Thank you for purchasing the HIOKI "9277,9278
UNIVERSAL CLAMP ON CT". To obtain
maximum performance from the product, please
read this manual first, and keep it handy for
future reference.
Inspection
When you receive the product, inspect it
carefully to ensure that no damage occurred
during shipping. In particular, check the
accessories. If damage is evident, or if it fails to
operate according to the specifications, contact
your dealer or Hioki representative.
Preliminary Checks
Before using the product the first time, verify
that it operates normally to ensure that the no
damage occurred during storage or shipping.
If you find any damage, contact your dealer
or Hioki representative.
Before using the product, make sure that the
insulation on the cables is undamaged and
that no bare conductors are improperly
exposed. Using the product in such
conditions could cause an electric shock, so
contact your dealer or Hioki representative for
This product is designed to conform to IEC
61010 Safety Standards, and has been
thoroughly tested for safety prior to shipment.
However, mishandling during use could result
in injury or death, as well as damage to the
product. Be certain that you understand the
instructions and precautions in the manual
before use. We disclaim any responsibility for
accidents or injuries not resulting directly from
product defects.
Safety symbols
This manual contains information and warnings
essential for safe operation of the product and
for maintaining it in safe operating condition.
Before using the product, be sure to carefully
read the following safety notes.
Thesymbol printed on the product indicates
that the user should refer to a corresponding
topic in the manual (marked with the
before using the relevant function.
In the manual, thesymbol indicates
particularly important information that the user
should read before using the product.
symbol)
Indicates both DC (Direct Current) and AC
(Alternating Current).
Wear appropriate protective insulation (insulating
rubber gloves and boots, helmet and etc.) when
connecting and disconnecting from live electric
circuits.
This product complies with CATII (600V), CATIII
(300V) safety requirements.To ensure safe
operation of m easurement products, IEC 61010
establishes safety standards for various
electrical environments, categorized as CAT I to
CAT IV, and called measurement categories.
These are defined as follows.
CAT I:
CAT II: Primary electrical circuits in equipment
CAT III: Primary electrical circuits of heavy
CAT IV: The circuit from the service drop to the
Secondary electrical circuits connected
to an AC electrical outlet through a
transformer or similar device.
connected to an AC electrical outlet by a
power cord (portable tools, household
appliances, etc.)
equipment (fixed installations) connected
directly to the distribution panel, and
feeders from the distribution panel to
outlets.
service entrance, and to the power
meter and primary overcurrent protection
device (distribution panel).
Higher-numbered categories correspond to
electrical environments with greater momentary
energy. So a measurement device designed for
CAT III environments can endure greater
momentary energy than a device designed for
CAT II. Using a measurement product in an
environment designated with a higher-numbered
category than that for which the product is rated
could result in a severe accident, and must be
carefully avoided.Never use a CAT I measuring
product in CAT II, III, or IV envir o nments.
Follow these precautions to ensure safe
operation and to obtain the full benefits of the
various functions.
DANGE R
To avoid short circuits and potentially lifethreatening hazards, never attach the
UNIVERSAL CLAMP ON CT to a circuit that
operates at more than the 600 VAC(CATII) or 300
VAC(CATIII), or over bare conductors.
UNIVERSAL CLAMP ON CT should only be
connected to the secondary side of a breaker,
so the breaker can prevent an accident if a
short circuit occurs. Connections should never
be made to the primary side of a breaker,
because unrestricted current flow could cause a
serious accident if a short circuit occurs.
To avoid electric shock, do not allow the
product to get wet, and do not use it when your
hands are wet.
To avoid electric shock when measuring live lines,
wear appropriate protective gear, such as insulated
rubber gloves, boots and a safety helmet.
CAUTION
Note that the product may be damaged if current
exceeding the selected measurement range is
applied for a long time.
Do not store or use the product where it could be
exposed to direct sunlight, high temperature or
humidity, or condensation. Under such conditions,
the instrument may be damaged and insulation may
deteriorate so that it no longer meets specifications.
To avoid damage to the product, protect it from
vibration or shock during transport and handling,
and be especially careful to avoid dropping.
Measurements are degraded by dirt on the mating
surfaces of the clamp-on CT, so keep the surfaces
clean by gently wiping with a soft cloth.
Avoid stepping on or pinching the cable, which
could damage the cable insulation.
Keep the cables well away from heat sources, as
bare conductors could be exposed if the insulation
melts.
To avoid damaging the cables,do not bend or pull
the cables.
This product is designed for indoor use, and
operates reliably from 0to 40 .
When measuring the high-frequency large current,
over-heating of the core may occur. Note that the
input never exceed the maximum permissible input
range. See the figures in Chapter 3,"Specifications".
NOTE
Accurate measurement may be impossible in
the presence of strong magnetic fields, such
as near transformers and high-current
conductors, or in the presence of strong
electromagnetic fields such as near radio
transmitters.
The 9277, 9278 was developed for to provide a
20 A (9277), 200 A (9278) clamp sensor
corresponding to AC/DC current.
