Recent content by yahastu

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    Does wire length difference create phase shift?

    Awesome, thanks for explaining that. Makes sense! The replies i received there did not seem to address to the questions i asked. However, after doing additional research, and consulting with another electrician, i feel fairly confident that i have found the answers to my questions.
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    Does wire length difference create phase shift?

    When wiring a 240 volt AC circuit, I've always assumed that it's important for L1 and L2 wires to be the exact same length, in order to avoid introducing a phase shift that would reduce peak voltage. Length differences can accumulate when the wires enter a panel and need to go slightly...
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    Considering Earth ground vs floating ground in off grid solar

    As I specifically explained in my post, meeting code is not an objective unto itself. I am not asking what needs to be done "to meet code." I am asking what makes the most sense from the perspective of electrical shock protection, lightning protection, etc. I have discussed all of these topics...
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    Considering Earth ground vs floating ground in off grid solar

    Context: I'm building an off-grid, 100% solar powered home. I have a 12 kw solar array wired up to a Sol-Ark inverter and a Fortress 18.5 kwh lithium battery. Question: What is the ideal grounding/earthing scheme? Additional context: where I'm building, there is currently no requirement that...
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    Allowable uniform loads - W beams vs. LVL

    I'm trying to make a comparison between the maximum allowable uniform load of a beam made of steel vs LVL. Here is a table of allowable uniform loads for steel W beams: https://www.engineeringtoolbox.com/w-steel-beam-uniform-load-d_1722.html Here is a table of allowable uniform loads for LVL...
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    A What is the Probability of Sampling a Set with a Certain Size?

    I did a numerical simulation, and found that the relationship between M/N and any given percentile of the distribution of C is linear. Using a linear regression I computed that the solution to X above is approx given by: X = M( 0.922954 - 0.3144(M/N) ) So this is cool, can't beat it in terms...
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    A What is the Probability of Sampling a Set with a Certain Size?

    I've come up with a problem that's important for an algorithm I'm developing, and I don't know how to solve it. Wondering if anyone here can help? I have an initial set S1 of size N. S2 is created by randomly sampling M samples from S1 with replacement (meaning the same item could be selected...
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    System design for charging battery from turbine alternator

    here it is https://www.alibaba.com/product-detail/Micro-Turbine-7kw-Hydro-Generator-Pelton_1600128337643.html?spm=a2700.12243863.0.0.38403e5fy0zvkg They are asking me what voltage and frequency I want it manufactured to. eg, 240v/60 hz. If it really does output 240v/60hz, then I could just...
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    System design for charging battery from turbine alternator

    A minimum flow rate must be maintained at all times to prevent freezing. Flow rate through the turbine will be manually set by a spear valve at the location of the turbine.
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    System design for charging battery from turbine alternator

    The turbine will come pre-designed with a built in alternator, so I was just referring to the whole thing as a turbine...but yes I understand that the turbine converts head pressure into rotational kinetic energy, and the alternator component then converts the rotational energy into electrical...
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    System design for charging battery from turbine alternator

    I am designing a hydro power system that will tie into an off grid solar system. I will be using a 48v carbon AGM battery bank. Will be using the Sol-Ark 12kw inverter/charger, which has 2 built in MPPT charge controllers for solar. Assume the hydro power will be around 5 kw potential, and...
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    Estimating head loss from pipe slope?

    Nice, thanks for spotting that @gmax137! Thanks for the suggestion :) I constructed a couple simple weirs yesterday. I opted for a V-shaped design, since I read that it provides a more accurate flow measurement than other profiles. Here is a pic installed: Installing the weir was a bit...
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    Estimating head loss from pipe slope?

    @jrmichler @gmax137 Hmm...I'm having difficulty finding out the source of the discrepancy. I would like to know if the fundamental equations I'm using or wrong, or if I'm just misapplying them or what. I am using the exact equations from here...
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    Estimating head loss from pipe slope?

    Just walked around to scope out some new spots today, took some more flow rate measurements. I have concluded that my method of measurement, which consists of dropping a styrofoam ball into the water and timing how long it takes to travel, is a really terrible way of estimating average stream...
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    Estimating head loss from pipe slope?

    Yeah, I have begun the less fun process of investigating the various pathways for permitting such a project. There are a few different ways...and eligibility depends a lot on the system design. It's much easier to get it permitted if I do it as a Run of River project (ie, no dam, and no upstream...