Interested in being able to use generator to power hangar door. Have 40' x 12' bi-fold door with 1 hp motor at 115 volt. Motor data plate says 13.4 amp draw. Have tried Honda 3000is generator, and it bogs down, and won't open the door. Generator is rated at 23.3 amps. Understand that motors have an initial current demand when starting, and am wondering if this is the problem. Any thoughts on if the 3000is should work for this application, and maybe the generator needs service; or maybe a larger generator is needed to overcome the initial surge?
Generator for hangar door
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Capt. Geoffrey Thorpe
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Light and Sporty Guy
Honda claims that it will run motors such as furnaces and air conditioners.
Silly question - are you using an extension cord?
Silly question - are you using an extension cord?
That motor is likely trying to suck 30-40 amps on startup and that genset advertises 25 amp burst capacity, 23.3 steady state. So I think that's your problem.
There are a number of load calculators online to determine this. A quick check on one shows you need 4.8kw generator to run the motor which includes startup surge. Plenty of cheap 5kw generators out there which could also run an air compressor and anything else you may need.
172andyou is conservative in his initial current draw for an induction motor, particularly for a start under load application such as your door.
Your motor is starting with its maximum load, initial acceleration of the mass of the door, while at zero RPM, and dropping to the friction and increased energy of position as the door goes up and the motor has reached its most efficient speed..
I would not be surprised at a starting current draw of twice the running draw.
The generator has also the requirement of running at near idle throttle and no load, to full throttle, in less than a second, and any hiccup in reaching full throttle will result in a bog down failure. Small generators rarely have an adequate flywheel to deliver stored energy for this transition. Temporary reduced RPM and frequency increases the inrush current, further overloading the generator.
Consider renting a 5KW, and see if it will do the job, and if good enough buy the same make and model, or another which has about the same shipping weight. Weight matters in small generators.
Quality fixed emergency generators often have a flywheel that weighs as much as the engine and generator combined, to assure that initial load application does not cause slowdown problems. This is not practical for portable units.
Your motor is starting with its maximum load, initial acceleration of the mass of the door, while at zero RPM, and dropping to the friction and increased energy of position as the door goes up and the motor has reached its most efficient speed..
I would not be surprised at a starting current draw of twice the running draw.
The generator has also the requirement of running at near idle throttle and no load, to full throttle, in less than a second, and any hiccup in reaching full throttle will result in a bog down failure. Small generators rarely have an adequate flywheel to deliver stored energy for this transition. Temporary reduced RPM and frequency increases the inrush current, further overloading the generator.
Consider renting a 5KW, and see if it will do the job, and if good enough buy the same make and model, or another which has about the same shipping weight. Weight matters in small generators.
Quality fixed emergency generators often have a flywheel that weighs as much as the engine and generator combined, to assure that initial load application does not cause slowdown problems. This is not practical for portable units.
Craig
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You could also use a clamp on current meter and see what the starting current is when powered by the normal wall circuit.
Salty has the right answer in generic terms.
Testing with wall power does not measure the throttle reaction delay or reduced frequency current increase.
Those speed changes and reduced frequency conditions can swiftly destroy your motor. The may also damage the generator.
Testing with a larger generator, shut down the door motor if there is any delay in coming up to speed. This is why I recommend renting, as you have a minor investment before you find the right size generator.
Testing with wall power does not measure the throttle reaction delay or reduced frequency current increase.
Those speed changes and reduced frequency conditions can swiftly destroy your motor. The may also damage the generator.
Testing with a larger generator, shut down the door motor if there is any delay in coming up to speed. This is why I recommend renting, as you have a minor investment before you find the right size generator.
Concur. I picked up this one recently when doing a whole house energy audit for a backup battery, happy with the cost and results.
Lindberg
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To be effective, you have to be able to clamp it on only the hot leg going to the motor. That might mean opening your control or breaker panel.
Daleandee
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That was my thought when I began reading the thread. What size? I dunno ...
Gary Ward
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Do they have hangar doors that can be put up with chain on a pulley to be able to open or close them with no power?
I rent a shop with 14'X14' door that has chain pulley to use when the power is off like when I moved in before I opened a account with Duke.
My rented T hangar the power goes out pretty often when it is storming out. I learned I better get that door closed in case the storm killed the power which happens pretty often.
I rent a shop with 14'X14' door that has chain pulley to use when the power is off like when I moved in before I opened a account with Duke.
My rented T hangar the power goes out pretty often when it is storming out. I learned I better get that door closed in case the storm killed the power which happens pretty often.
Let'sgoflying!
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No easy way to re-gear the door mechanism? Slower lift but less torque?
Is there no power at your hangar? I'm curious what it costs to Open/Closes the doors (twice for days you go flying) to use the electricity?
Then what's the cost of the generator + fuel + any maintenance on the generator? I get that you can amortize the generator over a number of years. But is it still worth it to go that way?
