator

Painful to look at eh? Amazingly the UPS this fed actually worked off this trashy waveform. When we pulled a bit more power from the generator using some simple loads like light bulbs, the waveform smoothed out and became like a sine wave. However, the UPS did not like this visibly better power and went straight to battery.

If there is a moral to the story it is UPS units are finicky about the input power they receive in different ways. Some fault on low voltage while some also fault on too high voltage. Some analyze the sine wave and some don’t. Some require 60 Hz precisely while others can handle + or – 3 Hz or so. Experimentation is about the only way you are going to gain confidence in your generator power configuration.

One style of UPS that seems to consistently win (based on reports from the Internet) are the two-stage types which always generate their power from a dc to ac converter and then just electrically OR the battery and rectified ac mains together to provide a seamless transfer.

Running a UPS off a generator is possible, but allow some time and money to get it right.

Fuel Cap on Honda EU2000 Will Shut Off Generator

kx4o — Wed, 16 Jul 2008 20:30:36 +0000

The manual for the Honda EU2000 clearly states this, but you need to be sure you adjust that little circular knob on the Fuel Cap to the operating position or the generator will certainly quit after a few minutes operation.

Fuel cap with knob on Honda EU2000 Generator

Our problems occurred during the ARRL Field Day 2008 and were the result of tired operators stumbling around in the darkness dealing with the generators. We were quite safe with the refueling process, but always managed to forget that fuel cap switch.

Oh well, you learn something everyday.

I will note the Honda EU2000 generator is one of the finest small generators ever built and well worth the money. There are very quiet, provide more than enough power for multiple stations and run for quite a while on a tank of gas. Another measurable benefit is the inverter approach to generating power. The very clean and frequency stable 60 Hz waveform these units provide was compatible with the UPS units we used to power our logging server computers and wireless router.

Be sure to shop around for a good price. You should be able to find this for under $800 shipped to your door. My local Honda dealer wants about $1,100 for the EU2000; I do very much like supporting local businesses with purchases like this, but my charity only goes so far.