The Megohmmeter Models 1000N and 1100N are warranted to the
owner for a period of 1 year from the date of original purchase against
defects in manufacture. This limited warranty is given by AEMC
Instruments, not by the distributor from whom it was purchased. This
warranty is void if the unit has been tampered with, abused or if the
defect is related to service not performed by AEMC
®
What AEMC
Instruments Will Do:
If a malfunction occ urs within the 1
®
Instruments.
year period, you may return the instrument to us for repair or
replacement free of charge, provided we have your REGISTRATION
CARD on file. AEMC
®
Instruments will, at its opt ion, repair or repl ace the
faulty material.
Note: If a registration card is not on file, we will require a dated
proof of purchase as well as your REGISTRATION CARD
accompanied by the defective material.
REGISTER ON LINE AT:
www.aemc.com
®
What You Must Do:
or by fax from AEMC
First request a return authori zation form by phone
®
Instruments, then return the instrum ent along with
the signed authorization repair form. Return material, postage pre-paid
to:
Chauvin Arnoux
d.b.a. AEMC
®
, Inc.
®
Instruments
Service Department
15 Faraday Drive
Dover, NH 03820 USA
Tel:(800) 945-2362 (X360)
(603) 749-6434 (X360)
Fax:(603) 742-2346
Caution:
To protect against in-transit loss, we recommend you insure
your returned material.
For full warranty coverage, please r ead the Warranty Ca rd which is
affixed to the Warrant y Regist ratio n Card . Pleas e keep t he W arrant y
Card with your records.
These safety warnings are provided to ensure the safety of
personnel and proper operation of the instrument.
WARNING: HIGH VOLTAGE PRESENT
•
Do not attempt to perform any tests with these instruments
until you have read the instruction manual.
•
Safety is the responsibility of the operator!
•
Tests are to be carried out only on non-energized circuits!
Check for live circuits before making resistance
measurements (safety check).
•
The Megohmmeters Models 1000N and 1100N are sources
of high voltage, as is the sample connected to them. All
persons performing or assisting in the tests must em ploy all
safety precautions to prevent electrical shock to themselves
and to others.
•
AEMC
•
When testing capaci tance sam ples , m ak e sure that they h ave
•
Megohmmeters should never be used in an explosive
•
Use the leads supplied with the megohmmeters. If they are
®
considers the use of rubber gloves to be an excellent
safety practice even if the equipment is pro per l y oper ate d and
correctly grounded.
been properly discharged and that they are safe to touch.
Dielectric insulation samples should be short-circuited for at
least five times the amount of time they were energized.
environment.
defective or worn, replace before testing.
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This symbol signif ies that the instrument is protected b y double
or reinforced insulation. Use only specified replacement parts
when servicing the instrum ent.
This symbol signifies CAUTION! and requests that the user refer
to the user manual before using the instrument.
Risk of electric shock. The voltage at the parts marked with this
symbol may be dangerous.
- 4 -
Megohmmeter Model 1000N/1100N
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Upon receiving your shipment, make sure that the contents are
consistent with the packing list. Notify your distributor of any missing
items. If the equipm ent appears to be damaged, f ile a c laim immediatel y
with the carrier and notify your distributor at once, giving a detailed
description of any damage.
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The Megohmmeter Model 1000N (Cat. #185.100) is ship ped with eight
1.5V “AA” batteries, two color- coded safety leads with insulated all igator
clips, a separate shielded lead, a separate insulated alligator clip, test
probe, one spare fuse, carrying case and instruction manual.
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AC power supply module with line cord and plug for
switch-selectable 110/220V
AC
at 47 to 400Hz.....................
Cat. #100.142
Protective rubber case with handle ......................................
Rugged plastic carrying case, 19 x 14 x 7" ..........................
Fuse, set of five, 0.1A slow-blow for AC supply module ......
Fuse, set of one, 0.3A, for Model 1000 ................................
One test probe and one insulated alligator clip....................
Replacement leads for Models 1000N/1100N/5000N..........
7-pin shielded lead, 10 ft, for Models 1000N/5000N/5100...
Replacement Leads for Model 1000
Coaxial shielded lead ...........................................................
Set of leads: one coaxial shielded lead, pair of
safety leads, alligator clip, and test probe ............................
The AEMC® Model 1000N (Cat. #185.100) is a portable, multi-range,
high-sensitivity megohmmeter capable of measuring a wide range of
insulation resistanc es from 1 kilohm to 1000 gi gohms. The Model 10 00N
has five test voltages of 50, 100, 250, 50 0 and 1000V. E ach test vo ltage
setting has two resistance ranges: 1 to 1000MΩ and 1 to 1000GΩ.
In addition, the Mode l 1000N has a unique lo w insulat ion test ra nge of 1
to 1000kΩ with a constant current of 1mA (maximum voltage of
DC
1200V
voltmeter (safety check) with a range of 0 to 600V is standard.