The 9277, 9278 makes it possible to measure
AC/DC current in live power lines without c utting
into the lines. The sensor features good
frequency response (amplitude and phase),
good temperature response (sensitivity and
offset), and dielectric strength and is easy to
connect and use. Its versatility will find
application in a wide variety of fields dealing
with current and power measurement.
To avoid damaging the output cable, grasp the
connector, not the cable, when unplugging the
cable.
To prevent damage to the product and sensor,
never connect or disconnect a sensor while the
power is on.
The maximum continuous input range is based on
heat that is internally generated during measurement.
Never input current in excess of this level. Exceeding
the rated level may result in damage to the cable.
The maximum continuous input range varies
according to the frequency of the current being
measured. See the figures in Chapter 3,
"Specifications"
To measure small current levels, multiple
windings may be used to increase the relative
sensitivity. 10 windings multiplies the
measured current by about a factor of 10.
However, in this case the diameter of the
winding should be 20 cm or more, and radial.
This product has a resistance in series with the
signal output circuits. Therefore, if measuring
an output signal directly, ensure that the input
resistance of the measuring instrument is
sufficiently high.
7. Align the sensor so that the
current direction indication
corresponds to the direction
of current flow through the
conductor to be measured,
and clamp so that the
Power
supply side
conductor is in the center of
the sensor aperture.
Make sure that only one conductor is in the
core. Single-phase (2-wire) and three-phase
(3-wire) lines clamped together will not produce
reading.
8. Press the slider on the sensor
head and hold it until LOCK
appears, and check that the
lever is firmly locked.
After measuring rush current or similar of AC or
DC current measurement, micro voltage is
output even if there is no input on the clamp.
This is caused by the core characteristic using
the clamp and magnetic is remained in the
core. This remanent cause measuring error, but
it can be removed by pressing DMAG with no
input onto the clamp.
NOTE
_____________________________________________
After powering on, press DMAG.
It is possible to magnetize even if pressing
DMAG during input.
Always make sure that the clamp jaws are
completely closed during demagnetising.
Demagnetization occurs for about 3 seconds.
If an excessive amount of current was input so
that one attempt at demagnetization does not
completely rid of the remanence, open the
clamp jaws and press DMAG, then close the
clamps, and press DMAG again.
In case of closing the clamp and if the facing
surface of the core is subjected to shock,
offset maybe output. In this case, press the
DMAG switch with no input on the clamp.
When measuring DC current and applying
exceed continuous the maximum permissible
input, the malfunction may occur. Press the
DMAG switch with no input on the clamp, to
return to normal.
If it does not return to normal condition, or
even pressing DMAG, the magnetic is
remained in the core, contact your dealer or
Hioki representative.
Effect of external
magnetic field (400
A/m, 55 Hz and DC)
Dielectric strength3536 VrmsAC for 15 seconds.
Maximum rated
voltage to earth
Operating environment Indoor, <Height 2000 m (6562 feet)
Diameter of
measurable
conductors
Supply voltage12 V to 15 V (with accuracy
Power supply
capacity
Supply consumptionMax. 3.6 W
Dimensions and
mass
Cord lengthApprox. 3 m (9.84 feet)
Accessories9375 CARRYING CASE 1
StandardsSafety:
Max. 0.2 AMax. 1 A
(between case and clamp sensor
(aperture))
(between electric circuit and case,
between electric circuit and core,
between electric circuit and clamp
sensor (aperture)
600 V (CATII), 300 V (CATIII)
ASL
20 mm (0.79") or less
guaranty but tracking)
150 mA
(with rated input)
(with rated input)
Approx. 176W 69H 27D mm
(6.93"W
projections)
Approx. 470 g (16.6 oz.)
Instruction manual 1
Markband 6 (3 set)
EN61010-2-032:2002
Type B current sensor
Measurement category II, III,
Pollution Degree 2 (4000 V expected
Be careful to avoid connecting voltage improperly,
as the internal circuitry may be destroyed.
The capacity of the power supply is at least0.5 A.
Demagnetization occurs after pin 7 is shorted to
ground and then opened.
GND
1
(+) 2
(-) 3
(-) 4
(+) 5
(-) 6
GND
+12 V (to +15 V)
-12 V (to -15 V)
Vout (2 Vf.s./rated input)
GND
ID3 7
ID1 8
ID2 9
10
Output connector pin array
92779278
ID1Connect to GNDConnect to GND
ID2N.CConnect to GND
To clean the product, wipe it gently with a soft
cloth moistened with water or mild detergent.
Never use solvents such as benzene, alcohol,
acetone, ether, ketones, thinners or gasoline, as
they can deform and discolor the case.
4.2 Service
If the instrument seems to be malfunctioning,
contact your dealer or Hioki representative.
Pack the product carefully so that it will not
be damaged during shipment, and include a
detailed written description of the problem.
Hioki cannot be responsible for damage that
occurs during shipment.