Armed Polite Society
Main Forums => The Roundtable => Topic started by: Brad Johnson on April 26, 2021, 12:51:53 PM
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SWMBO and I are considering a home generator.
Option A is a semi-portable unit like the Honda EB10000. Based on rough calcs, the EB10000 it would power the whole house, including a single A/C unit. Pros are it is a true inverter unit, it isn't quite so spendy as a dedicated whole-home unit, and we could haul the generator somewhere else if needed (bulky, but doable). Cons are a measly 3-5 hour run time (read: regular fueling), on-demand setup and manual switchover, and the need to store it and fuel somewhere during the "most of the time" it wouldn't be in use.
Option B is a dedicated unit that will power the whole house, runs on natural gas, and has automatic switchover. Cons are a higher initial cost and no portability. Strong eyeball on Generac as they are a known quantity and I don't see them going away any time soon (i.e reliability, support, service, maintenance parts, etc).
My question revolves around power waveforms. I've found several waveform images for the Honda (FYI, it's gorgeous) but can't find any for the Generac. I know Generac has been around forever, but therein lies the problem. Long histories come with a tendency towards "the way we've always done it". Sure, their units have a track record for reliable power output, but what about the quality of that power? Just because you can churn out steady-state 120v 60Hz power doesn't automatically mean the waveform isn't equipment-killing crap. They don't mention anything about inverter tech, nor do they publish any type of measured or graphed examples. I don't see anything in their documentation that talks about output quality other than a few frilly marketing blurbs. I want to see something objective, preferably an o-scope image of the waveform.
No matter which way we go, mission-critical items like our computers will be on a UPS for both backup power and power conditioning reasons. It's the other stuff that concerns me... HVAC controls, microcontrollers in appliances, expensive home theater equipment, etc.. Those quickly add up to serious coin and I'd like to mitigate the risk as much as possible.
Brad
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Can't answer your question, but I can tell you that friends of mine bought a house about 3 years ago that has a Generac whole house unit (32Kw, I believe).
It's kicked in several times after storms. Longest they've been on it has been about a day, I believe.
They have the full bevy of modern appliances -- computers, refrigerators, TVs, a couple of freezers, etc., and everything has survived.
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Just a guess, but I would think the Generac units provide a standard sinusoidal waveform. It is a generator (alternator actually) and they typically produce sine wave outputs. The 60Hz output is maintained by the genset's governor. That may be a mechanical or electronic governor depending on the sophistication of the unit.
Modern appliances prefer sine waves, though many will tolerate square waves well enough.
To get a sawtooth or square wave output would require running the output of the generator through an inverter of some sort, and it doesn't really make sense to me that Generac would do that.
You might shoot them an email asking them about the waveform from their whole house units.
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Just a guess, but I would think the Generac units provide a standard sinusoidal waveform. It is a generator (alternator actually) and they typically produce sine wave outputs. The 60Hz output is maintained by the genset's governor. That may be a mechanical or electronic governor depending on the sophistication of the unit.
Agreed.
Also, by and large, most "sensitive electronics" immediately rectify the incoming AC as the first stage of a switched mode power supply. They don't care about waveform.
Electromagnetic devices like motors and transformers may be somewhat more annoyed about modified square waves like those produced by cheap inverters.
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My friend the appliance guy says that smaller generators seem to kill appliances. The bigger ones don't bog down when appliances like freezers kick in. High school physics was a few years ago, but I'm thinking, when the generator gets a heavy load, the voltage drops and the amps go up.... or something like that, and the sensitive stuff gets burned up.
I have that 32k generator, and it's nice to be able to run multiple buildings, freezers, pool pump, a/c, etc., during an outage. The downside is that it is a gas sucking beast. I have a 500 propane tank which will likely work for about 1 week but kill me on cost!
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In general when you bog down the engine by adding load, the frequency dips badly. The voltage tends to be pretty steady inside the range of the AVR, until the regulator trips and opens the circuit. I suppose the really small (like 5kw and under) portable sets may have a shittier voltage regulator, but most of the gens I play with will pop the circuit open if voltage deviates more than 7ish% from nominal.
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I have that 32k generator, and it's nice to be able to run multiple buildings, freezers, pool pump, a/c, etc., during an outage. The downside is that it is a gas sucking beast. I have a 500 propane tank which will likely work for about 1 week but kill me on cost!
