Pelton wheel generator

[IndyIan]

Maybe the turbine could be run on one jet for more time? 80 psi with a low flow runing for days at a time could produce enough electricity to keep the battery topped up and then the shock of an auto valve isn't as big of a problem?
Depening on the battery it can also be better to have it stay at 95%, instead of discharging and charging cycles.
If he can adjust the turbine output easily he could have quite a small battery as well.

 

[expat]

We are almost ready to run now, but have a small problem.
We understand that the Pelton wheel should never run without a 'load' or resistance. I'm not too sure why? But suspect that the turbine may over rev and Burst if there is no load.
So the question is, What would be a suitable load?
The power going to out battery pack and control panel is routed through a 60amp breaker, the voltage from the Pelton wheel generator is 24v so I guess we are dealing with a potential of 1440 Watts? But I doubt the wheel will ever , realistically produce this. Many suppliers sell heating elements for these Power dumps, some suggest multiple elements that are 'Specially wired for 24volts ??? They are expensive!
What would be wrong with using a 'normal' 110volt household heater for the Dump? (At least until we can test and get to see how many Watts we will have to deal with)
What would we require in a 110v rated heater to deal with 1500 watts at 24V?
What would happen if the Dump receptacle (Heater) was too great a capacity? Someone said it would stall the turbine!! My Gut says Garbage to this! What do you think?
Thanks in advance.

 

[Shannow]

Back in the good old days, they used to do stress tests on transformers using a 44 gallon drum (55USg)of Caustic Soda (don't know the concentration *).

They used dipper plates of mild steel to vary the load on the tranny. Drums got hot, and needed mak-up water to replace evaporation and hydrogen losses.

They were cheap transportable and adjustable.

 

[expat]

Originally Posted By: Shannow
Back in the good old days, they used to do stress tests on transformers using a 44 gallon drum (55USg)of Caustic Soda (don't know the concentration *).

They used dipper plates of mild steel to vary the load on the tranny. Drums got hot, and needed mak-up water to replace evaporation and hydrogen losses.

They were cheap transportable and adjustable.


I'm not sure that is what we're looking for in this application

 

[Shannow]

Cheap adjustable resistive load for the off load application ?

 

[XS650]

Originally Posted By: expat
We are almost ready to run now, but have a small problem.
We understand that the Pelton wheel should never run without a 'load' or resistance. I'm not too sure why? But suspect that the turbine may over rev and Burst if there is no load.
So the question is, What would be a suitable load?
The power going to out battery pack and control panel is routed through a 60amp breaker, the voltage from the Pelton wheel generator is 24v so I guess we are dealing with a potential of 1440 Watts? But I doubt the wheel will ever , realistically produce this. Many suppliers sell heating elements for these Power dumps, some suggest multiple elements that are 'Specially wired for 24volts ??? They are expensive!
What would be wrong with using a 'normal' 110volt household heater for the Dump? (At least until we can test and get to see how many Watts we will have to deal with)
What would we require in a 110v rated heater to deal with 1500 watts at 24V?
What would happen if the Dump receptacle (Heater) was too great a capacity? Someone said it would stall the turbine!! My Gut says Garbage to this! What do you think?
Thanks in advance.


A pelton wheel at no load will turn twice as fast as it will at full design load. Maybe not a problem in a small well built wheel, but I'm not so sure about your generator being good for double design RPM.
To save me some typing about wheel load vs speed, see the end of this article
http://eetd.lbl.gov/inventors/hydro/hydro-learn-adv-eu.html

A 1500 Watt heater would absorb a lot less power at 24 volts. You won't hurt the heater but you might not get as much load as you want. If heater resistance were a constant as voltage varies the heater would only load 24 volts to about 60 Watts. It will actually do a bit better, maybe 80 Watts.

 

[expat]

So, even a Dozen 1500 watt domestic (110v) baseboard type heaters would not be up to the job?

Sorry if I'm a little slow getting my head around this, But we are using heavy 8 gauge wiring from the generator 'Because' (we are told) we will have MORE resistance at the low (24v) voltage!
and a smaller gauge wire would incur losses and (possibly) over heat!


We have been warned by the manufacturer NOT to let the wheel run un-loaded, and seeing as there is a bunch of $ tied up in this thing, we don't want to take any chances.

Sorry shannow, I don't think the idea of drums of caustic soda will fly with the owner

 

[Gary Allan]

Surely there is something that they REALLY USE that draws the required current.

Tell them to leave it on. How hard can that be?

 

[IndyIan]

Originally Posted By: expat
So, even a Dozen 1500 watt domestic (110v) baseboard type heaters would not be up to the job?

Sorry if I'm a little slow getting my head around this, But we are using heavy 8 gauge wiring from the generator 'Because' (we are told) we will have MORE resistance at the low (24v) voltage!
and a smaller gauge wire would incur losses and (possibly) over heat!


We have been warned by the manufacturer NOT to let the wheel run un-loaded, and seeing as there is a bunch of $ tied up in this thing, we don't want to take any chances.

Sorry shannow, I don't think the idea of drums of caustic soda will fly with the owner

You have more amps to deal with at 24V, VxA=watts, that's why you are using heavier wire, look at the wiring to your car starter, more amps heat up small wires. If car batteries were 120V then they could use much smaller wires to the starter.
As for a power dump, what about a 24V inverter to 110V then have a normal space heater attached to that?

Maybe at this point they need to bite the bullet and get a inverter/charger that has all the electronics for automatic switching to power dumps or even controlling electric valves?

 

[expat]

Originally Posted By: Gary Allan
Surely there is something that they REALLY USE that draws the required current.

Tell them to leave it on. How hard can that be?


Well as I see it, if they left an appliance on that would take the full load from the generator, they would not have anything left to charge batteries.
What they need is a load that switches on automatically 'only' when the batteries are fully charged.
They DO have a control panel that does just that, but the automatic Dump is 24volts 'before' the inverter.

But you are right, for testing purposes leaving a load on the inverter would provide a safety margin.

 

[Shannow]

If the energy source is going to be there 24/7, and only turned into productive electricity for part of the time, then ultimately there should be something done with it other than at commissioning time.

Could be used to heat water prior to hot water service, heat storage for home heating, greenhouses etc etc.

 

[expat]

Originally Posted By: Shannow
If the energy source is going to be there 24/7, and only turned into productive electricity for part of the time, then ultimately there should be something done with it other than at commissioning time.

Could be used to heat water prior to hot water service, heat storage for home heating, greenhouses etc etc.


Agree, but these people have been off the grid for more than 20 years, they are pretty well set-up and used to not having 'instant' electricity.
The Kitchen uses an AGA stove fired by wood, during the winter months this supplies unlimited Hot water and basic heat, as well as cooking facilities. A hot water heating element was considered, but the expense of the element, Tank and extra plumbing (for something that was not considered needed) did not appeal.
But I suspect once they get used to easy electricity, they will get Hooked.