Introduction

The OSM38 automatic circuit reclosers are designed for use on overhead distribution lines as well as distribution substation applications for voltage classes up to 38kV.

The 300 series tanks are manufactured from stainless steel and powder coated a light grey colour.

The product is supplied complete with an RC10 control and communications cubicle. The RC10 control cubicle is a microprocessor based controller that provides all the protection, data logging and communications functions in a single device. The OSM has been designed for use as a stand alone device that is easily integrated into distribution automation and remote control schemes using the in-built communications capability.

The product has been extensively type tested by independent laboratories to ensure long life and reliability under the harshest environmental conditions. The OSM automatic circuit recloser is the only solid di-electric insulated recloser to provide controlled arc fault venting and independent testing provides verification of this important safety feature.

The product uses technology developed and refined over the last decade and follows on from the successful 200 Series model.

The in-built user configurable distribution automation functionality can be used with or without a communications system and will reduce outage time and increase profitability in your network.

Overview

The OSM automatic circuit reclosers incorporate vacuum interrupters inside an aromatic epoxy resin housing within an arc vented stainless steel tank. This ensures the maximum in life and reliability with a fully insulated arrangement inside the long life housing.

Voltage is measured on all six (6) bushings using capacitively coupled carbon fibre screens. Current is measured on all three (3) phases using current transformers.

The recloser mechanism is operated by three (3) separate magnetic actuators, one per phase. These magnetic actuators are mechanically interlocked to guarantee correct three (3) phase operation.

The device is latched in the closed position by magnetic latching. Each magnetic actuator uses a single coil. The recloser can be mechanically tripped using the yellow mechanical hook stick operated lever in the base of the tank. The device Open / Close indication, also located in the base of the tank, uses a green ‘0’ to designate contacts are open and a red ‘I’ to designate contacts closed.

The status of the recloser is also reflected by a microswitch connected to the control electronics. The electronic circuit board that provides CT shorting when the control cable is disconnected has no active elements which dramatically improves impulse immunity.

The main circuit bushings are manufactured from aromatic epoxy resin and have a silicone rubber bushing boot providing the required creepage distance.

The magnetic actuators are operated from stored energy charged capacitors located in the RC10 control cubicle. There is a rating plate located in the base of the tank that provides tank rating details in accordance with the requirements of ANSI C37.60. There is an earthing point on the side of the tank.

The 300 Series OSM is supplied with tin plated brass cable connectors on each bushing. The cable connectors can be supplied in the form of tunnel terminals to suit cable up to 260mm2 or 2 hole NEMA cable palms .

The cross sectional diagram below details the OSM tank configuration and main components.

Electronic Controls

The RC10 control and communications cubicle is a microprocessor based controller that provides a directional overcurrent, earth fault and sensitive earth fault relay, auto reclosing relay, instantaneous metering, event log, demand logger and remote terminal unit (RTU) for remote control in a single package.

The operator control panel is provided with a large backlit LCD display and keypad to provide local control functions.

Remote Control

A USB front panel interface is provided to connect to a PC running CMS. This provides full settings and data management facilities. An RS485/RS232 RTU interface offering 300-19.2k baud, full and half duplex modes, is provided to connect to remote control systems. DNP3 and Modbus communications protocols are provided in the standard product combined with our ability to engineer new protocols to meet specified customer requests.

Protection

• 4 Independent Protection Groups
• Directional over current and earth fault protection
• Inverse Time Protection
• Definite Time Protection
• High set Instantaneous element
• Directional Sensitive Earth Fault Protection
• Under and Over Voltage Protection Element
• Under and Over Frequency Protection Element
• Zone Sequence Co-ordination
• Voltage reclose control with automatic back feed restoration provides loop automation functionality.
• Live Line Function & Hot Line Tag Function

Specification

Part Number	OSM38-12-630
Current Sensing	3 x Current Transformers
Voltage Sensing	6 x Voltage Screens
Control Type	RC
Rated Maximum Voltage	38kV
Rated Continuous Current	630A
Fault Make Capacity RMS	12.5kA
Fault Make Capacity Peak	31.5kA
Fault Break Capacity	12.5kA
Mechanical Operations	30,000
Full Load Operations	30,000
Fault Break Capacity Operations	200
Phase to Phase & Phase to Ground	195 kV
Short Time Current Withstand	12.5kA/3 secs
Mainly Active Breaking Capacity	630A
Cable Charging Current	40A
Line Charging Current	5A
Impulse Withstand Phase to Earth & Phase to Phase	195kV
Impulse Across the Interrupter	170kV
Power Frequency Withstand Phase to Earth (Dry)	70kV
Across the Interrupter	70kV
Ambient Temperature	-40°C to +55°C
Humidity	0-100%
Altitude	3000M
Weight of the Tank	140kg