The Model 1000N may be powered by either AC or DC. DC power is
supplied by eight 1. 5V alkaline “AA” batteri es. As an option, an AC line
supply module and c ord for 110/220V
in the battery compartment.
An audible signal consisting of approximately ten beeps per minute is
present when the megohmm eter is ON, and serves as a time base for
tests of long duration. A green LED, when ON, indicates that the
batteries are good when the PUSH-T O-T EST button is depress ed. It also
serves as a warning li ght when the instrument is in us e, indicating that
the selected test voltage is present at the terminals.
), which is useful for testing old or flooded installations. A
AC
at 47 to 400Hz can be i nserted
- 6 -
Megohmmeter Model 1000N/1100N
6SHFLILFDWLRQV
INSULATION TESTS
DC Test Voltages:
50, 100, 250, 500, 1000V
Megohm Ranges:
For each test voltage two direct reading ranges:
1 to 1000M
1 to 1000G
Automatic discharge when test button is released; 0.1 seconds/µF
Scale:
Two large overlapping scales: 4.7" (119 mm) for each range
Test Voltage Generation:
Solid state circuitry generating rated test voltage across the full range
5% of reading typical
15% of reading between 100 and 1000GΩ on the 50V range
5mA (max)
RESISTANCE TESTS
Test Current:
Kilohm Range:
Maximum Test Voltage:
Accuracy:
Constant 1mA DC
1 to 1000kΩ (1MΩ)
1200V
5% of reading typical
DC
CONTINUITY TESTS
Resistance Range:
0.1 to 100Ω; 3Ω mid-scale
Accuracy:
Audible Tone:
Fuse:
6% of reading
Continuous for continuity resistances under 200
High interrupting capacity (0.315A)
Ω
- 7 -
Megohmmeter Model 1000N/1100N
VOLTAGE TESTS (SAFETY CHECK)
Voltage Range:
Accuracy:
3% of full scale
0 to 600V
AC/DC
GENERAL SP E CIFICATIONS
Audible Test Signal:
Ten beeps per minute (constant tone for continuity resistance under
200Ω)
Power Supply:
Eight 1.5V “AA” alkaline batteries (NEDA 15A). Typical battery life: 350
one-minute tests; power consumed only when test button is depressed;
built-in battery check by green LED.
Option:
110/220V selectable, 47 to 400Hz AC supply module
AC
Dielectric Test:
4000V
Fuse Protection:
0.3A high interrupting capacity fuse between line and guard terminals
2. Battery Power Indicator:
Green lamp ON indicates batteries are good when PUSH-TO-TEST
button is depressed. Audible “beep” is also emitted approximately
every 6 seconds.
3. Mechanical Zero Adjust
4. Selection Switch
5. GUARD terminal (blue):
Used to minimize the effect of leakage current.
Also used for the 10Ω range.
6. LINE terminal (black):
Connects to the equipment to be tested.
7. EARTH terminal (green):
Connects to ground for insulation testing.
8. PUSH-TO-TEST button
Lock “ON” by turning button a quarter turn to the right.
OFF Position: Voltmeter position
ON Position: Test position with voltage present at outputs
0
5
2
0
0
0
3
0
0
2
5
MEGOHMMETER
5
0
0
V
V
0
5
2
M
Ω
Ω
G
M
Ω
Ω
5
0
m
V
0
1
1
0
0
2
0
0
1
0
.
5
0
.
2
0
.
4
0
1
0
5
0
0
6
0
V
MODEL 1000N
5
0
0
V
G
Ω
1
0
M
0
0
Ω
V
1
G
0
Ω
0
0
V
Ω
A
k
x
a
m
m
1
V
0
0
2
1
A
Bat.
5
0
0
kΩ x 10
Ω
1
1
0
0
0
GΩ
MΩ
2
3
4
5
Ω
- GUARD- LINE
- 9 -
Megohmmeter Model 1000N/1100N
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The Model 1000N is powered by eight 1.5V “AA” batteries. To replace
the batteries, disconnect the instrument from any circuits, verify the
PUSH-TO-TEST button is in the OFF position and proceed as follows.
Access panel
screws
Access panel
•
Unscrew the four standard
screws on the four corners of
the battery pack and remove
the battery pack.
•
Replace the batteries, observing
the proper polarities.
•
Replace the battery case, taking
care not to pinch the
connecting wire, and tighten
the four screws.
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The optional AC supply module (Cat. #100 .142) provides power to the
Model 1000N at 110 or 220V
designed to plug into the back portion of the instrument, directly
replacing the batteries. The module is protected by a 0.1A slow-blow
fuse.
Note:
Cat. #100.142 is supplied with 110V US plug.
•
Unscrew the four screws on the corners of the back panel battery
pack.
•
Disconnect and remove the battery pack.
•
Connect the AC supply module to the power supply connector.
