Aemc instruments JM861 User Manual

AC Current Probe
Model JM861

User Manual

DESCRIPTION

The JM861 (Catalog #2110.90) is designed for use in industrial environments. The “squared” jaws permit
multiple conductor or bus bar positioning. The Model JM861 accurately measures AC current waveforms
and has proportional mV output for direct readings on oscilloscopes. Three-position slide switch on the
handle selects ranges. The Model JM861 offers an insulated 6.5 ft. coaxial cable with insulated BNC
connector rated 600Vrms and is compatible with any AC voltmeter, multimeter, or other voltage measuring
instrument with an input impedance greater than 1M, 47 pF. To achieve the stated accuracy, use the
JM861 with a voltmeter having an accuracy of 0.75% or better.

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 600V 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 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.

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.

4.72"

(120 mm)

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.

1.89"

(48 mm)

P1 P2

12.40"

(315 mm)

ELECTRICAL SPECIFICATIONS

Current Range:

1 to 30A AC continuous cycle; 90A peak to peak
1 to 300A AC continuous cycle; 900A peak to peak
1 to 2400A AC continuous cycle; 9000A peak to peak
1 to 2400A AC continuous cycle for the
full temperature range
(3000A if temperature is < 35°C or 95°F)

Output Signal:

10 mV AC/A AC (0.3V at 30A)
1 mV AC/A AC (0.3V at 300A)

0.1 mV AC/A AC (0.3V at 3000A)

Accuracy and Phase Shift*:
30A RANGE

Primary current 1.5A 6A 30A

Accuracy % 2% ± 1 mV

Phase shift 20° 10° 5°

300A

RANGE

Primary current 15A 60A 300A

Accuracy % 2% ± 0.5 mV

Phase shift 3° 1.5° 1°