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Single-Phase Recloser

Eaton/Cooper Power Recommended Maintenance Cycles:

  • Three years for oil-insulated, oil-interrupting type reclosers including: H, 4H, L, E, 4E, D, DV, Switches, & Sectionalizers.
  • Six years for oil-insulated, vacuum-interrupting type reclosers including: V4H, V4L, V4E, & VXE.
  • Six years for air-insulated, vacuum interrupting type reclosers including: Nova-TS

Per Bulletin B280-03008

Q. We are preparing for our yearly change-outs and are debating where to have the equipment repaired. Could you explain your service process?
A. We pride ourselves on attention to detail and comprehensive test procedures. We believe that this is what makes our work so reliable. There are many variables that come into play when servicing a unit, but here is a brief description of what we do to maintain/repair a single-phase recloser:At our shop we test the units’ insulation and continuity values and replace any wet or worn parts as necessary. All gaskets are changed including; terminal, bushing, head, and upper and lower coil gaskets. We evaluate the internal components searching for cracks, arcing, and carbon tracking. Also all units receive a thorough cleaning to remove carbon build up, new dielectric oil, and new tank liners. The units are then meticulously tested at our multi-amp on three different points of its timing curve and kept within plus or minus ten percent of that time curve as specified by Eaton/Cooper Power Systems. It is then painted and stenciled appropriately based upon the customer’s request and ready to be returned.
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 “Nova-TS” reclosers made by Cooper Power Systems. The “Nova-TS” has a feature called “Sequence Coordination” that will prevent those blinking lights when a fault is beyond a down line closure.

 

Three-Phase Recloser

Eaton/Cooper Power Recommended Maintenance Cycles:

  • Three years for oil-insulating, oil-interrupting type three-phase reclosers including: 3H, 6H, R, RE, RXE, RVE, W, WE, WVE, & CXE.
  • Six years for oil-insulating, vacuum-interrupting type three-phase reclosers including: V6H, VWE, VWVE, & VSO.
  • Six years for air-insulating, vacuum-interrupting type three-phase reclosers including: Three-phase Nova, Nova-STS, & VSA.

Per Bulletin B280-03008

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. 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 any blinking lights or prior indications of a fault. Even though, 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.Note: The “Nova-TS” and “Nova-STS” can be programmed to operate in a similar fashion.
Q. We had a fault on one of our lines that caused our Three-Phase Nova to trip and lockout. After we cleared the line, we returned to close in the breaker and found that when the breaker was given a “close” signal it would immediately trip again. What could have caused this?
A. From 2002 to 2014, the Three-Phase Nova was equipped with an “Encoder” to detect the position of the breaker. The “Encoder” was susceptible to dirt and dust and would sometimes be unable to read its position which would result in the breaker tripping open after receiving a close signal. This part has since been replaced by a “Dash-Pot” kit to eliminate the problem.Note: Similar occurrences can take place on type “R” and “W” Three-Phase reclosers when springs in the head mechanism have been stretched due to a faulty closing coil.
Q. We recently received some new Form 6 Three-Phase recloser controls and noticed that it had a “Non-Reclose” button and a “Hotline Tag” Switch. What is the difference?
A.
  • When “Non-Reclose” is activated and under a fault, the breaker will operate once and lockout. Its operating time is determined by what the customer has pre-designated as its first fast operation, or its first “TCC” time. “TCC” times can vary widely. Note: Even though the breaker has been tripped and locked-out under “Non-Reclose” conditions. The breaker can still be closed in both manually and remotely through SCADA.
  • When “Hotline Tag” is activated and under a fault, the breaker will operate once and lockout. Its operating time is dependent upon the applied control. If a Form 5 is in use, the control is set to a factory default and it overrides any “TCC” time curves. The breaker opens as fast as physically possible, approximately .05 seconds. If a Form 6 is in use, the “TCC” time curve can be altered from its factory setting to a user selected “TCC” time curve. Note: With “Hotline Tag” applied, any attempts to close the breaker will be overridden so long as “Hotline Tag” is active.
Q. I was having problems with one of my Three-Phase breakers not operating during a fault and the upstream breaker had to pick it up. The breaker had a Form 6 on it, so I brought it back to the office to download the sequence of events and oscillography. However, after finishing the download, I found that the sequence of events had transferred but not the oscillography. Why is this?
A. The control settings, parameters, and the sequence of events are all stored in non-volatile memory. However, the oscillography data is stored in volatile memory meaning that, once the control loses its 120vac and 24vdc power supplies, the data is immediately lost. If the oscillography data was to be saved to an external device it must be done either prior to the controls removal from service and subsequent power loss, or it must be transported with the 24vdc battery still connected to the control.

 

Single-Phase Regulator

Eaton/Cooper Power Recommended Maintenance Cycles:

  • Ten years, or 200,000 operations, if regulator is being operated at less than 50% load.
  • Four years, or 100,000 operations, if regulator is being operated at greater than 50% load.
Q. Its 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-7 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. I have a regulator that has a bad capacitor inside the tank and I need to step it back to neutral to remove it from service. What are the connections I need to make inside the cabinet?
A. There are a few different types of regulators. Here are the back panel positions and wire colors for the capacitor connections:               Cooper                             Siemens                      G.E.

Raise –     R/ Blue wire                    J / Black wire              27/ Red wire

Lower-    L / Green/Black wire        K/ Red wire                 28/ Green wire

 

Note: Be careful not to step the regulator up to its limit switch position (example 10% limit switch=step +16 or -16). If reached, due to the capacitors “temporary” positioning, the motor circuit will open and the regulator will be unable to step.

Q. We have all different kinds of regulators on our line and we are having trouble keeping straight which size capacitors go to which regulator. Is there some way to know what is what?
A. **All capacitors should be rated for 440 volts AC and for 100 degrees Celsius** 

Cooper                                         Siemens                                       G.E.

Spring Drive – 7.5uf                         Small Motor – 6.5uf                          All – 6.5uf

Direct Drive – 40uf pre-1994            Large Motor – 18uf

Direct Drive – 50uf 1994+

QD3 – 12uf

QD5 – 50uf

QD8 – 50uf

Q. We’ve been having problems with blinking lights on one of our single phase lines. However, after searching our fault data and checking our operations counters we cannot find the cause of the problem. Any thoughts on what it could be?
A. Try checking your up-stream single phase regulator for proper step voltage regulation. For example, a regulator on a 7200 volt line with a 60:1 ratio should exhibit approximately 45 volts change with each step taken. If it does not step-regulate properly the problem is likely a burnt contact or possibly one leg of the reactor has failed open. Either of these scenarios will cause blinking lights and can cause further internal and downstream failure if not attended to.

 

 Metering 

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.

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