•
Place the AC supply module into the back of the instrument and
tighten the four corn er screws, making sure not to p inch the wires of
the power supply connector.
•
With the tip of a screwdriver, select the proper voltage with the
110/220 supply switch on the back panel of the AC supply module
•
Plug AC supply cord into the appropriate voltage receptacle.
AC
. The AC power supply module is
- 10 -
Megohmmeter Model 1000N/1100N
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7KH$QDORJ6FDOH
Before taking any measurements, verify that the pointer is zeroed
correctly (AC scale "0"). If it is not , adjust w ith th e mechanical zero
adjust screw.
The analog scale serves two functions. First, it indicates the actual
resistance of the insulating material under test (black scales). The top
scale is used for measur ement on the MΩ and GΩ ranges. The bottom
half (MΩ) covers the range of 1MΩ to 1000MΩ, reading from left to r ight
The upper portion of th e s c ale (GΩ) covers the rang e of 1GΩ to 1000G
and reads left to right.
The center scale is used for the low insulation test range of 1kΩ to
1000kΩ, reading from right to left.
The bottom arc is an AC/DC voltmeter which is divided into 10-volt
increments. The voltm eter function is operable any tim e the PUSH-TOTEST button is out. The voltmeter detects th e pres ence of volt age on the
equipment to be test ed.
the insulation test.)
The voltmeter function also indicates if, after completing insulation
testing, the samp le un der tes t has s tore d a dangerous c a pac it i ve c harge.
The instrument disc harges th is capac itance intern ally an d the need le wil l
drop accordingly. Disconnect the meter when the sample is discharged.
(If voltage is detected, do not proceed with
Ω
Warning:
Electrical equipm ent an d cab les m a y have suff icient cap acit ance t o s tore
a dangerous charge from the instrument test current. For proper
discharge to occur the PUSH-TO-TEST button must be in the OFF
position with the sample connected between the EARTH and LINE
terminals.
On prolonged tests, the PUSH-TO-TEST button may be locked in the ON
position; care should be tak en in this m ode th at no d am age is do ne if the
instrument is left unattended.
- 11 -
Megohmmeter Model 1000N/1100N
3UHOLPLQDU\&KHFN
When the PUSH-TO-TEST button is in the OFF position, the pointer
should be on zero of the vo ltmeter scale, and on t h ree of th e GΩ scale. If
it is not, use the mechanical zero adjust on the front of the instrument.
•
Detach the leads from the instrument.
•
Press the PUSH-TO-TEST button into the ON position. The pointer
should deflect com pletely to the f ar right of the sc ale. The green neon
“Bat.” lamp should light up.
Note:
Ensure that the “Bat.” light (green) does not go out at any point
during the testing. If the light does not illuminate, stop the test and
change the batteries before continuing.
Verify that NO VOLTAGE is present on the circuit to be tested.
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OFF:
PUSH-TO-TEST button is in the raised position. This is for
measurement of AC or DC voltages (safety check).
Note:
Do not depress the PUSH-TO-TEST button if voltage is present.
ON:
PUSH-TO-TEST button is d epres s ed and he ld down for the duration
of the test. This is for insulation resistance tests.
LOCK-IN:
90° to lock into position. This is for insulation resistance tests of long
duration such as the Time Resistance or Absorption Test.
PUSH-TO-TEST button is depressed and turned clockwise
- 12 -
Megohmmeter Model 1000N/1100N
Utilizing the Guard Terminal
Guard terminals are useful when measuring high resistance values and
for stabilizing readings.
When testing the insulation at the end of a cable, it is necessary to
eliminate the error from surface leakage which occurs, particularly at
high resistance values. The guard terminal provides a third terminal
within the path of the surface leakage “E”. Connect the instrument as
shown in Figure 3.
ABCD
The guard terminal
is useful when
measureing very
high resistance
values.
Conductor
to
Line (-)
Terminal
Insulation
to
Guard
Terminal
Exposed
Surface
Shield
to
Earth (+)
Terminal
Figure 3
If there is no shield at “B”, use a copper wire wound several times around
the exposed surface “B”. (Note: If a shield is not available and you do not
make up a shield around
“B” and connect to the
guard terminal (-), the
measurement will be
No Connection to
Guard Terminal
B
i
1
erroneous and lead to
confusion as to the
cable’s condition.)
If the guard terminal is
Ry
Rz
not connected at “B”, the
instrument measures the
current “I” flowing through
the insulation and a
surface leakage current
1
“i
”. See Figure 4.
Figure 4
To EARTH
Terminal
AC
Rx
i
To LINE
Terminal
- 13 -
Megohmmeter Model 1000N/1100N
When the guard term inal is connected at “B”, the instrument meas ures
the current “I” and not the surface leakage current “i
included in the m easurement. See Figure 5. This type of m easurement
will give the true value of
the resistance “Rx”,
providing the “Ry” and
1
”, which is not
To Guard
Terminal
i
B
1
“Rz” are not too low.
