Electrical Question

You really do need to find a local expert to help you with this, but here are a few of the sort of questions they will need to research on your proposal.

Firstly: What is the total storage capacity of the battery set? This is so that while the compressor is going through a run cycle, there will be enough available "power" to complete the fill cycle.

Next: What is the "inrush" current/power for your compressor to start? They might be able to determine this from the manufacturer's name plate.

Next: I'm already presuming that your inverter is large enough to actually run the compressor.

Next: Is the need to have enough solar collection to re-charge the battery set in each cycle over the day. In rough terms over the day you need to be able to collect more power (Efficiency of converters/inverters/chargers etc ) than the total amount to be used. Eg a 1kW system will only collect 8kWh over 8 hours (perfect alignment and such), If the compressor is drawing 4kw and running 30 minutes per hour it will not work. Your not topping up the tank as quick as you are draining it.

Your compressor probably already has capacitor start, so that might be an exotic experiment that gives you nothing. Your local expert might be able to determine how much power the motor would use if running "unloaded" so that you do not need to start the motor each cycle.

Good luck.

Oh, by the way, welcome to CR4.

Solar panels.. not panel

It may not be a good idea because of how long the compressor will be running but maybe more info would help or it may still be useless.

Battery:

https://www.princessauto.com/en/detail/8d-commercial-battery/A-p8620171e

Capacitor:

https://www.ebay.ca/i/392021659354?chn=ps&dispItem=1&ul_ref=https%253A%252F%252Frover.ebay.com%252Frover%252F1%252F706-89093-2056-0%252F2%253Fmpre%253Dhttps%25253A%25252F%25252Fwww.ebay.ca%25252Fi%25252F392021659354%25253Fchn%25253Dps%252526dispItem%25253D1%2526itemid%253D392021659354%2526targetid%253D296570367735%2526device%253Dm%2526adtype%253Dpla%2526googleloc%253D9000864%2526poi%253D%2526campaignid%253D798988068%2526adgroupid%253D47089348212%2526rlsatarget%253Dpla-296570367735%2526abcId%253D1063836%2526merchantid%253D116255371%2526gclid%253DCjwKCAjwkrrbBRB9EiwAhlN8_C5Etoap2rj7u0ZlkBFvORigjy3EF0rLPV1G2Mf1uVn_iouI_TYrvhoCeOUQAvD_BwE%2526srcrot%253D706-89093-2056-0%2526rvr_id%253D1628383640832%2526rvr_ts%253D292137ab1650a99c1501bb92fff684af

Inverter:

http://www.canadiantire.ca/en/pdp/motomaster-eliminator-power-inverter-with-bonus-cables-3000w-1999930p.html

And I was thinking of also using a battery charger with the solar panel but it kind of defeats the purpose unless I can charge it over night and have it run all day slowly being recharged by the solar panel(s)

Charger:

http://www.canadiantire.ca/en/pdp/dewalt-30a-battery-charger-with-80a-engine-start-0111922p.html#srp

Also I forgot, this is the compressor I would like to run, but I could probably go smaller if it would make the battery last longer

https://www.homedepot.ca/en/home/p.15-continuous-hp-568l-200-psi-compact-workshop-air-compressor.1000529113.html

That solar power kit seems like overkill to me. And i have gas powered air compressors so I don't really need a generator.

The problem is my guys will leave the gas compressor running all day rather than turn it off every time they take a break or have to do something that doesn't require the nail gun. I only need the compressor to run when they are nailing which isn't steady for 8 hours a day. If I had to guess I would say the compressor would actually run for a total of 3 hours of a 10 hour work day. But kicks in to refill the tank like 100 times. My goal here is to stop wasting money on gas in a compressor that's used only half of the time it's running. Also to save money by running a compressor off grid and reducing carbon output at the same time.

I never knew those existed. Thank you.

Though they are pretty expensive. And still cost money for gas over time. Also I wonder if it uses more gas to turn back on and fill up than if it were already running.. Maybe that's why these are not as popular as ones that stay on?

I think the best option for me is to use the electric compressor on site where there is power and use the gas compressor when there is no power available. Should help save a little money in the long run

Yeah plugging into somebody else’s electric is always going to be cheaper...

I think originally what I really wanted to know - besides the solar power requirements which doesn't seem worth it - is if using a capacitor between the battery and compressor would help save the battery from being damaged because of the large draw in power.

What if my set up was more like this.. (since I always pop breakers on the average home)

Shore line --> Battery charger --> Battery --> Capacitor --> Inverter --> Compressor / Mini-fridge / lights / power tool battery chargers / alarm / etc.

then have my generator for back-up if there is no shore line.

