Greenlee CMGL-10 User manual

999 3279.2 © 1999 Greenlee Textron IM 1414 7/99
CMGL-10
CLAMP-ON AMMETER
AND LEAKAGE
CURRENT DETECTOR
AMPERÍMETRO
CON PINZA Y
DETECTOR DE
CORRIENTE DE FUGA
PINCE
AMPEREMETRIQUE
ET DETECTEUR DE
FUITE DE COURANT
ZERO
MAX/MIN
HOLD
V
40mA
COM V Ω
400mA 4A 40A
60A
OFF
Ω
WIDE
50/60 Hz
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 estas
herramientas o darles 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.
INSTRUCTION MANUAL
MANUAL DE INSTRUCCIONES
MANUEL D’INSTRUCTIONS

2
Description
The Greenlee CMGL-10 Clamp-on Ammeter and Leakage Current Detector is a hand-held
testing device with the following measurement capabilities: AC voltage, AC current, and
resistance. The unit is also intended to verify continuity.
Much more sensitive than most clamp-on ammeters, the CMGL-10 can detect very small
amounts of current that may indicate that some current is leaking to ground.
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
This instruction manual is intended to familiarize all personnel with the safe operation and
maintenance procedures for the Greenlee CMGL-10 Clamp-on Ammeter and Leakage Current
Detector.
Keep this manual available to all personnel.
Replacement manuals are available upon request at no charge.
and are registered trademarks of Greenlee Textron.
KEEP THIS MANUAL

CMGL-10
3
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 can result in an accident causing serious injury or death.

4
Important Safety Information
Electric shock hazard:
Contact with live circuits can result in severe injury or death.
Electric shock hazard:
• Do not use the unit if it is wet or damaged.
• Use test leads or accessories that are appropriate for the application. See the
category and voltage rating of the test lead or accessory.
• Inspect the test leads or accessory before use. The item(s) must be clean and dry,
and the insulation must be in good condition.
Failure to observe these warnings can 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 can result in severe injury or death.
• Do not operate with the case open.
• Before opening the case, remove the test leads or jaw from the circuit and shut off
the unit.
Failure to observe these warnings can result in severe injury or death.

CMGL-10
5
Do not change the measurement function while the test leads are connected to a
component or circuit.
Failure to observe this precaution can result in injury and can damage the instrument.
• Do not attempt to repair this unit. It contains no user-serviceable parts.
• Do not expose unit to extremes in temperature or high humidity. See Specifications.
Failure to observe these precautions can result in injury and can damage the instrument.
Unless measuring voltage or current, shut off and lock out power. Make sure that all
capacitors are discharged. Voltage must not be present.
Set the selector and connect the test leads so that they correspond to the intended
measurement. Incorrect settings or connections can result in a blown fuse.
Using this unit near equipment that generates electromagnetic interference can result
in unstable or inaccurate readings.

6
Identification
1. Jaw
2. Lever
3. ZERO Button
4. Display
5. VΩTerminal
6. COM Terminal
7. MAX/MIN Button
8. Frequency Filter Switch
9. HOLD Button
10. Selector
ZERO
MAX/MIN
HOLD
V
40mA
COM V Ω
400mA 4A 40A
60A
OFF
Ω
1234
5
6
78910
WIDE 50/60 Hz

CMGL-10
7
Display Icons
11. MAN Manual Ranging
12. - Polarity for Numeric Display
13. AC AC measurement is selected
14. Low Battery
15. ZERO ∆Relative Zero function is enabled
16. HOLD Hold Function is enabled
17. MAX MAX hold function is enabled
18. MIN MIN hold function is enabled
19. Continuity
20. V Volts
21. A Amps
22. M Mega (106)
23. k Kilo (103)
24. ΩOhms
25. Overload for Bar Graph
26. Bar Graph Element
27. - Polarity Indicator for Bar Graph
Symbols on the Unit
Read the instruction manual
Double Insulation
AC
ZERO ∆
MAN
HOLD MAX MIN
VA
MkΩ
100203040
11
12
13
14 15 16 17 18 19
20,21
26 2527
22,23,24

8
Using the Features
Automatic Power Off To extend battery life, the meter will shut itself off after approximately
30 minutes of inactivity. The only way to restore power is to press
HOLD. To disable this feature, press HOLD while turning the meter on.
MAX/MIN Holds the minimum or maximum value on the display. Press once to
hold the minimum value; press again to hold the maximum value.
Press again to exit this mode.
ZERO Finds the difference between two measurements. While taking a
measurement, press ZERO to set the display to zero. ZERO ∆will
appear on the display. Take the second measurement. The value on the
display will be the difference between the two measurements. Press
and hold to exit this mode.
HOLD Press momentarily to hold the present value on the display. Press
again to exit this mode.
Frequency Filter Filters out unwanted harmonics and other unwanted signals, which
can interfere with measurements. To prevent this type of interference,
select the 50/60 Hz position; the filter will limit any signals that are
higher than 100 Hz.
To measure higher frequency signals, select the WIDE position.

CMGL-10
9
Operation
1. Set the selector according to the Settings Table and connect the test leads to the unit.
Start with the highest measurement range.
Settings Table
Electric shock hazard:
Contact with live circuits can result in severe injury or death.
To measure set the this icon will connect the and the
this value … selector to appear on red lead black lead
this symbol … the display … to … to …
AC Voltage VAC and V VΩCOM
AC Current * 40 mA, 400 mA, AC and A or N/A N/A
4 A, 40A or 60 A AC and mA
Resistance Ωand ΩVΩCOM
Continuity ** Ωand ΩVΩCOM
* To measure current draw, clamp the jaw around one conductor only. The display will show
the current draw. To measure leakage, clamp the jaw around all of the conductors (except the
ground wire). Any reading other than zero amps indicates that some current is leaking to
ground. For a precise measurement of the amount of leakage, clamp the jaw around the
ground conductor only. See the illustrations under Typical Measurements.
** Tone indicates circuit resistance is less than approximately 40 Ω.
2. See Typical Measurements for illustrations of typical uses.
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
batteries.
• If the unit still does not function as expected, send the unit to Greenlee for repair.
4. Take the reading from the circuit to be tested. If the resolution is not satisfactory, remove
the meter from the circuit and change to the next lower range.

10
Typical Measurements
Current Measurement
Voltage Measurement
ZERO
MAX/MIN
HOLD
V
40mA
COM V Ω
400mA 4A 40A
60A
OFF
Ω
WIDE
50/60 Hz
ZERO
MAX/MIN
HOLD
V
40mA
COM V Ω
400mA 4A 40A
60A
OFF
Ω
WIDE
50/60 Hz