Tektronix A621 User manual

A621
1000 Amp AC Current Probe
Instructions
*P070888205*
070-8882-05

A621
1000 Amp AC Current Probe
Instructions
www.tek.com
070-8882-05

Copyright © Tektronix. All rights reserved. Licensed software products are
owned by Tektronix or its subsidiaries or suppliers, and are protected by
national copyright laws and international treaty provisions. Tektronix products
are covered by U.S. and foreign patents, issued and pending. Information in this
publication supersedes that in all previously published material. Specifications
and price change privileges reserved.
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
Contacting Tektronix
Tektronix, Inc.
14150 SW Karl Braun Drive
P.O. Box 500
Beaverton, OR 97077
USA
For product information, sales, service, and technical support:
■In North America, call 1-800-833-9200.
■Worldwide, visit www.tek.com to find contacts in your area.

Warranty
Tektronix warrants that this product will be free from defects in materials and
workmanship for a period of one (1) year from the date of shipment. If any such
product proves defective during this warranty period, Tektronix, at its option,
either will repair the defective product without charge for parts and labor, or will
provide a replacement in exchange for the defective product. Parts, modules and
replacement products used by Tektronix for warranty work may be new or
reconditioned to like new performance. All replaced parts, modules and
products become the property of Tektronix.
In order to obtain service under this warranty, Customer must notify Tektronix
of the defect before the expiration of the warranty period and make suitable
arrangements for the performance of service. Customer shall be responsible for
packaging and shipping the defective product to the service center designated by
Tektronix, with shipping charges prepaid. Tektronix shall pay for the return of
the product to Customer if the shipment is to a location within the country in
which the Tektronix service center is located. Customer shall be responsible for
paying all shipping charges, duties, taxes, and any other charges for products
returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by
improper use or improper or inadequate maintenance and care. Tektronix shall
not be obligated to furnish service under this warranty a) to repair damage
resulting from attempts by personnel other than Tektronix representatives to
install, repair or service the product; b) to repair damage resulting from
improper use or connection to incompatible equipment; c) to repair any damage
or malfunction caused by the use of non-Tektronix supplies; or d) to service a
product that has been modified or integrated with other products when the effect
of such modification or integration increases the time or difficulty of servicing
the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THE
PRODUCT IN LIEU OF ANY OTHER WARRANTIES, EXPRESS OR
IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE. TEKTRONIX' RESPONSIBILITY TO REPAIR
OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE
REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS
WARRANTY. TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE
FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE
VENDOR HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH
DAMAGES.
[W2 – 15AUG04]

Important safety information
This manual contains information and warnings that must be followed
by the user for safe operation and to keep the product in a safe
condition.
To safely perform service on this product, see the Service safety
summary that follows the General safety summary.
General safety summary
Use the product only as specified. Review the following safety
precautions to avoid injury and prevent damage to this product or any
products connected to it. Carefully read all instructions. Retain these
instructions for future reference.
This product shall be used in accordance with local and national codes.
For correct and safe operation of the product, it is essential that you
follow generally accepted safety procedures in addition to the safety
precautions specified in this manual.
The product is designed to be used by trained personnel only.
Only qualified personnel who are aware of the hazards involved should
remove the cover for repair, maintenance, or adjustment.
Before use, always check the product with a known source to be sure it
is operating correctly.
This product is not intended for detection of hazardous voltages.
Use personal protective equipment to prevent shock and arc blast injury
where hazardous live conductors are exposed.
To avoid fire or personal injury
Observe all terminal ratings. To avoid fire or shock hazard, observe all
ratings and markings on the product. Before using the product, consult
the product manual for futher ratings. Do not exceed the Measurement
Category (CAT) ratings and voltage or current rating.
Do not apply a potential to any terminal, including the common
terminal, that exceeds the maximum rating of that terminal. Do not use
the probe anywhere beyond the tactile barrier.
A621 Instructions vii

Do not operate without covers. Do not operate this product with covers or
panels removed, or with the case open. Hazardous voltage exposure is
possible.
Avoid exposed circuitry. Do not touch exposed connections and
components when power is present.
Use only specified replacement parts.
Do not operate in wet/damp conditions. Be aware that condensation may
occur if a unit is moved from a cold to a warm environment.
Do not operate in an explosive atmosphere.
Keep product surfaces clean and dry. Remove the input signals before
you clean the product.
Probes and test leads
Connect and disconnect properly. Connect the probe output to the
measurement product before connecting the probe to the circuit under
test. Disconnect the probe from the circuit under test before
disconnecting the probe from the measurement product.
Do not connect a current probe to any wire that carries voltages,
current, or fequencies above the current probe rating. The tactical
barrier is located at the base of the jaw. Refer to the A621 current
probe figure in the section of this document.
Inspect the probe and accessories. Before each use, inspect probe and
accessories for damage (cuts, tears, or defects in the probe body,
accessories, or cable jacket). Do not use if damaged.
Important safety information
viii A621 Instructions

