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Frequently Asked Questions - Electrical
  • I already have surge protection on the power supplying my instrumentation, why would I need protection on the 4-20 mA loops as well?
    View answer
    • Transient current surges from nearby lightning strikes can be induced into your signal loops via remotely mounted 4-20 mA transmitters of various types and damage anything that is connected to the loop. Also, a surge protector installed on each instrument sharing a signal loop will save the other instruments if a surge is introduced through one of them.
  • Recently another water operator told me that I can use variable frequency drive on my single phase motors. Is this true?
    View answer
    • NO! A VFD can be used on a system that has single phase power coming in to control 3 phase motors. It does not have any control value for single phase motors. And remember always use VFD’s on inverter duty motors that are specially rated for this application.
  • I have a problem with my pumps causing water hammer, damaging the motors and other equipment, what should I do?
    View answer
    • Have you ever considered using a soft start with your pumps? It allows the motor to ramp up it’s speed on start up and ramp down on shut down, eliminating jack rabbit starts and abrupt stops, which contributes to damage of equipment.
  • I am tired of taking my 4-20 mA equipment out of service when I want to check my signal. Is there an easier way?
    View answer
    • Of course there is! Have you check out the Fluke 771 meter? It is a clamp meter that allows the user to check their signal without breaking the connection. All you do is clamp the meter around the wire and it will give you a reading!
  • Can we use a recycle timer in place of our interval timer?
    View answer
    • What you need to consider is that both units do a specific function. The interval timer is energized for a specific length of time after supply voltage is applied to the timer. the supply voltage must be removed to reset the timer. While the recycle timer will apply the supply voltage once the off cycle begins timing. When the delay is finished, the timer will energize along with the on cycle. the timer will continue cycling until the supply voltage is removed, on and off can be equaled or of unequal duration. So to answer your question, no you cannot substitute one for the other.
  • I heard that Siemens sold, can we still get their starters?
    View answer
    • Yes, they sold off the name along with the manufacturing of the units. Most of their starters are still in production, the ones that are not can sometimes be found on our suppliers shelves. If they are not, we have a vast supplier list and I am sure we can get one that works for your application.
  • We have a small water utility in the mountains and the well is about 2 miles away down the mountainside. We can not get a phone because of how remote the area is. What do you suggest for our application?
    View answer
    • Well, you are in luck. Right now wireless communication is all the rage. You have two bidirectional point to point communication units which allow you to have the control in one location and transfer information for control to another location. The units use rapidly hopping sound waves to transmit the signal, giving you reliable, fast communication. They will work in clear areas along with wooded areas depending on the antenna and mast requirements. A range of 30 miles can be achieved depending on the addition of repeaters and antennas.
  • What can you tell us about using solar to run our flow meters out in the field?
    View answer
    • The small solar packages offer a great power source for small instrumentation in remote locations where electricity is not available. Used with a 12v deep cycle battery can power your instruments for hours. Be sure you orientate the unit towards the sun as much as possible to insure the maximum solar hours available, and face them due south.
  • Everyone stresses that you have the correct frame size when ordering a motor. Is it really that critical or can I order a 213 frame when my motor says 213T?
    View answer
    • You really need to purchase a motor with the same frame size as the one you are replacing: it determines the shaft size of your motor. Please look at the chart below showing the correlation of frame size and shaft size.
      Motor frame size
      Click her to enlarge
  • What does NO and NC mean as applied to electricity?
    View answer
    • A simple way to illustrate the difference is to simply draw a circle, but don’t connect the two ends, this would represent an open circuit or normally open (NO). This means that the electrical current can not complete the circuit allowing power to connect. Then continue the circle around until it connects the two ends, this is a normally closed (NC) circuit. Allowing the current to complete its intended path.
  • Why is this important to know?
    View answer
    • This will tell you which switch will provide power and which will not. In a level application where floats are used it will determine a pump up or pump down application.