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Loadside residual current device Advanced RCD820

The "Advanced" residual current devices of type RCD820 are available as an accessory for 3VA2 molded case circuit breakers.

Front view of Advanced RCD820

Description of front panel view

Display elements

"Ready" signals, communication status and alarms

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  • "Ready" signal of the residual current device:
    The LED labeled "ACT" ① stands for ACTIVE and lights up when the device is ready to operate.

  • Communication status:
    The LED labeled "COM" ② stands for COMMUNICATION and indicates the communication status of the residual current device.

  • Pre-alarms:
    The Advanced RCD820 has two LEDs labeled "AL1" (ALARM 1) ③ and "AL2" (ALARM 2) ③ which light up successively or simultaneously to promptly indicate potential shutdown of the installation due to residual current.

LED displays

Tripped display

If the residual current device is tripped by a residual current, a remote trip command or actuation of the test button, the trip is signaled mechanically on the RCD, i.e. by a rotating disk.

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Residual current device is operating normally and has not tripped

Residual current device has tripped

NOTE

In the case of infeed from below, an auxiliary switch must be connected by means of auxiliary contacts CB-S to ensure correct functioning of the tripped display (for description, see auxiliary contacts CB-S).

Operator controls

Insulation tests

It is absolutely essential to isolate the evaluation electronics circuit while insulation tests are in progress in order to protect the circuit against potential damage on the one hand and to prevent detection of insulation faults due to the power pack on the other. This is done simply by withdrawing (15 - 17 mm) the circuit breaker which is anchored in the enclosure.

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Disconnection of the main conductor connections is thus unnecessary. On completion of the tests, the circuit breaker must be pushed back into position before the residual current device is commissioned.

Testing and resetting the residual current device

Testing

Depending on operating conditions, the test button on the front panel of the residual current device should be pressed in order to function-test the device. The test button is labeled with the letter "T". If the test button is pressed, the device is tested immediately irrespective of the current delay time setting.

If the test button is pressed, a residual current is simulated on a test winding attached to the summation current transformer. If the residual current device is functioning properly, it must trip the molded case circuit breaker.

The test button must be held down for at least 2 seconds. The design of the test button prevents unintentional actuation.

NOTE

The residual current device can be successfully tested only if it is connected to a rated operational voltage which equals at least 85% of the minimum rated operational voltage.

Resetting

The residual current device and the "tripped" display are reset by means of the handle of the molded case circuit breaker, or the handle of the manual operator or by means of the motor operator.

Parameterization of the residual current device

Button for setting the response current IΔn

The response current can be set in 10 steps, ranging from 0.03 A to maximum 30 A. A residual current of type A is detected within the 0.03 A to 10 A range. If the response current is set to 30 A, the device detects only residual currents of type AC (i.e. purely sinusoidal currents).

Each response current has a dedicated setting range. The corresponding response current is set as soon as the button is latched in the setting range.

If the white setting arrow is resting between two setting ranges, the residual current device is automatically set to 0.03 A for safety reasons.

If the response current is set to 0.03 A, the delay time setting is deactivated and the breaker is tripped instantaneously in order to afford personal protection in the case of direct contact.

The factory setting for the response current is 0.03 A.

Button for setting the delay time Δt

The delay time can be set in 10 steps, ranging from 0 (instantaneous) to a maximum value of 10000 ms.

Each delay time has a dedicated setting range. The corresponding delay time is set as soon as the button is latched in the setting range.

If the white setting arrow is resting between two setting ranges, the residual current device trips instantaneously in response to residual currents.

The factory setting for the tripping delay is 0 ms.

Recommended procedure for setting the response current and the delay time

  1. Switch off the molded case circuit breaker.

  2. Open the transparent protective cover over the setting buttons.

  3. Adjust the setting values for response current and delay time on the residual current device to the maximum value in each case.

  4. Switch on the molded case circuit breaker.
    The LED labeled "ACT" on the residual current device now lights up, the residual current device is ready.

  5. Reduce the setting for the response current until the LED labeled "AL1" lights up.
    The residual current is now 30% higher than the response current setting.

  6. By turning the setting button clockwise, set the next higher response current.
    The LED "AL1" goes out, the correct response current is now set.

  7. Set the required delay time.

  8. Close the transparent protective cover over the setting buttons.
    The device is now fully parameterized.

Sealable protective covers of the residual current device

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Contact hazard protective cover over main current paths and auxiliary contacts

Transparent protective cover over setting buttons

Transparent protective cover over setting buttons

In order to prevent unauthorized access to the setting buttons for IΔn and Δt, the transparent cover over the settings buttons can be optionally sealed.