We have two AC units, both 2 ton, but little else that's power hungry save the clothes dryer and oven. According to Generac's estimator, the 22Kw unit is sufficient to provide us full home power with plenty to spare. If we decide to go the installed-generator route, we'd go the natural gas option. Service here is both super reliable and ridiculously cheap. It also gives us the option of quickly converting to tanked-in propane if all else fails.
This will be in the context of intermittent service interruptions, not constant power. Unfortunately, with our provider's switch to ERCOT, we presume our historically reliable service will become much less so in the future.
The whole-home genset is likely a pipe dream anyway, as I'm coming up with somewhere in the neighborhood of $9-10k for a turn-key setup. What will probably happen is a 6-8Kw portable which will be enough to run the freezer, fridge, a smattering of small appliances, and maybe some entertainment/comms gear on extension cords. I might get fancy and install a dedicated connector for the service panel where I can manually kill the service breaker and switch over to the genset for powering specific circuits. No AC in the dead of summer would suck, but we would have food storage and most of our electronic conveniences. I'd probably include the air handler circuit, too. Losing power during a bitter cold spell entails a lot more negatives than just being sweaty and losing a few things in the freezer. Our heat is gas fueled so all that's needed keep warmth flowing is having power to the furnace cabinet. If we went this route, storing 50+ gallons of fuel would be a pain, and topping off the fuel tank every 4-6 hours would suck, but we would have several days of uninterrupted heat and power. Many more if we rationed a bit. I figure it would run us $3-4k if we went all-in with the panel upgrades.
Brad
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Thinking more on this...
Is there any reason I can't simply backfeed the panel through a circuit breaker? By that I mean installing a 14-50 plug somewhere outside that I could plug the generator into, and connecting it to the panel via a simple 50A breaker. If the power fails, I plug the genset into that plug. It would require manually configuring the breakers, sure, but that's as easy as labeling the breakers as "Hey dummy, only these breakers when on gen power!". Simply trip the main panel cutoff, fire up the generator, and re-enable only the breakers feeding designated circuits. It would also allow the use of pretty much any decent genset with 240V capability.
If it would work, this setup would be super easy to install, essentially a breaker, plug, weather tight mounting box, and a few feet of wire. I'm fairly up to speed on basic wiring but this is beyond my experience and ability to confidently infer. I don't want to presume anything when it comes to wrangling angry pixies.
If this type setup would work, I suppose I could use the existing dryer plug to do the same thing. Only problem is I'd have to string a power cable through the back door, meaning compromised security, though I suppose I could piggy-back off that plug to an external connection seeing as how the dryer plug is on an exterior wall. Only issue there is the dryer is a 30A circuit and not a 50A. That creeps me out a little just from not having a big chunk of current headroom, though I suppose if I'm only running absolute essentials like freezer, fridge, a few LED lights, a microwave, and maybe the air handler for winter heat (nat gas fuel, not resistive), then I'm way under any danger threshold.
*Edit to add* After doing some digging, looks like Square D actually makes an interlock setup just for this purpose. Installs directly in the breaker panel and includes a simple mechanism which effectively blocks the backfeed breaker until the main breaker is in the off position. https://www.youtube.com/watch?v=6RG9nfFE7Zw I'll have to check and see what brand our panel is.
Brad
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Around here the most likely time for power outage is an ice storm so people around here with portable gen sets move the dryer, run the cable threw the vent and can run fridge, freezer and gas furnace.
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Around here the most likely time for power outage is an ice storm so people around here with portable gen sets move the dryer, run the cable threw the vent and can run fridge, freezer and gas furnace.
Damn, that's a brilliant idea. Saves having to keep the door open.
Brad
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We have two AC units, both 2 ton, but little else that's power hungry save the clothes dryer and oven. According to Generac's estimator, the 22Kw unit is sufficient to provide us full home power with plenty to spare. If we decide to go the installed-generator route, we'd go the natural gas option. Service here is both super reliable and ridiculously cheap. It also gives us the option of quickly converting to tanked-in propane if all else fails.
This will be in the context of intermittent service interruptions, not constant power. Unfortunately, with our provider's switch to ERCOT, we presume our historically reliable service will become much less so in the future.