Ry
Rz
To EARTH
Terminal
AC
Rx
i
To LINE
Terminal
Figure 5
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Insulation resistance tests are to be car ried o ut on n on-en ergize d circ uits
only. Voltage measurements are made as a safety precaution. If any
voltage is present do not proceed with insulati on resistance t esting. This
instrument can measure both AC or DC voltages. For voltage
measurements, proceed as follows:
•
The PUSH-TO-TEST button should be in the OFF position.
•
Connec t the instrum ent with the vo ltage lea ds connect ed bet ween the
Line (-) and Earth (+) terminals on the unit.
•
Read the voltage directl y on the volta ge sc al e.
- LINE
+ EARTH
MEGOHMMETER
Figure 6
- 14 -
Megohmmeter Model 1000N/1100N
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When the PUSH-TO- TEST button is in the ON or LO CK-IN position, an
audible signal wil l result. This s ignal consists of approxim ately one beep
every six seconds (ten beeps per minute). The signal c an be used as a
time base for monitoring the duration of the test. On the MΩ and G
ranges, the signal indicates that the instrument is i n operation and that
the selected DC test voltage may be present on the terminals of the
instrument.
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•
The equipment should b e taken off the line suff iciently in advance to
permit it to cool to ambient temperature.
•
When you are testing windings, they should be clean and dry; let
solvents and cleaners evaporate. Should foreign matter or wet
surfaces be present, erroneous readings may result. (A clean, dry
sample’s resistanc e ma y rise for 5 to 15 m inutes , where as a wet, dir ty
one will stabilize quick l y).
•
Make sure that the equipment tested is properly discharged and
grounded before testing.
•
When testing individual windings, connect all other windings (not
under test) together and ground to motor frame.
•
When testing phases, be sure they are open to test each individually.
•
Af ter applying a tes t voltage , allo w sufficient d ischarge time. As a rule,
discharge twice as long as tested.
Note:
The instrument voltmeter will indicate the discharge volt age at the
terminals.
Ω
- 15 -
Megohmmeter Model 1000N/1100N
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Conductor under test
Figure 7 shows the connections to measure the
insulation of one conductor
to the other conductors.
The cable should be
disconnected at both ends
to avoid leakage through
switchboards and panels.
GUARD
+ EARTH- LINE
MEGOHMMETER
Figure 7
Figures 8 and 9 sho w the connection f or testing ins ulation f rom a supply
conductor to a ground (motor frame). The connection to the guard
terminal is used to eliminate the effects of surface leakage across
exposed insulation at one end of the cable . Refer to the sec tion “ Utilizing
the Guard Terminal.” T he cable should b e disconnected at both ends to
avoid leakage through switchboards and panels.
Conductor under test
GUARD
+ EARTH- LINE
MEGOHMMETER
Figure 8
- 16 -
Conductor under test
Megohmmeter Model 1000N/1100N
GUARD
+ EARTH- LINE
MEGOHMMETER
Figure 9
Figure 10 shows the connections to a transformer. Make sure that the
switches and/or circu it breakers on both sides are o pen. Check the high
voltage winding to ground, low voltage to ground, and the resistance
between them with no winding grounded.
Winding under test
Transformer
grounding lug
GUARD
+ EARTH- LINE
MEGOHMMETER
Figure 10
- 17 -
Megohmmeter Model 1000N/1100N
Figure 11 shows the conn ections f or meas uring the insulation of a thre ephase line to ground by connecting the jumpers between phases. This
gives a reading of all conductors at once. If a load such as a motor,
heater, etc., is attached to the other end of the line, it will read the l oad
resistance to ground at the same time. By removing the jumpers,
readings can be made between the individual conductors and ground.
A
Jumper
B
Jumper
C
GUARD
+ EARTH- LINE
MEGOHMMETER
Figure 11
- 18 -
Megohmmeter Model 1000N/1100N
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Figure 12 shows reading the
resistance to ground of a threephase motor winding. Since the
three-phase motors are internally
connected, it is only necessary to
connect one lead to the motor lead
and the other lead to the motor
frame as shown.
GUARD
+ EARTH- LINE
MEGOHMMETER
Figure 13 shows the
windings of a three-phase
motor separated. Sometimes this can be done at
the lead terminals while
other times the end bells
must be removed to get at
the lead wires of the coils.
By connecting the m egohmmeter as shown, the phase
insulation resistance value
can now be determined.
Read between phases “A”
and “B”, then “B” and “C”,
then “C” and “A”.
A
Figure 12
C
B
GUARD
+ EARTH- LINE
MEGOHMMETER
Figure 13
- 19 -
Megohmmeter Model 1000N/1100N
Figure 14 shows connections for testing insulation from a supply
conductor in a switchbox to ground (m otor frame). An identical t est may
be carried out from the motor starter.
