EcoRenovator  

Go Back   EcoRenovator > Improvements > Renovations & New Construction
Advanced Search
 


Blog 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
Thread Tools Display Modes
Old 01-12-16, 08:34 PM   #21
ToddT
Lurking Renovator
 
Join Date: Jan 2014
Location: Arkansas
Posts: 9
Thanks: 9
Thanked 0 Times in 0 Posts
Default

I'd like to add a couple of tips for long term generator operation. I run my small business off the grid, mostly on renewable energy. I was running a diesel generator on biofuels and it had a 30 gallon fuel tank. That runs for days and days! But for now am having to use different gasoline generators. One has a 6 gallon fuel tank. Not bad, able to pour a full 5-gal can of gasoline in there without fear of overflow. Now I'm using a smaller one and the tank must be less than four gallons. Having to watch the fuel level is a drag.

I'm a stickler for filtration and heartily recommend the Mr. Funnel fuel filter. It has a filter element that I believe goes down to 30 micron (not quite as good as an oil filter but still worthwhile) plus a sump to catch any water.

For the gasoline generators, I'm thinking of setting up a gravity feed system. Using a universal low pressure fuel pump, I'll draw out of an old car fuel tank and pump through a filter and up to a small tank positioned slightly higher than the generator. I repurposed a stainless steel tank from an oil-fired hot water pressure washer. It has a drain on the bottom as well as a drain on the side. The bottom goes to the carb on the generator and the side port goes back to the fuel tank as an overflow. This way, there won't be any more gravity fuel pressure on the carb than regular. It also gives a way to continuously polish the fuel with a good 6 micron spin on fuel filter. Again, a stickler for filtration!

Attached Thumbnails
Click image for larger version

Name:	Mr Funnel.jpg
Views:	788
Size:	9.5 KB
ID:	6508   Click image for larger version

Name:	fuel pump.jpg
Views:	762
Size:	165.9 KB
ID:	6509  
ToddT is offline   Reply With Quote
Old 01-13-16, 02:30 AM   #22
WyrTwister
Master EcoRenovator
 
Join Date: Jun 2013
Location: USA
Posts: 543
Thanks: 6
Thanked 44 Times in 38 Posts
Default

https://www.johnstonesupply.com/stor...ep?pID=B18-842

https://www.johnstonesupply.com/stor...ep?pID=B18-843

Have not tried these . So no personal experience . I have wired / installed 3 phase soft starts & VFD's .

My cost on either of these is $ 235.00 .

You can probably google search soft starts for more information .

God bless
Wyr
WyrTwister is offline   Reply With Quote
Old 01-13-16, 07:46 AM   #23
stevehull
Steve Hull
 
Join Date: Dec 2012
Location: hilly, tree covered Arcadia, OK USA
Posts: 826
Thanks: 241
Thanked 165 Times in 123 Posts
Default

It is my understanding that "softstarts" reduce the initial current peak (6-7 times nominal running current) from a few msec to a couple hundred msec. By spreading out the starting load/torque, the peak current is reduced, the undervoltage minimized and electric motor/compressor is less stressed both electrically and mechanically.

This could be a very good item to add to a deep well submersible water pump.

What I don't know is the amps x time characteristic of deep well pumps vs a standard above grade compressor/electric motor.

I do see a softstart on the geothermal units I have here and the start up voltage drop is much reduced as there is little start up "blink" observed on house lights (compared to a unit with no softstart).

My clamp on current meter only tells me peak current or steady state current - not the time issue. I suppose I could drag out my storage oscilloscope to the pump house and look at starting current with a limiting resistor to get the time duration of this start up current surge.

Again, the issue is supplying the well pump with generator power during grid power loss. Even though the start current is only a fraction of the run current, I have observed what happens when the generator is not large enough to supply start up pump current.

During a former power outage (spring storms), my neighbor burned out his deep well pump by having a generator that was big enough to supply running steady state current, but not the starting peak current. In addition to being out of power, he was then out of water.

