Fluke 1550 User manual

®
1550
MegOhmMeter
Users Manual
October 2001 (English)
©2001 Fluke Corporation. All rights reserved.
All product names are trademarks of their respective companies.

Limited Warranty and Limitation of Liability
Each Fluke product is warranted to be free from defects in material and workmanship
under normal use and service. The warranty period is two years and begins on the
date of shipment. Parts, product repairs, and services are warranted for 90 days. This
warranty extends only to the original buyer or end-user customer of a Fluke
authorized reseller, and does not apply to fuses, disposable batteries, or to any
product which, in Fluke’s opinion, has been misused, altered, neglected,
contaminated, or damaged by accident or abnormal conditions of operation or
handling. Fluke warrants that software will operate substantially in accordance with its
functional specifications for 90 days and that it has been properly recorded on non-
defective media. Fluke does not warrant that software will be error free or operate
without interruption.
Fluke authorized resellers shall extend this warranty on new and unused products to
end-user customers only but have no authority to extend a greater or different
warranty on behalf of Fluke. Warranty support is available only if product is purchased
through a Fluke authorized sales outlet or Buyer has paid the applicable international
price. Fluke reserves the right to invoice Buyer for importation costs of
repair/replacement parts when product purchased in one country is submitted for
repair in another country.
Fluke’s warranty obligation is limited, at Fluke’s option, to refund of the purchase
price, free of charge repair, or replacement of a defective product which is returned to
a Fluke authorized service center within the warranty period.
To obtain warranty service, contact your nearest Fluke authorized service center to
obtain return authorization information, then send the product to that service center,
with a description of the difficulty, postage and insurance prepaid (FOB Destination).
Fluke assumes no risk for damage in transit. Following warranty repair, the product
will be returned to Buyer, transportation prepaid (FOB Destination). If Fluke
determines that failure was caused by neglect, misuse, contamination, alteration,
accident, or abnormal condition of operation or handling, including overvoltage
failures caused by use outside the product’s specified rating, or normal wear and tear
of mechanical components, Fluke will provide an estimate of repair costs and obtain
authorization before commencing the work. Following repair, the product will be
returned to the Buyer transportation prepaid and the Buyer will be billed for the repair
and return transportation charges (FOB Shipping Point).
THIS WARRANTY IS BUYER'S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT
LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE. FLUKE SHALL NOT BE LIABLE FOR ANY
SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR
LOSSES, INCLUDING LOSS OF DATA, ARISING FROM ANY CAUSE OR THEORY.
Since some countries or states do not allow limitation of the term of an implied
warranty, or exclusion or limitation of incidental or consequential damages, the
limitations and exclusions of this warranty may not apply to every buyer. If any
provision of this Warranty is held invalid or unenforceable by a court or other decision-
maker of competent jurisdiction, such holding will not affect the validity or
enforceability of any other provision.
Fluke Corporation
P.O. Box 9090
Everett, WA 98206-9090
U.S.A.
Fluke Europe B.V.
P.O. Box 1186
5602 BD Eindhoven
The Netherlands
Visit Fluke’s web siteat:www.fluke.com11/99

i
Table of Contents
Title Page
Introduction................................................................................. 1
Contacting Fluke ........................................................................ 1
Unpacking the Meter .................................................................. 2
Safety Information...................................................................... 3
Symbols...................................................................................... 4
Operating the Meter ................................................................... 4
Turning the Meter On and Off................................................. 4
Using the Pushbuttons............................................................ 5
Understanding the Display...................................................... 6
Charging the Battery............................................................... 7
Using the Guard Terminal....................................................... 9
Making Measurements............................................................... 11
Connecting to the Circuit Under Test...................................... 11
Setting the Test Voltage.......................................................... 12
Performing an Insulation Test................................................. 13
Performing a Ramp Test......................................................... 15
Making a Timed Test .............................................................. 17
Viewing Results Stored in Memory......................................... 18
Downloading Your Test Results................................................. 19
Installing the Quicklink Software............................................. 20
Downloading Test Results to PC............................................ 20
Deleting Your Test Results..................................................... 21
Maintaining the Meter................................................................. 21
Cleaning.................................................................................. 21
Replacing the Guard Fuse...................................................... 22
Principle of Measurement and Resistance................................. 23
Replacement Parts and Accessories.......................................... 23
Specifications............................................................................. 24
General Specifications............................................................ 24
Electrical Specifications.......................................................... 25