And I'm assuming you're taking the Generator outside to start and then running a heavy duty wire/extension cord into the door motor? That can get to be a pain.
Then what's the cost of the generator + fuel + any maintenance on the generator? I get that you can amortize the generator over a number of years. But is it still worth it to go that way?
And I'm assuming you're taking the Generator outside to start and then running a heavy duty wire/extension cord into the door motor? That can get to be a pain.
Good question. Hangar has electric power, sufficient to run the hangar door system. Very heavy cord runs from motor to plug, and plugs into typical 20A plug circuit. However, power has been a bit fickle here. A lot of big infrastructure construction in the area with lots of excavation and utility work on expanding roadway arterial, and storms can sneak up, while out on a fly about. If power is lost, upon return to the hangar I would be unable to open the door to put airplane away. This would be especially concerning if a storm is approaching. As such, a generator would be a"back up" source that I could use to raise the door, and also run important appliances using extension cords on temporary basis (ie, won't connect generator to home electric system). Kind of a dual purpose generator.
Oh, yeah. With that in mind if there was any way to do a manual system, that's the way I'd do it. But I'm cheap. Even if I ended up using the genset to power the door a hundred times, that's still like $40 bucks a time. I'd pull on a chain before I paid that!
Most industrial generators have permanent magnet exciters rated about 300% kVA for motor starting duty. That said the kW rating needs to be at least 3x the HP rating of the motor. You have that, but I doubt you have a PME, so the short circuit capability will be greatly reduced, perhaps as little as 125%. You will likely need a 5-6 kW generator to start it. I've seen motors draw 6x the current at 1/2 the voltage on initial spin up. Large motor circuit breakers often have a short time curves set to trip at 6x at 1 second.
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Jim
I don't know beans about generators, but I know my sister bought one "for peace of mind" after her power went out for several days a few years ago. Now I'm constantly hearing about her maintenance work on it: Periodically draining / refilling gas in the generator itself and in her emergency stockpile, cranking it for test runs, breaking her back hauling it in and out of its storage nook, etc. There has not yet been another power outage where it has come in handy. I question just how much "peace" she's getting out of that decision.
Maybe using avgas helps with the fuel going "stale", and you wouldn't be stockpiling fuel like my sister for extended runtime, but I wonder if there might still be other work required to keep that generator ready for use that makes it more trouble than it's worth, compared to occasional-use manual solutions.
Maybe using avgas helps with the fuel going "stale", and you wouldn't be stockpiling fuel like my sister for extended runtime, but I wonder if there might still be other work required to keep that generator ready for use that makes it more trouble than it's worth, compared to occasional-use manual solutions.
When I did my house testing I just built up a short pigtail with exposed single insulated wire for each leg and a male and female cord end.
More good ideas. The hangar door is a "Hi-Fold" and uses a 1-hp motor, with worm gear, driving gears in a gear box, driving chains, driving a large pipe that rolls 4 cables, and lifts the door. Would be difficult to make a manual system. But the battery idea is intriguing. A huge 6000W inverter came with the hangar, along with 12 large lead/acid batteries, and a few old broken solar panels. But the batteries are old and dead. Maybe acquisition of a lithium or deep discharge type battery to drive the inverter, and then a charger driven by the house/gen set to keep the battery topped - as noted in post #24. Will give this idea some added thought. The inverter could deliver up to 50A at 120 volts. Will have to consider how long it takes to raise and lower the door, and efficiency of inverter, to get some idea of energy storage required for the battery. Or a larger gen set (about 5Kw) seems to be another option.
Roller
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Is the motor itself AC or DC?
Motor data plate shows 115 VAC at 13.4 amps (running). Inverter is an old 12 V model that delivers 6000 W at 110 VAC, and weighs 30 lbs. User manual says modified sine wave output, with 12000 W surge capacity. May try connecting to my car 12 V battery just to see if it works. One concern is the post that indicates door manufacturer advises against using generator for the hangar door. Contacted the manufacturer using email a few days ago, and have not heard a reply to my inquiry about using a generator. Might be that no answer is a way of saying "no generator"??
GoFly
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Having a set of batteries and an inverter already there is a huge hint to me. Some of the electrical engineer folks on here can help you size batteries properly, but it sounds like you may already have the solution in place
AV8R_87
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Avgas is not compatible with (semi)synthetic oils, so it would have yo be run on straight mineral. Also, the jets might make it run too rich, with lead fouling being a potential issue. Not sure on valve guide clearance and how lead might affect that.
AKA square wave and not great for motors. Not my first choice.
Is there any exposed motor shaft? That's where you could attach a pulley for manual or small/slow DC motor operation.
If using a generator, here's what you could do. There are modern generators that have AVRs (Automatic Voltage Regulators), and older ones without one, labeled as "Brushless".
