Greenlee GT-540 User manual

999 4757.9 REV 1 © 2003 Greenlee Textron 11/03
GT-220 •GT-540
Electrical
Testers
Verificadores
eléctricos
Contrôleurs
électriques
INSTRUCTION MANUAL
MANUAL DE INSTRUCCIONES
MANUEL D’INSTRUCTIONS
Read and understand all of the instructions and
safety information in this manual before
operating or servicing this tool.
Lea y entienda todas las instrucciones y la
información sobre seguridad que aparecen en
este manual, antes de manejar esta herramienta
o darle mantenimiento.
Lire attentivement et bien comprendre toutes les
instructions et les informations sur la sécurité de
ce manuel avant d‘utiliser ou de procéder à
l‘entretien de cet outil.

2
Description
The Greenlee GT-220 and GT-540 Electrical Testers are hand-held testing
devices with the following measurement capabilities: automatic selection
of AC voltage, DC voltage, resistance, and continuity with low input
impedance to mask “ghost” voltage. They also have non-contact and
single-probe voltage detection capability.
In addition, the GT-540 measures AC and DC voltage with high impedance
to minimize circuit loading. The GT-540 also measures capacitance, checks
diodes, and has a low ohms, fast continuity mode.
Safety
Safety is essential in the use and maintenance of Greenlee tools and
equipment. This instruction manual and any markings on the tool provide
information for avoiding hazards and unsafe practices related to the use of
this tool. Observe all of the safety information provided.
Purpose of This Manual
This instruction manual is intended to familiarize all personnel with the
safe operation and maintenance procedures for the Greenlee GT-220 and
GT-540 Electrical Testers.
Keep this manual available to all personnel. Replacement manuals are
available upon request at no charge.
KEEP THIS MANUAL
All specifications are nominal and may change as design improvements occur.
Greenlee Textron shall not be liable for damages resulting from misapplication or
misuse of its products.
® Registered: The color green for electrical test instruments is a registered trademark
of Greenlee Textron.

3
GT-220 • GT-540
Important Safety Information
This symbol is used to call your attention to hazards or unsafe
practices which could result in an injury or property damage. The
signal word, defined below, indicates the severity of the hazard. The
message after the signal word provides information for preventing or
avoiding the hazard.
SAFETY ALERT SYMBOL
Immediate hazards which, if not avoided, WILL result in severe injury
or death.
Hazards which, if not avoided, COULD result in severe injury or death.
Hazards or unsafe practices which, if not avoided, MAY result in injury
or property damage.
Read and understand this material before
operating or servicing this equipment. Failure to
understand how to safely operate this tool could
result in an accident causing serious injury or
death.

4
Important Safety Information
Electric shock hazard:
Contact with live circuits could result in severe
injury or death.
Electric shock and fire hazard:
• Do not expose this unit to rain or moisture.
• Do not use the unit if it is wet or damaged.
• Use test leads or accessories that are appropriate for the application.
Refer to the category and voltage rating of the test lead or
accessory.
• Inspect the test leads or accessory before use. They must be clean
and dry, and the insulation must be in good condition.
• Use this unit for the manufacturer’s intended purpose only, as
described in this manual. Any other use can impair the protection
provided by the unit.
Failure to observe these warnings could result in severe injury or death.
Electric shock hazard:
• Do not apply more than the rated voltage between any two input
terminals, or between any input terminal and earth ground.
• Do not contact the test lead tips or any uninsulated portion of the
accessory.
Failure to observe these warnings could result in severe injury or death.

5
GT-220 • GT-540
Important Safety Information
Electric shock hazard:
• Do not operate with the case or battery cover open.
• Before opening the case or battery cover, remove the test leads from
the circuit and shut off the unit.
Failure to observe these warnings could result in severe injury or death.
Electric shock hazard:
• Unless measuring voltage, shut off and lock out power. Make sure
that all capacitors are discharged. Voltage must not be present.
• Using this unit near equipment that generates electromagnetic
interference can result in unstable or inaccurate readings.
Failure to observe these warnings could result in severe injury or death.
Electric shock hazard:
Do not use the tester to measure voltages in circuits that could be
damaged by the Auto V•Ωmode’s low input impedance
(approximately 4 kΩ).
Failure to observe this precaution may result in injury and can damage
the unit.

6
Important Safety Information
Electric shock hazard:
• Do not attempt to repair this unit. It contains no user-serviceable
parts.
• Do not expose the unit to extremes in temperature or high humidity.
Refer to “Specifications.”
Failure to observe these precautions may result in injury and can
damage the unit.
Electric shock hazard:
Do not change the measurement function while the test leads are
connected to a component or circuit.
Failure to observe this precaution may result in injury and can damage
the unit.