1550
Users Manual
ii

iii
List of Tables
Table Title Page
1. Symbols................................................................................... 4
2. Replacement Parts................................................................... 23
List of Figures
Figure Title Page
1. Standard Accessories.............................................................. 2
2. Pushbuttons............................................................................. 5
3. Display Features...................................................................... 6
4. Power Supply Connections...................................................... 7
5. Surface Leakage Current......................................................... 9
6. Guard Terminal Connection..................................................... 10
7. Improved Guard Terminal Connection..................................... 10
8. Connecting to the Circuit Under Test....................................... 11
9. IR Port on 1550 MegOhmMeter............................................... 19
10. Replacing the Guard Fuse....................................................... 22

1550
Users Manual
iv
FUNC.
ON/
OFF
UP SCROLL
IRDA
PORT
DOWN ENTER
TEST
Terminals
Display
(LCD)
Pushbuttons
Handle
Cover
Safety Shutter
IR Port
Latch
ADB16F.EPS
Fluke 1550 MegOhmMeter

1
1550 MegOhm Meter
Users Manual
Introduction
The Fluke 1550 MegOhmMeter (hereafter "the Meter") is a high voltage
insulation tester that tests general circuits, including switchgear and cables.
The Meter has the following features:
⇒Four test voltage settings: 500 V, 1000 V, 2500 V, and 5000 V
⇒Resistance measurement range of 0 Ωto 1 T Ω
⇒Large liquid crystal display (LCD) with text display
⇒Infrared (IR) port for downloading test data
⇒Ramp mode that gradually increases the applied test voltage
⇒Test timer and storage for test results
⇒Rechargeable lead-acid battery
The Meter meets EN 61557 Parts 1 and 2; and EN 61010-1, CAT III 600 V
Pollution Degree 2 standards. CAT III equipment is designed to protect against
transients in equipment in fixed-equipment installations, such as distribution
panels and lighting systems in large buildings.
Contacting Fluke
To contact Fluke for product information, operating assistance, service, or to
get the location of the nearest Fluke distributor or Service Center, call:
1-888-99FLUKE (1-888-993-5853) in U.S.A.
1-800-36-FLUKE (1-800-363-5853) in Canada
[phone] in Europe
[phone] Japan
[phone] Singapore
[phone] from other countries
Visit Fluke’sweb site at: www.fluke.com.
Register your Meterat register.fluke.com.

1550
Users Manual
2
Unpacking the Meter
The Meter comes with the items shown in Figure 1. If the Meter is damaged or
an item is missing, contact the place of purchase immediately.
13
5
7
6
4
2
ADB01F.EPS
Item Description
1Users Manual (English, French, German, Spanish)
2AC Power Cord
3Test Cables with Alligator Clips (red, black, green)
4DC Charger Lead
5Soft Carrying Case
6Quicklink Communication Software Disk
7Infrared Adapter with interface cable
Figure 1. Standard Accessories

