Caltest CT3686 User manual

CT3686 & CT3687
User Manual

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Safety Summary
To avoid personal injury and/or product damage, review and comply
with the following safety precautions. These precautions apply to both
operating and maintenance personnel and must be followed during all
phases of operation, service, and repair of this probe.
A WARNING statement calls attention to an operating procedure,
practice, or condition, which, if not followed correctly, could result in
injury or death to personnel.
A CAUTION statement calls attention to an operating procedure,
practice, or condition, which, if not followed correctly, could result in
damage to or destruction of parts or the entire product.
Do Not Work Alone
Do not work alone when working with high voltages.
Inspect the Probe
Inspect the probe and accessories for cracks and frayed or broken
leads before each use. If defects or damages are noted, DO NOT USE
the probe.
Dry Conditions
Hands, shoes, oor and work bench must be dry. Avoid making
measurements under humidity, dampness or other environmental
conditions that might affect safety.
Do Not Remove the Probe’s Casing
Removal of the probe’s casing may expose you to electric shock.
If necessary, disconnect the inputs and outputs of the probe before
opening the case.
Hazardous Contact
To avoid injury, remove jewelry such as rings, watches, and other
metallic objects. Do not touch exposed connections and components
when power is present.
Unexpected Charges
Hazardous voltages may be present in unexpected locations in circuitry
being tested when a fault condition in the circuit exists. Capacitors

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inside the instrument may retain a charge even if the instrument is
disconnected from its source of supply.
Use Only in Ofce-Type Indoor Setting
The probe is designed to be used in ofce-type indoor environments.
Do not operate the probe:
zIn the presence of noxious, corrosive, or flammable fumes,
gases, vapors, chemicals, or finely-divided particulates.
zIn environments where there is a danger of any liquid being
spilled on the probe.
zIn air temperatures exceeding the specified operating
temperatures.
zIn atmospheric pressures outside the specified altitude limits
or where the surrounding gas is not air.
Not for Critical Applications
This probe is not authorized for use in contact with the human body or
for use as a component in a life-support device or system.
Do Not Substitute Parts
Do not install substitute parts or perform any unauthorized modication
to the instrument.
Only Qualied Personnel
Only qualied personnel should use this probe. This differential
voltage probe is designed to be used by personnel who are trained,
experienced, or otherwise qualied to recognize hazardous situations
and who are trained in the safety precautions necessary to avoid
possible injury when using such a device.
Observe Maximum Working Voltage
Do not use the CT3686 or CT3687 probes above their maximum
working volatage ranges. See “Electrical Specications” on page 10.
Use Proper Power Source
To ensure this probe functions well, use four AA cells or 6 VDC/200
mA or regulated 9 VDC/120 mA mains adapter or power leads. Do not
operate this probe from a power source that applies more than the

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voltage speci ed.
Must be Grounded
This probe is grounded by the shell of the BNC connector through the
grounding conductor of the power cord of the measurement instrument.
Before making connections to the input leads of this probe, ensure
that the output BNC connector is attached to the BNC connector of
the measurement instrument, and that the measurement instrument
is properly grounded. Whenever it is likely that the ground protection
is impaired, you must make the instrument inoperative and secure it
against any unintended operation.
Use Fused Test Probes if Necessary
If this probe is intended to use for measurements in circuits of
installation CAT III, it should incorporate the use of fused test probes.
Compliance Statements
Disposal of Old Electrical & Electronic Equipment
(Applicable in the European Union and other European
countries with separate collection systems). This product
is subject to Directive 2012/19/EU of the European
Parliament and the Council of the European Union on
waste electrical and electronic equipment (WEEE), and in
jurisdictions adopting that Directive, is marked as being
put on the market after August 13, 2005, and should not
be disposed of as unsorted municipal waste. Please utilize
your local WEEE collection facilities in the disposition of
this product and otherwise observe all applicable requirements.
This probe is in compliance with IEC-61010-031 CAT II, Pollution
Degree 2.

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1 Introduction
1.1 Overview
Differential probes allow safe, accurate measurement between two
voltage points where neither point is referenced to ground. The
CT3686 and CT3687 both offer 100 MHz bandwidth and can test up
to ±700 V (DC + AC peak) and ±1400 V (DC + AC peak), respectively.
Compatible with oscilloscopes from all major manufacturers, the
probes can be battery operated, powered by a universal adapter
(optional), or powered by USB power lead (optional) if the oscilloscope
is so equipped.
Features:
zMeets IEC 61010-031 safety standard
z100 MHz bandwidth (-3 dB)
zUp to ±700 V (DC + AC peak) common mode (CT3686)
zUp to ±1400 V (DC + AC peak) common mode (CT3687)
zSelectable attenuation settings of 10x/100x (CT3686)
zSelectable attenuation settings of 100x/1000x (CT3687)
zPower and over-range indicators
zHigh accuracy (±2%)
zHigh CMRR
zPowered by 4 AA batteries (included)
zPower adapter, CT3723 (optional)
zUSB power lead, CT4122 (optional)