1.0 SAFETY NOTICES
RCW Type recloser should be installed within the design limitations as described on its nameplate and in these instructions.
Follow your company’s safety procedures.
This recloser should not be used by itself as the sole means of isolating a high voltage circuit. For the safety of personnel performing maintenance operations on the recloser or connecting equipment, all components should be electrically disconnected by means of a visible break and securely grounded.
This product is intended to be operated and maintained by qualified persons thoroughly trained and knowledgeable of the hazards involved. This publication is written only for such qualified persons and is not intended to be a substitute for adequate training and experience in the safety procedures for this device.
Detailed descriptions of standard repair procedures, safety principles, and service operations are not included. It is important to note that this document contains some warnings and cautions against some specific service methods that could cause personal injury to service personnel, or could-, damage equipment or render it unsafe. These warnings do not cover every conceivable way in which service (whether or not recommended by ROCKWILL) may be done or possible hazardous consequence of each conceivable way, nor could ROCKWILL investigate all such ways. Anyone using service procedures or tools, whether or not recommended by ROCKWILL, must satisfy himself thoroughly that neither personal safety nor equipment safety will be jeopardized by the service method or tools selected. All information contained in this manual is based on the latest product information available at the time of printing. The right is reserved to make changes at any time without notice.
In the interest of clarity, a single identification number is used for each individual item throughout this book in every relevant figure or diagram.
These instructions do not attempt to provide the user of this equipment with every possible answer to questions which may occur in the application, operation and maintenance of the product. Also, as improvements in parts and assemblies are made, some parts may differ in appearance than depicted in illustrations; however, functionality will be equivalent.
The type RCW vacuum recloser is a sophisticated, high-voltage, three-phase device incorporating three vacuum interrupters. Together with the specialized control functions, the recloser will sense an overload and automatically open. Then after a pre-set time delay, the recloser will close again. If the overload condition still exists, the recloser will again trip and reclose. RWK-351 Type Automatic Recloser controller will allow up to four reclosing operations before the recloser will lock open. The source of the fault condition must then be removed before normal service can be restored.
Satisfactory performance of the recloser is contingent upon correct installation, adequate maintenance and service of the product. Careful study of these instructions will permit the user to obtain maximum benefit from this device.
3.0 RECEIVING AND STORAGE
Each recloser is assembled and tested at the factory prior to being prepared for shipment. This equipment is packed and shipped in perfect condition from the factory. If damage is noticed, pls notified us.
3.1 Receiving Inspection
Upon receipt, it is important to inspect promptly to be certain that the correct material has been received. In case of shortage,pls contact ourcompany. Check all parts against the shipping list as they are unpacked. Instructions and literature packed with the recloser should be kept with the unit. The low-voltage control cabinet provides a convenient place to keep this instruction book, a copy of the schematic diagram, and the card carrying the service record of the unit.
If the recloser is not to be placed in service immediately, it is essential that proper care be exercised in handling and storage to ensure good operating conditions in the future.
For prolonged storage, indoor storage is recommended. If either cabinet is stored outdoors, there are two options to prevent condensation problems. The first option consists of energizing the anti-condensation heaters inside the high voltage cabinet and the low voltage control cabinet. This can be done with cable that connects the high voltage cabinet or the low voltage cabinet to energize the heaters. The second option is to have each unit pretreated at the factory with a special vacuum wrapping to prevent water penetration. See factory representative for more information.
The low voltage control cabinet comes with rechargeable batteries that should have power of the proper voltage and frequency supplied to the input of the charger assembly. A periodic check of battery voltage is also advised.
4.0 GENERAL DESCRIPTION
4.1 High-Voltage Assembly
The high-voltage assembly of the RCW recloser consists of three individual phase poles mounted onto a common housing. Each of poles is a separate module comprised of a vacuum interrupter and current sensor encapsulated in Polyurethane (Molded pole assembly), coupled to a magnetic actuator.
The position indicators for each phase are mounted in the floor of the cabinet and are visible from below. The recloser nameplate that shows rating information, serial number, and shop order number is mounted on the right-hand side of the housing. A heater is provided to prevent condensation.