The whole-home genset is likely a pipe dream anyway, as I'm coming up with somewhere in the neighborhood of $9-10k for a turn-key setup. What will probably happen is a 6-8Kw portable which will be enough to run the freezer, fridge, a smattering of small appliances, and maybe some entertainment/comms gear on extension cords. I might get fancy and install a dedicated connector for the service panel where I can manually kill the service breaker and switch over to the genset for powering specific circuits. No AC in the dead of summer would suck, but we would have food storage and most of our electronic conveniences. I'd probably include the air handler circuit, too. Losing power during a bitter cold spell entails a lot more negatives than just being sweaty and losing a few things in the freezer. Our heat is gas fueled so all that's needed keep warmth flowing is having power to the furnace cabinet. If we went this route, storing 50+ gallons of fuel would be a pain, and topping off the fuel tank every 4-6 hours would suck, but we would have several days of uninterrupted heat and power. Many more if we rationed a bit. I figure it would run us $3-4k if we went all-in with the panel upgrades.
Brad
Didn't you have a bunch of cash from the sales of both of your houses? Don't dick around by going the cheaper route, just buy the whole house Generac. You'll probably save money in the long run.
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"Is there any reason I can't simply backfeed the panel through a circuit breaker? "
You can, but I believe that it's illegal in a lot of jurisdictions.
Guy I know did just that kind of set up, only he would run double male-end extension cords from the generator to a particular outlet circuit
He would throw the breaker on that particular circuit so that it wouldn't back feed the the service.
Only problem with that was when he discovered that... when he threw the breaker to isolate the circuit... it didn't isolate the circuit. He had a Federal Pacific panel with Stablok breakers and over half of the breakers in the panel had failed. And when Stabloks fail, they invariably fail on and won't trip under any circumstances.
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Didn't you have a bunch of cash from the sales of both of your houses? Don't dick around by going the cheaper route, just buy the whole house Generac. You'll probably save money in the long run.
I have the Vanguard account I created with the sale of a house. Pulling that money out would incur a significant tax penalty, not to mention reducing the performing asset by that amount (which, at current returns, would be a brick-dumb move).
I would love the convenience and reliability of the Generac but $10k is a hard pill to swallow for an occasional-need item, especially if I can easily and simply accommodate the need for less than half that amount. For the $5k-$6k difference, I can figure out a place to put the genset and safely store fuel.
Brad
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I have the Vanguard account I created with the sale of a house. To pull that money out would incur a significant tax penalty, not to mention reducing the performing asset by that amount (which, at current returns, would be a brick-dumb move).
I would love the convenience and reliability of the Generac but $10k is a hard pill to swallow for an occasional-need item, especially if I can easily and simply accommodate the need for less than half that amount. For the $5k-$6k difference, I can figure out a place to put the genset and safely store fuel.
Brad
Portable generator also doesn't start itself if the power goes out if you are away from home.
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Portable generator also doesn't start itself if the power goes out if you are away from home.
That's one of the variables we're considering before making any decision.
Unfortunately we just got our tax returns and Uncle Sam came knocking hard this year. With the way the ranch returns worked out, our tax bill is a good bit higher than expected. It's punched a huge hole in our cash reserves and kinda torpedoed our whole-house genset plans.
Brad
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You can backfeed through a 50A 220 plug (Stove and Dryer are the common choices, Welder works too) but as you mentioned you have to be careful about what you leave on, and as Hawk mentioned it's illegal without an interlock.
If you can swing the interlock, that's really the way to go for safety. In FL at least that requires hiring and electrician to attach 6 wires, pulling a permit, and having the power company bless it, which is why I haven't gotten around to it yet.
Whole house auto switching is very nice, but is very pricey. Even with hurricanes I only lose power long enough to want a Genset once or twice a year, and the delta between the portable and fixed gensets is to much for me to stomach for a use case that rare. YMMV.
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You can backfeed through a 50A 220 plug (Stove and Dryer are the common choices, Welder works too) but as you mentioned you have to be careful about what you leave on, and as Hawk mentioned it's illegal without an interlock.
If you can swing the interlock, that's really the way to go for safety. In FL at least that requires hiring and electrician to attach 6 wires, pulling a permit, and having the power company bless it, which is why I haven't gotten around to it yet.
