2 wire non-tripping loop testers
兩線非跳閘環路測試儀
Model : LTW335
The Megger LTW335 have two wire earth loop testers verify the loop impedance of a live electrical circuit, ie without the need to disconnect the electrical supply. The new LTW300 series instruments offer a 2 wire loop testing solution that does not trip 30 mA RCDs and can be used on a wide range of voltages.
* Specification
General Specification
Only values with tolerances or limits are guaranteed data. Values
without tolerances are for information only.
Accuracy
All accuracy statements are based on:
Ambient temperature: 23º ± 2ºC
Nominal source voltage: 230 V a.c ± 1%
Voltage measurement
(ac only) 50V to 440 V
Accuracy: ±2% ±1V
Frequency measurement
Range: 25Hz to 99.99Hz
Accuracy: ±0.1Hz
A warning will be shown if applied voltage exceeds 440 V.
Damage will occur if applied voltage exceeds 600 √ rms.
Loop testing
Accuracy
+/-5% +/-0.03 ohms @ 230 V a.c.
+/-10% +/-0.03 ohms @ 100 V a.c. and 300 V a.c. (LTW335)
+/-15% +/-0.03 ohms @ 50 V a.c. (LTW335)
NO-TRIP Loop and High current Loop test
Source voltage:
LTW335 50V to 440V (49Hz to 50.1Hz)
Display range: 0.01 Ω to 2000 Ω
Accuracy: ±5% ±0.03 Ω
Nominal test current:
No-Trip loop test 15 mA (at nominal 230 V a.c supply)
High current loop test 4 A (at nominal 230 V a.c supply)
EN61557
Operational range: 0.30 Ω to 1000 Ω
Prospective Fault Current (PFC)
Prospective fault current = Measured Source Voltage / Loop r
esistance
Maximum range: No trip mode: 20 KA
High current mode: 20 KA
Hi resolution mode: 40 KA
Accuracy is derived from loop test and voltage measurement.
Environmental
Temperature and humidity
Operating Range: -10°C to +50°C
Operating Humidity: 90% R.H. non-condensing at
+40°C max.
Storage Range: -25°C to +70°C
Maximum altitude: 2000m to full safety specification
Dust and water ingress: IP54
Safety
IEC61010
Designed to IEC61010-1
Designed for 300 volts to Earth Category IV, with Phase to Phase
voltages to 440 Volts.
Fuse protected to 600 volts rms ac.
EN61557
Complies with the following parts of EN61557, Electrical safety in
low voltage systems up to 1000V ac and 1500V dc- Equipment for
testing, measuring or monitoring of protective measures:
Part1-General Requirements
Part3-Loop resistance
E.M.C
In accordance with IEC61326-1
Power supply
Battery: 8 x 1,5 V cells IEC LR6 type (AA alkaline).
Rechargeable: 8 x 1.2VNiCd or NiMH cells
Battery life: 2000 consecutive testsNO-TRIP Loop and High current Loop test
Source voltage:
LTW335 50V to 440V (49Hz to 50.1Hz)
Display range: 0.01 Ω to 2000 Ω
Accuracy: ±5% ±0.03 Ω
Nominal test current:
No-Trip loop test 15 mA (at nominal 230 V a.c supply)
High current loop test 4 A (at nominal 230 V a.c supply)
EN61557
Operational range: 0.30 Ω to 1000 Ω
High resolution loop test (LTW425 only)
Source voltage: 50 V to 440 V (50Hz)
Display range: 0.001 Ω to 2000 Ω
Accuracy: ±5% ±0.01 Ω
Nominal test current: 4 A at nominal 230 V supply
EN61557
Operational range: 0.30 Ω to 1000 Ω
Prospective Fault Current (PFC)
Prospective fault current = Measured Source Voltage / Loop r
esistance
Maximum range: No trip mode: 20 KA
High current mode: 20 KA
Hi resolution mode: 40 KA
Accuracy is derived from loop test and voltage measurement.
Environmental
Temperature and humidity
Operating Range: -10°C to +50°C
Operating Humidity: 90% R.H. non-condensing at
+40°C max.
Storage Range: -25°C to +70°C
Maximum altitude: 2000m to full safety specification
Dust and water ingress: IP54
Safety
IEC61010
Designed to IEC61010-1
Designed for 300 volts to Earth Category IV, with Phase to Phase
voltages to 440 Volts.
Fuse protected to 600 volts rms ac.
EN61557
Complies with the following parts of EN61557, Electrical safety in
low voltage systems up to 1000V ac and 1500V dc- Equipment for
testing, measuring or monitoring of protective measures:
Part1-General Requirements
Part3-Loop resistance
E.M.C
In accordance with IEC61326-1
Power supply
Battery: 8 x 1,5 V cells IEC LR6 type (AA alkaline).
Rechargeable: 8 x 1.2VNiCd or NiMH cells
Battery life: 2000 consecutive testsNO-TRIP Loop and High current Loop test
Source voltage:
LTW335 50V to 440V (49Hz to 50.1Hz)
Display range: 0.01 Ω to 2000 Ω
Accuracy: ±5% ±0.03 Ω
Nominal test current:
No-Trip loop test 15 mA (at nominal 230 V a.c supply)
High current loop test 4 A (at nominal 230 V a.c supply)
EN61557
Operational range: 0.30 Ω to 1000 Ω
High resolution loop test (LTW425 only)
Source voltage: 50 V to 440 V (50Hz)
Display range: 0.001 Ω to 2000 Ω
Accuracy: ±5% ±0.01 Ω
Nominal test current: 4 A at nominal 230 V supply
EN61557
Operational range: 0.30 Ω to 1000 Ω
Prospective Fault Current (PFC)
Prospective fault current = Measured Source Voltage / Loop r
esistance
Maximum range: No trip mode: 20 KA
High current mode: 20 KA
Hi resolution mode: 40 KA
Accuracy is derived from loop test and voltage measurement.
Environmental
Temperature and humidity
Operating Range: -10°C to +50°C
Operating Humidity: 90% R.H. non-condensing at
+40°C max.
Storage Range: -25°C to +70°C
Maximum altitude: 2000m to full safety specification
Dust and water ingress: IP54
Safety
IEC61010
Designed to IEC61010-1
Designed for 300 volts to Earth Category IV, with Phase to Phase
voltages to 440 Volts.
Fuse protected to 600 volts rms ac.
EN61557
Complies with the following parts of EN61557, Electrical safety in
low voltage systems up to 1000V ac and 1500V dc- Equipment for
testing, measuring or monitoring of protective measures:
Part1-General Requirements
Part3-Loop resistance
E.M.C
In accordance with IEC61326-1
Power supply
Battery: 8 x 1,5 V cells IEC LR6 type (AA alkaline).
Rechargeable: 8 x 1.2VNiCd or NiMH cells
Battery life: 2000 consecutive tests
Mechanical
Weight: 1000g ±10% excluding test leads
Dimensions: 203 x 148 x 78 mm
Patents
The loop testing technologies used in these instruments are subject
to the following patent applications:
UK Patent no. 0518089.9
European Patent no. 06119110.2
US and Canadian patent application.