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    5 hp motor switch??

    Please listen to Steve. The code requires conductors and equipment to inductive loads to be sized at 125% of operating current. It's not always as simple as reading a nameplate or a chart somewhere. This is because many motors draw huge starting (inrush) currents before they reach synchronous speed. Contactors that aren't properly selected, or set up will only work for a while. I've replaced contactors that were welded in the on position, and I've replaced others that were burnt in two. Purpose-built motor starters combine the appropriate contactor with an overload relay. They are often sized by the motor's horsepower but you have to be very careful not to stumble into a 3-phase motor starter since those are much more common. Finally, I think it's really, really, important to point out that electrical equipment voltage ratings are nominal. The actual supplied voltage is always different than the system name would suggest. Devices properly rated for an installation might sport any of the following ratings; 210V, 220V, 225V, 230V, 240V, or 250V. "Intelligent" devices might have labels that read 100V~250V which means the device can accept a range of voltages. None of this stuff is made for installation by unqualified personnel so the installation instructions/schematics tend to be pretty minimalist.
  2. I've recently come across a few articles on Artificial Intelligence research which suggests that independent price setting algorithms have "learned" to collude with one another to maximize profitability. Researchers are still working out whether this is happening in the real world. One of the most distressing comments in the article is that the researchers mentioned that these algorithms are capable of colluding without direct communication. The AI programs learn to respond to their digital competitors price in a way that maximizes the "punishment" to whoever gives the lower price. Within a few iterations, the programs "learn" that it's mutually beneficial to set the price just below monopoly level. This gives the impression of competitive market without the risk of accepting less profit. The researchers ran tests with more AI "competitors" which didn't change the results. All the AI programs learned to avoid competitive pricing. Human nature being what it is, I think it's very possible that plausible deny-ability is potent incentive. "We didn't teach it to cheat", isn't the same as "we taught it right from wrong". The article suggests this AI behavior doesn't meet the current legal definition of collusion. Even if it did, proving real-world examples of this are going on may be very difficult. Interestingly, studies done on human subjects suggests that people were unable to achieve the same level of price fixing without direct communication. I think that's an erroneous conclusion. People programmed the algorithm that taught itself to cheat. The AI is just a tool allowing people to bypass a human limitation. One of the more potent aspects of this tool may be the way it illustrates how people often separate stated intentions from measured outcomes to obscure what they're really trying to achieve.

    Keeping pace with changes Man vs. Machine

    Latticino, Most of the design-build projects I've done suffered from poor time management. There were long pauses in productivity while the client and Architect met weekly to talk over different options. All the engineering disciplines were expected to attend these meetings but nothing in their scope was allowed to progress for fear of conflicting with a future resolution. If the design schedule was ten weeks total, we'd feel lucky to get two and a half weeks to complete the electrical design. There are engineering consultants who barely look up from their computer during a meeting. I've seen some of them working on a completely different project during the meeting.

    Keeping pace with changes Man vs. Machine

    Kozzy, I have a lot of moments at work where I ask myself why some obviously necessary bit of information wasn't provided. Back when I was starting out, I used to assume it was just an oversight or an unintentional omission. As time went on, I noticed patterns in what was and wasn't revealed. One day I was discussing this problem with a client and I joking asked "why is this a secret?". That thought stuck with me because it changed my perspective of the whole situation. Really often, it's a "secret" because the missing information would reveal something inconvenient about their motivations. I've discovered quite a few nasty surprises by asking myself; "What if they're hiding something?".