Whole house auto switching is very nice, but is very pricey. Even with hurricanes I only lose power long enough to want a Genset once or twice a year, and the delta between the portable and fixed gensets is to much for me to stomach for a use case that rare. YMMV.
Hard-eyeballing the interlock setup. It's cheap, it works, and it keeps us in good graces with both the power company and local code enforcement. If I'm going to install a dedicated breaker, the couple bucks and extra few minutes to install an interlock plate are a no-brainer.
We may go ahead and piggyback the genset port install onto electrical work we're having done in a couple weeks. Even if we plan to eventually get a whole-house unit, going ahead with the port install as part of an already-planned project would be simple, cost-effective, and give us near-term options until we can pop for the more comprehensive setup.
*Edit to add* Kinda eyeballing this. https://www.generac.com/all-products/generators/portable-generators/gp-series/gp15000e
If I've calculated correctly, we would be at roughly 8500w constant draw for pretty much everything in the house (one A/C unit, not both). Add 5000w for the A/C starting draw and a genset rated for 15Kw constant and 22.5Kw start seems more than enough, plus plenty of headroom if I miscalculated. The GP15000 also has a 14-50 plug, not a common item on portables, or so it seems. Combined with the 16 gallon tank and reasonable price, it's a darned attractive solution. I figured about a grand in parts and labor for panel install, so less than $5k total and we still have a generator we can haul around for other needs. Fuel storage would still be a headache but I could come up with something.
Brad
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Steering away from shopping purely by wattage and brand reputation. Dropped my self-imposed requirement of being able to run at least one AC unit and backed off to a few necessities, some basic comforts, and keeping heat flowing for winter possibilities. Revising focus to only inverter units and finding that higher-wattage inverters are a different set of issues. Seems as the inverter genset market is primarily built around portability and sound levels. There are lots of models in the 2000-3000 watt range, but offerings in the 7000w-plus range are much more limited. Cream of the crop is Honda's eu7000i, a fantastic unit with plenty of power, typical Honda reliability, and amazingly precise power output characteristics. Unfortunately its premium quality is matched by a similarly premium price ($4600 street). There are some store-brand units which I don't trust one bit, at least in terms of longevity and reliability.
Then there is Champion. I see the name everywhere but have zero experience with the brand. Anyone here who's dealt with their products? They have an inverter genset that's comparable in power to the Honda, but the HUGE difference in price ($1200 street) makes me leery. I have an inherent distrust of "similar" products which cost 75% less than the benchmark product.
Brad
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Just a random thought, Onan seems to have the RV genset market wrapped up but being in an area where there is a lot of RV snowbirds I see Onan 4k and 5.5K generators for sale on a regular basis. Maybe something you could look into. It should'nt be that hard to adapt for residential use.
bob
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Just a random thought, Onan seems to have the RV genset market wrapped up but being in an area where there is a lot of RV snowbirds I see Onan 4k and 5.5K generators for sale on a regular basis. Maybe something you could look into. It should'nt be that hard to adapt for residential use.
bob
Onan (Cummins) was on the list, but ended up a non-contender because they don't have a 240v-capable inverter genset. That's one of my criteria. 240V makes it easier to set up at the panel. One double-pole breaker and the whole panel gets power. This setup also gets us future-proofed for 50a service. If we do the 240v 30a setup with oversized wire, jumping to 50a is a simple input plug and breaker swap.
Brad
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I did emergency power for years by backfeeding through a 30-amp welder outlet in my main garage. That generator was an old Coleman with a 3-conductor plug. It finally died and I replaced it with a new one, slightly more output, from Harbor Freight. The new one has a 4-conductor, twist-lock receptacle so I bought the matching cable and replaced the welder outlet with a recessed, male receptacle made for the purpose. And it was only then that I realized the inherent danger of doing a backfeed through a normal receptacle:
With a backfeed to any normal receptacle, the plug is male and the prongs are exposed. If you plug in the generator end first and start the generator, you now have a cord with exposed, hot prongs. Not really a good idea. If nothing else, get a proper receptacle and be safe. And, to keep the NEC people happy, look into an interlock for your breaker panel. Have you determined who made the panel? Do you have any unused spaces?