Contact hazard protective cover over main current paths and auxiliary contacts including sealing option

After the residual current device RCD820 has been mounted on the 3VA2 molded case circuit breaker, a contact hazard protective cover is installed over the main current paths to protect against direct contact. This cover can be sealed optionally in order to block any attempt to dismantle the residual current device from the molded case circuit breaker.

Terminals

NOTE

Cables for the following terminals must be routed separately from the main circuits. Their maximum cable length is 300 m.

A number of auxiliary contacts which perform a broad range of functions are located underneath the contact hazard protective cover.

Alarm switch

Floating auxiliary contacts for 3 different alarms are provided:

  • AL1
    Signaling switch for pre-alarm threshold 1. This auxiliary switch operates as soon as the residual current exceeds 30 % of the operating current setting value.

  • AL2
    Signaling switch for pre-alarm threshold 2. This auxiliary switch operates as soon as the residual current exceeds 60 % of the operating current setting value.

  • TRIP-IND (TRIP INDICATOR)
    A tripped signal can be output via this auxiliary switch for connection to a warning lamp, for example. The switch operates as soon as the residual current reaches or exceeds the response current setting value and has therefore caused the residual current device to trip.

The standard auxiliary switches for pre-alarms and tripped signals have changeover contacts and screw-type connections.

The terminal designations of the relevant contact, the maximum rated voltage and the current carrying capacity are shown in the diagram below.

Each relay contact has a maximum rated operational current of 5 A at 230 V AC. Since the terminals have a maximum current carrying capacity of 13.5 A, the current flow across the common terminal (01C = Common) must be limited to 13.5 A when all three signaling switches are used.

The relays for the pre-alarm signals (AL1 and AL2) drop out again as soon as the residual current reaches or exceeds the relevant pre-alarm thresholds.

The relay for the tripped signal (TRIP-IND) drops out again as soon as the residual current device is reset again by means of the molded case circuit breaker handle, or the handle of the manual or motor operator.

Since the relay for the tripped signal (TRIP-IND) is a bistable relay, the relay contact states remain "stored" even in the event of a power outage. When the power supply recovers, the indicated relay contact states are those which existed before the power outage.

Other auxiliary inputs

Two further auxiliary inputs in the form of screw terminals are also provided:

REMOTE-T

The residual current device can be remotely tripped via this auxiliary input for test purposes ("Remote test button"), for example.

To utilize this function, the customer must connect, for example, a pushbutton (NO contact) to terminals 1Y1 and 1Y2 by means of a two-core, twisted cable which must not be more than 300 m in length. The switching contact should have a minimum breaking capacity of 5 V / 1 mA. The residual current device trips if the pushbutton is actuated for at least 2 ms. The terminals 1Y1 and 1Y2 are galvanically isolated from the mains supply (functional extra low voltage, FELV).

In special cases, such as cable installation outdoors, the amplitude of overvoltages (e.g. overvoltages due to thunderstorms) between the conductor and ground must be limited to 2.5 kV by suitable routing of the cable or other protection measures.

Each residual current device requires a separate NO contact and cable for remote tripping. It is not possible to use one cable and connect two or more residual current devices in parallel.

It is necessary to use an unshielded cable or a shielded, twisted-pair cable with a maximum capacitance of 36 nF as well as a maximum resistance of 50 ohms (total length out and back).

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CB-S (Circuit Breaker Switch)

If the molded case circuit breaker / RCD820 assembly has an infeed from below (reverse feed), it is absolutely essential to install a standard auxiliary switch (NO contact) 3VA9988-0AA13 for interrogation of the circuit breaker status to allow resetting of the tripped signal.

This switch is installed in the accessories compartment of the molded case circuit breaker. The auxiliary switch is then connected to terminals 2Y1 and 2Y2 of the floating contact CB-S. It is necessary to use an unshielded or shielded twisted-pair cable, no more than 1 m in length, with a maximum capacitance of 36 nF as well as a maximum resistance of 50 ohms (total length out and back).

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When the molded case circuit breaker is reset and then switched on again, the contacts .1C and .2NC of the auxiliary switch are closed and the tripped display on the residual current device is reset.

The auxiliary switch is not included in the scope of supply and must be ordered separately. The method for connecting the auxiliary switch to auxiliary contact CB-S is described in the Operating Instructions for the RCD820 residual current device.

Status indicators

The table below illustrates the behavior of pre-alarm and tripped signals on RCD820 devices in response to various user actions and residual currents.

Cable installation

Cable ducts for bringing out cables are provided to the left and right on the residual current device.

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Cable duct

Other labels on front panel

Approvals

The residual current device bears the CE mark. For an overview of all approvals, please refer to Appendix.

For all queries relating to approvals, please contact Technical Support.

