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Fluke 377 FC Non-Contact Voltage True-rms AC/DC Clamp Meter with iFlex

Key features

  • Measure voltage and current with your clamp jaw
  • Faster, safer testing – all without touching a live wire – using FieldSense™ technology
  • Complete 3-phase voltage and current tests in 3 quick steps

Voltage and current measurements with FieldSense™ technology

The Fluke 377 FC true-rms clamp meter uses FieldSense™ technology to make testing faster and safer, all without contacting a live conductor. You get accurate voltage and current measurements through the clamp jaw. Simply clip the black test lead to any electrical ground, put the clamp jaw around the conductor and see reliable, accurate voltage and current values on the display.

Measure extremely high current with iFlex® probe

Use the included iFlex flexible current probe to measure ac current as high as 2500 A. The iFlex probe provides access to large conductors in tight spaces.

Complete 3-phase measurements in quick, easy steps

  • Complete 3-phase voltage and current tests in 3 easy steps
  • Full set of phase-to-ground and phase-to-phase values calculated and shown on the meter
  • Values are also displayed on your smart phone and saved to the cloud via Fluke Connect software
  • Phase rotation auto-calculated and shown on the Fluke Connect software
  • No more hand-written notes or complicated math.

Easy to see, easy to use with included tools

Your job will get easier when you use the 377 FC clamp meter. The display turns green when a stable FieldSense measurement is detected. Visual Continuity also provides a bright green screen for easy detection of continuity in noisy work areas.

Record, analyze, share results with Fluke Connect® software

With Fluke Connect software you can remotely log, trend and monitor measurements to pinpoint intermittent faults. Fluke Connect also allows you to gather data as the basis for a preventive maintenance program.

  • Save measurements to your phone and the Fluke Cloud, for comparison of readings over time.

    Save measurements to your phone and the Fluke Cloud, for comparison of readings over time.

    See a full set of phase to phase measurements, quickly, simply and safely.

    Fluke Connect allows you to see voltage and current displayed as concurrent graphs over time.

What’s in the box:

The 377 FC current clamp includes:

  • 377 FC Non-Contact Voltage True-rms Clamp Meter
  • iFlex flexible current probe (18 inches; 48 cm)
  • TL224 silicone insulated test leads
  • TP175 adjustable length test probes
  • AC285 grounding clip (black, quantity one)
  • TPAK magnetic hanging kit, with 9 inch (23 cm) hanging strap
  • Premium Carrying case
  • Quick reference guide