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Panel is CH (Cutler-Hammer, now Eaton). 200 amp with a vertical-throw master breaker. Breakers will be reconfigured so that the genset feed is the 1/3 slots (top left). Has to be that way for interlock function. Feed box will be a proper box with male receptacle. GE and Westinghouse both have 30 amp UL-listed inlet boxes. There are a bunch of cheapo ETL-listed boxes, but no. I want UL and a name I at least recognize. We have an exterior closet that's ostensibly for yard tools but will also make a handy protected area to mount the inlet box out of the weather and away from most critters. It's also less than ten feet from the main panel with nice, open attic space above for install access. Guesstimating $200-$225 in parts plus install. Electrician will be by next week to quote the project addition.
Brad
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Sounds like a plan.
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After doing a bunch of self-education, mostly about plug types and available cabling configurations, I've been able to plan a setup that's actually a bit better in terms physical connection, and a lot better in terms of future-proofing.
I had intended to go with a 30a inlet box and breaker, but wire with 6ga so that the circuit could be converted to 50a if needed. Since 30a and 50a boxes aren't much different in price, I've decided to go with a 50a box and breaker. Wire will be significantly more expensive, but it's a one-shot deal and makes the setup 50a capable right from the start. No "down the road" conversion costs if we ever pop for a 50a genset. Box is a GE T050N. It's not your typical "square box with a hole in the front" type connecter. It's a downward-angled receptacle with a box that has plenty of space for wiring (saw lots of grumbles about limited wiring space in the typical square inlet boxes). It's a skosh thicker than most boxes, but that's the net thickness even when in use. No connector and cable jutting straight out of it when plugged in. The configuration also takes strain off the cable and the box can be closed while in use to provide a bit of extra protection. Iron Box makes a cable just for this application (IBX-6112-25). It's already set up as L14-30P to CS6364 (typical genset 30a/240v connector to typical 50a inlet box connector). No adapter required.
In addition to simplifying generator hookup, the revised configuration gives ridiculous amounts of headroom for 30a service and more solidly future-proofs the overall setup. Should we ever take the dive, all that's required for a 50a genset upgrade will be a new cable. Also, if I ever need high-juice power at the back of the house, the GE box's standard opening means I can easily convert it from power inlet to power outlet by simply changing the insert. Not sure I'd ever need it, but nice to know I can.
Brad
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Brad -
If you can find a reasonably priced DIESEL generator that fits your needs, this might be better. With diesel, you won't use the fuel as quickly nor will you risk it going "bad" the way ethanol-enhanced gasoline does so frequently. You might even be able to mount a 55 gallon drum on a framework to feed the generator directly rather than the tank on the unit.
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Unfortunately a mounted tank isn't an option. I'd love a diesel for the efficiency and reliability, but they are just too darned expensive for what I'm trying to accomplish. Also, I have access to non-oxygenated gasoline so storage isn't an issue. Easy enough to use it in the truck and refill the fuel containers every six months or so to keep the fuel rotated and fresh.
Brad
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How much fuel are you allowed to store in your property? I'm going to guess probably not more than a couple days worth for the generator. My experience that a larger gas generator is going to burn about a gallon of fuel per hour at half load.
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Trying to get a number from the city, but they're in a zoning revamp right now and I gave up trying to find someone who will give me a straight answer. I figure what they don't know won't hurt them, and it wouldn't be more than twenty or thirty gallons anyway. How much exactly is entirely dependent on energy rationing strategies and I'm still mulling those over.
Giving some thought to a hybrid solution... a generator to power the panel combined with a battery-based power unit for fridge and freezer. Something like the Jackery Explorer 1000 or similar. That would give 24/7 power for food storage, firing up the the generator only enough to recharge the power unit or to supply as-needed supplemental power. Using typical demand estimators and a couple of in-use reviews, I figure the 1000 would probably give us a rolling 12 hr schedule (4-6 hrs on battery and 6-8 on generator). The power unit would be handy for day-to-day uses, too. At only 22lbs and relatively small, I can think of a whole host of uses for it. Only downside is price. It's a spendy little sucker.
The probability of losing power more than 48 hours is very, very low so I'm using three days as my spread, including last-resort contingencies to five days in case we're unable to relocate (extremely unlikely for multiple reasons, at least in the context of most-probable scenarios).
