RCM420CH-D-1 Residual current monitoring device

The AC and pulse current sensitive residual current monitoring device RCM420-D (type A) is used for fault and residual current monitoring in earthed systems (TN and TT systems), in which a signal is preferably issued in the event of a fault, but no disconnection is permitted. It can also be used to monitor individual conductors, e.g. PE conductors, N-PE bridges, PE-PAS bridges.

The pre-warning level (50...100 % of the set response value I∆n2) allows a distinction to be made between pre-warning and alarm. As the measured value is recorded via measuring current transformers, the device is virtually independent of the load current and nominal voltage of the system.

Features and functions:

- AC and pulse current sensitive residual current monitoring device type A according to IEC 62020

- RMS value measurement (AC)

- Two separately adjustable response values

- Frequency range 42...2000 Hz

- Start, response and release delay adjustable

- Restart function

- Digital measured value display via LC display

- Measured value memory for trigger value

- Connection monitoring measuring current transformer

- Indicator LEDs for operation, alarm 1, alarm 2

- Internal/external test/reset button

- Two separate alarm relays with 1 changeover contact each

- Working/quiescent current and fault memory behavior selectable

- Password protection for device settings

- Device self-monitoring

- Sealable transparent cover

- 2-module housing (36 mm)

- RoHS-compliant

- Spring terminal (two terminals per connection)

Technical features:

- Classification according to IEC 60755 - Type A

- Mains form: TN / TT systems

- Special firmware suitable for Swiss applications

- Supply voltage: 16-72 VAC / 9.6-94 VDC

- Measuring channels 1

- Residual currents AC + pulsating DC

- Rated frequency 42 ... 2000 Hz

- Response value I n1: 50 ... 100 %

- Response value I n2: 10 mA ... 10 A

- Alarm relay main message: 1 changeover contact

- Alarm relay pre-warning: 1 changeover contact

- Designed for W ..., WR ..., WS ... series transformers

- Dimensions: W 36 x H 90 x D 70.5 mm

Applications:

- Residual current monitoring in earthed 2-, 3- or 4-wire systems

- Current monitoring of normally de-energized individual conductors

- Socket outlet circuits for devices that are operated unattended for long periods and must not fail

- Alarm systems, safety devices

- Air conditioning systems, EDP systems

- Cooling systems with valuable refrigerated goods

- Commercial kitchens

- Monitoring earthed power supplies for stray currents

- Loading of N conductors

- Pipe trace heating systems

Installation position:

According to technical device manual: Any orientation

Application note:

In applications with electrical or electronic loads with a direct current component, an all-current sensitive solution such as the RCMA423 or equivalent must always be implemented.