He was using a small Honda (~1.5 kW) generator only to the well pump (1 HP). At pump start up, the pump house electric light bulb would noticeably dim for 8-10 seconds and the generator slowed considerably. Then, the generator would speed up, the light brightened and he had water. Then, about two days later, the pump died while on this generator. When we pulled it and did the tear down necropsy, the motor windings appeared burned. My belief was that this repeated starting high current and low voltage fried his pump (caused by the too small generator).

Of course, this could just be coincidence, but the pump was only three years old.

I clearly want to avoid that situation . . . That is why I have been using larger PTO generators and running through lots of fuel.

Bottom line - do you think that a softstart would be beneficial for the water pump when running on emergency power?. $235 is a lot for just a "look see". Maybe it would also extend water pump life . . .

Steve
__________________
consulting on geothermal heating/cooling & rational energy use since 1990
stevehull is offline   Reply With Quote
Old 01-13-16, 07:55 AM   #24
simenad
Lurking Renovator
 
Join Date: Jan 2014
Location: Ottawa
Posts: 11
Thanks: 1
Thanked 0 Times in 0 Posts
Default

soft starts use older large capacitors of about 1 farad but new super/ultra capacitors have about 350 farads at 2.7 volts in the size of a d cell battery so they can run support loads for longer periods.

simenad is offline   Reply With Quote
Old 01-13-16, 08:20 AM   #25
WyrTwister
Master EcoRenovator
 
Join Date: Jun 2013
Location: USA
Posts: 543
Thanks: 6
Thanked 44 Times in 38 Posts
Default

The time from the initial application of voltage , to full motor speed is known as ramp up . The 3 phase soft starts & VFD's I have been involved with , ramp up was adjustable / user set-able . Do not know about the small single phase units ?

I do not know but just a tiny bit about single phase submersible pumps . I know they have a " box " with a start capacitor and maybe a run capacitor ? And a relay that I think switches the start windings out of the circuit when the the motor reaches full speed .

Are the bearings or seals on submersible pumps " cooled " or " lubricated " by the water . When I worked maintenance , we had hot water pumps and chill water pumps in which the seals were water lubricated & maybe cooled ?

Where I am going with this line of question , is , would ramping up have a negative effect on the pump ? I doubt it would harm the electric motor .

Should you seriously consider this , I recommend you ask the vendor for recommendations as to your application .

God bless
Wyr
WyrTwister is offline   Reply With Quote
Old 01-13-16, 11:45 AM   #26
oil pan 4
Land owner
 
Join Date: Nov 2012
Location: NM
Posts: 1,026
Thanks: 12
Thanked 127 Times in 107 Posts
Default

You don't want to run VFD on single phase.
Typically for high starting torque motors you use capacitor start. Capacitor start uses a mechanical centrifuge to turn the start circuit on and off. During run up the start circuit does not cut out until the motor is almost at operating speed.
If the motor runs for more than 5 or 10 seconds with the start circuit powered up it will fry something in the start circuit, usually the capacitor or the windings.
If you drop the motor speed down too low the start system will reengage, frying the starter.

This is why industrial pumps are pretty much always use 3 phase inverter duty rated motors connected to VFDs. The motors and what ever they drive can be soft started and ran at variable speed, usually any speed between 20hz and 60hz. Some VFDs can produce 100hz.
You can get a 3 phase VFD that can be powered single phase 240vac power.
oil pan 4 is offline   Reply With Quote
Old 01-13-16, 11:51 AM   #27
oil pan 4
Land owner
 
Join Date: Nov 2012
Location: NM
Posts: 1,026
Thanks: 12
Thanked 127 Times in 107 Posts
Default

Quote:
Originally Posted by stevehull View Post
using a small Honda (~1.5 kW) generator only to the well pump (1 HP). At pump start up, the pump house electric light bulb would noticeably dim for 8-10 seconds and the generator slowed considerably. Then, the generator would speed up, the light brightened and he had water. Then, about two days later, the pump died while on this generator. When we pulled it and did the tear down necropsy, the motor windings appeared burned. My belief was that this repeated starting high current and low voltage fried his pump (caused by the too small generator).