7
GT-220 • GT-540
Identification
Display Icons
6. Automatic ranging is enabled
7. Hold function is enabled
8. AC measurement is selected
9. –Polarity indicator
10. LoZ Low input impedance is active
11. OL. Overload indicator
12. m milli (10-3)
13. V Volts
14. M Mega (106)
15. k kilo (103)
16. ΩOhms
17. Low battery indicator
18. Diode
19. Continuity
20. µmicro (10-6)
21. F Farads
22. n nano (10-9)
1. Display
2. Feature buttons
3. Selector
4. Positive (+) input terminal for all
measurements
5. Negative, common (COM), or
ground input terminal for all
measurements
1
2
3
45
6
7
8
9
10
20–22
17–19
14–16
12–13
11
Symbols on the Unit
Warning—Read the instruction manual
Double insulation

8
Using the Features
•Low Impedance Auto V·ΩMode In this mode, the tester automatically
selects the proper measurement based on the input.
–If there is no input, “Auto”appears on the display.
–If voltage above approximately 2 volts AC or DC is present, voltage is
displayed.
–If both AC and DC voltages are present, the larger voltage is
displayed.
–If no voltage is present and there is resistance less than 6 MΩ,
resistance is displayed.
This mode features low input impedance to mask stray or “ghost”
voltage pickup. The input impedance is approximately 4 kΩat low
voltage, increasing to approximately 500 kΩat 1000 V.
• Intelligent Automatic Power Off (APO) To extend battery life, the tester
shuts itself off after approximately 3 minutes of inactivity. Inactivity
occurs when buttons are not pressed or the selector is not turned. The
tester will not enter APO when there are significant readings over 10%
of the range or non-OL readings for resistance and continuity. To restore
power, press any button or turn the selector to OFF and back on again.
•SELECT (GT-540 only) Press momentarily to toggle between functions.
• HOLD Press momentarily to hold the present value on the display.
Press again to exit this mode.
•EFPress momentarily to detect the electric field that surrounds current-
carrying conductors. Signal strength is displayed as a series of dashes
on the display.
–Use the tester’s built-in antenna (located along the top, near the LCD)
for tracing live circuits or locating a break in a wire.
–For more precision, such as distinguishing between current-carrying
and ground wires, connect a test lead to the +input terminal and use
it as a probe.
• RANGE (GT-540 only) Press once to enter the manual ranging mode.
The icon will disappear from the display. Press repeatedly to
step through the ranges. Press and hold to return to the automatic
ranging mode.

9
GT-220 • GT-540
Operation
1. Refer to the Settings Table. Set the selector to the proper setting,
press SELECT (when instructed to do so), and connect the test leads
to the tester.
2. Refer to “Typical Measurements”for specific measurement
instructions.
3. Test the unit on a known functioning circuit or component.
•If the unit does not function as expected on a known functioning
circuit, replace the battery.
•If the unit still does not function as expected, send the unit to
Greenlee for repair. Refer to the instructions under the Warranty.
4. Take the reading from the circuit or component to be tested.
Electric shock hazard:
Contact with live circuits could result in severe
injury or death.
Electric shock hazard:
Do not use the tester to measure voltages in circuits that could be
damaged by the Auto V•Ωmode’s low input impedance
(approximately 4 kΩ).
Failure to observe this precaution may result in injury and can damage
the unit.

10
The following settings apply to the GT-220 and GT-540:
The following settings apply to the GT-540 only:
To measure
this value
Set the
selector to
this symbol
These icons
will appear
on the
display
Connect
the red
lead to
Connect
the black
lead to
Auto select AC volts,
DC volts, resistance,
and continuity*
(low impedance
measurement)
COM+
AutoV•
**
+
(optional)
EF (electric field
detection) Any function and press EF
momentarily
E.F. N/A
AC voltage
(high impedance to
minimize loading)
COM+
~, V
DC voltage
(high impedance to
minimize loading)
COM+
V
Low resistance
(600 Ω), fast
continuity test
COM+
Diode, fast
continuity test COM+
and press
SELECT
Capacitance†COM+
nF or µF
and press
SELECT twice
Operation (cont’d)
Settings Table
*Tone indicates continuity. Threshold is 0.025 kΩnominal.
**Refer to “Using the Features”for a detailed description of this mode.
†Discharge capacitor before measurement.

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GT-220 •GT-540
Typical Measurements
Voltage Measurement
Resistance Measurement
Note: GT-540 can
also use the
selector setting to
measure voltage.

