AEMC JM850A Operating Manual

AC Current Probe
Model JM850A

User Manual

DESCRIPTION

The JM850A (Catalog # 2110.87) is designed for use in industrial environments. The “squared” jaws
permit multiple conductor or bus bar positioning. The current output makes it the perfect tool for
measurement with DMMs, recorders, power and harmonic meters. Three ranges allow you to obtain the
best resolution even on low current measurement.

WARNING

These safety warnings are provided to ensure the safety of personnel and proper operation of the
instrument.

• Read the instruction manual completely and follow all the safety information before attempting
to use or service this instrument.

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

• Read the Safety Specifications section prior to using the current probe. Never exceed the
maximum voltage ratings given.

• Safety is the responsibility of the operator.

• ALWAYS connect the current probe to the display device before clamping the probe onto the
sample being tested.

• ALWAYS inspect the instrument, probe, probe cable, and output terminals prior to use.
Replace any defective parts immediately.

• NEVER use the current probe on electrical conductors rated above 600 V in overvoltage
category III (CAT III). Use extreme caution when clamping around bare conductors or bus bars.

INTERNATIONAL ELECTRICAL SYMBOLS

This symbol signifies that the current probe is protected by double or reinforced insulation. Use
only 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.

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.

PACKAGING

The shipping container includes the probe, this instruction manual and a product registration card.
You can now register online at www.aemc.com.

INSTRUMENT COMPATIBILITY

The Model JM850A is compatible with any AC Ammeter, multimeter, or other current measuring
instrument with an input impedance lower than 2.5Ω. To achieve the stated accuracy, use the JM850A
with an Ammeter having an accuracy of 0.75% or better.

INSTRUMENTS

fi

Ø=2.52" (64 mm)

Cable max.

1.97 x 5.31" (50 x 135 mm) or

2.52 x 3.94" (64 x 100 mm)
Bus Bar max.

12.40"

(315 mm)

P1 P2

4.72"

(120 mm)

ELECTRICAL SPECIFICATIONS

Current Range:

1 to 1000A AC continuous cycle
1 to 2000A AC continuous cycle
1 to 2400A AC continuous cycle for the
full temperature range
(3000A if temperature is < 35°C or 95°F)

Transformation Ratio:

1000:1, 2000:1, 3000:1

Output Signal:

1 mA AC/A AC (1A at 1000A)

0.5 mA AC/A AC (1A at 2000A)

0.333 mA AC/A AC (1A at 3000A)

1.89"

(48 mm)

Red Black

S2S1

Accuracy and Phase Shift*:
1000A RANGE

Primary current 50A 200A 1000A

Accuracy % 3% 1.5% 1%

Phase shift 3° 1.5° 1°

Load Impedance: 2.5Ω
Overload: 1400A for 10 mn
Ampere Second Product: 25 A.s
Accuracy: Per IEC 185-26-27

Class 1 (2.5 VA) from 48 to 1000 Hz