4.3 Pole Assembly
Picture at the end of the article shows the details of the pole assembly. The top terminal stud (1) is attached directly to the fixed contact stud on the top end of the vacuum interrupter (3). The current transfer assembly housing (10) is fastened to the opposite end of the vacuum interrupter. In the current transfer assembly, contacts transfer current from the moving contact of the vacuum interrupter to the current transfer assembly housing, which is directly connected to the lateral stud terminal (4). The lateral stud terminal passes through a ring-type current sensor (5)
before it exits the molded assembly. The two leads carrying the transformer’s secondary current output are also encapsulated and brought down to a terminal block mounted on the actuator assembly. If the control cable is disconnected while the recloser is carrying load current, resistors are installed on the terminal block across the CT leads to prevent open circuit conditions. The stainless steel mounting flange is attached to the molded pole assembly by four bolts, two of which also provide support for the magnetic actuator.
4.4.1 Low Voltage Control Cabinet
A separate weatherproof cabinet houses the low voltage control components. A hinged panel allows front and rear access to the control components. Other devices can be mounted on the side walls of the cabinet. Connections to the recloser are made through a plug-connected, shielded 24-pin cable. The hinged door has provisions for a 1/2 inch diameter padlock shackle.
For power, communication, and control inputs to the control cabinet, the floor is equipped with removable access plate and two knockout holes. A knockout is also provided for a radio antenna connection. A 45 W thermostatically controlled heater is provided to prevent condensation. (Note that the thermostat only controls the control cabinet heater. The recloser cabinet heater is constantly energized.) A typical unit comes standard with 48 VDC batteries. These batteries are rated to last 48 hours during a loss of AC if fully charged. The batteries should be checked periodically and replaced every three to five years.
4.4.2 RWK-351 Controller
The control supplied with the RCW is the microprocessor-based PCD Power Control Device. This sophisticated controller integrates most of the normal recloser control functions into a single device, providing a wide range of metering and remote control options. For details on programming, operating, and testing the PCD refer to Instruction book IB38-737-1. For details on the overall control circuit, refer to the specific wiring diagrams supplied with the recloser. Table 2 below shows voltage and power requirements for the RCW recloser with a PCD control.
|VR-3S Power Requirements|
|Nominal Control Voltage||Allowable Voltage Range||Nominal VA Burden*||Maximum VA Burden*||Anti-Condensation Heater VA Burden|
|48 VDC||38-56 V||20||See below**||N/A|
|125 VDC||100-140 V||20||See below**||N/A|
|120 VAC||104-127 V||30||75||45|
|240 VAC||208-254 V||30||75||45|
5.0 STANDARD PRODUCTION TESTS
Standard production tests include:
1. Verification of all wiring per connection diagrams.
2. Electrical operation: Close and trip. Overcurrent response and automatic reclosing.
3. Check functioning of all manual controls on the RWK-351: Local/remote, non-reclosing, ground fault bypass, etc.
4. Three readings of contact pole resistance are made on each phase of a complete recloser. Typical values do not exceed 150 micro ohm (.00015 ohms).
5. 60 Hz Voltage Withstand: The complete recloser is tested (a) between live parts and tank, (b) across open contacts, and (c) between phases. In compliance with ANSI C37.60, applied test voltage is 50 kV for 15.5 kV rated maximum voltage, 60 kV for 27 kV rated maximum voltage, and 70 kV for 38 kV rated maximum voltage. Test duration is 1 minute.
6. Wiring Insulation: The terminal block connections (with the foil leads and microprocessor controller) are given an over-voltage test of 1500 volts AC to ground.
In the open position, the armature rests against the non-magnetic spacer in the actuator assembly. The armature is held there by the opening spring and a small force developed by the magnet. When the coil is energized with the correct polarity, the magnetic flux generated is in the same direction as the magnet assembly. The armature is drawn into the coil and brought into contact with the upper pole piece. In this position, the coil is de-energized and the armature is held in position by the magnet alone. As the armature is drawn into the coil, the operating rod (6), which is attached to the top guide rod, moves the moving contact of the vacuum interrupter (3) towards the closed position. The actuator has more stroke than the vacuum interrupter. The interrupter contacts make contact before the actuator has completed the stroke. The additional movement of the operating rod after the contact closes is needed for the contact pressure spring to compress at the top of the operating rod. This “over travel” allows for contact wear in service and provides low contact resistance.
