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  1. larrym

    Nuisance tripping of house hold AFCI breaker power small UPS

    This is a work at home issue. We have a user running a 1500VA UPS powering a desktop and monitor from a 15 Amp outlet protected by an AFCI. She is getting nuisance trips when she is not even working on the machine? My guess is probably when the UPS does it's periodic battery test. This is...
  2. larrym

    35KVAC Load Break in a below grade manhole system

    We are working on a project installing a submarine power cable. It has been suggested that we install load breaks in the manhole where the cable transitions from submarine cable to terrestrial cable to allow isolating the two segments for troubleshooting in the future. My first inclination was...
  3. larrym

    Bridge Deck options for 15'X35' vehicle bridge

    OK, after figuring out that I can't count or measure....and apologizing to my long since passed (master carpenter) Grandfather for not measuring twice, etc. etc....apologies for that The Bridge deck dimensions are 25ft X 12ft. 27 each deck boards (2 1/2" X 9" 12ft long) spacing between deck...
  4. larrym

    Bridge Deck options for 15'X35' vehicle bridge

    15’x35’ field measured. Apologies on limber size. I can’t count and am Not used to lumber this size ;-) I’ll measure the boards and get some underneath pictures tomorrow Regards Larry Larry Mackey
  5. larrym

    Bridge Deck options for 15'X35' vehicle bridge

    Greatly appreciate responses. Picture of bridge deck attached. 5 steel beams spanning between abutments. Bolts in deck boards are attaching to wood laid on top of beams (I assume but have not seen clips holding those boards onto steel beams. Many of bolts holding down the deck boards have...
  6. larrym

    Bridge Deck options for 15'X35' vehicle bridge

    We have a privately own/maintained bridge that is 15'W X 35'L. With Concrete abutments, 4-5 steel I beams spanning between the abutments and wooden decking (4X10s??). We are working with a structural engineer and looking for a crew to do needed maintenance on the bridge. I am looking to...
  7. larrym

    Resource for Sizing ducts for power cables and inner ducts

    Any suggestions for properly sizing HDPE conduits for 4/0 power conductors for a 2200 ft conduit run and sizing an outer conduit to nest three power conduits into? Regards Larry Larry Mackey
  8. larrym

    Timber decking inspection/repair on Small bridge on residential road

    I live in an allotment that has a bridge (rated at 25 tons) across a small creek ~30 ft span that consists of I beams between the abutments with timber deck boards (4X12) lag bolted into a board that sits on top of the I-beam (not sure I know the proper name of the component of a bridge?) The...
  9. larrym

    Modeling distributed generator(s) in a distribution feeder grid connection

    Thanks Had found GridLab-D earlier but not OpenDSS. Regards Larry Larry Mackey
  10. larrym

    Modeling distributed generator(s) in a distribution feeder grid connection

    I am looking for modeling tools that I can use to model a distribution feeder network that is fed power from substation(s) as well as one or more generators diversely located in the distribution grid. We have a project where we are looking at connecting one or more alternate energy generators...
  11. larrym

    CAN over T1

    If you are running data only on the T1 then it needs to be configured as a DS1. The T1 output from the westel box needs to connect to a router at each end that converts the T1 signal into ethernet that the Ethernet to CAN Bus media converters can connect to. As per usual...some assembly...
  12. larrym

    Reference Design for multiplexing RS232 channels

    We used a overclocking method that sampled each RS232 data channel at ~10X the data rate. At the time I think we used a small PLD that sampled 8 RS232 channels each using a 1MHZ clock which allowed us to pass 38Kbps serial data without any problems. It was a bit of overkill but the circuitry...
  13. larrym

    Reference Design for multiplexing RS232 channels

    Does anyone know of a reference design for multiplexing RS232 channels by over sampling each data channel as opposed to separate UARTS for each data channel at both end of the mux?? I have not worked down at this level in a number of years and got rid of all my reference designs a few moves...
  14. larrym

    Basement wall has I-beams

    This house is not in an incorporated city or township and permits are managed rather loosely by the county. While technically this would require a permit since the without a doubt is structural...since it was indoors...who knows. The house went under contract with someone else before we could...
  15. larrym

    Basement wall has I-beams

    True...the heaving slab is in the driveway...:-) Pouring a slab on a driveway with a steep incline and not securing it to anything......gravity does amazing things :-) So does winter road salt in our neck of the woods Larry Larry Mackey
  16. larrym

    Basement wall has I-beams

    KootK, I do appreciate the discussion and thoughts. While walking away from this house might be the easy thing to do... Doing some diligence on their part may allow them to get into a home at a really good price in exchange for some risk in the future. As long as they fully understand the...
  17. larrym

    Basement wall has I-beams

    Thanks to all for the responses. I love Eng-Tips forums... Yes, the I-Beams are vertical. I appreciate and agree with KootK that one of the major problems here is selling not buying this house. With the exception of this issue a few other cosmetic (paint, carpeting, etc. from the 1980's)...
  18. larrym

    Basement wall has I-beams

    My daughter is looking at buying a house that has rather substantial looking I-Beams evenly spaced along one wall in the basement. Basement wall is block. 1970-80's vintage. I don't see any indication of horizontal cracks. There is a obvious vertical crack to the left of the array of beams...
  19. larrym

    Budgetary costs and schedule for burial of power cables

    We are trying put together an initial budget for some alternate energy projects. Does anyone have a "rule of thumb" or SWAG for a budget to install buried 36KV power cables (2/0 conductors) along a major state highway (2 lane plus shoulders). We need to get the power from the alternate energy...
  20. larrym

    Modeling power distribution grid and distributed power sources

    I am trying to show a customer what happens to a distributed grid when a remote power source has a transient. I understand IEEE 1547 requirements for flicker, et al but would like to be able to provide a reasonably accurate analysis of what happens when a 10MW power source drops offline or...

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