TECHNICAL DESCRIPTION

Transcription

1 DC Circuit Breaker TECHNICAL DESCRIPTION TRK Ed.1 of 23/07/13 CONTENTS 1. INTRODUCTION DESCRIPTION Description of circuit breaker Operating mode Variants and Accessories INTEGRATION CHARACTERISTICS Standards General features Power circuit Breaking capacity Control Circuit Auxiliary contacts Wiring diagram DIMENSIONS /9

2 1. INTRODUCTION The ARC 850 and ARC 1550 circuit breakers are direct current unipolar devices with a bi-directional over-current and trip free release. These are electromagnetic control devices. Products from 5000A ARC range have a common general architecture and differ by the size of the arc chute (function of the operating voltage). ARC Nominal voltage (10 2 V) Nominal current (10 2 A) Fig.1.1 Identification mode Their compactness make the A circuit breakers particularly adaptable to assembly in shielded cases of the industrial type cabinets for fixed installations. The circuit breaker design leads to an easy maintenance and high number of operations. The main wearing parts may be changed without completely dismantling the circuit breaker. 2. DESCRIPTION 2.1 Description of circuit breaker The circuit breaker consists of two main part assembly : - the body (also called frame - 1) which is common part of the range - the arc chute (2) with two main versions (for 750V and 1500V applications) Fig.2.1 ARC850 circuit breaker 2.2 Operating mode Mechanical operation Closing The energizing of the electromagnet causes the movement of the main contacts and the movable pole contact comes to the fixed pole contact. Opening by holding current cut off Due to the effect of springs the breaking of the holding current pull the moving pole contact arm to the "open" position. Opening by direct over-current release When the current travelling through the circuit breaker exceeds the release setting threshold, the equilibrium is broken and the movable pole contact arm is pulled back to the "open" position by the effect of return spring. Electrical operation During opening the electric arc develops between the contacts and then, under the effect of the magnetic field, progresses onto the horns. The arc is forced to enter the arc chute by thermodynamic and magnetic effects. The arc chute consists of metal plates which are intended to fraction the arc and to develop the back-electromotive force required for its extinction. 2/9

3 Operation counter In the standard version, a counter for the number of operations as a maintenance help is supplied. Longitudinal opening 2.3 Variants and Accessories Variant 1 : Arc chute The sizes of the 750V and 1500V arc chutes are linked to the number of metal plates in the stacking. 750V version Variant 3 : Electromagnet device 1500V version The electromagnet device is composed of two internal coils, one for closing, one for holding. The energising closing coil causes the movement of the moving pole contact which comes against the fixed pole contact. To rest in closed position, the holding coil should be supply before closing coil. Control voltages available to supply the electromagnet device are 48V, 110V and 125V. Note: A variant is available with magnetic holding instead of holding coil. Variant 2 : Arc chute moving. In the standard version of A DC circuit breaker, the way to move the 750V or 1500V arc chute is lateral as described in the picture, however a longitudinal version is available. Lateral opening Variant 4 : Tripping range The circuit breaker is equipped with an overcurrent release device which is operated directly by the magnetic field of the fault current which crosses the main circuit following two directions (bi-directional release). See below available tripping ranges where the threshold can be adjusted to 5000 A 5000 to A 7500 to A 9000 to A Note : It is possible to adapt an uni-directional release system. The minimum threshold setting is 2500 A. See unidirectional variant 3/9

4 Variant 5 : Uni-directional release device This variant allows to have only one way of tripping the circuit breaker in case of fault current by using permanent magnet device on tripping unit. This release operates only in one direction when current flowing into the circuit breaker top power connection. In the other direction, a permanent magnet is used to maintain the circuit breaker in closed position and to withstand short circuit current Option 1 : Over-current release signalling contact An over-current release signalling contact indicates the state of the circuit breaker : when this contact is in close state, the circuit breaker is open following an tripping event. Option 2 : Ultra-rapid release This option allows high-speed opening upon an external command via the discharge of a capacity into an electromagnet coil, which causes the breaking of the equilibrium between the lower end of the contact arm and the lever. In addition to the first function, there is an over-current release signalling contact. Option 3 : Indirect over-current or manual tripping option This option allows opening upon an external command via a manual action on lever, which causes the breaking of the equilibrium between the lower end of the contact arm and the main lever. In addition to the first function, there is an over-current release signaling contact This option, when it is chosen, replaces the over-current signalling contact / external high-speed release. 3. INTEGRATION The integration of the DC circuit breaker inside a cubicle is an important matter. Attention has to be paid on volume of free air around the product, evacuation of ionized gas and risk of flashover to metal parts. See outline drawing for more information. 4/9

5 4. CHARACTERISTICS 4.1 Standards The HSCB is compliant with: - EN : Railway applications Fixed installations D.C. switchgear - EN : Railway applications Insulation coordination - NF F : Fire behaviour-material choice - NF F : Fire behaviour-material choice and application for electric equipment 4.3 Power circuit Features ARC820 ARC1520 Nominal voltage (UN) 750V 1500V Rated insulation voltage (UNm) 900V 1800V Exceptional voltage Umax2 1000V 1950V Rated impulse withstand voltage (UNi) 1.2/50 µs Overvoltage category Pollution degree 20 kv OV3 PD3 4.2 General features Features Min Max Nominal Operating Temperature Tu -15 C +50 C Storage Temperature Ts -40 C +70 C Altitude Alt 1400m Humidity % 95% at 40 C Dielectric strength between poles (1mn / 50Hz) Dielectric strength between HV and ground/lv (1mn / 50Hz) Rated service current (INE) Overload (from stabilized) Overcurrent tripping device 8 kv rms 10 kv rms 5000 A 10 ka DC during 60s internal overcurrent tripping Bidirectional or unidirectional Mechanical endurance Weight Dimension (mm) HV connections LV connections Fire behaviour Cycles (at 25 C) ARC850 : 160 kg ARC1550: 185 kg ARC850 : 900x500x720 ARC1550 : 900x500x815 HV input and HV output : 5 11mm holes on electrical connection Fixed FCI connector type R-22-B-41-SNH068 (mobile connector supplied) In agreement with standard for installation in technical area 4.4 Breaking capacity Features Maximum prospective current (ka) (INSS) ARC * Time constant (TNC) (ms) Voltage (V) 900 Features ARC1550 Maximum prospective current (ka) (INSS) Time constant (TNC) (ms) Voltage (V) 1500 (*) : It is the peak current value ÎNSS for low inductive circuit. 5/9

6 4.5 Control Circuit 4.7 Wiring diagram Designations Cross section of wiring is 0.93 mm² or more Voltage variants Overvoltage protection device on holding coil Dielectric strength between LV and ground (1mn / 50Hz) Opening time at Un by holding current cut off Power 48 V DC, 110 V DC and 125 V DC Yes 2 kv rms < 40ms 0W when open 40 W at holding 5000 W when closing during 0,5s 4.6 Auxiliary contacts Designations Typ. Min Max Voltage (AC or DC) 50 V 250 V Current 10 ma 2 A Breaking current cycles under 1A, 90V, L/R=15ms cycles under 1A, 90V, L/R=40ms Mechanical endurance Insulation voltage between auxiliary contacts and earth Sequence Cycles 2000 V 4 NO + 6 NC Fig.4.7 Standard wiring* (*) for 48V supply, electromagnet wiring is modified, please consult us for more details 6/9

7 5. DIMENSIONS Overall dimensions of ARC /9

8 Overall dimensions of ARC 850 8/9

9 ARC 850 outline drawing Longitudinal tipping 9/9