|
| Author |
Message |
Nobadays
Member
|
# Posted: 31 Jan 2023 02:16pm
Reply
The dilemma...
My neighbor has a HF 5 ton, 1.8hp, 12amp, electric log splitter. It worked fine on his large Onan generator before it went kaput. Now neither his or my 4,000 watt, 30amp generators will start it. If you keep bumping the start button sometimes you can get it to go. Once running it works fine. The crazy thing is, I have a nearly identical electric splitter though it is a 7 ton, but the same motor and it starts on both my 3,500 and 4,000 watt generators. It was used and had, had a lot of use so maybe "loosened up?"
I tried replacing the start capacitor for his motor thinking that was the culprit but no love.
Searching around I found a YouTube video showing a simple soft start device using thermistors to... I assume slow the inrush of current allowing the motor to start without killing the generator. In the video he is using an under powered inverter but really the same issue.
Here is a link to the video
I ordered two 25amp thermistors (might be too small?) and will put them in series but they got forwarded to Colorado... I'm in AZ, plus the splitter is up there. Just wanting to see if those of you smarter than me can shed light on this idea!
Thanks!
|
|
rpe
Member
|
# Posted: 31 Jan 2023 03:44pm
Reply
Sounds like you need to adapt a recoil starter to the end of the motor. Strong pull to spin motor, while buddy simultaneously plugs it in to generator! That will drop the starting current requirement considerably. Theoretically you could disconnect the start windings and nasty capacitor completely in that case as you've mechanically biased the motor for correct start direction. Of course adapting a starter recoil to the back of an electric motor isn't so simple though...
|
|
BRADISH
Member
|
# Posted: 3 Feb 2023 02:33pm
Reply
I recently bought a soft starter on amazon for my fridge at the cabin. I'm not smart enough to spec out the particular pieces to build it myself. If you care to hear, I can report back my review when I bring it up there next weekend.
|
|
Nobadays
Member
|
# Posted: 3 Feb 2023 07:17pm - Edited by: Nobadays
Reply
Bradish.... would love to know which one and how it worked! Thanks!
Edit... I found THIS ONE that is rated for 14.7amps continuous. It has a timec lock out to supply mains after a set time that bypasses the thermistors.
|
|
Nobadays
Member
|
# Posted: 3 Feb 2023 07:19pm
Reply
I'm afraid continuously running power through the thermistors will burn them out. I did get them in the mail but it will have to wait until I return to Colorado to try them.
|
|
BRADISH
Member
|
# Posted: 4 Feb 2023 08:19pm
Reply
Quoting: Nobadays Bradish.... would love to know which one and how it worked! Thanks!
This is the one I ordered:
https://www.amazon.com/dp/B07VQ2RZSN?psc=1&ref=ppx_yo2ov_dt_b_product_details
Probably wildly overpriced, but I don't have the know-how to build one myself, nor the time, so it fit the bill for now. Should be able to escape the the cabin next thursday, so I'll let you know how it works.
My goal with it is to stop our lights from flickering everytime the fridge compressor kicks on. Using my Honda 2200, so saying 'flicker' is really underselling it. Its about a 1 second long strobe light party throughout the house every time the fridge kicks on  It's not enough to kill my Samsung TV, but it would trip a cheaper tv I had up there.
So i figure this will hopefully be kinder to all of my electronics.
|
|
Nobadays
Member
|
# Posted: 5 Feb 2023 08:57am
Reply
I saw that one but I'm looking for a cheap solution saw my neighbor can use his log splitter. Not sure he'd want to shell out $140. I will definitely show him that option if the cheap ones don't work.
Thanks!
|
|
travellerw
Member
|
# Posted: 5 Feb 2023 11:26am
Reply
Quoting: Nobadays I'm afraid continuously running power through the thermistors will burn them out. I did get them in the mail but it will have to wait until I return to Colorado to try them.
As long as they are rated for the current, you won't burn them out. Once they hit operating temps the resistance drops to a VERY low value. This essentially removes them from circuit.
I worry more that you might have some other issues starting the motor. It might get stuck on start because there isn't enough "poop" to get it spinning.
|
|
|
Nobadays
Member
|
# Posted: 5 Feb 2023 05:25pm
Reply
Travellerw... thanks!
So if resistance drops to very low shouldn't I be getting near full current through them? I have 2 x 25amp thermiistors that I will solder together in series. The idea is the first heats then passes current through and the other isn't far behind.
I'm guessing the start load is about 36amps where as the operating load is only about 12 amps.
Obviously I'm doing some guessing here! But I like to think of it as a slightly educated guess!
|
|
travellerw
Member
|
# Posted: 5 Feb 2023 08:53pm
Reply
Quoting: Nobadays So if resistance drops to very low shouldn't I be getting near full current through them? I have 2 x 25amp thermiistors that I will solder together in series. The idea is the first heats then passes current through and the other isn't far behind.
