AC Current Probe
Models MN252 and MN253
User Manual
DESCRIPTION
The MN252/MN253 (Catalog #2115.78 and #2115.79) 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 MN252/MN253 are compatible with any AC voltmeter, multimeter, or other voltage
measurement instrument that is capable of displaying 10 mV of output per amp of measured current,
voltmeter accuracy of 0.75% or better and an input impedance of 1M.
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 II: For measurements performed on circuits directly connected to the electrical distribution system.
Examples are measurements on household appliances or portable tools.
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 IV: For measurements performed at the primary electrical supply (<1000V) such as on primary
overcurrent protection devices, ripple control units, or meters.
RECEIVING 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)
MN252 MN253
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: 10mV/A
Accuracy and Phase Shift*:
Accuracy: 0.5 to 10A: 3.0% Reading ± 5mV
10 to 40A: 2.5% Reading ± 5mV
40 to 100A: 2.0% Reading ± 5mV
100 to 240A: 1.0% Reading ± 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° 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 > 1M.
Overload: 240A for 10 min ON, 30 min OFF
Frequency Range: 40 to 10kHz