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  1. abl33

    Combining multiple CTs and dealing with bi-directional flow

    The existing CTs and PTs are connected to the MV side of our equipment. they are physically inside the MV disconnect switches on the side of the switch between the switch and the transformer. The meters use the PTs for voltage to convert the 13.2kV to 120V for the meter and use the CTs as is...
  2. abl33

    Combining multiple CTs and dealing with bi-directional flow

    Bill, I know "normally", when the assumed flow of the current is in the same direction, that joining CTs this way provides good information for this purpose, but does is that still valid when you have changing directions of flow on either CT? As for if it that or moving the CTs to an upstream...
  3. abl33

    Combining multiple CTs and dealing with bi-directional flow

    The issue isn't with the physical meters, but a limitation with the accounting software. They are able to aggregate multiple importing meters and combine them for billing. We currently have two meters that are handled this way. The problem is that apparently the software cannot aggregate...
  4. abl33

    Combining multiple CTs and dealing with bi-directional flow

    Our company is looking to expand a PV solar installation at our facility and because of accounting limitations with the local utility we may need to find a hardware solution to address what they cannot do in software. At present, our single utility feed comes in to two 13.2kV switches which...
  5. abl33

    How to determine Ice cooling rates

    so what you three are saying is that you don't know the answer, so you would rather avoid the question? As I mentioned, this was originally direct refrigerant, but that solution is not capable of the turndown ratio and response time required. I won't get into all the reasons why refrigerants...
  6. abl33

    How to determine Ice cooling rates

    if this was a batch process, I'd consider crushed ice a viable solution, but this is a continuous process with a variable load up to 120,000 BTU. Beyond the fact that crushing ice is more complicated to produce than ice rods and requires moving parts which would be more susceptible to breaking...
  7. abl33

    How to determine Ice cooling rates

    I don't think it is arbitrary at all, but I'll restate it in case that helps. I didn't leave specific numbers at the beginning because I'd rather have a formula than just a value so I can apply it under other conditions (like if I instead increased the water temperature to 35F). "How much...
  8. abl33

    How to determine Ice cooling rates

    "However when you do even a little bit of research, you find that the water ice interface zone is a complex, uncertain area of physics and not studied well. But whatever it is as the temperature difference between the ice and the water gets smaller and smaller the required surface area will get...
  9. abl33

    How to determine Ice cooling rates

    Sorry for the confusion. I do not care about the temperature uniformity within the ice bath tank. I care that the water I draw out of that tank is always 34F and never goes over a maximum of 35F nor under a minimum of 32F. My intention in mentioning the current uniformity of the temperature...
  10. abl33

    How to determine Ice cooling rates

    Definitely sorry if I offended anyone in my responses. That is definitely not my intent. When the tank was built, we didn't consider the water-ice barrier to be a capacity constraint at all and instead designed it for ease of fabrication... the tank is a cylinder with the return at the top...
  11. abl33

    How to determine Ice cooling rates

    that was the first thing we tried. Technically there is always room for "more" movement, but I do not believe it is our solution here. I've tried to survey the water temperature around a number of locations and the water temperature does not have a large variation (generally +/- 1F) I'm...
  12. abl33

    How to determine Ice cooling rates

    For a couple reasons. 1. The load is both moderately variable over a short duration and over the course of the year has a >10:1 load change. The system used to use direct refrigerant, but the variable loading and the resulting cycling was both terrible for process consistency which caused...
  13. abl33

    How to determine Ice cooling rates

    sorry for the delayed response. I checked the notify me box but it didn't do anything. Its 60kBTUh - 5Ton. per stage. I plan on three stages. Thats what, about 17.5kW per stage. I know fast moving water with crushed ice/slush would give the most surface area and therefore the highest...
  14. abl33

    How to determine Ice cooling rates

    I have an application where I need to use an ice bath to store cold for an application requiring a constant feed of cold water just above freezing and while I can determine the mass of the ice required to prevent equipment short-cycling with a variable load, I'm not confident in my ability to...
  15. abl33

    Salvage a type K TC probe reading from a type J meter

    >Yup. It is a custom, multiple thermocouple source and an operating range characterization of the hot junction would be valid only under the assumption that the intermediate junctions are held at a constant temperature at whatever temperature the characterization occurs. If the intermediate...
  16. abl33

    Salvage a type K TC probe reading from a type J meter

    It is not physically possible to replace the TC in that part, so a replacement TC in this situation will not do us any good. The part is used as temperature monitoring sample for processing other similar parts and it is not possible to change any of the physical items I mentioned above. The...
  17. abl33

    Salvage a type K TC probe reading from a type J meter

    Not a bad idea. I'm concerned about a couple key temperature points. 125C and 40C being the two most critical. I might be able to take a meter setup for type J, connect a type J extension to it and plug in a type K thermocouple to that all within a temperature controlled space and observe...
  18. abl33

    Salvage a type K TC probe reading from a type J meter

    I've run into an issue where a part was produced with a TC that was specified to be type J, but was delivered as Type K. It is impossible to replace this TC without replacing the entire parts which is something that we really want to avoid. My problem is that this part will go into a vessel...
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