Innovative technologies for safe handling of electrical power to achieve high availability

We offer you first-class quality and safety combined with global service and every support in resolving your monitoring problems.

  • Electrical safety for unearthed power supplies (IT systems)
  • Insulation monitoring equipment, insulation fault location systems
  • Power supplies for medical applications
  • Measuring and monitoring relays
  • Electrical safety for earthed power supplies (TN systems)
  • Using renewable energies efficiently: wind power, photovoltaics
  • Test systems for electrical equipment and medical technology


The CTUB100 series measuring current transformers are combinations of CTBC… measuring current transformer cores and CTUB10… electronic modules, which convert AC and DC currents into an evaluable measurement signal. The measurement signals can be evaluated using devices of the RCMA420/423, RCMS460/490 or EDS440/EDS441LAB series.

The measuring current transformers are connected to the respective devices via a 2- or 6-core cable. They can be used in DC, AC, and 3(N)AC systems.

The CTUB101-CTBCxx measuring current transformers are intended for connection to devices of the RCMA420/423 series and are supplied directly from the evaluator with the supply voltage DC ±12 V via the 6-core cable.

The CTUB102-CTBCxx measuring current transformers are intended for connection to an RCMS460/490. If the CTUB102-CTBCxx measuring current transformers are connected to an RCMS460/490 system, a DC 24 V power supply unit is required for the measuring current transformers, which is available as an accessory.

The CTUB104-CTBCxx measuring current transformers are intended for connection to an EDS440 or EDS441LAB. If the CTUB104-CTBCxx measuring current transformers are connected to such an insulation fault locator, a DC 24 V power supply unit is required for the measuring current transformers, which is available as an accessory.

The measuring current transformer cores of the CTBC20P…210P series feature an integrated magnetic shield and are suitable for applications with high load currents or inrush currents.


  • Combined test and reset button
  • Multicolour LED for operation, fault and status messages
  • Exchangeable electronic module without mechanical separation of the primary conductors
  • Extension/retrofitting or modification of functionalities in case of changed monitoring requirements
  • Insensitive to load currents due to full magnetic shield (CTUB10x-CTBC20P…210P only)
  • Monitoring of the connection to the measuring current transformer
  • Supply voltage DC ±12 V/DC 24 V
  • CTUB10x-CTBC20…210 for residual current monitoring systems of the RCMS460/490 series as well as for RCMA420/423 residual current monitors
  • CTUB10x-CTBC20P…210P for residual current monitoring systems of the RCMS460/490 series as well as for RCMA420/423 residual current monitors. Can be used for very high system-related peak load currents.
  • CTUB104-CTBC20…210(P) for insulation fault locators of the EDS440 and EDS441LAB series


Downloads for LINETRAXX® CTUB100 series

Datenblätter CTUB100-Serie 717.2 KB DE15.06.2022 06:13:57D00362
Datenblätter CTUB100 series 712.7 KB EN15.06.2022 06:13:48D00362
Handbücher CTUB100-Serie 1.2 MB DE15.06.2022 06:14:08D00362
Handbücher CTUB100 series 1.2 MB EN15.06.2022 06:14:20D00362
Datenblätter CTUB100 serie 717.5 KB ES15.06.2022 06:13:35D00362
Datenblätter CTUB100 série 715.8 KB FR29.06.2022 08:07:12D00362
Technische Informationen CTUB100 wiring addendum (US) 244.9 KB EN19.11.2020 18:14:05
Handbücher CTBC-Serie 1.0 MB DE24.11.2021 10:20:48D00336
Handbücher CTBC series 1.0 MB EN24.11.2021 10:20:59D00336

Optional accessories for LINETRAXX® CTUB100 series

Spare parts electronic modules

TypeSupply voltage UsSuitable for evaluatorArt. No.
CTUB101DC ±12 VRCMA420/423B78120050
CTUB102DC 24 VRCMS460/490B78120051
CTUB104DC 24 VEDS440/441LABB78120053

Required terminals are included in the scope of delivery.
Connecting cables are optionally available.

Spare parts measuring current transformer cores

TypeInternal diameterArt. No.
CTBC2020 mmB98120001
CTBC20P20 mmB98120002
CTBC3535 mmB98120003
CTBC35P35 mmB98120004
CTBC6060 mmB98120005
CTBC60P60 mmB98120006
CTBC120120 mmB98120007
CTBC120P120 mmB98120020
CTBC210210 mmB98120008
CTBC210P210 mmB98120021

P = full magnetic shield

Connecting cables

Length (m)Connection toNameArt. No.
1RCMS46…, RCMS49…, EDS44…CTXS-100B98110090
2,5RCMS46…, RCMS49…, EDS44…CTXS-250B98110091
5RCMS46…, RCMS49…, EDS44…CTXS-500B98110092
10RCMS46…, RCMS49…, EDS44…CTXS-1000B98110093

Voltage supply

Typemax. connected current transformersArt. No.
STEP-PS/1 AC/24 DC/0.54B94053110
STEP-PS/1 AC/24 DC/1.7514B94053111
STEP-PS/1 AC/24 DC/4.234B94053112


Type designationArt. No.
Snap-on mounting for CTBC20 and CTBC20PB91080111
Snap-on mounting for CTBC35 and CTBC35PB91080112

(included in scope of delivery)

LINETRAXX® CTUB100 series Variants

TypeSuitable for evaluatorSupply voltageCurrent transformer diameterShieldingArt. No.
CTUB101-CTBC20RCMA420, RCMA423DC ±12 Vø 20-B78120010
CTUB101-CTBC20PRCMA420, RCMA423DC ±12 Vø 20xB78120020
CTUB101-CTBC35RCMA420, RCMA423DC ±12 Vø 35-B78120012
CTUB101-CTBC35PRCMA420, RCMA423DC ±12 Vø 35xB78120022
CTUB101-CTBC60RCMA420, RCMA423DC ±12 Vø 60-B78120014
CTUB101-CTBC60PRCMA420, RCMA423DC ±12 Vø 60xB78120024
CTUB101-CTBC120RCMA420, RCMA423DC ±12 Vø 120-B78120016
CTUB101-CTBC120PRCMA420, RCMA423DC ±12 Vø 120xB78120026
CTUB101-CTBC210RCMA420, RCMA423DC ±12 Vø 210-B78120018
CTUB101-CTBC210PRCMA420, RCMA423DC ±12 Vø 210xB78120028
CTUB102-CTBC20RCMS460, RCMS490DC 24 Vø 20-B78120011
CTUB102-CTBC20PRCMS460, RCMS490DC 24 Vø 20xB78120021
CTUB102-CTBC35RCMS460, RCMS490DC 24 Vø 35-B78120013
CTUB102-CTBC35PRCMS460, RCMS490DC 24 Vø 35xB78120023
CTUB102-CTBC60RCMS460, RCMS490DC 24 Vø 60-B78120015
CTUB102-CTBC60PRCMS460, RCMS490DC 24 Vø 60xB78120025
CTUB102-CTBC120RCMS460, RCMS490DC 24 Vø 120-B78120017
CTUB102-CTBC120PRCMS460, RCMS490DC 24 Vø 120xB78120027
CTUB102-CTBC210RCMS460, RCMS490DC 24 Vø 210-B78120019
CTUB102-CTBC210PRCMS460, RCMS490DC 24 Vø 210xB78120029
CTUB104-CTBC20PEDS440, EDS441LABDC 24 Vø 20xB78120033
CTUB104-CTBC35PEDS440, EDS441LABDC 24 Vø 35xB78120034
CTUB104-CTBC60PEDS440, EDS441LABDC 24 Vø 60xB78120035