Connect to one leg on
the motor side of the switch
Starter in
Grounded
motor frame
GUARD
+ EARTH- LINE
MEGOHMMETER
Figure 14
- 20 -
Megohmmeter Model 1000N/1100N
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Insulation is the m aterial betwe en two points of different potent ial which,
through high resistivity, prevents the flow of current between those
points. Insulation f ailure is one of the most comm on problems associated
with electrical equipm ent breakdown.
A megohmmeter is an insulation resist ance tester whic h is essentia lly a
high resistance ohmmeter (MΩ or greater) providin g a high DC potential
(up to 5000V). This high potent ial causes lo w amounts of c urrent to flow
through and over the insulation which is under test.
Many factors can cause insu lation to fail: m echanical dam age, moisture,
heat, foreign debris, corrosion, etc. As time passes, these factors
combine to perm it excessive current to flo w through insulation at points
where it would norm ally be bloc ked by the insu lation resistance. Usua lly,
the resistance on degrading insulation will drop gradually, providing
plenty of warning. Other times it will drop suddenly, as when it is
immersed. With periodic r esistance tests and good rec ord keeping, it is
possible to get an acc urate picture of the insulat ion condition. Insulation
resistance testing is intende d to in dica te n ot onl y if equipment is bad, but
also whether it is becoming bad.
Resistance of many types of insulation can vary greatly with
temperature. The resistance data obtained should be corrected to the
standard temperature for the class of equipment under test.
Please note that although we present information on test procedures,
values and recomm ended freque ncy of testing , the manuf acturer of your
particular piece of equipment is the definitive source for testing
parameters and procedures. While we refer to commonly applied ru les
and practices, every test will not be practical to each piece of electrical
equipment in your facility.
- 21 -
Megohmmeter Model 1000N/1100N
1
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SPOT READING TEST
Method
For this test, the m egohmmeter is connect ed acros s the insulati on of the
windings of the m ac hine bei ng t es ted . A tes t vol tag e is a pp li ed f or a fixed
period of time, usually 60 seconds, and a reading is taken. The spot
reading test should only be carried out when the wind ing temperature is
above the dewpoi nt
so that the reading may be corrected to a base temperature of 20°C
(68°F).
Test Duration
To obtain comparable results, tests must be of the same duration.
Usually the reading is taken after 60 seconds.
Interpreting the Results
Proper interpretation of spot reading tests requires access to r ecords of
results from previous spot re ading tests . For concl usive resu lts, only use
results from tests performed at the same test voltage for the same
amount of time under similar temperature and humidity conditions. These
readings are used to p lot a c urv e of the his t ory of insulation resist anc e. A
curve showing a downward trend usually indicates a loss of insulation
resistance due to unfavorable conditions such as humidity, dust
accumulation, etc. A very sharp drop indicates an insulation failure.
1
. The operator shou ld note the winding temperature
RATIO TESTING
In time resistance reading (die lect ric absor pt ion r ati o), r ead in gs are taken
at 30 seconds and 60 seconds to obtain the dielectric absorption ratio.
This test is useful for increas ing the accurac y of spot testing. I n general,
a ratio of 1.25 to 2 or bett er shou ld be required. (B el o w 1 .1 is dangero us;
1.1 to 1.25 is quest ionable; 1.25 to 1.4 is fair; and 1. 4 to 2 and above is
good.) A ratio below this indicates that repair is probably needed.
Dewpoint temperature is the temperature at which the moisture vapor in the air condenses as a liquid.
= Dielectric Absorption Ratio (DAR)
- 22 -
Megohmmeter Model 1000N/1100N
2
Remember that a DC insulation tes t m ay be used for acceptanc e testi ng,
but is more commonly used to check the gradual deterioration of
equipment over its lifetime. Consult your equipment manufacturer for
specific test or test voltage if not known.
Insulation resistance decreases with moisture, tem perature and age, and
should be recorded over time at a given temperature and corrected.
DIELECTRIC ABSORPTION TEST
Method
This test is based on the comparison of absorption characteristics of
good insulation vs. the absorpt ion characteristics of humid or other wise
contaminated insulatio n. During the test, a test voltage is ap plied for an
extended period, usual ly 10 m inutes . T he operator takes a rea ding ever y
10 seconds for the first m inute, and then every minute up to 10 minutes .
A curve is drawn showing the insulation resistance value versus time.
Test Duration
10 minutes
Interpreting the Results
If the results were plotted on a graph, the slope of the curve would
indicate the conditi on of the insulation under test. A good insu lation will
show a continual increase in resistance for typically 10 to 15 minutes.
Contaminated, moist, or cracked insulation will produce a relatively flat
curve.
A ratio known as the
polarization index
can be obtained by dividing the
value from the 10-minute reading by the value from the one-minute
reading. This polarization index is indicative of the slope of the curve.