1550 MegOhmMeter
Safety Information
3
Safety Information
XWarning
Before and after testing, confirm that the Meter does not indicate the
presence of a hazardous voltage. (See Figure 3.) If the Meter beeps
continuously and a hazardous voltage is shown on the display,
disconnect test leads and remove power from the circuit under test.
WWarning: Read Before Using the Meter
•To avoid possible electric shock or personal injury:
•Use the Meter only as specified in this manual, or the protection
provided by the Meter might be impaired.
•Do not disconnect the test leads before the test has been completed
and the test voltage at the terminals has returned to zero. This
ensures that any charged capacitance is fully discharged.
•Ensure there is no power to the circuit under test and that all circuit
capacitances are fully discharged prior to testing with this
instrument.
•Avoid working alone or around explosive gas, vapor or dust.
•Do not use the Meter in a wet environment.
•Inspect the test leads for damaged insulation or exposed metal.
Check test lead continuity. Replace damaged leads. Do not use the
Meter if it looks damaged.
•Be careful when working above 30 V ac rms, 42 V ac peak and 60 V
dc. Such voltages pose a shock hazard.
•When using the probes, keep your fingers behind the finger guards.
•Measurements can be adversely affected by impedances of
additional operating circuits connected in parallel.
•Place test leads in proper input terminals.
•Do not use the Meter with any parts or cover removed.
•Disconnect the test leads from the circuit under test and from the
Meter before changing the fuse.
•Use only Fluke approved replacement fuse(s), parts, and accessories
as specified in this manual.
•Do not use the Meter if the safety shutter is impaired in any way. The
safety shutter (see Frontispiece) prevents access to the test
terminals and charger terminals at the same time.
•There are no user replaceable parts inside the instrument.
•Use the guard terminal only as specified in this manual. Do not allow
other accessories or foreign objects to come into contact with the
guard terminal as safety may be compromised.

1550
Users Manual
4
Symbols
Symbols on the Meter and in the manual are explained Table 1.
Table 1. Symbols
PConforms to European Union standards.
Underwriter’ Laboratories, Inc.
TÜV Product Services. Technischer Überwachungs Verein.
Conforms to Canadian Standards Association requirements.
Risk of danger.
Important information. See Manual.
Potentially hazardous voltage
Fuse
Equipment protected by double or reinforced insulation.
MInterference is present. Displayed value might be outside of
specified accuracy.
Operating the Meter
Turning the Meter On and Off
To turn the Meter on and off:
1. Press
Oto turn on the Meter.
The Meter performs a self-check, self-calibration, displays the current
software version, and starts in Ready mode.
In Ready mode, you can:
⇒Change test parameters
⇒Start an insulation test
⇒View stored test results
⇒Download test results
2. Press
Oagain to turn off the Meter.

1550 MegOhmMeter
Operating the Meter
5
Using the Pushbuttons
Use the pushbuttons (Figure 2) to control operation of the Meter, select test
results for viewing, and scroll through selected test results.
ON/
OFF
FUNC. UP SCROLL DOWN ENTER
TEST
12 3 4 5 6 7
ADB02F.EPS
Item Button Description
1OTurns the Meter off and on.
2GFunction button. From Ready mode, the Function button
scrolls through test voltage selection, ramp test setup, time
limit setup, and results (memory functions). In Results mode,
use the Function button to choose between the view,
download, and delete screens.
3VUp button. Used to scroll through test voltages, stored test
results, timer duration, and to select memory locations. Also
used to answer “yes” to yes/no prompts.
4RScroll button. After you select a memory location, use the
Scroll button to display the test parameters and test results
stored in the memory location.
5dDown button. Used to scroll through test voltages, stored test
results, timer duration, and to select memory locations. Also
used to answer “no” to yes/no prompts.
6eEnter button. Used to select the Result function. After you
select the Result function, use the up and down buttons to
move through the stored tests. Use the scroll button to view
test parameters and test results.
7TTest button. Starts and stops a test. Push and hold the
button for 1 second to start a test. Push the button again to
stop a test.
Figure 2. Pushbuttons

1550
Users Manual
6
Understanding the Display
Display annunciators are shown and described in Figure 3.
00k
0
0M G
V
0G
T
00G
GT
Mk
00M
M
000V 500V
5000V 2500V
1
28
11
10
9
3456
7
ADB03F.EPS
Item Description
1Interference present. Displayed readings may be outside the specified
accuracy range.
2Blown Guard fuse indicator.
3Electrical breakdown in Ramp mode.
4Ramp mode indicator.
5Potentially hazardous voltage is present at the test terminals.
X
Warning: Before and after testing, confirm that the Meter does not
indicate the presence of a hazardous voltage. If the Meter beeps
continuously and a hazardous voltage is present, disconnect test leads
and remove power from the circuit under test.
6Voltage sourced by the Meter or from the circuit under test that is present
at terminals of the Meter.
7Test voltage selection (500 V, 1000 V, 2500 V, or 5000 V)
8Battery charge status.
9Bar graph display of insulation resistance.
tDigital display of insulation resistance.
uText display. Indicates voltage, test current, capacitance, and menu
options. Figure 3. Display Features