When the coil is energized with the reverse polarity, the magnetic flux generated opposes the force generated by the magnet assembly. This reduces the holding force and the armature is released. The opening spring (with an initial assist from the contact pressure spring) drives the operating rod to the open position.
7.0 OPERATIONAL CHECK PRIOR TO INSTALLATION
The recloser should be tested for mechanical and electrical operation before it is energized in the power system. Make the necessary control power connections, including the cable between the high voltage compartment and the low voltage control cabinet. If necessary, remove the cover of the high voltage compartment to observe the mechanical operations.
Caution: Do not ground either side of the battery or attach ground to the terminals of the actuator operating coils.
This will result in permanent damage of the unit.
7.1 Electrical Close - RWK-351
Observe the position-indicating LED located between the Open and Close pushbuttons on the front panel of the RWK-351. If the LED is green, the recloser is open. To close, depress the Close push button. The RWK-351 will initiate a closing pulse to each actuator simultaneously and the recloser will move to the closed position and the LED will change to red. The duration of the closing pulse is precisely controlled by the RWK-351.
7.2 Electrical Trip - RWK-351
Observe the position-indicating LED located between the Open and Close pushbuttons. If the LED is red, the recloser is closed. To trip, depress the Open push button. The RWK-351 will initiate a tripping pulse to each actuator and the recloser will move to the open position. The duration of the tripping pulse is controlled by the PCD.
Note: In the event of a malfunction, the indicating LED will blink Red/Green.
The front panel of the RWK-351 also has control push buttons for several standard recloser functions. When these functions are activated, an LED adjacent to the push button provides indication.
7.3 Vacuum Test
Run an over-voltage test on each interrupter to verify that there has been no loss of vacuum during transportation or handling. Experience has indicated that while a vacuum interrupter with the vacuum seal intact will withstand 35 kVAC across the open contacts, the same interrupter open to normal atmosphere will flashover at the gap at a much lower voltage.
High voltage applied across an open gap in a vacuum can produce X-radiation. No radiation is emitted when the recloser is closed since no gap exists. Also, when the recloser is open to the specified contact spacing in service or tested within the voltages specified, X-radiation at one meter is below the level of concern. A danger could exist at voltages above or contact spacing below that specified on the nameplate.
1. With the recloser in the open position, jumper the three top terminals together. Connect the three lateral terminals and ground the lateral terminals and the housing. Connect the high voltage to the top terminals.
2. Stand clear more than one to three meters before energizing the high voltage source.
3. Do not exceed 37.5 kVAC and do not apply voltage for more than 60 seconds.
4. If internal flashover occurs, isolate the phases and test each one independently to identify the defective interrupter. Any defective pole assembly must be replaced prior to the recloser being placed in service.
The VR-3S recloser can be installed in a substation frame, pole-mounting frame, or can be mounted into a customer supplied structure. However, it is required that in all of the mounting methods the recloser be vertical and level, and securely fastened. Follow your company guidelines and various codes for setting the height of the recloser, securing the frame to the pole or foundation, and making connections.
The recloser is shipped with either a pole mounting frame, substation frame or no frame.
The following is the recommended installation procedure for each frame:
8.1.1 Pole Mounting
For pole frames, do the following:
1. Attach the lifting brackets to the sides of the recloser as indicated in the section on lifting.
2. If the frame is not shipped assembled, put it together on a flat surface per the assembly instructions. Follow the drawing closely, making sure to use the correct bracket for mounting the recloser frame to the pole.
3. Install mounting bolts (not supplied) in the pole for the recloser and the control cabinet.
4. Lift the recloser by the lifting bracket at four points and bolt the frame to the two holes on the bottom of the bracket at both sides of the recloser.