    Keeping pace with changes Man vs. Machine

    CMS3900 The ISO comment reminds me of "best practices". In theory, everyone knows that "best practices" should be followed. In practice, everyone games the standards in proportion to their status in the hierarchy. For example, quality control is mostly citing "design intent" whenever production-level work descends to design-level quality.
  6. Yesterday I had three completely different jobs all suffer from the same basic problem. The designers weren't updating their design to include changes from people outside their office. One job had all the HVAC equipment located in the middle of every partition wall in the project. If the Mechanical engineer had bothered to consult the floor as well as the ceiling plans, they might have avoided this rather obvious problem. Another job came in over budget so we came up with a cheaper lighting package. The architect never updated their plans to include the new fixture specs so when the city planning and zoning department approved their exterior plans, they committed to using overpriced fixtures. Now we have to figure out if it's cheaper to resubmit for permit, or to simply buy the overpriced lights. Finally, we have a job which has a complex ceiling system with custom-made light fixtures that must fit perfectly. This system is compartmentalized so that there are seven variations of the same theme. The Architect provided a single "typical" detail giving the component dimensions in Feet, Inch, and Fractional inches. This Architect didn't give overall lengths for the assemblies with one exception. When I had to calculate the fixture lengths, I used all the component dimensions to arrive at my total. When the ceiling installer laid out the system, he used the only overall length dimension that this Architect provided. There's a 1/4" difference that "stacks up" due to the compartmentalization. The largest assembly generates several inches of difference which will be visible from some distance away. I've spent the last two days trying to get "professionals" to stop converting the measurements into decimal feet so they could use an excel spreadsheet to do the math. It only takes a moment to do these calculations by hand, but everyone is so afraid of appearing incompetent that they're spending hours trying to get a computer program to do the math for them. Everyone is assuming that CAD generated drawings can't have dimensional mistakes. I suspect it hasn't occurred to these folks that Architects might find it's easier to adjust the labeled dimension, than to actually change the length of a drawing. Taking that shortcut on a component dimension was easy. Calculating the overall length wasn't.

    Reading a ruler, the other way

    I've noticed that a lot of people never really grasp the notion that doubling the denominator in a fraction divides the quantity in half. Tripling gets you a third, and so on. Another super-quick way to get equal divisions using a straight ruler is to mark perpendicular lines at your end points. Now take a ruler that's longer than the marked end points and set it diagonally across those perpendicular lines. Tilt it until you arrive at a even or odd number which corresponds to easy division for your problem. Let's say you've got a piece of stock that's 7-5/16" long and you want to divide that length into equal thirds. Mark the 7-5/16" length with a perpendicular line at the origin and the end point. Now take the rule and lay it diagonally until the zero and the 9" mark cross the origin and the end point line respectively. Mark where the 3" and the 6" appear on the ruler. Now take those points and pull down a perpendicular line from them. The distance is perfectly divided into thirds with easy math.

    Fuzzy Math

    There's a 13 mile stretch of interstate near me getting a lane added in each direction. It's pretty much straight as an arrow, perhaps five overpasses, and no seismic activity to worry about compared to AK. The project is anticipated to take nine years. Just for giggles, I googled the production rate of the transcontinental railway. On their most productive day, they laid ten miles of track. From what I can tell, that doesn't include time cutting and grading. It was however twelve hours of setting ties and track. All work done by either man or beast. I had a few classes on road construction so I'm not an expert by any means. That said, I've worked for firms that hired paving firms to build public and private roads. When the road designs were identical , the private roads consistently took less than a quarter of the time to get built. In my experience, most of the additional time was generated by leaving the site after the prep was completed, and not coming back until a day or two before the deadline whereupon the paving is completed in one or two hard-driving shifts. Typically they'd be gone for several months between prep and pave with all the traffic control stuff left in the public's way. There were no inspection, permit, or weather related delays to justify this behavior. This delay was built into their schedule. Every paving company was basically the same. All of their estimators/salesmen would swear up and down that it simply couldn't be done any faster.

    how much

    acronin, I'm not sure you're picking up on Mike Thurston's point. He gave an example of how people undervalue things when they price them off the cuff. You might want to browse online looking at knives of similar description. My thinking is that you'll find some that compare favorably so you'll see what those makers are asking.

    Fuzzy Math

    Glenn, As a professional estimator with ten years of experience, I can say that it's very rare for competing bids to perfectly agree on quantities, but very common for them to be virtually identical in cost. The principle difference is the round up/ round down function of judgement. People get hung up on precision because it gives them something to measure, so they feel better about it. Accuracy is hitting the right answer. Good judgement can look a lot like luck to an uninformed bystander. Really often, the influential factors aren't that difficult to roughly calculate. The hard part, is knowing which factors to look for.

    Fuzzy Math

    ausfire, I got all the way to college before I encountered a teacher who presented a lesson showing how fractions were more precise and intuitive than decimal approximations in practical applications. Huge physics calculations could be done in your head if you kept everything in fractions. Trying to get the solution using decimal approximations just made it a lot harder. That teacher had a knack for writing exam questions that were virtually impossible to solve any other way.