Technical Specifications

General specifications
General Maximum Voltage between any Terminal and Earth Ground 1000 V
Type 2 AA IEC LR6 alkaline
Life 200 hour
Display Dual readout
Automatic Power Off 20 minutes
AC Current: Jaw
Range 999.9 A
Resolution 0.1 A
Accuracy 2 % ±5 digits (10 Hz to 100 Hz)
2.5 % ±5 digits (100 Hz to 500 Hz)
Crest Factor (50/60 Hz) 3 @ 500 A
2.5 @ 600 A
1.42 @ 1000 A
Add 2 % for C.F. >2
AC Current: Flexible Current Probe
Range 2500 A
Resolution 1 A (≤2500 A) 0.1 A (≤999.9 A)
Accuracy 3 % ±5 digits (5 Hz to 500 Hz)
Crest Factor (50/60Hz) 3.0 at 1100 A
2.5 at 1400 A
1.42 at 2500 A
Add 2 % for C.F. >2
Position Sensitivity
Distance from Optimum i2500-10 Flex i2500-18 Flex Error
A 0.5 in (12.7 mm) 1.4 in (35.6 mm) ± 0.5 %
B 0.8 in (20.3 mm) 2.0 in (50.8 mm) ± 1.0 %
C 1.4 in (35.6 mm) 2.5 in (63.5 mm) ± 2.0 %
Measurement uncertainty assumes centralized primary conductor at optimum position, no external electrical or magnetic field, and within operating temperature range.
DC Current
Range 999.9 A
Resolution 0.1 A
Accuracy 2 % ±5 digits1
[1]When using the ZERO function to compensate for offsets
AC Voltage: Field Sense
Range 1000 V
Resolution 1 V (≤1000V)
≤4/0 AWG 3 % ±5 digits (45 Hz to 66 Hz)
≥4/0 AWG 5 % ±5 digits (45 Hz to 66 Hz)
Position wire as close as possible to jaw opening (see illustration).
AC Voltage: Test Leads
Range 600.0 V 1000 V
Resolution 0.1 V (≤600.0 V)
1 V (≤1000 V)
Accuracy 1 % ±5 digits (20 Hz to 500 Hz)
DC Voltage
Range 600.0 V
1000 V
Resolution 0.1 V (≤600.0 V)
1 V (≤1000 V)
Accuracy 1 % ±5 digits
mV dc
Range 500.0 mV
Resolution 0.1 mV
Accuracy 1 % ±5 digits
Amps Frequency: Jaw
Range 5.0 Hz to 500.0 Hz
Resolution 0.1 Hz
Accuracy 0.5 % ±5 digits
Trigger Level 5 Hz to 10 Hz, ≥10 A
10 Hz to 100 Hz, ≥ 5 A
100 Hz to 500 Hz, ≥ 10 A
Amps Frequency: Flexible Current Probe
Range 5.0 Hz to 500.0 Hz
Resolution 0.1 Hz
Accuracy 0.5 % ±5 digits
Trigger Level 5 Hz to 20 Hz, ≥25 A
20 Hz to 100 Hz, ≥20 A
100 Hz to 500 Hz,≥25 A
Range 60.00 kΩ
6000 Ω
600.0 Ω
Resolution 0.1 Ω (≤600.0 Ω)
1 Ω (≤6000 Ω)
10 Ω (≤60.00 kΩ)
Accuracy 1 % ±5 digits
Range 1000 μF
Resolution 0.1 μF (≤100.0 μF)
1 μF (≤1000 μF)
Accuracy 1 % ±4 digits
Size (L x W x H) 274 mm x 86 mm x 47 mm
Weight (with Batteries) 463 g
Jaw Opening 34 mm
Flexible Current Probe Diameter 7.5 mm
Flexible Current Probe Cable Length (head to electronics connector) 1.8 m
Rogowski Coil Length 450 mm
Operating Temperature -10 °C to 50 °C
Storage Temperature -40 °C to 60 °C
Operating Humidity (without condensation) Non condensing (<10 °C)
≤90 % RH (10 °C to 30 °C)
≤75 % RH (30 °C to 40 °C)
≤45 % RH (40 °C to 50 °C)
Temperature Coefficients Add 0.1 x specified accuracy for each degree C >28 °C or <18 °C
Ingress Protection IEC 60529: IP30 (jaw closed)
Operating Altitude 2000 m
Storage Altitude 12 000 m
Electromagnetic Compatibility (EMC)
International IEC 61326-1: Portable Electromagnetic Environment
IEC 61326-2-2, CISPR 11: Group 1, Class B
Group 1: Equipment has intentionally generated and/or uses conductively-coupled radio frequency energy that is necessary for the internal function of the equipment itself.
Class B: Equipment is suitable for use in domestic establishments and in establishments directly connected to a low voltage power supply network which supplies buildings used for domestic purposes.
Emissions that exceed the levels required by CISPR 11 can occur when the equipment is connected to a test object.
Korea (KCC) Class A equipment (Industrial Broadcast & Communications Equipment)
Class A: Equipment meets requirements for industrial electromagnetic wave equipment and the seller or user should take notice of it. This equipment is intended for use in business environments and not to be used in homes.
USA (FCC) 47 CFR 15 subpart B. This product is considered an exempt device per clause 15.103.
General IEC 61010-1: Pollution degree 2
Measurement IEC 61010-2-032: CAT III 1000 V / CAT IV 600 V
IEC 61010-2-033: CAT III 1000 V / CAT IV 600 V
Current Clamp for Leakage Current Measurements IEC 61557-13: Class 2, ≤30 A/m
Wireless Radio
Radio Frequency Certification FCC ID: T68-FBLE IC:6627A-FBLE
Frequency Range 2405 MHz to 2480 MHz
Output Power <100 mW
Radio Frequency Data Radio Frequency Data For Class A Devices
Hereby, Fluke declares that the radio equipment contained in this Product is in compliance with Directive 2014/53/EU. The full text of the EU declaration is available at the following internet address:




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  • Fluke 377 FC Non-Contact Voltage True-RMS AC/DC Clamp Meter
  • TL224 Test Leads
  • TP175 TwistGuard™ Test Probes
  • AC285 black grounding clip (1 only)
  • i2500-18 iFlex® Flexible Current Probes 18 inch (48 cm)
  • TPAK ToolPak™ Magnetic Meter Hanger
  • Premium carrying case
  • Quick reference guide