5. Once mounted, lift the assembly onto the bolts in the pole. If Voltage Transformers (VTs) are used, it is recommended to install the frame without the transformers and then install them once the recloser and VT mounting brackets are on the pole. Alternatively, if it is desired to mount VTs on the frame before mounting the frame on the pole, do the following: Without mounting the recloser to the frame, install and wire the VTs on the frame and lift the frame up onto the pole using a four point lift at the corners of the frame. Then, with the lifting bracket attached to the recloser, lift the recloser up onto the frame and bolt into place.
6. Bolt the pole-mounting bracket to the control cabinet and then bolt the control to the pole.
7. Make sure all hardware is tight.
CAUTION: DO NOT EXCEED 50 LBS FORCE ON ANY OF THE TERMINALS IN ANY DIRECTION. FAILURE TO COMPLY WILL RESULT IN PERMANENT DAMAGE!
8.1.2 Substation Mounting
1. With the lifting brackets mounted to the substation frame, lift the frame off the pallet and move into position.
2. Bolt the frame to the pad and raise the upper portion to the desired height. The frame allows adjustment in 3” increments (see Figure 11: the substation frame drawing).
3. Remove the lifting brackets from the frame and bolt to the sides of the recloser.
4. Lift the recloser over the top of the frame and lower into place.
5. Bolt the control cabinet to the cross-members on the side of the substation frame.
6. Make sure all hardware is tight.
8.1.3 No Frame
1. With the lifting brackets mounted to the recloser, lift the frame off the pallet and move into position.
2. If an alternate customer-provided bracket is used for mounting the recloser, use caution when lifting the recloser. Do not lift the recloser by the poles, as this may cause damage to the poles.
3. If a forklift is used to raise the recloser from the bottom, use caution to avoid damaging the open/close indicators below the high voltage cabinet.
The recloser high voltage cabinet includes a standard NEMA 2 hole drilled stainless steel pad on the rear for grounding. Any voltage transformers used should be grounded to the main ground wire leading from the recloser to ground. To ground the low voltage control cabinet, use the connector provided (see the shipping bag in the control cabinet) which accepts a #6 - 2/0 AWG conductor. Ground the control cabinet to the main ground wire from this external connector. All ground wire used must be #6 AWG minimum. Both the high voltage cabinet and low voltage control cabinet are to be firmly grounded in series when installed. Grounding is important to ensure proper operation of all electronic components to prevent penetration of EMC noise and other transients into the sensitive electronic circuits (RWK-351, modems, radios, etc.)
8.3 Arrester Protection
Surge arresters must be supplied on both the source and load sides of the recloser. It is recommended that the arrester grounds be connected to the recloser ground and continued to the pole ground. The leads connecting to the arresters should be as short as feasible to limit stray inductance and to maximize the arrester’s effectiveness.
8.4 Control Power
Supply the control power as indicated on the wiring diagram. If 240 VAC is used, verify the connections for the heaters and the isolation transformer before applying power. The ground fault receptacle, if supplied, may need to be energized by the user by connecting the Hot and Neutral to the desired source. If the control is supplied with an optional 2-pin power connector and 10’ power cable, connect the AC source to this cable. Otherwise, one of the knockouts may be used or the removable plate drilled to suit for conduit. Three phase voltage wiring is provided from the recloser to the low voltage control cabinet terminal block and then on to the voltage inputs on the PCD control for metering and voltage dependent protection purposes. When the recloser cabinet is supplied with a 5-pin connector at the bottom, the customer may connect the VTs through the recloser as shown on the wiring diagram. Otherwise, wire the three VTs directly to the terminal block in the control cabinet. It is not necessary to wire any voltage inputs directly to the back of the PCD relay. If it is desired to obtain control power from one of the three VTs used for metering, jumpers must be added to the control cabinet to connect one of the voltage sources to the control power input. Following the wiring diagram, in the control cabinet, add a connection from terminal block point VA1 (alternatively VB1 or VC1) and VN to the control power inputs. Check all terminal block connections for proper tightness. For details of the overall control circuit refer to the specific wiring diagrams supplied with the recloser.
