Checking protection against electric shock and short circuits in low-voltage networks up to 400/690 V means measuring the fault loop impedance and knowing the prospective short-circuit current without taking circuits out of service. The AMZC-306 measures ZL-PE, ZL-N and ZL-L from 0.13 to 1999 Ω per IEC 61557 with 0.01 Ω resolution and ±(5% m.v. + 3 digits), with a test current of up to 36.7 A at 690 V; it displays the prospective short-circuit current from 0.055 A to 69.0 kA, measures without tripping RCDs of 30 mA or more from 0.43 Ω and works in eight rated networks with a 100 to 750 V range.
AMZC-306 key data
- Loop impedance: ZL-PE, ZL-N and ZL-L from 0.13 to 1999 Ω per IEC 61557 (1.2 m leads), 0.01 Ω resolution, ±(5% m.v. + 3 digits) up to 19.99 Ω and ±(4% m.v. + 3 digits) above.
- Networks: 110/190, 115/200, 127/220, 220/380, 230/400, 240/415, 290/500 and 400/690 V; the AMZC-306 operates from 100 to 440 V for ZL-PE and ZL-N and from 100 to 750 V for ZL-L, at 45-65 Hz.
- Test current: a maximum of 36.7 A (10 ms) at 690 V, 24.5 A at 230 V, 21.3 A at 400 V and 12.2 A at 115 V.
- No RCD tripping: ZL-PE RCD mode from 0.43 Ω, without tripping RCDs of IΔn ≥ 30 mA, from 100 to 440 V and with ±(6% m.v. + 10 digits) up to 19.99 Ω.
- Short-circuit current: displayed from 0.055 A to 69.0 kA (up to 40.0 kA in RCD mode), with RS and XS for ZS < 200 Ω at ±(5% + 5 digits) of the ZS value.
- Voltage: 0 to 750 V, with 0.1 V resolution and ±(2% m.v. + 4 digits) up to 249.9 V, and an overvoltage alarm.
- Power and memory: the AMZC-306 runs on four LR14 batteries or a 4.8 V NiMH accumulator, makes more than 5000 measurements on alkaline batteries, switches off after 300 s and stores 990 cells downloaded over USB.
- Safety: CAT IV 600 V (CAT III 1000 V) with double insulation, IP54, 0 to +45 °C, 288 × 223 × 75 mm and about 2 kg.
Advantages
Resolution of 0.01 Ω
Loop impedance from 0.13 to 1999 Ω per IEC 61557 with 0.01 Ω resolution and high-current measurement up to 36.7 A (10 ms at 690 V), separating the resistive and reactive components of the loop.
Every LV network covered
Measurements in installations of 110/190 V, 115/200 V, 127/220 V, 220/380 V, 230/400 V, 240/415 V, 290/500 V and 400/690 V, over a voltage range of 100 to 750 V at 45-65 Hz.
No nuisance tripping
The ZL-PE RCD mode measures the loop without tripping residual-current devices rated above 30 mA, from 0.43 to 1999 Ω in the 100-440 V range.
Safe, verified connections
A contact electrode checks the correct connection of the PE terminal, the measurement continues when L and N are swapped and an overvoltage alarm protects the operator.
Field-ready autonomy
Four LR14 alkaline or NiMH batteries deliver more than 5000 measurements, with auto-off after 300 seconds, a 990-cell memory (3500 entries) and USB transfer to a PC.
Applications
- Verification of protection against electric shock in LV installations.
- Fault-loop measurements in industrial networks up to 690 V.
- Circuits protected by residual-current devices.
- Calculation of prospective short-circuit currents in distribution boards.
- Periodic inspections with documented results.
About the product
The AMZC-306 is rated CAT IV 600 V (CAT III 1000 V) with double insulation and IP54 protection and weighs 2 kg; it is supplied with the UNI-SCHUKO adapter, 1.2 m test leads, pin probes, crocodile clips, carrying case, USB cable, harness, NiMH battery pack, Z7 power adapter and calibration certificate, with 5 to 20 m leads and three-phase socket adapters as options.
Technical specifications
| Loop impedance | ZL-PE, ZL-N, ZL-L; resolution 0.01 Ω |
| Measuring range | 0.13-1999 Ω (1.2 m leads) per IEC 61557 |
| Accuracy | ±(5 % m.v. + 3 digits) to 19.99 Ω; ±(4 % + 3 digits) above |
| RCD mode | No tripping of RCDs >30 mA; 0.43-1999 Ω; 100-440 V |
| Networks | 110/190 V to 400/690 V; range 100-750 V; 45-65 Hz |
| Short-circuit current | Calculated for nominal voltage; R and X components |
| Voltage measurement | 0-750 V; 0.1 V resolution up to 250 V |
| Memory and interface | 990 cells (3500 entries); USB |
| Power supply | 4 × LR14 alkaline or NiMH; >5000 measurements |
| Safety | CAT IV 600 V (CAT III 1000 V); IP54 |
| Operating conditions | 0 to +45 °C; humidity 20-80 % |
| Dimensions and weight | 288 × 223 × 75 mm; 2 kg |
| Test current | Max. 36.7 A (10 ms) at 690 V; 24.5 A at 230 V |
| Displayed short-circuit current | 0.055 A…69.0 kA (RCD mode: up to 40.0 kA) |
| Range by test lead | From 0.13 Ω (1.2 m), 0.17 Ω (5 m), 0.21 Ω (10 m), 0.29 Ω (20 m), 0.19 Ω (WS-01, WS-05) |
Frequently asked questions
Up to what short-circuit current can the AMZC-306 display?
The AMZC-306 calculates the prospective short-circuit current from the measured impedance and the rated voltage and displays it from 0.055 A to 69.0 kA; in no-trip RCD mode, up to 40.0 kA. Measured per EN 61557, it suits installations with fault currents of up to 5.3 kA.
Does it run on batteries or on a rechargeable accumulator?
Both. The AMZC-306 takes four LR14 (C) alkaline batteries, good for more than 5000 measurements, or the 4.8 V NiMH accumulator supplied with the meter, charged with a 100 to 240 V, 50-60 Hz adapter; charging starts at temperatures from +10 to +40 °C.
Can it measure without tripping the RCD?
Yes. The ZL-PE RCD mode measures the loop impedance without tripping residual-current devices rated above 30 mA.
Which networks does it cover?
Installations from 110/190 V to 400/690 V, with a measuring voltage range of 100 to 750 V at 45-65 Hz.
Does it calculate the short-circuit current?
Yes. It calculates the prospective short-circuit current for the nominal voltage and displays the resistive and reactive components of the loop.
What accessories are included?
The UNI-SCHUKO adapter, 1.2 m test leads, probes, crocodile clips, carrying case, USB cable, harness, NiMH battery pack, Z7 power adapter and a calibration certificate.
How long do the batteries last?
More than 5000 measurements on one set of alkaline LR14 batteries, helped by automatic power-off after 300 seconds.