A low polarization index usually indicates excessive moisture and
contamination. On larg e motors or gener ators, values as h igh as 10 are
commonly expected.
Polarization index =
10-minute reading
1-minute reading
The IEEE Std 43-1974
2
lists the following minimum values for the
polarization index for AC and DC rotating machines:
Class A: 1.5Class B: 2.0Class C: 2.0
IEEE Std. 43-1974, -
Recommended Practice for Testing Insulation Resistance of Rotating Machinery
- 23 -
Megohmmeter Model 1000N/1100N
STEP VOLTAGE TEST
Method
In this test, the operat or applies two or m ore test volt ages in steps . The
recommended ratio f or the test voltage s teps is 1 to 5. A t eac h step , test
voltage should be applied for the same length of time, usually 60
seconds. The applic ation of i ncreased voltage creates electr ical s tresses
on internal insulat ion c rack s . This c an revea l aging and physical dam age
even in relatively dry and clean insulation which would not have been
apparent at lower voltages.
Test Duration
A series of “steps,” each step lasting 60 seconds.
Interpreting the Results
Compare the readings taken at diff erent voltage levels, looking for an y
excessive reduction in ins ulation resistance va lues at the higher voltage
levels. Insulation that is thoroughly dry, clean, and without physical
damage should provide roughly the same resistance values despite
changes in test voltage levels . If r es is tance values decrease substantiall y
when tested at higher voltag e levels, t his should s erve as a warning that
insulation quality may be deteriorating due to dirt, moisture, cracking,
aging, etc.
- 24 -
Megohmmeter Model 1000N/1100N
7KH(IIHFWVRI7HPSHUDWXUH
Insulation resistance measurements are changed by variations in
temperature of the insulation material. T ypically, when the temperature
goes up, the insulation resistance will go down. Inversely, when the
temperature drops the insulat ion r es istanc e wi ll inc reas e in va lu e.
The best way to obtain consistent measurement results is to test the
insulation at a standard temperature, typically 68°F (20°C). If the
temperature of the material you ar e testing is eith er higher or lo wer than
68°F (20°C), refer to t he temperature correctio n chart (see table). As a
general rule the insulation resistance value may be corrected by:
•
Halving the resistance meas urement value for every 10°C above t he
base temperature of 68°F (20°C), or
•
Doubling the resistance value for every 10°C below 68°F (20°C)
Insulation resistance values are a function of the type of insulating
material. The actual value you read may vary greatly and is not as
important as the trends of the values over time. This is why the
resistance measurem ent must be tak en in a greater context. Some other
factors to consider are:
Previous Testing Results
These are very important, since they will indicate the decline in the
insulation resistance over time. All new equipm ent should be tested and
documented to serve as a benchmark for future testing.
Careful Visual Inspection
By taking a very close l ook at the equipment you are testing it may be
possible to see crack s, exc essive m ois ture, burn m ark s, etc ., which m a y,
over time, cause catastrophic equipment failure.
Manufacturers’ Recommendations for Specific Equipment
The definitive sour ce for information o n a specific piece of equipment is
its manufacturer. Most manufacturers will provide basic information
about the insulation resistance which may be encountered during testing.
Comparisons with Similar Equipment
Similar equipment should provide similar insulation resistance values.
This would also remain true when testing cables. For three-phase
systems, it would be v ery useful to compare r es isti ve values bet wee n th e
phases.
By performing insulation resis tance tests regularl y and recordin g the test
results, it may be possible to predict failure by detecting a downward
trend in the resistance. Careful notations should be made as to
time/date, temperature, applications, etc.
The information co ntained in this manual is intended only as a g uide to
acceptable procedure; it is not inte nded to be used as a tes t spec ific ation
for specific electrical equipment.
- 26 -
Megohmmeter Model 1000N/1100N
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0RGHO1
5HFHLYLQJ<RXU6KLSPHQW
Upon receiving your shipment, check that the contents agree with the
packing slip. Notify your distributor at once of any shortages. If the
equipment appears to be damaged, file a claim immediately with your
carrier, and notify your distributor at o nce, gi ving a det ailed des cript ion of
the damages. Save t he damaged pac king container to s ubstantiate your
claims.
3DFNDJLQJ
ESD Conductivity Tes t Kit Megohmmeter Model 1 100N (Cat. #2110.03)
is shipped with the AEMC
weights, 25-foot shielded lead, two safety leads, an alligator clip, test
probe, batteries, carrying case and ins tr uct ion manual.
ESD Conductivity Test Kit Megohmmeter Model 1100N Kit (Cat.
