How to install ABB VSC vacuum contactor?

Short circuit closing capacity (A) 13000 13000

Opening time (ms) 35~60 35~60

Closing time (ms) 60~90 60~90

3.2 Load capacity limit (12kV model)

Electric motor: maximum 3000 kW

Transformer: Maximum 4000 kVA

Capacitor: Maximum 4800 kVAR (requires installation of lightning arrester)

Back to back capacitor bank: rated current 250A, maximum closing inrush current 8kA, frequency ≤ 2.5kHz

3.3 Auxiliary Contact Parameters

The contactor provides two sets of auxiliary switches (5 normally open+5 normally closed), with a specified heating current Ith=10A, suitable for 24-250V AC/DC. In addition, the power module outputs two binary signals:

DO1: Control and excitation circuit ready (including power module ready, capacitor voltage normal, coil continuity)

DO2: System status (capacitor operating status, module temperature)

Signal contact parameters: maximum power 1200VA (resistive), maximum voltage 277V AC/30V DC, breaking current 3A.

Operation mode: SCO and DCO selection

VSC contactors support two control modes, which users can choose according to their automation system requirements.

4.1 SCO (Single Command Operation)

Principle: When the auxiliary power supply continues to supply power, the contactor closes; When the power is cut off (active disconnection command or power failure), the contactor opens.

Features: No need for opening pulses, the power supply itself closes to maintain the signal. Automatically disconnect when under voltage.

Applicable scenarios: Simple circuits that require voltage loss tripping, or controlled by PLC output normally closed contacts.

4.2 DCO (Dual Command Operation)

Principle: When receiving a closing pulse with a minimum pulse width of 30ms, close the circuit; when receiving an opening pulse, close the circuit. Both are independent.

Features: It has anti bounce function - when both closing and opening commands are present, opening takes priority, and the contactor remains open until the opening signal disappears. Optional undervoltage trip (UV) function with adjustable delay (0-5s).

Applicable scenarios: Complex interlocking systems that require separate control of closing and opening, or situations where undervoltage delay tripping is required.

4.3 Under voltage trip delay setting (DCO type)

The undervoltage trip delay can be set through the dip switch S1 (S1-3, S1-4, S1-5) on the power module:

Delay (s) S1-3 S1-4 S1-5

Instantaneous 0 0 0

0.3 0 0 1

1 0 1 0

2 0 1 1

3 1 0 0

4 1 0 1

5 1 1 1

Installation and wiring points

5.1 Environmental conditions

Environmental temperature: -15 ℃~+40 ℃ (24-hour average ≤ 35 ℃)

Relative humidity: daily average ≤ 95%, monthly average ≤ 90%

Altitude: ≤ 1000m (for higher altitudes, reduced capacity is required)

Avoid condensation: Heaters need to be installed in high humidity areas

5.2 Installation of Fixed Contactors

It can be installed vertically (with the moving contact moving downwards) or horizontally against the wall (with the terminal facing downwards).

Main circuit connection: The surface of copper or aluminum conductors must be silver plated, and the contact surface must be flat and clean. Tightening torque: M6=10Nm, M8=25Nm, M10=50Nm, M12=86Nm.

Grounding: achieved through grounding bolts, the cross-section of the grounding wire is selected according to standards, and the joint is coated with Vaseline for rust prevention.

Auxiliary circuit: Cable cross-section ≥ 1.5mm ², rated voltage 450/750V, threaded through metal hoses or cable trays.

5.3 Pull out contactor (VSC/P) interlock

The pull-out version is installed inside the UniGear ZS1 switchgear and has comprehensive mechanical and electrical interlocking:

Anti closing interlock: When the handcart is not in the working/testing position, the electrical circuit is prohibited from closing.

Anti misoperation: When the contactor is in the closed state, the mechanical interlock prevents the handcart from shaking in/out.

Fuse monitoring: When there is a phase loss or the fuse is blown, the electrical interlock prohibits closing.

Grounding switch interlock: When the grounding switch is closed, the mechanical stop pin prevents the handcart from shaking into the working position; On the contrary, when the handcart is in the middle position, the grounding switch cannot be closed.

Valve interlock: After the handcart is pulled out, the valve automatically closes to prevent accidental contact with the static contact.

Aviation plug interlock: The handcart cannot remove the aviation plug when in the working position or during the rocking in and out process.

Locking electromagnet (optional): When the auxiliary circuit is not powered on, the electromagnet loses power and locks the handcart to prevent misoperation when there is no control power supply.

Maintenance and Inspection

The VSC vacuum contactor has a long maintenance free cycle as a whole, but regular inspections can ensure its reliable operation.

6.1 Inspection cycle

Under normal conditions: run for 1 year or operate 50000 times (whichever comes first).

Adverse environments (dust, corrosive gases, high humidity): shortened to six months or less.

6.2 Daily Inspection Items

Appearance and Cleaning: Remove dust and oil stains from the surface of insulation components. Use dry soft cloth or weakly alkaline cleaning agent, and prohibit carbon tetrachloride and trichloroethylene.