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Product description

Typical applications for draw-out versions of 3VA molded case circuit breakers are installations in which inspections and overhauls need to be carried out at regular intervals and, for reasons of safety, clear visual evidence of safe electrical isolation of plant sections must be provided at short notice so that work can commence. Draw-out versions of 3VA molded case circuit breakers are also suitable for applications which require that molded case circuit breakers or switch disconnectors can be replaced very rapidly when necessary.

In the draw-out version, the 3VA molded case circuit breaker is supported by the side walls of the draw-out unit and can be moved into three defined positions by rotation of a crank handle. The current breaker position is indicated by the position indicator.

Defined positions

If the molded case circuit breaker is not in any of these defined positions, the switching position indicator displays the word UNBLOCK on a white background. When the breaker is in this position, its main contacts cannot be closed if the autotrip plunger is correctly installed (see below).

Move the molded case circuit breaker into a defined position

NOTE

If the switch position indication is CONNECT, TEST or DISCON, the sliding clutch of the crank gear is engaged and rotation of the crank handle has no effect.

By removing and reinserting the crank handle, it is possible to disengage the gear. The switching position indicator will then show UNBLOCK. The molded case circuit breaker can now be moved to a new position.

  1. If the crank handle is inserted in the crankcase, pull it out.

  2. Insert the crank handle into the crankcase again.
    By removing and reinserting the crank handle, it is possible to disengage the gear.

  3. Turn the crank handle until the switching position indicator shows the required position.

Remove the molded case circuit breaker

  1. Move the molded case circuit breaker into the DISCON position.
    The molded case circuit breaker is electrically isolated.

  2. To disengage the lock, press the safety lock slide underneath the switching position indicator downwards as indicated by the arrow.

  3. Remove the molded case circuit breaker.

Components of a complete kit for draw-out technology

A complete kit for draw-out technology contains all the components required to convert the fixed mounting version of a molded case circuit breaker or switch disconnector to a draw-out version.

NOTE

Information about the crank handle

The crank handle is not supplied as part of the complete kit and must be ordered separately.

Components of a conversion kit for draw-out technology

Installation instructions

The draw-out socket is permanently mounted in the cubicle by means of the fastening bolts included in the complete kit for draw-out technology.

The molded case circuit breaker / switch disconnector in molded case circuit breaker design is supplied with two assembly bolts (3-pole version) or four assembly bolts (4-pole version). These bolts are not required if the device is to be converted to a draw-out unit.

Terminal cover

Two terminal covers are included in the scope of supply of the complete kit for draw-out technology and the conversion kit for draw-out technology for the molded case circuit breaker. These two terminal covers are intended for installation over the molded case circuit breaker. If terminal covers are to be attached to the busbars of the draw-out socket, they must be ordered separately, see chapter Insulating equipment.

Autotrip plunger

An autotrip plunger is supplied as standard with every complete kit and every conversion kit for converting a molded case circuit breaker to draw-out technology.

WARNING

Make sure that the autotrip plunger is correctly installed

The molded case circuit breaker cannot be safely moved into or out of the socket without an autotrip plunger. Moving it into or out of the socket when the main contacts are closed (breaker position ON) can cause arcs to form between contacts and result in irreparable damage to the circuit breaker or the electrical installation, and possibly cause physical injury to personnel.

Once installed, the autotrip plunger cannot be dismantled again!

Note the color coding and labels for the autotrip plunger:

  • Plug-in technology: Black, labeled "Plug-in"

  • Draw-out technology: Grey, labeled "Draw-out"

When a 3VA molded case circuit breaker is converted to a 3VA draw-out unit, this plunger is installed from the rear of the device and latched.

The plunger performs various safety functions in operation:

Auxiliary circuit connectors

3VA molded case circuit breakers or 3VA switch disconnectors are frequently equipped with internal accessories, e.g. auxiliary switches and auxiliary releases. A broad range of internal accessory components is also available for the 3VA molded case circuit breaker. For further information, please refer to chapter Internal accessories.

To ensure that the electrical connections required by draw-out units can be quickly and safely disconnected, auxiliary circuit connectors can be installed.

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The breaker-end half is attached to the underside of the molded case circuit breaker and electrically connected to the internal accessories. Appropriate openings and cable ducts are provided in the 3VA molded case circuit breaker for routing stranded wires. The socket-end half of the auxiliary circuit connector with the movable telescopic rail is inserted in the socket and electrically connected to the customer's installation.

When the molded case circuit breaker is inserted into the draw-out unit, an electrical connection between the internal accessories in the breaker and the customer's installation is quickly established.

NOTE

Plug-in and draw-out units use different versions of the auxiliary circuit connector.

The draw-out version has a longer, movable telescopic rail because the distance to be bridged in the draw-out socket is longer.

Further details about auxiliary circuit connectors can be found in chapter Auxiliary circuit connector.

Position signaling in the draw-out socket

Several position signaling switches (number depends on socket size) can be installed in the right-hand side wall of the draw-out socket. These auxiliary switches are capable of signaling breaker positions DISCON, TEST and CONNECT. The auxiliary switches also output a position indication signal if the molded case circuit breaker in the draw-out socket is not in one of the positions specified above. For information, please refer to chapter Position signaling switches.