Your compressor should already have a start capacitor, most all compressors have start capacitors as part of the system....that's those Mickey Mouse ears on the motor...Circuit breakers have a time delay built in to accommodate starting motors, if you are tripping breakers you are drawing overamps for an extended period of time, or you have a weak breaker that needs to be changed out...

Sounds like you're plugging in to 15amp circuits, when you need 20amp...Have you checked the amp draw on your compressor? Should be a FLA (full load amps) rating on the electrical tag on the unit....

If the compressor is toggling often when not in use, it may be that the system has some leaks. I also wonder if the refill pressure is set too close to the full tank pressure and it's topping off often in short bursts.

....oh, and by the way, you'll still need the generator as a backup if you go with the solar system....

IMO forget the capacitor... the battery itself is better than any capacitor as a low impedance source.
A capacitor is just something else to go wrong.
Keep it simple.
Keep the low voltage and high voltage sides nicely separated and isolated. Match the solar panels (with fuse and isolator) to the battery. Run the inverter from the battery suitably fused and isolated.
Del

I'd have to go with the cordless idea in reply#3. Compressed air as a power source is very inefficient; use it only when absolutely necessary. Cordless power is more direct with much less losses.

My solar-power setup included a home-made 12v charger from a lawn-mower engine driving a car alternator. You could use more than one alternator on one engine. That way, you could get substantial on-demand available power, with the batteries buffering the over-demand periods while continuously charging the batteries for the next over-demand period. Once the power-draw is over, and the charge-demand is near the solar capacity, you could turn off the alternators' engine at let the solar panels top-off the batteries.

The cordless guns that I was referring to in number three only use battery power to ignite a gas charge from a cartridge in the gun to create the driving force and for a small cooling fan.

The Paslode brand that I am familiar with will drive around 1000 nails from one cartridge and about 3 times as many on one battery charge.

For framing they are far superior to air driven devices and no hoses to drag around or trip over or have to pack up afterwards.

For fast work such as flooring or cladding they may be a little slow for some operators as they recommend firing only about 2 shots per second.

"...gas charge from a cartridge in the gun to create the driving force" I realize that, but it's still a better idea. I only added the solar/alternator system as an alternative, just in case. I guess I could have worded it better, but I don't like typing. Sorry.

You are overestimating the power available from the sun, especially if you're just trying to save some gasoline. The capacitor is a bad idea, and adds to the cost for no return on investment (ROI). Most fixed frequency static inverters are not very good at handling the highly inductive starting currents of a motor that are near its overload limit, and will self-destruct after too many 6.5 times rated current overloads. You could try a VFD (Variable Frequency Drive) which basically slowly ramps up the power to the motor, but they're expensive.

You already have all you need for either electric or gasoline operation, why throw all that extra money at something that may never return your investment in it?

The output of the inverter is a pseudo sine wave made up of small pulses of DC coming out of high speed transistors that when put together in strings of varying pulse and gap durations, approximates an AC output. Putting a capacitor on the output is like putting a bomb on it as far as those transistors are concerned. Capacitors charge and discharge almost instantly and the charging current is pulled into them at the maximum available current rate. But pulling current through the transistors that fast exceeds there capacity to handle that and the little layers of silicon inside of them that facilitate their functionality will eventually break down, rendering them useless. At the same time, the capacitors, which like nice smooth AC sine waves, will absorb the harmonics created in that inverter pseudo sine wave, which will over heat them until their internal components break down. So basically it’s a race to the bottom to see who fails first, the transistors in the inverter or the capacitors.

You can get away with the capacitors built into the single phase motor because they are only on for a second when the motor is first starting, and they are in series with an inductor (the motor windings) which mitigates these issues. Adding your own capacitors outside will do nothing but harm.

I have read the previous replies. Your implementation is marginal depending on the compressor load. I believe that it will work however. There is a better supercap for your application https://www.digikey.com/product-detail/en/maxwell-technologies-inc/BMOD0058-E016-B02/1182-1027-ND/3079291, this device is designed to handle starter loads in auto applications.

Be sure to regulate the charging voltage maximum from the solar panels.

Good luck!

2Hp, 1500W 14A@110V 180A@12V. A typical storage battery is rated about 100AH. Your battery would take a damaging discharge after < 1/2 hour. You should size the solar panels for the 1500W average motor draw and use the battery/capacitor combo for startup of the compressor only. 1500W is a lot of solar panels.

Lithium storage batteries are available, they have higher maximum currents for the same storage size. They are also very pricey.

Lithium batteries have a longer life under severe duty such as your application.

Acid batteries are damaged every time they go below about 80% charge its about the worst technology for a storage battery ever devised, they are cheap to make.