That is correct. They take a very short amount of time to come up to temp (like miliseconds), slowing the inrush. However at that point are pretty much just a wire.
2 in series will increase time for starting (more of a soft start). 2 in parallel will mean you can have a higher starting current, but shorter starting time.
They are great devices, but not really awesome for heavy motors or motors with a heavy hydraulic load. Those devices need that big kick to get the motor started spinning. The spike can be HUGE.. Like 60-150A (seriously). Of course its only for a few miliseconds, but yes that big!
My fingers are crossed.. but I think 1 of 2 things will happen. The motor won't start... Or the thermisters will burn out due to the huge inrush!
|
|
Nobadays
Member
|
# Posted: 6 Feb 2023 08:34am
Reply
Quoting: travellerw My fingers are crossed.. but I think 1 of 2 things will happen. The motor won't start... Or the thermisters will burn out due to the huge inrush!
Thanks for the explanation! Guessing again.... the 30amp generators will "almost" start the splitter. If I bump the button a few times it will often take off. So thinking the in rush is somewhere in the 30-40amp range, just over what the generators can handle.
My fingers are crossed as well, but the experiment is worth the $7.00 I paid for the thermistors!
|
|
groingo
Member
|
# Posted: 6 Feb 2023 09:12pm
Reply
Had a similar issues with my fridge, problem vanished when I ran it via a Pure Sine Wave Inverter.
|
|
toyota_mdt_tech
Member
|
# Posted: 7 Feb 2023 08:02am
Reply
Ok, when you say it wont go, is it popping a fuse or just stalls and hums?
OK, start capacitor was a good move, I assume the can for the cap was metal, if not, it was a run cap. Does it have a motor run cap (plastic can?) Could the centrifigual switch at the end opposite of drive end be hung up in the run spot not giving it enough power to start easily, but run OK?
Other options, windings (magnet wire) got warm and shorted to itself.
A new electric motor would be an easy deal to do, look at frame number type, HP and good to go.
|
|
Nobadays
Member
|
# Posted: 7 Feb 2023 09:43am
Reply
Toyota....
If I just push and hold the start/on-off button it will kill the generator. No buzzing or humming I can hear from the motor but then a generator is running a few feet away. This is a nearly new HF 5 ton splitter that ran fine on a larger Onan generator, I think it was 5,000 watt? Not sure as it isn't mine.
The crazy thing is I have a nearly identical splitter, 7 ton, but the motor looks to be the same... didn't check specs. My 3,500 and 4,000 watt generators will both start and run my splitter. If it is cold, i.e. hydraulic oil cold, it will some time not start but normally it fires right up.
Plastic capacitor... motor turns freely and there is no switch opposite the drive end, just fan blades.
I doubt there is anything wrong with the motor as it is nearly new. It may have split 1/2 cord of wood... at the most.
|
|
gcrank1
Member
|
# Posted: 7 Feb 2023 10:47am
Reply
Dont not assume anything about that set up vs yours; fact is yours works and this one doesnt so something is different.
Maybe change the hydraulic fluid?
Could swap your motor in to see what happens?
|
|
Nobadays
Member
|
# Posted: 7 Feb 2023 01:17pm
Reply
Gcrank1... true dat! I'm just trying to figure out a sot start method that doesn't cost too much. Not about to go swapping motors, I have PLENTY of projects to keep me busy!
Not my splitter so no skin off my b#tt, that said I want to help my neighbor.
|
|
BRADISH
Member
|
# Posted: 10 Feb 2023 03:00am
Reply
Well I got to the cabin tonight and as promised here is my report.
The soft start worked so well I thought the fridge didn't run for hours while I was running around warming things up. it was a brisk 8°F when we arrived. I assumed the fridge was already below it's set temp and didn't need to run. Once we got up to habitable temps, I decided to mess around with it further. Lights turned on just fine, so I knew power was passing through. Freezer plate felt specifically cold, but never did notice it turn on. After dinner I decided I better dig into it further as I was nervous it may have fried the motor or something. Went to go investigate and realized it was currently running! Pleasant surprise.
So anyways, it seems to work fantastic. No strobe light show on the cabin lights, and even removed the audible knock when it turned on. Only way to notice it running is to stand nearby and listen. So despite the high price, I am a big fan.
I don't have any fancy tools, or knowledge on how to figure out what it's drawing, but I am a big fan already.
Best of luck in your build!
|
|
Nobadays
Member
|
# Posted: 10 Feb 2023 09:22am
Reply
Thanks for the report!
I'll let my neighbor know what likely will work if my cheap fix fails. Now gotta get it built and then wait until Apr/May when we return to the cabin to try it.
|
|
|
