Ammeter for measuring differential or residual currents (up to four simultaneously) using a external toroidal or for the measurement of the line currents (possibly also separate lines between them) using appropriate external CT.

Technical Characteristics CTT-4 | CTT-8
Auxiliary Supply
Nominal voltage Us 110 - 230 - 400 VAC
Operating voltage range ±15%
Power consumption 3VA
Frequency 50 – 60 Hz
Voltage Inputs
Measurement range52…693VAC L-L (30…400VAC L-N)
Method of measuring True RMS value
Measuring input impedance1 MΩ
Method of connection Single-phase, two-phase, three-phase orbalanced three-phase system
Current Inputs
Reference current 5A
Measurement range 0,05…5A
Method of measuringTrue RMS value
Overload capacity+30% by an external current transformer
Self-consumption< 0,5VA
MeasuresVoltage -
Current 0,5%
Power -
Frequency -
Active energy -
Insulation voltage 3kVAC for 1 minute
Ambient Condition
Operating temperature -10…+60°C
Storage temperature -25…+80°C
Version Flush mount 96 x 96 mm
Degree of protection IP52 on front - IP20 Housing and terminals
Weight 500g
Certifications and Compliance
Reference standardsIEC/EN 50081-2, IEC/EN 61000-6-2, IEC/EN 61010-1, IEC/EN 61036-1
Order Code Description
C1 Auxiliary supply 20÷60 VAC/DC
C2 Auxiliary supply 85÷230 VAC/DC
CT5 Current inputs by exteral CT 5A
CT1 Rated current inputs by external CT 1A
DO 2 digital outputs
A 1 analog output
Communication Ports
485 RS485 serial interface

Wiring connection (External CT)

Wiring connection (Differential current inputs)

Mechanical Dimensions (mm)