8.5 Line Connections
The recloser is connected in series with the line and does not require to face one direction or the other. However, there are two considerations:
1. The voltage transformer used for supply power must be installed on the source side of the recloser in order to avoid unnecessary drain on the battery backup system when the circuit is open at the recloser.
2. When voltage transformers are used for metering and protection purposes, they must be installed on the source side. The top terminal of the poles must also be connected to the source side. This is necessary for proper power flow metering, and for the directional protection elements to work according to programmed settings.
8.6 Final Inspection
When the recloser has been installed and all mechanical and electrical connections completed, EXCEPT ENERGIZING THE POWER LINE, the following points of inspection are recommended:
1. Ensure the recloser is properly leveled and securely anchored.
2. Make a final check of tightness of all hardware.
3. Securely tighten terminal and ground connections.
4. Check control cable entrance fittings for tightness.
5. Ensure that the high voltage and low voltage control cabinets are grounded.
6. Operate the recloser from the control box to verify normal operation.
7. If the relcoser has been improperly stored or it is suspected that the unit was handled roughly during shipping, it is advisable to check the recloser alignments (VI open gap, VI contact wipe, microswitches, etc.)
9.0 INSPECTION MAINTENANCE AND ADJUSTMENT
The RCW is an extremely simple device and will require minimal maintenance if handled properly and depending on the frequency of operation and local environmental conditions.
To a large extent, the safety and successful functioning of any apparatus or system connected with the recloser depends on the proper installation commissioning and programming of the unit.
To provide long, reliable service, the recloser should be inspected at regular intervals. Operating experience,
environmental conditions, the number of operations, the magnitude of current and any unusual service conditions
will guide you in establishing a maintenance schedule. The following check list is a minimum guide:
1. Check the molded pole assemblies for external damage and clean if contamination is evident. The poles the can be cleaned with de-natured Alcohol.
2. Check contact wear. As a vacuum interrupter continues to switch current, material from the contacts slowly erodes away, and the moving contact is driven deeper into the interrupter by the operating mechanism. The over-travel spring at the upper end of the operating rod ensures that proper contact pressure is maintained in the closed position. Contact erosion reduces the compression of the over-travel spring, which in turn increases the contact travel (Total travel of the actuator is fixed). A gauge is provided with the recloser to allow easy confirmation of the allowable contact erosion. (Ref Figure 6.) Raise the operating rod using the lever on the underside of the adapter (04) until the contacts touch. Contact touch can be verified by using a continuity meter.
Contact touch is not the same as the unit being closed because, when the unit is in the full closed position, the operating rod travels the distance of contact touch and then travels further by depressing the over-travel spring.
Verify the contact wear using the gauge by inserting the short side of the gauge between the base of the actuator and the flange nut. If the short side of the gauge will fit into the space, no adjustment is required. If the short side of the gauge will not fit into the space, the entire interrupter pole assembly should be replaced due to excessive contact wear.
3. Verify that the recloser operates correctly using the electrical controls.
4. A Hi -Pot test can be performed to verify the vacuum integrity.
RADIATION WARNING: High voltage applied across an open gap in a vacuum can produce X-radiation. No radiation is emitted when the recloser is closed since no gap exists. Also, when the recloser is open to the specified contact spacing in service or tested within the voltages specified, X-radiation at one meter is below the level of concern. A danger could exist at voltages above or contact spacing below that specified on the nameplate.
A. With the recloser in the open position, jumper the three top terminals together and the three lateral terminals. Ground the lateral terminals and the housing. Connect the high voltage to the top terminals.
B. Stand clear more than one meter before energizing the high voltage source.
C. Do not exceed 37.5 kV and do not apply for more than 60 seconds.
D. If internal flashover occurs, isolate the phases and test each one independently to identify the defective interrupter. Any defective pole assembly must be replaced prior to the recloser being placed in service.
5. Contact Resistance: Measure contact resistance with suitable equipment rated not less than 100 A. The value should not exceed that shown in the rating table.
1.Top Terminal Stud; 2.casing; 3.Vacuum Interrupter; 4.Lateral Terminal Stud; 5.voltage transformer; 6.Insulation rod；7.Operating mechanism；8.nut； 9.Controller cable socket； 10.current transformer