15kv/27kv/38kv Distribution Line Electronic Sectionalizer

Introduction
The electric sectionalizer has been developed for use on overhead distribution lines to improve reliability and service continuity. It enhances the protection of the distribution system in a simple, economical way which is free from maintenance and spares. Statistics indicated that 70% - 90% of fuse cutout operations are in response to transient faults. The electronic sectionalizer enables customers to better manage these types of transient faults. It is designed to substitute a fuse cutout, ensuring effective isolation only in the event of a sustained fault. It remains unresponsive to transient faults. The sectionalizer is a self-contained device, designed to be used in a coordinated overcurrent protection scheme with automatic reclosers.
The electronic sectionalizer is not a fault interrupting device.
Application
The sectionalizer is designed to be installed in traditional fuse cutout mounts, in lieu of the fuseholder. It is also suitable for ganged cutout mounts providing two or three pole operation. The electronic sectionalizer operates in the same way as an expulsion fuse cutout. Its "drop-down" manner makes it easy for field staff to readily identify fault affected overhead lines. The sectionalizer operates during the "dead" time of the automatic recloser, when there is no voltage on the system. It eliminates the emission of sparks during the tripping operation, which reduces the risk of fire.
Construction
The sectionalizer is designed to withstand the mechanical forces generated by high fault currents. Its design also caters for the durability needed with repetitive hook stick closing in harsh outdoor environments.
The electronic sectionalizer incorporates electronic logic and trip circuits which are controlled and powered by a dual core current transformer mounted on the copper conductive tube. 
The current transformer is mounted externally to the conductive tube and encapsulated in a durable weatherproof epoxy. 
The electronic circuit provides the necessary intelligence for counting recloser tripping operations and provokes the opening of the sectionalizer at the appropriate time. The electronic circuit is encapsulated with epoxy, within the environmentally sealed conductive tube. The tube acts as a faraday cage, protecting the electronic circuit from the influence of magnetic fields.
Tripping is achieved when a solenoid located in the lower half of the conductive tube is energized and the trip arm is released enabling the hinged trunnion to collapse.
Construction
The sectionalizer is designed to withstand the mechanical forces generated by high fault currents. Its design also caters for the durability needed with repetitive hook stick closing in harsh outdoor environments.
The electronic sectionalizer incorporates electronic logic and trip circuits which are controlled and powered by a dual core current transformer mounted on the copper conductive tube. 
The current transformer is mounted externally to the conductive tube and encapsulated in a durable weatherproof epoxy. 
The electronic circuit provides the necessary intelligence for counting recloser tripping operations and provokes the opening of the sectionalizer at the appropriate time. The electronic circuit is encapsulated with epoxy, within the environmentally sealed conductive tube. The tube acts as a faraday cage, protecting the electronic circuit from the influence of magnetic fields.
Tripping is achieved when a solenoid located in the lower half of the conductive tube is energized and the trip arm is released enabling the hinged trunnion to collapse.
Operation
The sectionalizer is inactive under normal load conditions.
The electronic sectionalizer recognizes any fault as an overcurrent. If the fault current is higher than the preset pick-up current, the sectionalizer becomes active. It awaits an open operation from the upstream automatic recloser. At the occurrence of a current zero, the sectionalizer registers the first count. If the upstream automatic recloser closers and no further fault is detected within the reclaim time, the sectionalizer will timeout and return to an inactive state. However, if the upstream automatic recloser detects the fault is still present, the sectionalizer registers a second count at the next current zero and this process continues.
When the sectionalizer reaches the preset number of counts, it trips the fault affected circuit during the 'dead' time of the upstream device
Counts 
The number of counts differentiates real faults from transient faults. When the preset number of counts is registered, the electronic sectionalizer will operate. 
The sectionalizer can be set to 1, 2, 3, or 4 counts. It registers a count when a current dead time exceeding 200 milliseconds occurs, immediately after a current pick up. This ensures the sectionalizer only registers a count when a recloser has tripped due to a fault current.
The count setting should be one count less than the immediate upstream recloser.
Pick up current
The pick up current is the threshold, which must be exceeded in order to register a count. The pick up requires a minimum
fault pulse that is 10% greater than the pick up current setting and is longer than 20 milliseconds in duration. Resetting
The electronic sectionalizer will reset itself during the drop out operation.  Do not need remove the unit from its mount using a hook stick and reset it manually. 
Service conditions 
a) The ambient air temperature is not above 55ºC or below -40ºC.
b) The average value of the ambient temperature, measured over a period of 24h,does not exceed 25ºC.
c) The altitude does not exceed 1000 m (3300ft).
d) The wind speed does not exceed 34 m/s (corresponding to 700 Pa on cylindrical surfaces).
e) The ice coating does not exceed 1mm.
f) The sectionalizer should not apply to those flammable, explosive, corrosive and severe vibration conditions. As to other service conditions not covered in the manual, please contact and consult with the manufacturer for detail information.
Technical data 
Rated voltage: 38kV
Lighting impulse: 185kV
Rated continuous current: 200A
Rated 1s current: 10kA
Rated peak withstand current: 20kA
Rated actuating current: 8 to 400A Reclaim time: 20 ±5%s
Operation counts: 1-4
Sensitivity of pick up current: ±10% Max. load current prior to operation: 0.3A Total operation time: 200ms
Min. recloser dead time: 500ms
Min. duration of fault pulse: 20ms Selection list
Sectionalizer setting guide
1. Current setting
The sectionalizer current setting must be selected at 20% below the minimum associated recloser or circuit breaker trip current.
2. Number of count setting
Generally the number of count settings should be 'one' less than the number of trips to lockout of the recloser or circuit breaker.
Every type of sectionalizer has four pickup current and four counting times which are settable on site, the configuration method is described in the diagram and table below. Firstly dismantle M5 screws by special spanner to remove the upper contact on the upper end of conducting rod, then pull out red glue seal, red on-off switch can be seen.
There are four switches with white color, switch 1 and two are for pickup current, switch 3 and 4 are for counting times. Please see the methods showed in table  below, then different pickup current and counting times can be get by different combinations.
After configuration, please re-install glue seal and upper contact. Please pay attention to upper contact, it must be connected with conducting rod tightly, then fix screws. 
When the sectionalizer operates the lever is released thus unlatching the mechanism and the sectionalizer is then free to drop-out.
The sectionalizer will be reset by itself most of the times during the drop out action.As to other circumstances,will explain later.