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Q.It’s hunting season again in our area and someone shot the step position indicator on a pole mounted regulator. How can we determine neutral position so we can get this regulator out of service without de-energizing the line?
A.Contact our parent company for information on the “Neutral Position Detector” made by Hastings. You mount it on a hot stick and it indicates when the regulator is on neutral position. This is a great device that has proven itself well.
Q.A farm tractor got too close to a pole and damaged the control on an older regulator. What would you recommend for a replacement?
A.This would be a good time to upgrade to one of the new smart controls. We like the Cooper Power Systems “CRA”. It is their CL-5C control, packaged to work with any step voltage regulator. It comes complete with a new cabinet and is easy to install. Contact Us if you would like more information on retrofit control for step voltage regulators.
Q.This is driving us crazy. We have a single phase line and every time we have a fault on the line it blinks the whole circuit. Why does the backup recloser operate when the fault is beyond a down line closure?
A.Hydraulic single phase reclosers are usually configured for dual timing to coordinate with line fuses. Because of this feature, many times the backup recloser will operate on their fast curves when there is a fault on the load side of a down line recloser. You could consider using one of the new “VXE” reclosers made by Cooper Power Systems. The “VXE” has a feature called “Sequence Coordination” that will prevent those blinking lights when a fault is beyond a down line closure.
Q.We have some Cooper type 4C controls on our reclosers. Sometimes the event recorder shows a lower fault current value than we expect. What could explain this?
A.We have seen this type of event record when a down line device interrupts the fault during the time the 4C is sampling the fault current. Check the coordination with the down line devices when this occurs. This could help you improve your system coordination.
Q.Ever since we have had our new SCADA operating we have noticed one of our 7.2 kV circuit’s metering has always recorded a higher than expected ground current. We use the old rule of thumb for estimating expected ground current by subtracting the amp reading of the lowest phase from the current in the heaviest loaded phase.
A.We have seen this on another system. What we found was sometime in the past there must have been a low voltage problem on one phase of a grounded four wire system. Someone had installed two 100 kVAR single phase capacitors to give voltage support to that phase. No one had taken them off the line. Even when loading on the phases looked balanced, capacitive current that is not the same on each phase will be seen as ground current. A fuse out in a three phase bank will have the same affect. NOTE: The opposite affect may be noted if the capacitors are un-grounded. That is, the phase currents may be unbalanced while the ground current reading is not affected.
Q.One of our linemen lives on a circuit protected by a type 6H recloser. We can’t find anything wrong with the recloser but he reports his lights go out without ever recessing although the recloser is set for four operations to lockout.
A.The H family of Kyle three phase reclosers operate single phase during faults but open all three phases when lockout is reached. The fault is on one of the other phases. Keep a record of those phase counters.
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