This will be set up as a stop-gap, a short term solution. If it's going to be more than that, we have friends and family spread all over Texas, eastern New Mexico, and southern Oklahoma. Plenty of alternate locations. If it comes to it, we'll mothball the house and head to more hospitable environs.
Brad
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I think that National Fire Code only allows up to 25 gallons of fuel in approved containers to be stored at a residential property. Hopefully you have a detached shed away from your house and neighbors houses.
I've been thinking about a whole house generator after I get s new roof and HVAC system. No matter what price out on setting up for a portable 10kw generator, it's still cheaper in the end for a NG stationary 10kw generator to be installed.
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I can have a viable and reasonably full-function short term emergency power setup for around $2k, including the generator. Is it as convenient as an automated whole-house unit? Nope, not by a long shot. However, for the $10k (minimum) difference in cost, I'm willing to live with a few minor inconveniences.
If I were going to setup for longer-term 24/7 power, I could easily adapt to an NG-powered genset and still utilize the generator inlet port I'm having installed. There are tri-fuel gensets available and running an NG hookup to the back of the house would be simple and relatively inexpensive. No real need, though, as the scenarios we'll most likely face are short term. Tornado? Extremely localized. We can relocate. Severe winter weather? Around here that's a couple of days, tops. Even the recent extreme cold spell that had us in such a tailspin only lasted four days. My main concern is grid-wide loss of power, and that will likely be in the dead of summer when energy demand is highest. At that point, my primary focus will be food preservation and comms. I can't justify the expense of an automated whole house unit when I can easily meet that need with a more modest and much less expensive setup.
Would I go full-auto whole house if we could without putting us in a bind? In a heartbeat. However, the $9500 check we just wrote to the IRS pretty much guts our discretionary cash. We have an emergency reserve but it doesn't get touched for something like this.
Brad
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My wife can't even start my baby toro snowblower or lawn tractor and I can be gone from work for several days/nights in a row. I'll need to get an NG automatic whole hmmmm house generator.
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Pulled the trigger.
Champion 8750 Hybrid Inverter Genset (Hybrid in Champion-Speak means an inverter genset in an open-frame configuration)
GE T050N inlet box
Iron Box 30-to-50 cable (IBX-6112-25)
GenInterlock panel interlock kit
The only other main part is cabling between the inlet box and breaker panel. I'll let the electrician provide as part of the install. If all goes to plan he's supposed to be here mid-July.
I figure a simple battery tender to keep things healthy. If I get industrious I might put a quick-disconnect on the battery for storage convenience. Maybe replace the battery every year or two as a preventive maintenance item.
The only other issue still in play is fuel storage. I'm waffling between four 5-gallon race jugs and a single 55 gallon drum (race jugs = no frustrating EPA-mandated hose/spout). Drum would be more fuel, but then there's the hassle of storage location and fuel transfer. Jugs would be easier in terms of handling/storage/fueling but there's the issue of long-term fuel storage in plastic containers.
Brad
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Another option: https://colemans.com/nato-military-jerry-can
Steel can, accepts a variety of nozzles, seals well.
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Another option: https://colemans.com/nato-military-jerry-can
Steel can, accepts a variety of nozzles, seals well.
Thanks!
I wonder how well they can be relied on to not be full of rust.
Brad
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I wonder how well they can be relied on to not be full of rust.
I bought four when they were on sale for $25 each. The outsides had quite a bit of grime but the insides were pristine.
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Can you still get sealing rings for them?
Brad
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Can you still get sealing rings for them?
Yes. The gaskets in mine were good, though.
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How about the aluminum 30 gallon barrels that hold beer? (A "kegger" !)
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How about the aluminum 30 gallon barrels that hold beer? (A "kegger" !)
That's for fueling me, not the generator. =D
Brad
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Decided to bite the bullet and get a couple of Wavian's. Spendy, but I figure it's worth it to not have to worry.
Last of the main parts got here a couple days ago. Only things left are the gas cans and an Amazon-sourced battery tender. Electrician is supposed to install the inlet box end of next week. Short of a break-in cycle for the generator, I should be good to go.
Brad
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The cans arrived yesterday. Purty.