12
Typical Measurements
Continuity Check
Electric Field Detection
Note: GT-540 can
also use the
selector setting to
check continuity.

13
GT-220 •GT-540
Typical Measurements
Capacitance Measurement (GT-540 only)
Diode Measurement (GT-540 only)
Forward Bias
Reverse Bias

14
Accuracy
Refer to “Specifications”for operating conditions and temperature
coefficient.
Accuracy is specified as follows: ±(a percentage of the reading + a fixed
amount) at 23 °C ±5 °C (73 °F ±9 °F), less than 75% relative humidity.
DCV (Auto V•Ωlow impedance mode)
Range Accuracy GT-220 Accuracy GT-540
6.000 V ±(1.3% + 0.002 V) ±(0.8% + 0.002 V)
60.00 V ±(1.3% + 0.01 V) ±(0.8% + 0.01 V)
600.0 V ±(1.2% + 0.4 V) ±(1.2% + 0.4 V)
1000 V ±(1.5% + 8 V) ±(1.5% + 8 V)
Input impedance: Initial 4.2 kΩ// 90 pF
Auto Check trigger lever: > +1.5 V typical; < –1.0 V typical
ACV (Auto V•Ωlow impedance mode)
Range Accuracy GT-220 Accuracy GT-540
6.000 V ±(2.5% + 0.003 V) ±(1.5% + 0.003 V)
60.00 V ±(2.5% + 0.03 V) ±(1.5% + 0.03 V)
600.0 V ±(2.5% + 0.6 V) ±(2.0% + 0.6 V)
1000 V ±(2.8% + 8 V) ±(2.8% + 8 V)
Input impedance: Initial 4.2 kΩ// 90 pF typical
Auto Check trigger lever: > 2.0 V (50/60 Hz) typical
Resistance (Auto V•Ωmode)
Range Accuracy GT-220 Accuracy GT-540
6.000 kΩ±(0.9% + 0.004 kΩ)* ±(0.9% + 0.004 kΩ)*
60.00 kΩ±(0.9% + 0.04 kΩ)±(0.9% + 0.04 kΩ)
600.0 kΩ±(0.9% + 0.1 kΩ)±(0.9% + 0.1 kΩ)
6.000 MΩ±(1.2% + 0.004 MΩ)±(1.2% + 0.004 MΩ)
*±(0.9% + 0.024 kΩ) below 1.200 kΩ
Specification not guaranteed during first 2 minutes after measuring
voltages > 50 V.
Open circuit voltage: 0.4 Vdc typical

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GT-220 •GT-540
Accuracy (cont’d)
Wireless Electric Field Detection (EF)
Typical Voltage Bar Graph Indication* Frequency Range
15 V to 50 V •
30 V to 70 V ••
50 V to 100 V •••50 Hz to 60 Hz
70 V to 140 V ••••
More than 100 V •••••
*Bar graph indication and tone are proportional to signal strength.
DCV (high impedance mode) (GT-540 only)
Range Accuracy
6000 mV* ±(0.8% + 2 mV)
6.000 V ±(0.8% + 0.002 V)
60.00 V ±(0.8% + 0.01 V)
600.0 V ±(1.2% + 0.4 V)
1000 V ±(1.5% + 8 V)
*This range can only be entered using the RANGE button.
Input impedance: 5 MΩ// 90 pF
ACV (high impedance mode) (GT-540 only)
Range Accuracy
6000 mV* ±(1.5% + 3 mV)
6.000 V ±(1.5% + 0.003 V)
60.00 V ±(1.5% + 0.03 V)
600.0 V ±(2.0% + 0.6 V)
1000 V ±(2.8% + 8 V)
*This range can only be entered using the RANGE button.
Input impedance: 5 MΩ// 90 pF typical

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Accuracy (cont’d)
600 Ohm with Beeper (GT-540 only)
Range Accuracy
600.0 Ω±(2.0% + 0.6 Ω)*
*±(2.0% + 3.6 Ω) below 120 Ω
Beeper response time: 100 µs
Beeper on: R < 50 Ωtypical; 250 Ωmax
Open circuit voltage: 0.4 Vdc typical
Diode Test with Beeper (GT-540 only)
Range: 1.000 V
Beeper response time: 100 µs
Open circuit voltage: < 1.6 Vdc typical
Test current: 0.25 mA typical
Capacitance (GT-540 only)
Maximum
Range Accuracy Measurement Time
100.0 nF* ±(3.5% + 0.5 nF) 2.5 s
1000 nF ±(2.5% + 2 nF) 2.5 s
10.00 µF±(2.5% + 0.02 µF) 5 s
100.0 µF±(2.5% + 0.2 µF) 8 s
2000 µF±(2.5% + 5 µF) 85 s
*Accuracy not specified below 50 nF.
The accuracy specification is for capacitors that have negligible dielectric
absorption, or film capacitors.