Technical specifications

In ≤ ...A:

Specifies the highest permissible rated operational current of the molded case circuit breaker with which the residual current device may be combined.

Ue ∼ ...V:

Specifies the operating voltage range of the residual current device.

...Hz:

Specifies the operating frequency range of the residual current device.

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Denotes the response behavior to residual currents.

Installation

Installation

Regardless of the type of connection system installed on the 3VA2 molded case circuit breaker, the RCD820 is mounted underneath the electronic trip unit of the circuit breaker.

  1. Dismantle the loadside connection components of the molded case circuit breaker and install the supplied connection components for the residual current device.

  2. Insert the residual current device into the T slots of the molded case circuit breaker.

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  3. Push the residual current device backwards until its rear panel is flush with the rear panel of the molded case circuit breaker.

  4. Screw the molded case circuit breaker to the residual current device. Special connecting screws are provided on the line side of the residual current device for this purpose.

  5. Place a contact hazard protective cover over the circuit breaker/RCD assembly.

  6. Reinstall the loadside connection components of the molded case circuit breaker at the outgoing feeder end of the residual current device.

  7. Attach the assembly to a mounting plate using the fastening screws.

NOTE

Since the outgoing feeder end of the residual current device has exactly the same connection contours as the 3VA2 molded case circuit breaker, all connection accessories such as phase barriers, terminal covers, etc. can also be mounted on the residual current device.

Installation of the RCD-ETU connecting cable

  1. Remove the contact hazard protective cover.

  2. Open the slide over the interface <X3 RCD>.
    The slide is fitted as a protective guard (e.g. to protect the interface against soiling).

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  3. Insert one end of the connecting cable into the interface on the residual current device.
    The interfaces and the connecting cable are labeled to ensure that the cable ends are inserted in the right interfaces.

    NOTE

    Plug in or remove the RCD-ETU cable only when the residual current device is deenergized.

  4. Insert the other end of the connecting cable into the interface <X3 RCD> on the ETU.

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The RCD-to-ETU connecting cable is free of silicone and halogen and is electrically isolated from the main circuits.

The connecting cable is included in the scope of supply.

Tripping

The residual current device utilizes the maglatch of the electronic trip unit (ETU) in order to trip the molded case circuit breaker. It therefore needs to be connected to the ETU of the molded case circuit breaker. This connection is made by means of the RCD-ETU connecting cable.

Use of the residual current device as a pure display unit

The RCD820 residual current device can also operate as a pure display unit without a tripping function, i.e. it detects and signals residual currents, but does not trip the molded case circuit breaker or interrupt the circuit.

If the RCD820 device is to operate as a pure display unit, the connecting cable between the residual current device and the ETU of the molded case circuit breaker can simply be omitted. With the exception of its communications interface functionality, the residual current device can perform all its normal functions, e.g. status signaling via LEDs or alarm switches, etc., in "display mode". Since there is no connection between the RCD and the ETU, the LED "ACT" flashes continuously and the LED "COM" is not illuminated even if an ETU 5-series or 8-series is installed.

Communications interface

The RCD-ETU connecting cable not only carries the trip command, but also acts as the communications interface between the residual current device and the 3VA communication system.

Precondition for interface functionality:

  • The 3VA2 molded case circuit breaker is equipped with a communication-capable, electronic trip unit (ETU 5-series or 8-series).

  • The molded case circuit breaker is linked to the communication system via a COM060 communication module.

If the residual current device is linked to the communication system, the link can be used not only to interrogate the device for important status, diagnostic, maintenance and identification data, but also to transmit commands.

The residual current device is normally supplied with power by the main current paths. If the molded case circuit breaker is switched off, this power supply is also disconnected (infeed at top). In order to maintain the link to the communication system when the power supply from the main current paths is disconnected, the residual current device is supplied with the necessary power by the COM060 communication module.

The table below provides an overview of all the functions and data which are available in the residual current device environment:

Circuit breaker

Product version

Auxiliary contacts

Article number

Type designation

Maximum rated operational current, rated operational voltage and frequency

LED: ACTIVE, communication, pre-alarm

Setting button for response current

Tripped display

Transparent protective cover over setting buttons

Knowledge Manager

Test button (test device)

Setting button for delay time

Approval

Rated insulation voltage and rated impulse strength

Standard

Location and date of manufacture

RCD-to-ETU connecting cable

Device type

Contact hazard protective cover over main current paths with sealing option

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Setting button for response current IΔn

Setting button for delay time Δt

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1)

Infeed at top

2)

Infeed at bottom

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Value can be read

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Value can be edited

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Commands

1)

Reset by means of the molded case circuit breaker handle, or the handle of the manual or motor operator

2)

Reset in combination with motor operators

3)

On request

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