Service safety summary
The Service safety summary section contains additional information
required to safely perform service on the product. Only qualified
personnel should perform service procedures. Read this Service safety
summary and the General safety summary before performing any
service procedures.
To avoid electric shock. Do not touch exposed connections.
Do not service alone. Do not perform internal service or adjustments of
this product unless another person capable of rendering first aid and
resuscitation is present.
Disconnect power. To avoid electric shock, remove the current probe
from the circuit before removing any covers or panels, or opening the
case for servicing.
Use care when servicing with power on. Dangerous voltages or currents
may exist in this product. Disconnect power, remove battery (if
applicable), and disconnect test leads before removing protective
panels, soldering, or replacing components.
Verify safety after repair. Always recheck operation after performing a
repair.
Terms in the manual
These terms may appear in this manual:
WARNING. Warning statements identify conditions or practices that
could result in injury or loss of life.
CAUTION. Caution statements identify conditions or practices that
could result in damage to this product or other property.
Important safety information
A621 Instructions ix

Terms on the product
These terms may appear on the product:
■DANGER indicates an injury hazard immediately accessible as
you read the marking.
■WARNING indicates an injury hazard not immediately accessible
as you read the marking.
■CAUTION indicates a hazard to property including the product.
Symbols on the product
When this symbol is marked on the product, be sure to
consult the manual to find out the nature of the potential
hazards and any actions which have to be taken to avoid
them. (This symbol may also be used to refer the user to
ratings in the manual.)
The following symbols may appear on the product:
Important safety information
x A621 Instructions

Compliance information
This section lists European contact information, safety, and
environmental standards with which the instrument complies.
European contact:
Tektronix UK, LTD
Western Peninsula
Western Road
Bracknell, RG12 1RF
United Kingdom
Safety compliance
This section lists the safety standards with which the product complies
and other safety compliance information.
EU declaration of conformity – low voltage
Compliance was demonstrated to the following specification as listed
in the Official Journal of the European Union:
Low Voltage Directive 2014/35/EU
■EN 61010-1. Safety Requirements for Electrical Equipment for
Measurement, Control, and Laboratory Use – Part 1: General
Requirements.
■EN 61010-2-032. Particular requirements for handheld current
clamps for electrical measurement and test equipment.
U.S. nationally recognized testing laboratory listing
■UL 61010-1. Safety Requirements for Electrical Equipment for
Measurement, Control, and Laboratory Use – Part 1: General
Requirements.
A621 Instructions xi

Canadian certification
■CAN/CSA-C22.2 No. 61010-1. Safety Requirements for Electrical
Equipment for Measurement, Control, and Laboratory Use – Part
1: General Requirements.
Additional compliances
■IEC 61010-1. Safety Requirements for Electrical Equipment for
Measurement, Control, and Laboratory Use – Part 1: General
Requirements.
■IEC 61010-2-032. Particular requirements for handheld current
clamps for electrical measurement and test equipment.
Equipment type
Test and measuring equipment.
Safety class
Class 2
Pollution degree description
A measure of the contaminants that could occur in the environment
around and within a product. Typically the internal environment inside
a product is considered to be the same as the external. Products should
be used only in the environment for which they are rated.
■Pollution Degree 1. No pollution or only dry, nonconductive
pollution occurs. Products in this category are generally
encapsulated, hermetically sealed, or located in clean rooms.
■Pollution Degree 2. Normally only dry, nonconductive pollution
occurs. Occasionally a temporary conductivity that is caused by
condensation must be expected. This location is a typical office/
home environment. Temporary condensation occurs only when the
product is out of service.
■Pollution Degree 3. Conductive pollution, or dry, nonconductive
pollution that becomes conductive due to condensation. These are
sheltered locations where neither temperature nor humidity is
controlled. The area is protected from direct sunshine, rain, or
direct wind.
■Pollution Degree 4. Pollution that generates persistent conductivity
through conductive dust, rain, or snow. Typical outdoor locations.
Compliance information
xii A621 Instructions

Pollution degree
Pollution Degree 2 (as defined in IEC 61010-1). Note: Rated for
indoor, dry location use only.
IP rating
IP20 (as defined in IEC 60529).
Measurement and overvoltage category descriptions
Measurement terminals on this product may be rated for measuring
mains voltages from one or more of the following categories (see
specific ratings marked on the product and in the manual).
■Measurement Category II. For measurements performed on
circuits directly connected to the low-voltage installation.
■Measurement Category III. For measurements performed in the
building installation.
■Measurement Category IV. For measurements performed at the
source of low-voltage installation.
NOTE. Only mains power supply circuits have an overvoltage category
rating. Only measurement circuits have a measurement category
rating. Other circuits within the product do not have either rating.
Environmental compliance
This section provides information about the environmental impact of
the product.
Product end-of-life handling
Observe the following guidelines when recycling an instrument or
component:
Compliance information
A621 Instructions xiii