Of course, this could just be coincidence, but the pump was only three years old.
No coincidence.
That sums it up pretty well.
The motor was in startup for too long.
oil pan 4 is offline   Reply With Quote
Old 01-13-16, 01:53 PM   #28
pinballlooking
Super Moderator
 
pinballlooking's Avatar
 
Join Date: Jun 2013
Location: SC
Posts: 2,923
Thanks: 172
Thanked 564 Times in 463 Posts
Default

Thanks for posting very interesting. I really liked the info about your cattle and their water requirements.
I have a small generator but I have been thinking about a PTO generator. I have a small diesel 36 HP tractor.

This guy is a drivable distance for me to pick up.
St 10KW Gen Alternator PTO Gear Box Coupler Combo | eBay

I have been watching craigslist and natural gas one come up once in a while usually someone upgrading and the installer it selling the old one.
Or an office building but those are usually too big for me but would work for you.
You might fine a propane generator that a office building no longer needs on craigslist that would fill your requirements and not break the bank.
__________________
Current project Aquaponics system , Passive Solar Greenhouse build

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Solar Install 12.5 Kwh-
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Mini Split installs -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

EV Chevy Volt -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Last edited by pinballlooking; 01-13-16 at 02:33 PM..
pinballlooking is offline   Reply With Quote
Old 01-13-16, 02:29 PM   #29
WyrTwister
Master EcoRenovator
 
Join Date: Jun 2013
Location: USA
Posts: 543
Thanks: 6
Thanked 44 Times in 38 Posts
Default

Quote:
Originally Posted by oil pan 4 View Post
You don't want to run VFD on single phase.
Typically for high starting torque motors you use capacitor start. Capacitor start uses a mechanical centrifuge to turn the start circuit on and off. During run up the start circuit does not cut out until the motor is almost at operating speed.
If the motor runs for more than 5 or 10 seconds with the start circuit powered up it will fry something in the start circuit, usually the capacitor or the windings.
If you drop the motor speed down too low the start system will reengage, frying the starter.

This is why industrial pumps are pretty much always use 3 phase inverter duty rated motors connected to VFDs. The motors and what ever they drive can be soft started and ran at variable speed, usually any speed between 20hz and 60hz. Some VFDs can produce 100hz.
You can get a 3 phase VFD that can be powered single phase 240vac power.
Not sure if single phase VFD's are made ?

You are right , some single phase motors have centrifugal switches , but not all do . The submersible pump motors do not , there is a relay in the " box " that senses when it is appropriate for the start winding to be turned off .

Will have to check , but I think single phase A/C compressors do not use centrifugal switches .

Most single phase motors have capacitors .

With motors larger than a few hp , 3 phase is almost always better . It is certainly simpler .

With a VFD , the power AC is rectified to DC . The electronics then convert it back to a semblance of AC . Usually 3 phase . The VFD could be built to be feed single phase or DC from a source like wind turbine or PV cells .

God bless
Wyr
WyrTwister is offline   Reply With Quote
Old 01-14-16, 01:04 AM   #30
oil pan 4
Land owner
 
Join Date: Nov 2012
Location: NM
Posts: 1,026
Thanks: 12
Thanked 127 Times in 107 Posts
Default

A single phase VFD could be made but I don't know what the application would be or where you would buy one.

I work with rooms full of VFDs in all sizes. Little ones for up to 10hp and the big ones are for 700hp motors.

For home use I only ever use capacitor start, capacitor run for my air compressors I built to run sand blaster and orbital sander.

oil pan 4 is offline   Reply With Quote
Reply


Tags
generator, ice storm

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 07:23 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design