A brushless generator outputs a voltage proportional to RPM, so by adjusting the governor to a lower RPM you will get lower voltage and frequency. You'll find those generators in the cheap 2-stroke 900W units that Harbor Freight used to sell. Disconnect the governor, set a fast (1200 RPM) idle and then engage the motor. Slowly bring the RPM up and you might be able to slowly open the door at about 80-90 volts. Remember, power drops with the square of the voltage, so at 60 volts your 1hp motor (750W) would only pull 200W or so continous.
On an AVR generator, you'd have to do some electrical surgery and bypass the AVR to adjust the output voltage. That's a bit too complex for general use, but not impossible.
A capacitor in series with the motor might work, but I would need a picture of the dataplate and maybe a few other measurements before I could even recommend you a value.
Roller
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This is one of the reasons I’m a fan of diesel generators, some good mil surplus ones that can be converted for a house, they can also run more fuels, including some heating oils that you might already have
Dude, with that much legacy hardware, run over to DIYSolarForum.com and start asking questions about how to fulfill your needs. I bet you can solve the problem fairly cheaply.
Yeah, I didn’t really give much thought to the inverter / battery idea, until the post from @Roller. The old batteries are dead. The old solar panels are in bad shape and were taken down. But the inverter may be salvagable. Given the system had a basis in solar, I’ll check the DIYSolarForum to see what I can learn. No real interest in solar, but I may be able to use the inverter and maintain the battery(s) using power and/or gen set, as mentioned by Roller. Another item I’ll try to check into is the square wave, and implications for the motor. The inverter is pretty old (circa 2008, PowerBright PW6000-12), and don’t want to damage the motor with old technology.
AV8R_87
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As I asked above, do you have any part of the motor shaft accessible? If yes, you can use a 12V windshield wiper motor to drive it at slow speed (with some suitable reduction, if needed) and save yourself the trouble of dealing with the batteries.
Also, if you're going to use the inverter, don't bother with the batteries. You have a car, right? Connect the inverter to your car's battery. Even with the engine off, it will have enough juice to open/close the door.
Also, if you're going to use the inverter, don't bother with the batteries. You have a car, right? Connect the inverter to your car's battery. Even with the engine off, it will have enough juice to open/close the door.
SoCal 182 Driver
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FWIW, Harbor Freight often sells generators that have been returned by customers at a steep discount. There's no website, so it's a matter of finding one that suits your needs at your local store. They're definitely not the quality of a Honda, but for what sounds like occasional use, you might be able to find one big enough to handle the initial draw without bogging down. IIRC, there's a three-day return window for resale generators, so you would be able to try it and if it didn't suit your needs, return it within that window.
YMMV. HTH.
YMMV. HTH.
brien23
Pattern Altitude
1/8 | 275 | 400 | 600 | 850 |
1/4 | 400 | 500 | 850 | 1050 |
1/3 | 450 | 600 | 975 | 1350 |
1/2 | 600 | 750 | 1300 | 1800 |
3/4 | 850 | 1000 | 1900 | 2600 |
1 | 1000 | 1250 | 2300 | 3000 |
1-1/2 | 1600 | 1750 | 3200 | 4200 |
2 | 2000 | 2350 | 3900 | 5100 |
3** | 3000 | 3550 | 5200 | 6800 |
** Motors of higher HP are not generally used. |
[td]
Approximate Running Watts
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Universal Motors Small Appliance
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Reduction Induction Motors
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Capacitor Motors
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Update: I set up the PowerBright PW6000-12, and connected it to my car battery. While car engine running, the inverter voltage showed 14 volts DC input. I switched on the door lift system, and the door motor didn't do anything. The inverter voltage dropped to 10.0, and switched off in a matter of a quarter second. Apparently the DC current draw is so great that the car battery and generator couldn't keep up with the demand. I'm beginning the process of DIYSolarForum to gather input on the size of battery pack I would need to provide the current needed. Also, considering the idea of a returned Harbor Freight gen set, about 5 or 6 KW to try this option.
AV8R_87
Cleared for Takeoff
3000W or so surge power on start-up, add 20% inverter losses and you're looking at about 250 amps on the 12V side.
You need short cables and very good connections to the battery. No battery clamps, you need a solid connection.
It only takes 0.016 ohms to drop 4 volts (from 14V nominal with the engine running to the 10V at which the inverter cuts off) at 250A.
You need short cables and very good connections to the battery. No battery clamps, you need a solid connection.
It only takes 0.016 ohms to drop 4 volts (from 14V nominal with the engine running to the 10V at which the inverter cuts off) at 250A.
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Just put Stabl in the tank. It will last six months.
SoCal 182 Driver
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How much money are you looking to spend on this project?
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So you want to use this generator just at the hangar? I assume you can get into the hangar without opening the hangar door. You're going to store this generator at the hangar all the time just in case power goes out?
You're going to also have to add a transfer switch to the circuit you're plugging the generator into so you don't electrify the line and electrocute someone working on it. Or try and power everyone else who might be on the panel the circuit is on, the line feeding that panel, etc etc etc.
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