Aemc instruments MN251, MN250 User Manual

AC Current Probe
Models MN250 and MN251

User Manual

DESCRIPTION

The MN250/MN251 (Catalog #2115.76 and #2115.77) are the latest in compact AC Current probes.
Designed to meet the most stringent demands in industry and electrical contracting, they also meet the
latest safety and performance standards. The probes have a measurement range up to 240 Arms which
makes them perfect tools for measurement with DMMs, recorders, power and harmonic meters. The
Models MN250/MN251 are compatible with any AC voltmeter, multimeter, or other voltage
measurement instrument that is capable of displaying 1mV of output per amp of measured current,
Voltmeter accuracy of 0.75% or better and an input impedance of ≥ 1 M.

WARNING

The safety warnings are provided to ensure the safety of personnel and proper operation of the
instrument. Read the instruction completely.

• Use caution on any circuit: potentially high voltages and currents may be present and may pose
a shock hazard.

• Do not use the probe if damaged. Always connect the current probe to the measuring device
before it is connected around the conductor

• Do not use on non-insulated conductor with a potential to ground greater than 600V CAT III
pollution 2. Use extreme caution when clamping around bare conductors or bus bars.

• Before each use, inspect the probe; look for cracks in housing or output cable insulation.

• Do not use clamp in wet environment or in locations that hazardous gases exist.

• Do not use the probe anywhere beyond the tactile barrier.

INTERNATIONAL ELECTRICAL SYMBOLS

This symbol signifies that the current probe is protected by double or reinforced insulation. Use
only factory specified replacement parts when servicing the instrument.

This symbol signifies CAUTION! and requests that the user refer to the user manual before
using the instrument.

This is a type A current sensor. This symbol signifies that application around and removal from
HAZARDOUS LIVE conductors is permitted.

DEFINITION OF MEASUREMENT CATEGORIES
CAT IV: For measurements performed at the primary electrical supply (<1000V) such as on primary

overcurrent protection devices, ripple control units, or meters.

CAT III: For measurements performed in the building installation at the distribution level such as on

hardwired equipment in fixed installation and circuit breakers.

CAT II: For measurements performed on circuits directly connected to the electrical distribution system.

Examples are measurements on household appliances or portable tools.

RECEI

VING YOUR SHIPMENT

Upon receiving your shipment, make sure that the contents are consistent with the packing list. Notify
your distributor of any missing items. If the equipment appears to be damaged, file a claim immediately
with the carrier and notify your distributor at once, giving a detailed description of any damage.

2.56"

(65 mm)

.83"

(21 mm)

2.00"

(51 mm)

MN250 MN251

Tactical

Barrier

(keep hands below

this barrier)

5.47"

(139 mm)

(18.5 mm)

.1.18"

.73"

Black

Red

(30 mm)

ELECTRICAL SPECIFICATIONS

Nominal Range: 200A
Measurement Range: 0.1 to 240A
Transformation Ratio: Voltage output
Output Signal: 1mV/A
Accuracy and Phase Shift*:

Accuracy: 0.5 to 10A: 3.0% Reading ± 0.5mV

10 to 40A: 2.5% Reading ± 0.5mV
40 to 100A: 2.0% Reading ± 0.5mV
100 to 240A: 1.0% Reading ± 0.5mV

Phase Shift: 0.5 to 10A: Not Specified

10 to 40A: ≤ 5°
40 to 100A: ≤ 3°
100 to 240A: ≤ 2.5°

(*Reference conditions:18°C to 28°C, 20 to 75% RH, external
magnetic field < 40 A/m, 48 to 65 Hz sine wave, distortion
factor less than 1%, no DC component, no external current
carrying conductor, test sample centered.)
Load impedance > 1MΩ.

Frequency Range: 40 to 10kHz
Limit Operating Conditions:

200A permanently to 1kHz
Derating above 3kHz: 200 A x (1/0.333 F), F in kHz