My Ice storm/ generator lessons

[JFoy]

I never could find a 220volt KilloWatt monitor either and ended up buying a TED breaker box monitoring system. Expensive and I got additional monitors to follow other circuits but now I can tell you about my hot water heater usage, HVAC, office computers, etc. Here's what I got: The Energy Detective Pro Home Real-Time In-Home Electricity Monitor: Amazon.com: Industrial & Scientific
"Energy Detective Pro Home Real-Time In-Home Electricity Monitor" from Amazon.

 

[KYErik]

On the topic of voltage- I have an old Honda 3500 watt 2pole genny that uses engine speed to determine voltage. The governor works pretty well at responding to load, but I lose about 7 volts from light load to full load.

What is the best voltage to set the rpm adjustment to avoid problems with circuit boards/electronics? 125 volts at light load (118 at full load)? Or 120 volts at light load (113 volts at full load)? Or a slightly lower voltage?

 

[cqaigy2]

On the topic of voltage- I have an old Honda 3500 watt 2pole genny that uses engine speed to determine voltage. The governor works pretty well at responding to load, but I lose about 7 volts from light load to full load.

What is the best voltage to set the rpm adjustment to avoid problems with circuit boards/electronics? 125 volts at light load (118 at full load)? Or 120 volts at light load (113 volts at full load)? Or a slightly lower voltage?

Maybe drive a UPS with your Honda?

 

[brokenot]

+/- 7 volts isn't a huge thing. What kind of frequency fluctuation are you seeing with the change in rpm? We have a lot of equipment at work with onboard generators in the 6-7K range. Most of these machines have control circuit boards on the load of some type....and the lack of failures is pretty amazing. These are rental units, so all of the typical rental customer caveats come into play. Since some of these machines run 24/7 unattended, (heating or ground thawing applications), some other "operator-induced" things happen....such as running out of fuel at full load. Of course, while running out of fuel, (these are small diesels), the normal rpm surging takes places for a minute or so until the engine finally dies. To add insult to injury, the customer that ran the genset out of fuel in the first place forgets that he or she didn't switch any of the loads off before refueling. Fuel is added and, (maybe), the lines are bled out. As the engine is cranked, the normal spittin' and sputterin' goes on before all of the air is purged and the engine runs cleanly at its governed rpm again. A rough estimate of the total amount of time that elapsed while the engine was running out of fuel initially and the time it spent sputtering back to its governed rpm under load after refueling is probably two minutes....per occurrence.

During the heating season, this scenario is repeated several times per machine. And with 30+ of these out on rent, control board failures are rare. The last one I replaced was a couple of years ago. The heaters that use VFDs to control the blower fan speeds, well...that's another story altogether. VFDs are much touchier when it comes to input voltage and frequency than the control boards are. I should also say that these control boards are all off the shelf items from the big vendors that supply the HVAC industry. They aren't extra-robust, purpose-built controls designed to be used with gensets.

I'm a big fan of clean, stable power, but having said that....I think worrying about +/- a few volts is unnecessary.

 

[3930dave]

Good point brokenot about VFDs vs. frequency, old induction motors would often put up with a great deal in comparison.

My rule of thumb for motors+gens is the same as me lifting weights - if it causes a noticeable grunt, think twice about taking on more.

Kudos to OP for this thread...... may save some folks some $$, and has been pointed out, many times you can't find a repairman that fast !

Rgds, D.

 

[Ken45101]

On the topic of voltage- I have an old Honda 3500 watt 2pole genny that uses engine speed to determine voltage. The governor works pretty well at responding to load, but I lose about 7 volts from light load to full load.

What is the best voltage to set the rpm adjustment to avoid problems with circuit boards/electronics? 125 volts at light load (118 at full load)? Or 120 volts at light load (113 volts at full load)? Or a slightly lower voltage?

Either choice is within specs for your regular utility voltage.

 

[Ken45101]

Reason 2. They were too heavy for one guy easily handle at around 80 pounds. I can handle the 40 pound generator. Reason 3. They burn more fuel all the time VS running 2 generators only when needed.

I know what you mean about the extra weight however, that can help provide security: the heavier unit is less likely to walk off than the lighter one.

Have you actually measured the fuel economy? The Honda units are quite efficient on ECO mode. Remember, a 3000 watt gen will idle down with a 1500 watt load whereas a 2000 watt unit will be running flat out.

I do know that the Honda EU3000i is even quieter than the 2000i at the same loads (we have both). BTW, you can parallel generators of different sizes, such as the 2000 and 3000.

 

[bluestem99]

We live out in the sticks and the utility co likes to leave our little neighborhood last on the list during outage events so we bought a Honeywell 7900 watt generator a while back. I hook it up to one of these:Amazon.com : Reliance Controls 31406CRK Pro/Tran 6-Circuit 30 Amp Generator Transfer Switch Kit With Transfer Switch, 10-Foot Power Cord, And Power Inlet Box For Up To 7, 500-Watt Generators : Manual Transfer Switch : Automotive for ease of use. The generator is pretty loud but it runs everything we need it to in the house, furnace, well pump, etc. I think all had for around a grand.

 

[stuckmotor]

The most unbelievable thing about your whole story is that you had a furnace guy show up by 1 the same day during a major weather event!

I noticed that too.

 

[4570Man]

I know what you mean about the extra weight however, that can help provide security: the heavier unit is less likely to walk off than the lighter one. Have you actually measured the fuel economy? The Honda units are quite efficient on ECO mode. Remember, a 3000 watt gen will idle down with a 1500 watt load whereas a 2000 watt unit will be running flat out. I do know that the Honda EU3000i is even quieter than the 2000i at the same loads (we have both). BTW, you can parallel generators of different sizes, such as the 2000 and 3000.

I haven't done actual test. Fuel economy is excellent going either way. Piggy backing the 2000 watt generators gives you 3200 watts continues vs 2400 watts with the 3000 watt. The 3000 watt one weighs 78 pounds vs 43 pounds of the 2000 watt generator. The 3000 watt one cost $2500 vs $900 for the 2000 watt one. The 3000 watt one in question is 65 decibels which is louder than the 2000 watt one. They make a different 3000 watt one which is cheaper and quieter, but it weighs 130 pounds. 130 pounds is is way too heavy for my use.