Aemc instruments JM850A User Manual

AC Current Probe
Model JM850A

User Manual

DESCRIPTION

The JM850A (Catalog # 2110.87) is designed for use in industrial environments. The “sq uared” jaws
permit multiple conductor or bus bar positioning. The current output makes it the perfect tool for
measurement with DMMs, rec orders, power and harmoni c meters. Three ranges allo w you to obtain the
best resolution even on low current measurement. The Model JM850A is compatible with any AC
ammeter, multime ter, or other c urren t measu ring i nstrum ent with an in put im peda nce lower than 2.5Ω. To
achieve the stated accuracy, use the JM850A with an Ammeter having an accuracy of 0.75% or better.

WARNING

These safety warnings are prov ided to ensure the saf ety of personnel an d proper operatio n of the
instrument.

• Read the i nstruction ma nual completel y and follow all t he safety info rmation before attempting
to use or service this instrument.

• Use caution on any circuit: Potentiall y h igh vol t age s and currents may be prese nt and ma y 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.

• ALWA YS connect the curre nt probe to the display device be fore clamping t he probe onto t he
sample being tested.

• ALWA YS inspect the instrumen t, p ro be , pr obe ca bl e, an d ou tp ut te rm inal s pri or 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 cur rent prob e is protect ed by doubl e or reinfo rced ins ulation. Us e
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 m easurements performed on circuits directly co nnected to the electric al 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 imm edi a tel y with t he
carrier and notify your distributor at once, giving a detailed description of any damage.

Primary current

50A

200A

1000A

Accuracy %

3%

1.5%

1%

Phase shift

3°

1.5°

1°

Primary current

100A

400A

2000A

Accuracy %

1.5%

0.75%

0.5%

Phase shift

1.5°

0.75°

0.5°

Primary current

150A

600A

3000A

Accuracy %

1.5%

0.75%

0.5%

Phase shift

1.5°

0.75°

0.5°

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)

Accuracy and Phase Shift*:
1000A RANGE

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

99-MAN 100104.v7 03/17