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The CTH sensors convert dc and ac current to an isolated voltage or mA output with the ability to track ac waveshapes.  The CTH output is a faithful reproduction of the measured current, whether ac or dc.  All popular process control voltage and current loop outputs are available.  Through hole or split core options mean that connection is non-intrusive and straightforward.  The available input range of the CTH sensors is any value from 1A to 40000Adc. Optional dc offset control allows nulling of residual dc current to ensure best use of the output span.  The sensor power input is designed to operate over a wide voltage range associated with process control and sub-station auxiliary dc supply systems.  Active Hall Effect sensor technology allows measurement from DC-150kHz (depending on the sensor type) along with fast step response.  The CTH can be used to provide an instantaneous output for ac currents.  Typical applications are found in process control systems like PLC or SCADA, transportation, telecommunications, dc drives, welding and circuit breaker trip coils.  For all CTH models, a NIST/NPL (UKAS) traceable calibration certificate and certificate of conformance is supplied.

 << RS485 output now available >>
Outdoor models and weather proof cabling available
For alarm, protection and threshold monitoring please click Din trip relay

CTH Sensors General Datasheet pdf  | CTH Type 4, 4mini, 8, 8mini, 8ee, 8f, 9z  |  CTH with Integral Terminal Block Datasheet 
  CTH type G, 10 and 11 data sheet |  CTH Sensor User Manual  |  ISCTH datasheet  |  LMCVR Trip Relay

CTH through hole core Type 1

  • Type 1: Hole: 13.5mm (0.53") x 10mm (0.39")
  • Overall size 145mm (5.71") x 95mm (3.74") x 38mm (1.50")
  • Type 1 current ranges: 1 / 2 / 5 / 10 / 20 / 30 /
    40 / 50 / 75 / 100A

Type 1: DC-100kHz (internal filter 1500Hz). As
standard the sensor is supplied connected via a 100cm (39") cable

CTH Type 2

  • Type 2 current ranges: From 0-5A to 0-600A, 25.4mm dia

Type 2 - 24.5mm through hole DC-150kHz (internal filter 1500Hz)
As standard the sensor is supplied connected via a 100cm (39") cable

CTH through hole Type 3 (OEM only)

  • Hole diameter 3.2mm (0.125") Overall size 24mm (0.94") x 22.2mm (0.874") x 10mm (0.394")
  • Current ranges: 1 / 2 / 5 / 10 / 19A

Type 3 through hole DC-100kHz (internal low pass filter 1500Hz)

CTH split core Type 5

  • Hole diameter 21mm (0.83") Overall size 204mm
    (8.03") x 65mm (2.55") x 38mm (1.5")
  • Current ranges: 20 / 30A/ 40 / 50 / 100 / 200
    / 300 / 400A split core models.

Type 5 split core DC-25kHz (internal filter 1500Hz).
As standard the sensor is supplied connected via a 100cm (39") cable

CTH split core Type 6 / CTH split core Type 7

CTH split core Type 6
  • Hole: 104 (4.09") x 40mm (1.57") Outer: 159mm (6.26") x
    85mm (3.35") Current ranges: From 200A to 4000A
CTH split core Type 7
  • Hole: 163mm (6.42") x 50mm (2")Outer: 233mm (9.17") x
    95mm (3.74") Current ranges: From 500A to 4000A

Type 6: DC-10kHz Type 7: DC-4kHz (internal filter 1500Hz).
As standard the sensor is supplied connected via a 100cm (39" cable)

CTH Type 4 mini and CTH split core Type 8 mini

  • Hole: 28.5mm (1.125") round hole.
  • Outer: 102 mm (4") x 80mm (3.125") x 19mm (0.75")
  • Current ranges: 100 / 200 / 300 / 400A

Type 8 mini split core DC-400Hz supplied with 8ft cable

CTH Type 4 and CTH split core Type 8

  • Hole: 50mm (2") round hole Outer: 127mm (5") x
    105mm (4.125") x 31.75mm (1.25")
  • Current ranges: CTH / 200 / 300 / 400 / 500 / 800 /
    1000 / 1500 / 2000 / 2500A

Type 8 split core DC-400Hz supplied with 8ft cable

CTH Type 9z

  • Hole: 115mm x 33mm (4.5" x 1.25") rectangular hole
  • Outer: 199mm x (7.83") x 99mm (3.90") x 34mm (1.34")
  • Current ranges: CTH / 200 / 300 / 400 / 500 / 800 /
    1000 / 1500 / 2000 / 2500 / 3000A

