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  1. DRWeig

    Class 1 Div 1 requirements and testing protocols

    Hi Bill, If your product is to be employed in the US -- If you're going the explosion proof route, you'll need a copy of UL 1203. If you're trying for intrinsically safe, you'll need UL 913. You'll need testing, since your device does not qualify as "simple apparatus," which in and of itself...
  2. DRWeig

    COVERAGE OF A GAS DETECTOR AS PER NFPA

    There are no "coverage details" for gases, although some manufacturers go out on a limb and say they'll detect in a 50-foot radius if the gas mixes evenly with air (like carbon monoxide or carbon dioxide). Are you sure you want to measure H2S in a battery room and not H2? Natural gas is...
  3. DRWeig

    COVERAGE OF A GAS DETECTOR AS PER NFPA

    What sort of gas? Best to you, Goober Dave Haven't see the forum policies? Do so now: Forum Policies
  4. DRWeig

    Wiring in hazardous location - NEC Std. - On-Skid of Moto-Compressor

    In general, things that do not arc or spark or get really hot during normal operation can be used in Div 2 locations in general-purpose enclosures. You have switches and stuff that DO arc or spark, so they had to use a Class I Div 1 enclosure. As for cabling, it's only required to be sealed at...
  5. DRWeig

    Standards for Data Centers Master Ground Bar untilizing the P.A.N.I standard

    Are you asking about current in the case of a ground fault? Normally, there should be no current at all flowing in the ground conductor, and no voltage present on it. That's why you find it uninsulated. Sometimes, though, ground connections can be made at different locations, and those locations...
  6. DRWeig

    Differential pressure switch

    Hi Hassan, I think you mean "differential pressure transmitter" instead of "differential pressure switch." You'll also need a controller (your VFD on the secondary pump(s) will probably have one built in). Best place to put the dp transmitter is across the valve/coil combo that is physically...
  7. DRWeig

    Industrial Control Panel SCCR

    Agree with Lionel. Been through this with our UL inspector a few times... Best to you, Goober Dave Haven't see the forum policies? Do so now: Forum Policies
  8. DRWeig

    Advanced BIM tool for the design of HVAC systems for buildings

    Miroslav, I'm with a Revit group now, and based on what I'm seeing in the US, you'd better do Revit if you want to work with architects... It may be different where you are, so my advice is to check with your client base first before shelling out money on something that won't integrate with...
  9. DRWeig

    Reallly long panel feeder -- how to connect to panel and feeder breaker?

    Thanks Bill, I had not thought of that. I'll draw it out for them... Best to you, Goober Dave Haven't see the forum policies? Do so now: Forum Policies
  10. DRWeig

    Reallly long panel feeder -- how to connect to panel and feeder breaker?

    Thanks, crshears. In fact, I was asked to analyze that this evening as I left work. Buck/boost could be the way to go. I really like those Polaris connectors, too, though... It'll all boil down to $$. Best to you, Goober Dave Haven't see the forum policies? Do so now: Forum Policies
  11. DRWeig

    Reallly long panel feeder -- how to connect to panel and feeder breaker?

    Thanks jfpe, I'll have a few options now for my client. Eng-tips rules! Best to you, Goober Dave Haven't see the forum policies? Do so now: Forum Policies
  12. DRWeig

    Reallly long panel feeder -- how to connect to panel and feeder breaker?

    Thanks Hoxton and ScottyUK! Great ideas. I'm working with a generator on this job, too -- so I'll ask the Cat rep about the link boxes. I'll show the boss the stud terminals, too. I can size a box for them near each end of the feeder. Best to you, Goober Dave Haven't see the forum policies...
  13. DRWeig

    Reallly long panel feeder -- how to connect to panel and feeder breaker?

    Thanks folks, That's what I was thinking too... Best to you, Goober Dave Haven't see the forum policies? Do so now: Forum Policies
  14. DRWeig

    Reallly long panel feeder -- how to connect to panel and feeder breaker?

    Hi Fellows, I'm working a project involving great distances from a main switchboard or power panel to some 250A 480/3 panels. The champion is an 850-foot run. In order to keep voltage drop to less than 3 percent, I calculated the need for 4 sets of 350 MCM per phase at an 80 percent load on the...
  15. DRWeig

    4-20mA dueling

    From my former company: http://www.kele.com/Catalog/24%20Transducers/PDFs/UMM-1,%20UMM-2%20Series%20Catalog%20Page.pdf These can be cascaded as well, so two of them would take care of your six 4-20 mA signals. Best to you, Goober Dave Haven't see the forum policies? Do so now: Forum Policies
  16. DRWeig

    Simple Linear Regression with Weights

    You're a champion, Doug! Best to you, Goober Dave Haven't see the forum policies? Do so now: Forum Policies
  17. DRWeig

    Simple Linear Regression with Weights

    Thanks for the tip, IRstuff. Best to you, Goober Dave Haven't see the forum policies? Do so now: Forum Policies
  18. DRWeig

    Simple Linear Regression with Weights

    Thanks again all, I was able to un-function the VBA code from Doug to please the boss. It was a bit hairy, but it gives the same results as real-statistics (I didn't try ALGLIB). What a hassle it's been - but the boss is the boss, and he wants something that can be easily translated to a...
  19. DRWeig

    Simple Linear Regression with Weights

    Thanks all! IRstuff, that link hit the nail on the head for me. I have real-statistics add-in, but the function call for weighted linear regression is not documented well. However, I can use the real-statistics add-in to verify my work. Best to you, Goober Dave Haven't see the forum...
  20. DRWeig

    Simple Linear Regression with Weights

    Group, Does one of you perhaps have a VBA routine for linear regression with weighting, without using any built-in Excel functions or plug-ins (boss request). I've attached a very simple example of data. My program is much more complex, but I've never dealt with weighted regressions before...

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