Now waiting for the flex spout. Wavian was out of stock so I ordered two from Bob's Machine... who it turns out was also out of stock but didn't reflect that status on their web page. Bastiges.
Brad
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Finally took the time to unbox the generator and run the break-in cycle. A little noisier than anticipated but otherwise about what I expected. Only had it up to a 1500w sustained load but frequency stayed dead on the whole time. Seems to self-regulate just fine. I'll change the oil tomorrow evening to complete the break-in.
The thing sips fuel. After five hours, about half that under a 1500w load, it used roughly 1.5 gallons. I figure 1000w will be about the average sustained load in actual use so the four gallon tank should easily last 8-10 hrs. More if all we're doing is running lights and fridges. That gives a minimum of two full days on 20 gallons of fuel. Using moderate fuel conservation strategies, we could stretch that to three days. Maybe four. Agressive strategies could extend it to almost a full week.
The jerry cans showed no signs of leaks even after a couple months full of StaBil-laced ethanol free fuel. Took almost two months for the flex spouts to arrive but they finally made it, too. I need to number cans so I can track fuel rotation, but otherwise the fuel situation is good.
The electrician ran into work and health hiccups that put him months behind so no inlet port yet. If his schedule holds, he should be here Weds. I've spent the extra time mapping circuits to breakers and updating panel labeling. That needed to happen regardless because nothing was marked.
Brad
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Forgot to update after the electrician was here. My bad.
Had to relocate two breakers but otherwise uneventful. Conductor was hella expensive but we knew it was going to be. All told, about two hours for the install.
The interlock plate dimensions were a little off and interfered with breaker movement. A few seconds with a grinder fixed that. Once installed, slider plate movement was sloppy enough that it could be forced up and over the master breaker. No bueno because that's the safety feature part. No biggie, though. Two flat washers to eliminate the slop and all is well.
Short of a mains-off test to ensure everything works, I should be all set.
Brad
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Are you using it?
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Nope. Nice, stable power today. Other than a couple of planned runtime sessions it's been sitting in the shop, quietly sipping on the battery maintainer.
Brad
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Second exercise run today. No probs at all. Unhook it from the battery tender, roll outside, turn on fuel, partial choke, and hit the start button. Caught on the first spin. Ran it for an hour with a 1500w load, plus a couple of time with 3000w (finally found my heat gun). Next time I may borrow a couple space heaters and see what happens closer to it's claimed 7000w max sustained load.
Have begun my fuel can rotation, too. Nice to have a station close by which carries ethanol-free fuel. The Wavian flexi spout I got exactly fits the fuel fill door in the truck so it's a no-mess issue to empty the can. A little Sta-Bil and a five minute drive to refill. I even found a rack which perfectly fits a spot directly adjacent the garage door. Now they're inside, off the floor, away from ignition sources, and in a location with sufficient airflow to keep fuel vapors from being an issue.
Brad
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Somehow I missed this thread the whole time it has run. :laugh:
Sounds like you have the setup you want, which is very similar to mine. I did the interlock as well, no permit needed here. My electrician buddy hooked up the interlock and a dedicated plug for my generator at the service box right next to my well house. My setup is that if there's an outage, I hit the interlock, then I manually turn off stuff that the genny can't handle, which for me is the AC/heat pump. It will handle everything else, including the well pump, fine. For the HVAC, it never gets hot enough here that I couldn't live without AC for a while, and for heat, I would just switch to emergency heat and run the propane furnace, which only draws like 1400 watts.
I have an older Champion dual fuel (gasoline/propane) 9KW genset. It does the job, and I test it every month to make sure it starts. It has both electric and backup cord start. But man, it is LOUD. How is your Champion noise-wise Brad?
I've kinda been thinking of getting a second, smaller genny - maybe something like a 3.5kw-ish Honda inverter genset as youtube vids of those show they are quiet. I could use that for longer runtimes for fridges and other stuff, and it would even run the furnace if I watch the other loads, and then if I need big power or else to a couple of times a day fill the well tank, run the bigger one for shorter periods.
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About the same noise level as a typical push-type lawnmower. The generator section seems to make more noise than the engine but it's high frequency and attentuates quickly with distance. Would be nice if it was as whisper-quiet as the little Honda portables but I guess thats the tradeoff for open-frame simplicity.