    Fuzzy Math

    Glenn is spot on about "having a number" to check against the calculator. I've met a whole lot of people who get their order of operations wrong when they're using a calculator. Same numbers, same operations, different answers. One aspect of this that jumps out at me is how people love work out a rough percentage or ratio without much consideration for the driving relationships. That leads to a lot of incorrect assumptions. For example, you could take the total cost of a construction project and divide it by the square footage to get a square foot cost. OK fine. Now, you decide you want to build something the same size or slightly smaller with a more efficient layout and the budget jumps. What happened? Well, things like restrooms are driven by occupancy not square footage. Depending on local building rules, restrooms have to be made in groups of pairs or triplets. Restrooms require just about every skilled trade to work sequentially in a limited amount of space which makes them expensive. The further these rooms are away from the utility sources, the more the price will rise. Crossing the "occupancy threshold" where you have to add a bathroom group might also require that the groups be placed at opposing sides of the space which can boost their cost. The "right" way to ballpark this is to use a parametric estimate. Bathrooms can be priced as a standalone parameter. That gives you some way to quantify the cost impact of changing the occupancy.
  13. Buzzkill, sorry I mistook what you were getting at. You're describing a situation where you've got a lot more information to go on, than a poorly-defined conceptual pricing request from a new client. My original post obviously doesn't apply to situations where you're working with a lot of information. If you have past experience with any factor of the project, that knowledge becomes a baseline for the project scope. As you put it, this is the "real case" cost. We have some clients who get different pricing depending on which of their Project Managers will be running the job. Incompetence, and corruption, generates a lot of risk. Risk is expensive. I've struggled with situations similar to what you're describing because it's relatively easy to knock up a percentage, but it's difficult to prove that the percentage is driven by the correct factors. For example, let's say a client tends to dither on decisions. Past projects show they consumed X% more hours of management's time than the typical job. Management time isn't exclusively spent on client decisions. A large part of it is just processing paperwork, communicating, sitting in meetings, etc. Sometimes we're dealing with really poor designs that will generate lots of hard decisions for the waffling client. That's a perfect storm of intersecting professional incompetence. Working through that morass might take a different approach than just adding management hours. It might be better to price the necessary technical and administrative support to meet that challenge. In the past we've sought the services of an independent engineering consultant to counter problems generated by the clients incompetent design team. Contrary to my original expectations, it was actually cheaper to hire an engineering consultant to resolve major issues quickly, than it would have been to pay a manager to ride it out hoping the correct thing would eventually happen.
  14. George, Your comment reminds me of a story a Journeyman Electrician told me about his grandfather. Apparently his grandfather was quite a renaissance man. He played a part in designing things as varied as a limited slip differential for a light truck, and a hydro-electric power plant for a rural community. The grandson inherited a neat prototype 100 series pickup with tandem axles from the 1950's. Anyhow, the hydro plant originally had two buildings. The larger of the two housed the power generation, the smaller housed the management. Over the course of forty years or so, there were a lot of improvements made to that site. Three more buildings went up on the site, all of them were for management. When the whole plant was going to be decommissioned in the 1990's this guy's family was invited out to tour the facility one last time. He said that all the generation equipment was original. Maybe the expansion of administrative bureaucracy is the key to understanding why maintenance is so often neglected. There's a lot of cynicism applied to corporate takeovers that lead to mass layoffs. It seems plausible to assume that "greed" motivates the buyer to discard long-term employees of the purchased firm. However, it's pretty easy to show how human nature leads managers to propagate bureaucracy. Despite all evidence to the contrary, most bureaucrats are actually human. Most of them will figure out that any painless cuts to the bureaucracy threatens their continued employment. Costs constantly rise, quality constantly declines. If the means of operational production is in constant peril, there's a lot of justification for all that management. For the most part, none of that is true, which is why middle management gets wiped out in mergers and acquisitions. The question that's been cooking my noodle for some time, is; "If human nature is the cause, how do you prevent this from happening?" The best I can come up with so far is to arrange incentives so that it's profitable for the wrong people to do the right thing. I had a discussion similar to this with a fellow traveler several years ago. She thought my suggestion sounded "very expensive". I replied "You know what, you're absolutely right. How much is the national debt?"
  15. Buzzkill, five years ago I copied a blog post onto IFI that might help with your problem. The shorter version: Overhead is a time driven expense that gets paid for proportionately by the work that is ongoing when the overhead accrued. Long term projects generate more overhead than short term projects. When work is scarce, each individual job has to carry more of the overhead which really makes it hard to get prices low enough to beat a competitor. For some firms, the answer is to reduce overhead by downsizing.