1550 MegOhmMeter
Operating the Meter
7
Charging the Battery
W
Warning
To avoid possible electric shock or personal injury, disconnect the
test leads from the Meter before charging the battery.
Pb
Note
This instrument contains a lead-acid battery. Do not mix with the solid
waste stream. Spent batteries should be disposed of by a qualified
recycler or hazardous materials handler. Contact your authorized
Fluke Service Center for disposal and recycling information.
The Meter is powered by a rechargeable 12 V lead-acid battery. You can
recharge the battery using the AC power cord or the DC charger leads that are
shipped with the Meter.
Fully charging the battery typically takes 12 hours. Avoid charging in extremes
of temperature. Recharge the battery if the Meter has been stored for extended
periods. Figure 4 shows how to connect the Meter to a power supply.
12
Safety Shutter
ADB11F.EPS
Number Description
1IEC AC power socket.
2DC power input terminals.
Figure 4. Power Supply Connections

1550
Users Manual
8
To recharge the battery using an AC power supply:
1. Turn the Meter off.
2. Disconnect the test leads and/or any connectors from the Meter.
3. Rotate the safety shutter toward the top of the Meter to expose the power
supply connections.
4. Connect the AC power cord to the IEC AC power socket (1) on the Meter.
5. Connect the other end of the power cord to an AC power supply. See
“General Specifications” later in this manual for AC charger input
specifications.
6. The LCD on the Meter displays CHARGING. When the Meter is in Charging
mode, no other operations are possible.
To recharge the battery using a DC power supply:
1. Turn the Meter off.
2. Disconnect the test leads and/or any connectors from the Meter.
3. Rotate the safety shutter toward the top of the Meter to expose the power
supply connections.
4. Connect the DC charger lead to the 4 mm DC power input terminals (2)
on the Meter.
5. Connect the other end of the DC charger lead to the cigarette lighter of a
car. See “General Specifications” later in this manual for DC charger input
specifications.
6. The Meter displays the word CHARGING. When the Meter is in Charging
mode, no other operations are possible.

1550 MegOhmMeter
Operating the Meter
9
Using the Guard Terminal
Note
Insulation resistance is measured between the + and − output
connections. The Guard terminal (G) is at the same potential as the
negative (
− ) terminal but is not in the measurement path.
For most tests, only two test leads are used, connecting the positive (+) and
negative (−) terminals on the Meter to the circuit under test. The Guard (G)
terminal is left unconnected.
When measuring very high resistances, you can obtain more accurate readings
by making a three-wire measurement using the Guard terminal. The Guard
terminal is at the same potential as the negative (−) terminal, and can be used
to prevent surface leakage or other unwanted leakage currents from degrading
the accuracy of the insulation resistance measurement.
Figure 5 shows how to measure the resistance from one of the conductors to
the outer shield. In this case, there is a leakage current along the surface of the
inner insulation near the end of the cable. This leakage adds to the current that
the negative terminal detects, and will cause the Meter to read a lower
resistance than it should.
Surface Leakage
Current
Shield ( )
( )
ADB13F.EPS
Figure 5. Surface Leakage Current

1550
Users Manual
10
Figure 6 shows how to prevent surface current leakage by connecting a lead
from the Guard terminal to a conductor wrapped around the inner insulation.
The surface leakage current is directed to the Guard terminal. This removes the
leakage current from the measurement path between the positive and negative
terminals, and improves the accuracy of the test readings.
Leakage
Current
G
Shield ( )
( )
( )
ADB14F.EPS
Figure 6. Guard Terminal Connection
Figure 7 shows how to improve the measurement setup by connecting the
Guard terminal to the unused wire and coupling it to the inner insulation. This
insures that the Meter measures the leakage between the selected conductor
and the outer shield, but eliminates the leakage path between conductors.
Leakage
Currents
G
Shield ( )
( )
( )
ADB15F.EPS
Figure 7. Improved Guard Terminal Connection