Brad
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Quick update because I finally found a user-supplied oscilloscope reading buried in an Amazon review.
(https://images-na.ssl-images-amazon.com/images/I/51bCwqrLBqL._SL1600_.jpg)
Good to see it's the nice, clean power I was hoping for.
Full review. Lots of other good technical info in addition to the o-scope data.
https://www.amazon.com/gp/customer-reviews/RJYPALJBXSQMH/ref=cm_cr_getr_d_rvw_ttl?ie=UTF8&ASIN=B07KQ2P49Y
Brad
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Thinking more on this...
Is there any reason I can't simply backfeed the panel through a circuit breaker? By that I mean installing a 14-50 plug somewhere outside that I could plug the generator into, and connecting it to the panel via a simple 50A breaker. If the power fails, I plug the genset into that plug. It would require manually configuring the breakers, sure, but that's as easy as labeling the breakers as "Hey dummy, only these breakers when on gen power!". Simply trip the main panel cutoff, fire up the generator, and re-enable only the breakers feeding designated circuits. It would also allow the use of pretty much any decent genset with 240V capability.
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*Edit to add* After doing some digging, looks like Square D actually makes an interlock setup just for this purpose. Installs directly in the breaker panel and includes a simple mechanism which effectively blocks the backfeed breaker until the main breaker is in the off position. https://www.youtube.com/watch?v=6RG9nfFE7Zw I'll have to check and see what brand our panel is.
There is no reason you can't do what you describe. I've been doing it for years. And there's no need to play with circuit breakers ... just don't turn on the a/c and the electric oven.
As for the interlock -- it's required by the NEC, and there is a company that makes affordable retrofit interlocks for every make and model of panel.
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Quick revisit for a fuel consumption update.
Exercise run today. Uneventful, as always. Open fuel valve, give the float bowl a few seconds to fill, hit Start. Caught on the first spin. Full hour under constant 3000w load, two space heaters and two 16" pedestal fans. Guesstimating fuel use at about three pints.
Brad
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Another quick revisit because I finally did a run-to-empty session. It was mostly to use up the two year old fuel in the onboard tank, but also to see how close my full-tank runtime guesstimates were. With a 300 watt load I got just over of 13 hours before it started sputtering. I tried to give it a 3000 watt load with a couple of space heaters but it was warm enough they kept tripping off on overheat even with fans providing additional airflow. Our max average load will be somewhere just shy of 1000w if we're not running the A/C, maybe 750-ish if I take time to kill a bunch of vampire loads, so I figure a solid 9-10 hours runtime. Reduce by 30-35% if we need A/C to keep anything from overheating.
Fuel stagnation is my main concern. After each regular exercise run I refill the onboard tank from one of the storage cans, empty what's left into the truck, and refill the can with fresh fuel. I have four cans I rotate through so stored fuel is never older than eight or nine months, a year at most. Unfortunately, the generator only uses a couple pints per session so onboard fuel gets ever older over time. There's just not enough fresh fuel being added to keep up. An extended runtime session for tank draining is no biggie, but it's unnecessary runtime hours. Plus, it's just loud enough that I'm concerned an all-day session, or two long sessions over two days, will annoy the neighbors. A simple tank drain would solve the problem. I'm surprised it's not a factory provision since extended storage prep is a common thing.
I've kept it on a battery maintainer and so far no problems, starts right up with no hesitation or indications of a weak battery. Even so, I'll replace it at three years as a preventive maintenance item.
Brad
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Brad - a relative has a Generac 7500E portable that was bought in the summer of 2016. It has a battery starter as well as a pull cord - which has never been used. They use the blue "marine formula" Sta-Bil and they test run it for 10-15 minutes 2-3 times a year. It has only been used 2-3 times in those 7 years and they changed the oil for only the second time a couple of months ago. The battery for the starter has never been changed and it is still working fine.
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Quick revisit because I discovered Champion now has a tri-fuel 9000W inverter model.
https://www.championpowerequipment.com/product/201176-9000w-electric-start-tri-fuel-inverter-with-co-shield/
Output is significantly hobbled on natural gas, but still plenty to keep us in lights, fridges, coffee, and entertainment should power fail. Also has both 14-30 and 14-50 outlets, so plenty flexible for panel hookup. Wish it'd been available three years ago.
Brad