Protection against unauthorized operation of molded case circuit breaker

Padlocks for protection against unauthorized operation

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To provide protection against unauthorized operation of the molded case circuit breaker, padlocks can be inserted through the plastic frame opening of the padlock locking unit on the right side panel of the draw-out socket. The plastic frame is simple to pull out. The crank handle opening is mechanically sealed when the plastic frame is in the OUT position.

Openings for padlocks in plastic frame:

  • Up to 3 padlocks

  • Shackle diameter 8 mm (3/8 inch)

Attach padlocks

  1. Move the molded case circuit breaker into the CONNECT, TEST or DISCON position.
    The breaker must be in one of these positions before the plastic frame can be pulled out.

  2. Pull out the plastic frame.
    The crank handle opening is sealed off.

  3. Insert padlock shackles through the plastic frame and lock padlocks as illustrated above.

Cylinder lock for protection against unauthorized operation

A cylinder lock can be retrofitted in the right-hand side panel of the draw-out socket. Like the plastic frame and padlocks, this cylinder lock is capable of locking a molded case circuit breaker in either the CONNECT, TEST or DISCON position. The cylinder lock utilizes the locking mechanism of the plastic frame. This is evident from the way the plastic frame moves into or out of the socket as the cylinder lock is turned.

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Signaling of locked/unlocked status

The locked or unlocked status of a draw-out unit can be signaled electrically. This requires the installation of a position signaling switch (3VA9987‑0KB00) in the right-hand side panel of the draw-out socket. This switch signals whether the plastic frame described above is in the "IN" or "OUT" position. For further details, refer to chapter Position signaling switches.

Integration of molded case circuit breaker position signal into a communication network

The COM800 breaker data server can be used to interrogate various states of multiple molded case circuit breakers so that the information can be transferred by means of bus systems. This status information includes states such as "Breaker tripped", "Breaker on", "Breaker off", reason for tripping, etc. Actual current and voltage measurements can also be transmitted depending on the version of 3VA circuit breaker installed. To provide this communications capability, the molded case circuit breaker itself is equipped with a COM060 communication module which functions as the breaker's actual communications interface.

In addition to the status information listed above, the position of the molded case circuit breaker in the draw-out unit can also be transferred. For this purpose, the molded case circuit breaker and the draw-out socket must be equipped with the communications interface for the draw-out unit. This kit allows the position of the molded case circuit breaker in the draw-out unit to be picked up and transferred to the COM060 communication module and from there to the higher-level communication network. For further information about the communication kit for draw-out units, please refer to chapter Communications interface for draw-out unit.

Operation through the cubicle door

The molded case circuit breaker can be optionally installed in the cubicle in such a way that the breaker can be operated even when the cubicle door is closed. Draw-out versions of molded case circuit breakers can then be switched on or off when the cubicle door is not open. This is made possible by a cutout in the cubicle door which allows access to the main control elements, i.e the handle and the <PUSH TO TRIP> button of the molded case circuit breaker, but prohibits access to other live components inside the cubicle. This solution is referred to as a "door feedthrough".

Door feedthroughs are mounted on the front of the molded case circuit breaker and securely attached to the breaker by means of two bolts and a latch.

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The door cutout must be positioned such that it is flush with the door feedthrough. It must also be positioned in such a way as to minimize the size of the gap between the feedthrough walls and the cutout. An escutcheon can be fitted as well in order to obtain an optimum finish.

An opening in the cubicle through which the crank handle can be inserted must be provided in addition to the cutout for the door feedthrough.

With its straight sides, the door feedthrough is designed to allow the molded case circuit breaker to be moved through positions DISCON, TEST and CONNECT, while at the same time providing a permanently tight seal around the feedthrough area (degree of protection IP30) and preventing access to live components inside the cubicle.

Markings are visible on the door feedthrough to help the user identify the current position of the molded case circuit breaker as it is moved into or out of the cubicle. Since mounting dimensions may vary slightly, however, these markings should be regarded as a rough guide only. The crank handle mechanism provides the user with feedback information about the molded case circuit breaker position, e.g. whether it has been correctly inserted.

Benefits of draw-out technology

  • Defective molded case circuit breakers can be replaced quickly and easily

  • Clear visual evidence of safe electrical isolation of main circuits

  • Molded case circuit breaker and accessories can be function-tested in the TEST position

  • Remote signaling of molded case circuit breaker positions CONNECT, TEST and DISCON

  • Padlocks and / or cylinder locks can be used to lock draw-out unit so that the molded case circuit breaker cannot be inserted or removed by unauthorized persons

  • Molded case circuit breaker can be operated through the cubicle door

  • Degree of protection IP20 at all termination points

  • No grounding required

Plug-in contacts for attachment to the main terminals of the 3VA molded case circuit breaker

Side walls with guide bolts for mounting on the molded case circuit breaker

Screw-mounted terminal cover for the molded case circuit breaker

Autotrip plunger

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