1550 MegOhmMeter
Making Measurements
11
Making Measurements
Connecting to the Circuit Under Test
W
Warning
To avoid possible electric shock or personal injury:
•Remove all power from the circuit under test and discharge circuit
capacitance before testing a circuit with the Meter.
•Connect the test leads to the Meter inputs before connecting to the
circuit under test.
•Before and after testing, confirm that the Meter does not indicate the
presence of a hazardous voltage at the terminals. If the Meter beeps
continuously and a hazardous voltage is shown on the display,
disconnect test leads and remove power from the circuit under test.
To connect to the circuit under test:
1. Rotate the safety shutter to expose the terminal connections.
2. Insert the test leads in the terminals shown (Figure 8) and connect the test
leads to the circuit under test.
FUNC.
ON/
OFF
UP SCROLL
IR
PORT
DOWN ENTER
TEST
+ Terminal
Red
Black
Terminal
Safety Shutter
ADB09F.EPS
Figure 8. Connecting to the Circuit Under Test

1550
Users Manual
12
Setting the Test Voltage
To set the test voltage:
1. Press Oto turn on the Meter.
The Meter will be in TEST VOLTAGE mode with a 500 V default test
voltage.
00k
0
0M G
V
0G
T
00G
GT
Mk
00M
M
500V
Test Voltage Display
ADB05F.EPS
2. Press Vor dto scroll through the test voltage options (500 V, 1000 V,
2500 V, and 5000 V).
The selected test voltage appears in the upper-right of the display.
Note
The nominal test voltage is 5 % to 10 % higher than the test voltage
you select.

1550 MegOhmMeter
Making Measurements
13
Performing an Insulation Test
W
Warning
Measuring insulation resistance requires the application of
potentially dangerous voltages to the circuit. This may include
exposed bonded metalwork.
To avoid possible electric shock or personal injury:
•Remove all power from the circuit under test and discharge circuit
capacitance before testing a circuit with the Meter.
•Before proceeding, ensure that the installation is wired correctly and
no personnel are endangered by any tests.
•First connect the test leads to the Meter inputs before you make
connection to the circuit under test.
To perform an insulation test:
1. Press
Oto turn on the Meter.
The Meter will be in TEST VOLTAGE mode with a 500 V default test
voltage.
2. Press
Vor dto scroll through the test voltage options (500 V, 1000 V,
2500 V, and 5000 V).
The selected test voltage appears in the upper-right of the display.
Note
The nominal test voltage is 5 % to 10 % higher than the test voltage
you select.
3. Connect the probes to the circuit you want to test.
X
Warning
To avoid possible electric shock or personal injury: before and after
testing, confirm that the Meter does not indicate the presence of a
hazardous voltage at the terminals. If the Meter beeps continuously
and a hazardous voltage is shown on the display, disconnect test
leads and remove power from the circuit under test.
4. Press Tfor one second to start the insulation test.

1550
Users Manual
14
The Meter beeps 3 times as the test begins and the Wicon flashes on the
display indicating potentially hazardous voltages may be present on the
test terminals.
00k
0
0M G
V
0G
T
00G
G
00M
M
000V 500V
5000V 2500V
Bar Graph
Digital Main
Display
ADB08F.EPS
The digital display indicates the measured insulation resistance after the
circuit has stabilized. The bar graph displays this value continuously (in
real time) as a trend.
5. Press Ta second time to terminate the test.
The Meter beeps when a potentially hazardous voltage remains on the test
terminals due to charged circuit capacitances or from the presence of an
external voltage.
Note
The insulation test terminates automatically under the following
conditions:
• User stop
• Timer limit reached
• Interference on test circuit
• Breakdown occurs
• Battery depleted
6. When the test is complete, STORE RESULT? is displayed.
•Press
Vto save the measured insulation resistance and the test
parameters and return the Meter to Ready mode.
Or
•Press
dto ignore the test results and return the Meter to Ready
mode. Results will not be stored.