Equipment recycling. Production of this equipment required the
extraction and use of natural resources. The equipment may contain
substances that could be harmful to the environment or human health if
improperly handled at the product’s end of life. To avoid release of
such substances into the environment and to reduce the use of natural
resources, we encourage you to recycle this product in an appropriate
system that will ensure that most of the materials are reused or recycled
appropriately.
This symbol indicates that this product complies with the
applicable European Union requirements according to
Directives 2012/19/EU and 2006/66/EC on waste
electrical and electronic equipment (WEEE) and
batteries. For information about recycling options, check
the Tektronix Web site (www.tek.com/productrecycling).
Compliance information
xiv A621 Instructions

Operating basics
The Tektronix A621 current probe enables the display of current
waveforms up to 1000 amps RMS on Tektronix TDS, TAS, or general
purpose oscilloscopes. The A621 is especially useful where the display
and measurement of distorted current waveforms and harmonics is
required. The A621 is also compatible with DMMs by using the BNC-
to-banana plug adapter (see Replaceable parts on page 12).
Figure 1: A621 current probe
Symbol Description
Current flow symbol
This arrow shows the probe's polarity
convention for measuring current flowing
from positive to negative.
Range switch
Slide to select the measurement range of
the probe - 10/100/1000 A.
A621 Instructions 1

Operating procedure
WARNING. To avoid personal injury or damage to the probe, do not
clamp the probe onto circuits with voltages greater than 600 VAC.
Always connect the probe to the instrument before clamping onto the
circuit under test.
1. Connect the probe BNC connector to the oscilloscope input. Start
by setting the oscilloscope channel vertical coupling to AC volts,
the vertical deflection to 0.1 V/div, and the probe to 1 mV/A.
2. Connect the probe to the circuit by opening the jaws and clamping
around the conductor. Refer to the following figure.
NOTE. Clamping around both the “hot” and neutral wires may
give you a zero reading.
Figure 2: Connecting the A621
(Remember to unclamp the probe from the conductor before
disconnecting it from your meter or instrument.)
3. Adjust the probe range and oscilloscope channel as necessary to
get a clear view of the signal.
The current drawn by some devices will look much different than that
of others. While the RMS current may be low, the momentary peaks
may be quite high. The following figure shows the difference between
the line current drawn by a resistive load and a motor controller.
Operating basics
2 A621 Instructions

Figure 3: Typical current waveforms
If you are using the A621 with a multimeter, use the BNC-to-banana
adapter (recommended accessory) to connect the probe. Connect the
black lead to the meter COM, and the red lead to the VΩ input. Set the
meter to the AC Volts position.
To increase the measurement sensitivity of the A621, loop additional
turns of the wire under test through the jaws. See Figure 3. The
sensitivity of the A621 will be multiplied times the number of loops in
the jaws. For example: 10 mV/A X 4 turns = 40 mV/A.
CAUTION. To prevent damage to the probes, do not force the jaw
closed. If you cannot close the jaw around the conductor(s), either
reduce the number of conductors you are measuring, or, if possible,
take your measurement on a smaller conductor.
Operating basics
A621 Instructions 3

Figure 4: Increasing the A621 sensitivity
Operating basics
4 A621 Instructions

Maintenance
Use the information in this section to properly maintain the operation
of your current probe.
Cleaning
To clean the probe body, use a soft cloth dampened in a solution of
mild detergent and water. To clean the core, open the jaw and clean the
exposed core surfaces with a cotton swab dampened with isopropyl
alcohol (isopropanol) or ethyl alcohol (fotocol or ethanol). Lubricate
the jaws mating surfaces with a light oil.
Do not use chemicals containing benzine, benzene, toluene, xylene,
acetone, or similar solvents.
Do not immerse the probe in liquids or use abrasive cleaners.
Specifications
These characteristics apply to an A621 probe installed on a Tektronix
TDS320 oscilloscope. The oscilloscope must be warmed up for at least
20 minutes and be in an environment within the limits specified in
Table 3: Environmental characteristics on page 7.
Table 1: Electrical characteristics
Characteristics Description
Output 1/10/100 mV/A
Accuracy ±2% at 1 mV/A and 10 mV/A
±3% at 100 mV/A
Maximum working current 2000 Apeak at 1 mV/A
1000 ARMS at 1 mV/A
200 Apeak at 10 mV/A
20 Apeak at 100 mV/A
Maximum working voltage 600 V CAT III
Frequency range 5 Hz to 50 kHz
A621 Instructions 5

Table 2: Physical characteristics
Dimensions 206 mm x 48 mm x 105 mm
(8.11 x 1.89 x 4.13 inches)
Maximum conductor size 54 mm (2.13 inches)
Cable length 1.5 m (5 feet)
Weight 650 g (1.43 lb)
Figure 5: Physical dimensions
Maintenance
6 A621 Instructions