17
GT-220 •GT-540
Specifications
Display: 6000-count LCD
Polarity: Automatic
Display Update Rate: 5 per second
Temperature Coefficient: Nominal 0.15 x (specified accuracy) per °C
below 18 °C or above 28 °C
Intelligent Automatic Power Off: After 3 minutes of inactivity
Noise Rejection:*
Common Mode Rejection Ratio: > 60 dB from 0 Hz to 60 Hz
when measuring ACV
Common Mode Rejection Ratio: > 100 dB at 0 Hz, 50 Hz, and 60 Hz
when measuring DCV
Normal Mode Rejection Ratio: > 30 dB at 50 Hz and 60 Hz
when measuring DCV
Operating Conditions:
Temperature: –10 °C to 50 °C (14 °F to 122 °F)
Relative Humidity (non-condensing): 80% maximum for temperatures
up to 31 °C (88 °F), decreasing linearly to 50% maximum at
50 °C (122 °F)
Altitude: 2000 m (6500') maximum
Indoor use only.
Pollution Degree: 2
Storage Conditions: –30 °C to 60 °C (–22 °F to 140 °F),
0% to 80% relative humidity (non-condensing)
Remove battery.
Battery: 9 V (NEDA 1604, JIS 006P or IEC 6F22)
Overvoltage Protection: 1000 VDC/VAC RMS, 50/60 Hz
Overload Warning (voltage mode only): Meter displays “OL”and beeps
Measurement Categories:
Cat III, 1000 V per UL 61010B-1
Cat IV, 1000 V per IEC 61010-1, 2nd edition
Auto V•ΩMode Response Time: 1 second maximum
AC Response: Average-sensing, RMS calibrated

18
*Noise rejection is the ability to reject unwanted signals, or noise.
•Normal mode voltages are AC signals that can cause inaccurate
DC measurements. NMRR (Normal Mode Rejection Ratio) is a
measure of the ability to filter out these signals.
•Common mode voltages are signals present at the COM and +
input terminals, with respect to ground, that can cause digit rattle
or offset in voltage measurements. CMRR (Common Mode
Rejection Ratio) is a measure of the ability to filter out these
signals.
Specifications (cont’d)

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GT-220 •GT-540
Measurement Categories
These definitions were derived from the international safety standard for
insulation coordination as it applies to measurement, control, and
laboratory equipment. These measurement categories are explained in
more detail by the International Electrotechnical Commission; refer to
either of their publications: IEC 61010-1 or IEC 60664.
Measurement Category I
Signal level. Electronic and telecommunication equipment, or parts thereof.
Some examples include transient-protected electronic circuits inside
photocopiers and modems.
Measurement Category II
Local level. Appliances, portable equipment, and the circuits they are
plugged into. Some examples include light fixtures, televisions, and long
branch circuits.
Measurement Category III
Distribution level. Permanently installed machines and the circuits they are
hard-wired to. Some examples include conveyor systems and the main
circuit breaker panels of a building’s electrical system.
Measurement Category IV
Primary supply level. Overhead lines and other cable systems. Some
examples include cables, meters, transformers, and other exterior
equipment owned by the power utility.
Statement of Conformity
Greenlee Textron is certified in accordance with ISO 9000 (2000) for our
Quality Management Systems.
The instrument enclosed has been checked and/or calibrated using
equipment that is traceable to the National Institute for Standards and
Technology (NIST).

20
Maintenance
Electric shock hazard:
•Do not attempt to repair this unit. It contains no user-serviceable
parts.
•Do not expose the unit to extremes in temperature or high humidity.
Refer to “Specifications.”
Failure to observe these precautions may result in injury and can
damage the unit.
Battery Replacement
Electric shock hazard:
•Do not operate with the case or battery cover open.
•Before opening the case or battery cover, remove the test leads from
the circuit and shut off the unit.
Failure to observe these warnings could result in severe injury or death.
1. Disconnect the unit from the circuit. Turn the unit OFF.
2. Remove the two screws from the battery cover.
3. Remove the battery cover.
4. Replace the battery (observe polarity).
5. Replace the cover and screws.
Cleaning
Periodically wipe the case with a damp cloth and mild detergent; do not
use abrasives or solvents.