Bender Residual Current Monitor RCMS460-D

RCMS460-D Bender Residual Current Monitor is used to monitor fault currents or residual currents in grounded systems (TN and TT systems). The sum of all conductors except the ground wire is measured by measuring current transformers.

  • Measurement Types: Alternating current (AC), Pulsating current, AC/DC sensitive measurements;
  • Current transformer Selection: CTBS25 or CTUB100 series, CTAC, WR, WS, and WF;
  • Up to 1080 measuring channels (sub-circuits) can be monitored
  • Up to 90 residual current monitors can be connected
  • BMS bus with RS-485 interface and BMS protocol
  • 24 V DC power supply unit
  • 12 measuring channels
Contact us

Features of Bender Residual Current Monitor

  • Ground-fault monitoring relay with many channels for grounded and high-resistance grounded AC/DC systems
  • Observe up to twelve distinct channels, each having a set of customizable alarm trip values.
  • On-board menu and real-time readings on a digital display
  • Analysis of harmonics and customizable filtering choices
  • Connectivity to Ethernet and Modbus communication gateways, as well as contact outputs
  • The system has up to 1080 measurement channels and up to 90 RCMS displays.
  • Quick parallel channel scanning
  • Response ranges are as follows: 100 mA…125 A (42…2000 Hz), 6 mA…20 A (42…2000 Hz), and 10 mA‒10 A (0…2000 Hz). RCMS-D4: Preset feature
  • Modifiable time lags
  • It is possible to configure the frequency response characteristics for plant, fire, and human safety.
  • 300 data records/channel data logger
  • Each of the two-alarm relays has one changeover contact.
  • Selectable N/O or N/C operation and fault memory
  • External test/reset button connection
  • Seven-segment backlit graphical display with alarm LEDs
  • Data transmission through the BMS bus
  • Device settings password protection
  • Constant CT connection tracking that complies with RoHS

Applications of Bender Residual Current Monitor

  • Monitoring of ground faults in high-resistance grounded AC/DC systems that are grounded
  • Systems that use inverters, variable frequency drives, and other power conversion devices
  • DC systems for general purposes, as per NEC 250.167(B)
  • Distribution of power generally
  • Drives and motor management systems
  • Systems of control
  • The NEC 427.22 and CEC 62-116 guidelines for heat trace systems; the NEC 690.41(B) (2017 edition), NEC 690.5 (2014 edition), and CEC 64-064(4) guidelines for solar arrays
  • Systems for storing energy

Specification of Bender Residual Current Monitor

Distinctive device features RCMS460-D
Parameter setting function
Address Range 1…90







Measuring circuit

Measuring channels per device 12
CTAC…, CTUB100, CTBS25, WR…S(P), WS…, W…F series measuring current transformers
CT monitoring

Rated residual operating current I∆n2 (Alarm)

AC/DC sensitive 0…2000 Hz (Type B) 10 mA…10 A
pulsed DC sensitive 42…2000 Hz (Type A) 6 mA…20 A
pulsed DC sensitive 42…2000 Hz (Type A) for channels 9…12 (RCMS4x0-D4/-L4) 100 mA…125 A
Rated residual operating current I∆n1 (prewarning) 10…100 %, min. 5 mA
Function selectable per channel off, <, >, I/O
Cut-off frequency adjustable for personnel, plant, and fire protection
Preset function for I∆n2 and I/O
Hysteresis 2…40 %
The factor for additional CT
Switching elements Common alarm relay for all channels 2 x 1 changeover contact
Alarm relay per channel

Time response

Start-up delay 0…99 s
Response delay TV, adjustable 0…999 s
Operating time at I∆n = 1 x I∆n2: ≤ 180 ms
I∆n = 5 x I∆n2: ≤ 30ms




Displays, memory

Analysis of the harmonics (I∆, DC, THF)
History memory 300 data records
Data logger for 300 data records/ channel
Internal clock
Language English, German, French, Swedish
Backlit graphics LC display
7-segment display and LED line