INSTRUCTION MANUAL
INSTRUCTION MANUAL
MANUAL DE INSTRUCCIONES
MANUEL D’INSTRUCTIONS
CMGRT-100
CLAMP-ON GROUND
RESISTANCE TESTER
VERIFICADOR DE
RESISTENCIA DE
TIERRA CON PINZA
VERIFICATEUR DE
RESISTANCE DE
TERRE A PINCE
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.
999 3791.3
© 2001 Greenlee Textron
IM 1466 REV 1
12/01
Description
The Greenlee CMGRT-100 Clamp-On Ground Resistance Tester is a hand-held testing device intended to
evaluate grounding systems. It has two modes:
• Active Mode for measuring resistance
• Passive Mode for measuring current
The Active Mode induces a voltage into a conductor and measures the resulting current. It then
calculates the resistance. The Passive Mode senses the electromagnetic field surrounding a conductor
to determine the current flow.
A test resistance loop is provided to perform a quick check of the unit.
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 CMGRT-100 Clamp-On Ground Resistance Tester.
The CMGRT-100 is protected by U.S. Patent Number D-362639.
Keep this manual available to all personnel.
Replacement manuals are available upon request at no charge.
Greenlee and
are registered trademarks of Greenlee Textron.
KEEP THIS MANUAL
2
CMGRT-100
Important Safety Information
SAFETY ALERT SYMBOL
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.
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.
Electric shock hazard:
Contact with live circuits can result in severe injury or death.
3
Important Safety Information
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 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 can result in severe injury or death.
• Do not operate with the case open.
• Before opening the case, remove the jaw from the circuit and shut off the unit.
Failure to observe these warnings can result in severe injury or death.
• 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. See Specifications.
Failure to observe these precautions can result in injury and can damage the unit.
Using this unit near equipment that generates electromagnetic interference can result in unstable
or inaccurate readings.
4
CMGRT-100
Identification
1. Jaw
2. Lever
3. Memory Button
4. Alarm Button
5. Current and Decrement Button
6. Resistance and Increment Button
7. On/Off Button
8. Display
9. Hold Button
10. Test Resistance Loop
1
9
2
10
Display Icons
11.
12. HOLD
13. NOISE
Speaker is enabled
Hold function is enabled
Excessive stray noise (greater than approximately 5 A or 50 V);
when this appears on the display, resistance measurements
are not valid
Open jaw
Measured resistance is < 0.1
Ω;
when this icon appears on the display, measurements
may not be valid
Milliamperes or amperes
Ohms
Battery power (up to 100%) and alarm set point (up to 199
Ω)
stored in memory
Alarm
Power-Off function is disabled
Battery low
Memory location
Memory recall
Memory function is enabled
Measurement display; shows OL
(overload) when the measured
resistance is greater than 1200
Ω,
or
the measured current is greater than
29.99 A RMS
25
24
11
12
13
14
15
8
3 4 5 6 7
14.
15. R<.1Ω
16. mA, A
17.
Ω
18. 188
19. AL
20. P
21.
22. 88
23. MR
24. MEM
25. 8.8.8.8
16
17
18
23
22
20
21
19
Symbols on the Unit
Warning—Read the instruction manual
Double insulation
5