#2110.03) is designed specifically for floor resistance testing in areas
where electrostatic discharge is a problem, such as computer rooms,
electronic assembly rooms, hospitals, etc. The kit includes a 1000V
megohmmeter which features excellent resolution in the critical 10
9
Ω
ranges, and fine r esolution up to 1 0
10
12
Ω
; 25-foot shielded lead; and
two floor weights - NFPA probes for consistent and repeatable contact
with the surface under test. The Model 1100N is useful for testing
effectiveness of conductive carpets, mats, tables, chairs, etc.
The Model 1000N is es pecially su ited for this t ype of measur ement, due
to high accuracy and resolution in the megohm and gigohm ranges.
Conductivity testers are im portant in any operation wher e the presence
of electrostatic discharge charges poses a danger to personnel or the
operation of electronic equipment.
There are several standards in the industry which may be referenced
when performing ESD testing of conductive flooring or tiles.
Standard 99
Reduction in Electrostatic Hazar d
National Fire Protection Association
Batterymarch Park
Quincy, MA 02269
Standard F 150-72
Electrical Resistance of Conductive Resilient Flooring
American Society for Testing and Materials
1916 Race St.
Philadelphia, PA 19103
Standard #4 EOS/ESD
Standard for Protection of Electrostatic Discharge Susceptible Items
EOS/ESD Association inc.
201 Mill St.
Rome, NY 13440
Additional standar ds and specific recomm endations for your application
may be obtained from equipment and flooring manufacturers.
7
to
- 28 -
Megohmmeter Model 1000N/1100N
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INSULATION TESTS
DC Test Voltages:
50, 100, 250, 500, 1000V
Megohm Ranges:
For each test voltage two direct reading ranges:
1 to 1000MΩ (10
1 to 1000GΩ (10
6
to 10
9
to 10
9
Ω
)
12
Ω
)
Short Circuit Current:
Accuracy:
5% of reading typical
5mA (max)
Charging Time:
MΩ range: 0.3 seconds/µF
GΩ range: 4 seconds/µF
Discharging Time:
Automatic discharge when test button is released; 0.1 seconds/µF
Scale:
Two large overlapping scales: 4.7" (119mm) for each range
Test Voltage Generation:
Solid state circuitry generating rated test voltage across the full range
RESISTANCE TESTS
Test Current:
Kilohm Range:
Maximum Test Voltage:
Accuracy:
Constant 1mA DC
1 to 1000kΩ (1MΩ)
1200V
5% of reading typical
DC
CONTINUITY TESTS
Resistance Range:
0.1 to 100Ω; 3Ω mid-scale
Accuracy:
6% of reading
Audible Tone:
Continuous for continuity resistances under 200
Fuse:
High interrupting capacity (0.315A)
- 29 -
Ω
Megohmmeter Model 1000N/1100N
VOLTAGE TESTS (SAFETY CHECK)
Voltage Range:
Accuracy:
3% of full scale
0 to 600V
AC/DC
GENERAL SP E CIFICATIONS
Audible Test Signal:
Ten beeps per minute
(constant tone for continuity resistance under 200Ω)
Power Supply:
Eight 1.5V “AA” alkaline batteries (NEDA 15A). Typical battery life: 350
one-minute tests; power consumed only when test button is depressed;
built-in battery check by green LED
Option:
110/220V selectable, 47 to 400Hz AC supply module
AC
Dielectric Test:
4000V
Fuse Protection:
0.3A high interrupting capacity fuse between line and guard terminals
The Model 1100N is powered by eight 1.5V “AA” batteries. To replace
the batteries, disconnect the instrument from any circuits, verify the
PUSH-TO-TEST button is in the OFF position and proceed as follows:
•
Unscrew the four standard screws on the f our corners of the battery
pack and remove the battery pack.
•
Replace the batteries, observing the proper polarities.
•
Replace the battery case, taking care n ot t o p inch the connect ing wire,
and tighten the four screws.
Access panel
screws
Access panel
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The optional AC supply module (Cat. #100 .142) provides power to the
AC
Model 1100N at 110 or 220V
designed to plug into the back portion of the instrument, directly
replacing the batteries. The module is protected by a 0.1A slow blow
Note:
fuse.
•
Unscrew the four screws on the corners of the back panel battery
pack.
•
Disconnect and remove the battery pack.
•
Connect the AC supply module to the power supply connector.
•
Place the AC supply module into the back of the instrument and
tighten the four corn er screws, making sure not to p inch the wires of
the power supply connector.
•
With the tip of a screwdriver, select the proper voltage with the
110/220 supply switch on the back panel of the AC supply module
•
Plug AC supply cord into the appropriate voltage receptacle.
Cat. #100.142 is supplied with 110V US plug.
. The AC power supply module is
- 31 -
Megohmmeter Model 1000N/1100N
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Background
There are numerous standar ds currently being de veloped for m easuring
conductive flooring resistance under 100V and 500V. Actual resistance
values vary from specification to specification, but 10
typical values. The follo wing simplified procedure is a n ex tr a pol ation from
the ASTM standard F 150-72. You ma y also refer to other so urces, such
as the NFPA or EOS/ESD for alternate procedures.