Type 9z split core DC-400Hz

Type 9z with extended cable

CTH Type 8F

  • Hole: 57mm (2.25") round hole Outer: 137mm
    (5.375") x 134mm (5.25") x 42.00mm (1.625")
  • Current ranges: CTH / 200 / 300 / 400 / 500 / 800 /
    1000 / 1500 / 2000 / 2500A

Type 8F split core DC-400Hz supplied with 8ft cable

CTH Type 8EE

  • Hole: 108mm (4.25") round hole
  • Outer: 184mm (7.25") x 159mm (6.25") x 42.00mm (1.625")
  • Current ranges: CTH / 200 / 300 / 400 / 500 / 800 /
    1000 / 1500 / 2000 / 2500 / 5000A

Type 8EE split core DC-400Hz supplied with 8ft cable

CTH Type EE terminals on sensor head

  • Hole: 108mm (4.25") round hole
  • Outer: 184mm (7.25") x 159mm (6.25") x 42.00mm (1.625")
  • Current ranges: CTH / 200 / 300 / 400 / 500 / 800 / 1000 /
    1500 / 2000 / 2500A

CTH Type EE Datasheet

CTH Type D split core terminals on sensor head

  • Hole: 28.5mm (1.125") round hole.
  • Outer: 116.59mm (4.59") x 73.4mm (3.125") x 19mm (0.75")
  • Current ranges: 100 / 200 / 300 / 400 / 500A

CTH Type D Datasheet

CTH split core Type G

  • CTH Hole size 76.2mm (3.0") x 165.1mm (6.5").
  • Outer 196.85mm (7.75") x 304.8mm (12")
  • Current ranges 1000 / 2000 / 3000 / 4000 / 5000 / 6000A


CTH Type G Datasheet

Type G split core DC-400Hz supplied with 8ft cable

CTH split core Type 10

CTH split core Type 10
  • CTH Hole size 140mm (5.5") x 203mm (8"). Outer 254 (10") x 350 (13.75")
  • Current ranges 5000 / 6000 / 7000 / 8000 / 9000 /
    10000 / 15000 / 20000A
CTH split core Type 11
  • CTH aperture 330mm (13") x 330mm (13"). Outer 534mm
    (21") x 534mm (21")
  • Current ranges 25000 / 30000 / 35000 / 40000Adc

 CTH Type G, 10 and 11 data sheet
Type 10 & 11 split core DC-1kHz

ISCTH Type 8 ATEX and UL approved for Instrinsically safe environments

  • 50mm (2") round hole Outer: 127mm (5") x 105mm (4.125") x 31.75mm (1.25")
  • Current ranges: CTH / 100 / 200 / 300 / 400 / 500 / 800 / 1000 / 1500 / 2000 / 2500A

Model ISCTH type 8 intrinsically safe, models from 100A to 2500A

ISCTH datasheet

Molded integral 8ft cable for intrinsically safe connection

CTLP Loop powered dc current transducer

Current ranges: CTLP 25 / 50 / 100 / 400 / 500 / 600 / 800 / 1000 / 1500 / 2000 / 3000A

CTLP case A models 25A, 50A and 100A

CTLP 25A datasheet

CTLP case Z models 400, 500, 600, 800, 1000,
1500, 2000 and 3000A

CTLP datasheet

Signal conditioner terminal connections

Terminals from left to right:
output + / output - / power input ground -ve / power input positive +ve

Input and output grounds are isolated 250Vdc

Signal conditioner overall size 145mm (5.71") x 65mm (2.56") x 38mm (1.50")

DC current transducer general specifications

Ranges Depending on core type: 1A / 2A / 5A / 10A / 20A / 30A / 40A / 50A / 100A / 200A / 500A / 1000A / 2000A / 3000A / 4000A / 5000A / 6000A / 10000A / 20000A / 25000A / 30000A / 35000A / 40000A Amps peak
Outputs 0-100mV, 0-1V, 0-2V, 0-5V, 0-10V, 4-20mA.  All CTH outputs can be bipolar / instantaneous.  Non-standard outputs are available, USB, RS485 and WiFi interfaces available
Core type Through hole or split core clamp type, sense method based on dc Hall Effect
Insulation voltage rating Type 1, 2 & 5 rated insulation (Galvanic) 2.5kVpk 1 min 50/60Hz.  Type 6 & 7 3kVpk 1 min 50/60Hz. Type 4 & 8 5kVpk 1 min 50/60Hz
Power input 5V / 12Vdc / 24Vdc / wide range 9-36Vdc / 48Vdc / 72Vdc / 110Vdc / 125Vdc / 250Vdc / 115Vac / 230Vac - all fuse, polarity and surge protected
Accuracy �0.5% for a non split core, �1.0% for a split core. Conditions +23�C �5�C, traceable to UKAS NPL/NIST USA
Working temperature range Typically -20�C - 65�C (can be extended, check for exact model). Functional temperature range –20�C - 70�C (check for each model). CTH types 1 & 2 are –40�C - 85�C (sensor head only)
Protection Input fuse, output fuse, power input polarity diode, spike suppression
Frequency response Depending on sensor type/model. Type 1 & 2 DC- 150kHz max. Type 5, 6, 7, 8 & 9 split cores are DC-10kHz max.  Standard HF cut-off filter is 1.5kHz (other values available)
Adjustment Internal dc offset and gain controls
Mounting All signal conditioners and sensors have fixing points.  Current sensors up to 400A can be mounted on the signal conditioner case or via a cable.
Approvals CE Marked, EN61010 cat II & IEC348, UL/CSA rated materials.  Self extinguishing materials to UL94V0
Warranty 2 year warranty

