Clip on - Split Core - AC current sensors, AC+DC current transducers
Converting ac or ac+dc current to an isolated 0-100mV, 0-1V, 0-2V, 0-5V, 0-10V, 0-20mA, 4-20mA or  5-25mA 

UK Tel: +44 1788 519911
US Tel: +1 631 615 6279
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The CTHR current sensors convert ac, ac+dc and dc currents to a dc level proportional to the Arms.  The CTHR have excellent tolerance for distorted and complex wave shapes

Both CTHR can provide all popular process control voltage and current loop outputs along with custom output options.   A range of through hole or split core sensors means that connection is possible without shutting down manufacturing plants.   Optional offset control allows nulling of residual ac currents to ensure best use of the output span (CTHR). 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-100kHz, depending on the core type selected.  Typical applications are process control systems like PLC or SCADA, current monitoring in ac/dc drives, ultrasonics, welding and circuit breaker trip coils.  For all CTHR models, a NIST/NPL (UKAS) traceable calibration certificate and certificate of conformance is supplied.   All CTHR use UL or CSA approved materials.

CTHR split core Type 5
Hole diameter 21mm (0.90") Overall size 204mm (8.03") x 65mm (2.55") x 38mm (1.5")
Current ranges: 20A / 30A / 40A / 50A / 100A / 200A / 300A / 400A split core models.

CTHR through hole core Type 1 and 2
Type 1: Hole: 13.5mm (0.53") x 10mm (0.39")
Type 2: hole 24.5 diameter
Overall size 145mm (5.71") x 95mm (3.74") x 38mm (1.50")
Current ranges: 10A / 20A / 30A / 40A / 50A / 100A split core

CTH/200/4-20/SC/24V dc split core current sensor
Type 5 split core DC-25kHz (internal filter 1500Hz)

CTH 50A through hole dc current transducer
Type 1 through hole DC-100kHz (internal filter 1500Hz)

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Type 2 - 24.5mm through hole DC-150kHz (internal filter 1500Hz)

CTHR split core Type 6
Hole: 104 (4.09") x 40 mm (1.57")
Outer: 159mm (6.26") x 85mm (3.35")
Current ranges: CTHR 500A / 800A / 1000A / 2000A
CTHR split core Type 7
Hole: 163mm (6.42") x 50mm (2")
Outer: 233mm (9.17") x 95mm (3.74")
Current ranges: 1000A / 2000A / 2500A / 3000A

CTHR split core Type 8
Hole: 50mm (2") round hole
Outer: 127mm (5") x 105mm (4.125")
Current ranges: CTHR / 500A / 800 / 1000 / 1500 / 2000 / 2500A

CTH 500 - 3000A split core dc current transducer
Type 6: DC-10kHz   Type 7: DC-4kHz   (internal filter 1500Hz)

CTH 50mm dia hole 500A - 2500A dc current transducer
Type 8 split core DC-400Hz

CTHR split core Type 9z
114.3mm (4.5") x 31.75mm (1.25")
Outer 183mm (7.19") x 104mm (4.06")
Current ranges: 500A / 600A / 800A / 1000A / 1500A / 2000A / 3000A / 4000A / 5000A

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

CTH rectangular window 500A - 5000A dc current transducer
Type 9 split core DC-1kHz

CTH 5000A to 40000A dc transducer core
Type 10 & 11 split core DC-1kHz


CTHR signal conditioner terminal connections

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Output +ve / Output ground / Input ground / Input +ve

Input and output grounds are isolated


CTHR current transducer general specifications

Ranges 1A / 2A / 5A / 10A / 20A / 40A / 50A / 100A / 200A / 500A / 1000A / 2000A / 3000A / 4000A / 5000A / 6000A / 10000A / 20000A / 25000A / 30000A / 35000A / 40000A  Amps rms  
Outputs 0-100mV, 0-1V, 0-2V, 0-5V, 0-10V or 0-20mA, 4-20mA or 5-25mA outputs.  Instantaneous outputs are voltage only, rms outputs can be voltage or current loop
Core type Through hole or split core clamp type, based on dc Hall sensing
Insulation voltage rating Rated insulation (Galvanic) to 2.5kVpk 1 minute, 5kV possible for some models
Power input 12Vdc / 24Vdc / 48Vdc / 72Vdc / 110Vdc  / 125Vdc /  250Vdc / 115Vac /  230 Vac - fuse and surge protected
Accuracy 0.5% for a non split core, 1.0% for a split core.  Conditions +23C 5C, traceable to UKAS NPL/NIST USA
Working temperature range Typically -20C - 50C (can be extended, check for exact model).  Functional temp range > 20C - 70C (check for each model).  Extended temp range on some models 40C - 70C
Frequency response DC- 150kHz max, refer to sensor type, split cores are <DC-25kHz, refer to sensor type
Adjustment Internal dc offset and gain (span) controls
Mounting Current sensors up to 400A can be mounted on the transducer case or via a 300mm cable externally, fixing points provided
Approvals CE Marked, IEC1010 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 – 125A – Supplied attached or separate to conditioner
Type 2: 24.5mm diameter  5A - 500A – Supplied attached or separate to conditioner
Type 3: 30mm diameter  10A - 800A – Supplied attached or separate to conditioner
Type 4: 50mm diameter  25A - 2500A – Sensor connects to signal conditioner via 2M cable

Available split core hole sizes

Type 5: 21mm dia  20A - 400A Supplied attached or separate to conditioner 0.5M max
Type 6: 104 x 40mm  500A - 3000A Sensor connects to signal conditioner via 0.5M cable
Type 7: 163 x 50mm  500A - 3000A Sensor connects to signal conditioner via 0.5M cable
Type 8: 50mm dia  500A - 2500A Sensor connects to signal conditioner via 2M cable
Type 9z: 114mm x 31.75mm  500A - 5000A – Sensor connects to signal conditioner via 2M cable
Type 10: 140mm (5.5") x 203mm (8")  5000A - 20000A Sensor connects to signal conditioner via 2M cable
Type 11: 330mm (13") x 330mm (13")  25000A - 40000Adc Sensor connects to signal conditioner via 2M cable

Current transducer order codes

The order code is based on:-

CTHR / amps input / output / SC or TH /  power input + core type

SC = split core, TH = through hole (non-split core)

230Vac & 115Vac adapters are available (in this case the CTHR will be supplied with 9-36Vdc input and ac adapter)


Options - Environmental

Self extinguishing materials to UL94V0 and CSA
Extended temperature range -40C - 70C (not available for all sensor types)

Options – noise rejection and offset

Non standard input current
Non standard output voltage or current
User can specify upper or lower –3db point
External dc offset nulling control

CTHR order code examples

CTHR / 50A / 4-20 / TH / 24Vdc 50Arms input, 4-20mA output, through hole and 24Vdc aux power input
CTHR / 100A / 100m / SC / 72Vdc 100Arms input, 0-100mV output, split core and 72Vdc aux power input
CTHR / 100A / 5-25mA / TH / 48Vdc 100Arms input, 5-25mA output, through hole and 48Vdc aux power input
CTHR / 200A / 10 / SC / 110Vdc 200Arms input, 0-10V output, split core and 110Vac aux power input

All products have CE, IEC, EN, ASME or BS approvals.


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