Liam McDuffie

S Bengi wrote:If possible try and use all 5KW as it is being produced, a few irons, hot plates, heater, etc. Run the system at 90% load for 6 hours and see if the temp goes down.
If it does, then you dump load needs to be looked into.

It is also possible that your current load is too high turn off every single thing in the house and see if the temp goes down.

It's a grid tied system. I spoke to my engineering helper and he advised that some of the power the gen is producing is going to be converted into heat. Apparently the norm is that the case will be hot enough to hold your hand on for a few secs. As the ambient temp rises so does the case heat. I'll call Marathon tomorrow but at least I can sleep OK tonight.

My 5KW Induction generator case is hot. I can put my hand on it for a few seconds but it's too much after that.

Is that about normal?

Im going to get an instant read IR temp gun, but need to know if I should be worried - this is my first year of full start up and run, past owner of the property is not available.

Problem solved - we added more water and voile' got the HP and the generating power @ 4.5KW straight to the grid. That means flashboards on the dam.

The induction generator is best for our needs. The tach has a high and low RPM safety setting that automatically disconnects power and shuts down the water flow and stops the wheel. Similar safeties are in place for over & under voltage and over & under amps.

Hello Gents,

That Flashing info I have sent to my Son in law the engineer. He'll look at that. Noting else is connected in the way of other equipment. This was designed strictly to generate grid-tied electricity.

In that regard, it is tied to the grid and the previous owner advises to run the Gen rpm at min 1230 rpm with an overspeed safety at 1270 that will auto shut down the flume gate. There are other safetys, underspeed, over-voltage, ect.

Problems with an induction Generator

Marathon Electric 5kw induction Generator. 240 V, Single phase with synchronous speed of 1200 rpm

It appears that when connected, the Induction Gen is acting as a Motor. Regardless of the available power to increase the RPM’s higher to generate power, the motor is throttling that down to maintain the 1200 RPM sync speed.

Marathon believes if the connection is taking place at an RPM lower than the slip value (about 1180), then the Induction Gen is being energized as a Motor. If we test this by manually connecting the Generator load above the synchronous speed of 1200, the Gen should energize as a Generator.

So we tested multiple startup procedures with the manual cut in above 1200 RPM to see if we get a steady Gen. and the ability to run at 1250 to make power. The result was that we had the rpms up to 1350~1400 and when we cut in the gen, it immediately brought the rpms down to 1200 and stayed at sync speed – as a motor, and not generating power.

The drive train runs like silk when disconnected from the grid. When connected, the Gen holds the RPM’s @ 1200 and the drive train surges as the Gen (motor) is fighting the drive train to hold RPM’s down.

There does not appear to be any mechanical reason for this. The Gen has run at as a 5kw Gen in the past.

The previous owner has said that the Grid is holding the RPM’s back but that has to be complete bullshit.

Any electrical/engineering types have an idea of what could be wrong that is preventing the generation of power?

Here is the Hydro


Where This dam


Puts water down this Flume


Which turns the 16ft overshot wheel


Which drives the chain to the gearbox


Which turns the Generator


Which feeds power to the grid

The dam at the time pictured is during the spring thaw. Normal flow is about 3-4 inches over a 14ft or so? spillway opening. I have yet to measure the flow, however I will by Mid July at a point downstream where there is a flat bottomed section of the brook that can be easily measured for uniform depth and width and a good 30 ft section can be measured. For reference, here is a youtube video of the current water wheel operation. in early fall

Here are some answers and my thoughts.

The head or total fall is 20 ft top of dam to the mean water level of the brook
June measurement is 22 ft/sec2 - that is the low period flow. The majority of the time the flow will be higher.
Tther info: the brook is the sole drainage for 24 square miles.
The state has it permitted at 32Kw
A crossflow turbine (JLA 59?) charts the flow and head for an output of 30+kw Some other charts rate the potential at only 16kw max. So, something is not right.

Distance from the dam where the 24 inch pipe is stubbed in, to the power house is 40-45 feet. (Pipe is stubbed in under the flume)

There is a turbine bay poured into the power house. the right hand side of the power house has a 16ft steel overshot wheel in it right now - hooked up to a 5KW generator. Worst case is that I regen it for a 10 kw generator - there is enough torque there I'm sure. Calculated torque of the wheel is 7,253 ft lbs.

While the wheel is nice, I think a penstock and crossflow or other turbine will provide a huge increase in power output.

here is a pic, let me know if you want more info.

From the experts here, a little help please - I ahve to opportunity to buy this property

Current situation
New England
brook with dam
flow at 22 cubic ft/sec
Flume to Powerhouse
16 foot overshot wheel
Produces 5kw max - runs at 4KW
Net metered and excess sold to group members

Here is the problem, the permit is for 32kw. I am willing to invest in making it more effecient and profitable HOWEVER.. I can't find a penstock & turbine combination that will get me the 32KW!

With 19-20 ft of head and high flow of 22 ft3/sec I need to get the full 32 KW out of it.

Any thoughts?