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Recent content by justint

  1. justint

    Web Design and Process Control

    Hi I work with PLC and SCADA applications. Reacently we have been looking at monitoring our systems remotely, changing and monitoring variables via SMS, remote access to HMI etc. I have been thinking strongly about making a web page that would allow me to display and alter variables from any...
  2. justint

    Electrical power question

    Just had an after thought there and another look at the results. It seems that it isnt always the same phase current that is different than the other 3. Could it be that the power meter is taking a very quick sample each minute and is capturing instantaneous current on the wave form as they rise...
  3. justint

    Electrical power question

    Hello again. Ok, have been monitoring a number of parameters from my smart power meter now for over a week. The meter applies a CT to each of the incomming 3 phases and a connection to each phases voltage. While on site the current that we were seeing on the power meter was the same as the...
  4. justint

    Electrical power question

    Ok, have a better understanding of whats involved now. Thanks for the help. Justin
  5. justint

    Septicity Dosing guidelines

    Hi We are in the process of designing a septicity dosing system for a waste water pumping station to reduce the H2S04 further up the rising main, we are planning to dose with Nutriox (calcium nitrate) From looking at existing systems I can see that the inputs to the system are mainly the level...
  6. justint

    Electrical power question

    Ah so the KVAr is measured to be able to work out an average (if not totally accurate) power factor for the month that can be used to check if the power factor is within limits? From what I can see tho, I have either an option of a unit that provides KWHr information OR KVArHr. Surely this isnt...
  7. justint

    Electrical power question

    Thanks I have tried getting information from the supply company but am still waiting for someone from the industrial pricing section to get back to me. I have a smart power meter in at the moment (Socomec Diris A40) that Im extracting information on KVArH via modbus. Im presuming this is KVA...
  8. justint

    Electrical power question

    Hi Im involved in a project where I am setting up a system to remotely monitor the energy consumed by a industrial plant with a number of motors, pumps etc. Im in Ireland. I have gotten to the stage where I can send a CSV file each hour that lists the instantaneous KW, KVA, KVAR, power factor...
  9. justint

    Yaskawa Drive

    Thanks Skogsgurra When I posted the above I only had the brochure for the drive which stated 400V. I was a little worried that if I was installing on a site that the voltage may be 415 or 420, would this affect the operation of the drive and subsequently the pump motor. I have since found the...
  10. justint

    Yaskawa Drive

    Hi I have come across Yaskawa J1000 family of inverters and am considering purchasing one to control a pump on a variable frequency. I have read a few posts in this forum where the voltage used was slightly different to the rating of the inverted and this led to over excitation and tripping...
  11. justint

    Capacitor size for motors

    Hi Is there a calculator or rule of thumb to use for selecting start and run capacitors for single phase inductance motors if i know the supply voltage and current ratings for the motor. I normally refer back to the manufacturer but was hoping for an alternative method. Justin
  12. justint

    Sump pump with small flow rates

    The filter uses ultra filtration but the main point about it is the trans pressure across it and the flow rate required through it via the pump. ie 0.2 bar across it and 70 l/hour through it
  13. justint

    Sump pump with small flow rates

    The filter is in the botton of the sump. The pump sucks the water from the sump through the filter so it has to lift the water from the pump a distance of 1.5 metres and the trans filter pressure is 0.2 bar resulting in another 2 metres to the suction head (3.5 metres in total), 4 metres with a...
  14. justint

    Sump pump with small flow rates

    Hello Im searching for a pump for lifting water from a sump through a filter. The max distance to lift is 1.5 metres and the filter requires another 0.2 bar of suction. I require a pump with suction head of 4 metres but the flow rate must be kept at 70 l/hour. Does anyone have any...
  15. justint

    UltraSonic Level Sensor

    Thanks! danw2, what kind of money would i be looking at for the probe LU? justin

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