Available through hole sizes (some not pictured above)

  • Type 1: 13.5 x 10mm rectangular 1A – 100A – Supplied attached or separate to conditioner
  • Type 2: 24.5mm diameter 5A - 600A – supplied with 1 metre (39") from sensor - signal conditioner
  • Type 3: 3.2mm diameter 1A-19A (OEM only)
  • Type 4 mini: 28.5mm / 1.125" diameter 100A - 400A Sensor has integral signal conditioner supplied with 2.4M cable
  • Type 4: 50mm diameter / 2" diameter 100A - 3000A Sensor has integral signal conditioner supplied with 2.4M cable

Available split core hole sizes

  • Type 5: 21mm dia 20A - 400A supplied with 1 metre (39") cable from sensor - signal conditioner
  • Type 6: 104 x 40mm 500A - 3000A supplied with 1 metre (39") cable from sensor - signal conditioner
  • Type 7: 163 x 50mm 500A - 4000A supplied with 1 metre (39") cable from sensor - signal conditioner
  • Type 8 mini: 28.5mm / 1.125" dia 100A - 400A Sensor has integral signal conditioner supplied with 2.4M cable
  • Type 8: 50mm / 2" dia 100A - 3000A Sensor has integral signal conditioner supplied with 2.4M cable
  • Type 8F (maxi): 57.15mm / 2.25" dia 400A - 3000A Sensor has integral signal conditioner supplied with 2.4M cable
  • Type 8EE: 108.00mm / 4.25" dia 400A - 3000A Sensor has integral signal conditioner supplied with 2.4M cable
  • Type 9z: 115mm (4.5") x 33mm (1.25") 200A - 3000A Sensor connects to signal conditioner via 2.4M cable
  • Type G: 76.2mm x 165.1mm / 3.0" x 6.5" 2500A - 5000A Sensor has integral signal conditioner supplied with 2.4M cable
  • Type 10: 140mm (5.5") x 203mm (8") 5000A - 20000A Sensor connects to signal conditioner via 2.4M cable
  • Type 11: 330mm (13") x 330mm (13") 25000A - 40000Adc Sensor connects to signal conditioner via 2.4M cable
  • Longer cable lengths available - on request

Current transducer order codes

  • The order code is based on:-
  • CTH / amps input / output / SC or TH / power input + core type
  • SC = split core, TH = through hole (non-split core)
  • Note: 230Vac/dc and 115Vac/dc adapters are available (in this case the CTH will be supplied with 9-36Vdc input and ac adapter)
  • Options R :  Ruggedization (not available for all sensor types)
  • Option T : Extended temperature range -40�C - 85�C (not available for all sensor types)  
  • Options : noise rejection and offset, user can specify upper or lower frequency  –3db point
  • Non standard input current
  • Non standard output voltage,  current (25mA, 1A, 5A), USB, RS485 and WiFi interfaces available
    All models constructed with self extinguishing materials to UL94V0 and CSA

Order code examples

CTH / 50A / 4-20 / TH / 24Vdc type 1 50Adc input, 4-20mA output, through hole, 24V aux power input, core type 1 (13.5 x 10mm)
CTH / 400A / 10 / TH / 48Vdc type 4 �400Adc input, �0-10V output, through hole, 48Vdc aux power input core type 4 (50mm hole dia)
CTH / 800A / 5 / SC / 9-32Vdc type 8 RS485 �800Adc input, �0-5V output, split core, 9-32Vdc aux power input, core type 8 (50mm hole dia) RS485 interface
CTH / 2000A / 4-12-20 / SC / 110Vdc type 7 �2000Adc input, 4-12-20mA output (12mA = zero), split core, 110Vdc aux power input, type 7 core (163 x 50mm)