General Notes
The floor sample should consist of a section covering 48 x 48 inches
(1.22 x 1.22 meters) in area.
When the sample is to be tested after installation, the test area
dimensions should not exceed a section of floor 20 x 20 feet (6 x 6
meters).
Conditioning
Whenever possible, condit ion the test area at least twenty-four ho urs at
73.4°F ±1.8°F (23°C ±1°C) and 50% ±5% RH and test under the sam e
conditions.
4
to 10
10
Ω
are
Test Procedure
1.
For uninstalled panels:
General Notes #1 on a nonconductive surfac e and lightly wipe with a
lint-free cloth to rem ove any foreign material prior to the placing of
the weights. Place the weights 2" (50.8 mm ) in from an edge of the
sample and 36" (914.4 mm) apart. Apply 500 volts and take a
reading five seconds after application of the voltage.
2.
For installed panels:
least 36" (914.4 mm) from any ground connections or grounded
object resting on the floor sample described in General Notes #2.
Apply 500 volts and take a reading five seconds after application of
the voltage.
3. Unless otherwise spec ified, make five measurem ents on each floor
section with the weights at different loc ations for each m easurement
and record the value of two significant figures (see Figure 16).
Place the dry specimen as described in
Place the weights 36" (914.4 mm) apart and at
- 32 -
Megohmmeter Model 1000N/1100N
4. Repeat the above procedure with the megohmmeter connected
between one weight and a k nown electrical groun d (see Figure 17).
In the case of an unins talled floor sample as in step #1, the ground
should be part of the s ample panel. In the cas e of an insta lled floor
sample as in step #2 , the ground should be a water pipe or known
electrical ground. Interchange the leads at the megohmmeter for
each measurement and report the average value obtained as the
value for that measurement.
5. When finished, turn off the megohmmeter and return it to the case.
Note:
If the resistance changes with time during a measurement, the
value observed after about 5 seconds shall be considered to be the
measured value.
Table Top
Electrodes
36 "
GUARD
+ EARTH- LINE
MEGOHMMETER
Figure 16
- 33 -
Megohmmeter Model 1000N/1100N
Table Top
Groundable Points
Electrode
GUARD
+ EARTH- LINE
MEGOHMMETER
Figure 17
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Specific measur ement results for eac h in di vi du al app lic at io n of the Model
1100N are difficult to determine. The definitive information on which
voltage level to apply, as well as whic h meas urem ent values will indicat e
a proper resistivity, should be determined by the manufacturer of the
conductive flooring or tiles.
The following va lues (based on EOS/ESD, S4.1-199 0) may serve as a
minimum resistivity level which has been proven to provide an
appropriate level of protection in the manufacturing environment.
Resistance from test electrode to a groundable point (Figure 17):
Measured value: ≤ 10,000 megohms (10 gigohm s )
Resistance from electrode to electrode (Figure 16):
Measured value: ≥ 1 megohm
- 34 -
Megohmmeter Model 1000N/1100N
0DLQWHQDQFH
Warning:
•
For maintenance use only original factory replacement parts.
•
To avoid electrical shock, do not attempt to perform any servicing
unless you are qualified to do so.
•
Do not perform any service while the Megohmmeter Model
1000N/1100N is on any circuit.
•
To avoid electrical shock and/or damage to the instrument, do not let
water or other foreign agents into the electronic module.
Cleaning:
The megohmmeter may be gently cleaned with a soft cloth, soap and
water. Dry immediately after cleaning. Avoid water penetration into the
electronic module.
Make sure the megohmmeter and all leads are dry before further use.
- 35 -
Megohmmeter Model 1000N/1100N
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To guarantee that your instrument complies with the factory
specifications, we recommend that the megohmmeter be submitted to
our factory service center at one-year intervals for recalibration, or as
required by other standards.
For instrument repair and calibration:
Call (800) 945-2362 (X360) • (603) 749-6434 • Fax: (603) 742-2346
®
Chauvin Arnoux
d.b.a. AEMC
15 Faraday Drive
Dover, NH 03820 USA
(Or contact your authorized distributor.)
Costs for repair, standard calibration, and calibration traceable to N.I.S.T.
are available.
Note: All customers must call for a CSA# before returning any
instrument.
, Inc.
®
Instruments
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If you are experiencing any technica l pro bl ems, or require any as s istanc e
with the proper use or application of this instrument, please call our
technical hotline:
Chauvin Arnoux
d.b.a. AEMC
Phone: (800) 343-1391
(508) 698-2115
Fax:(508) 698-2118
www.aemc.com
®
, Inc.
®
Instruments
- 36 -
Chauvin Arnoux®, Inc. d.b.a AEMC® Instruments
99-MAN 100020 v7 01/02
15 Faraday Drive • Dover, NH 03820, USA
www.aemc.com
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