ALL-TEST
PRO
®
31 User Manual
©2011, ALL-TEST
Pro,
LLC
www.alltestpro.com
rev 2011-11F
20
Insulation Resistance Testing
To prevent electrical shocks and to assure safety of personnel the AT31 provides an insulation to ground
test. The insulation resistance test provides either 500 or 1,000 V
DC
, to measure the insulation resistance
up to 500 Meg-Ohm.
NOTE: The following tables provide the recommended voltages and Minimum Insulation Resistance to
Ground values. If these values differ from your equipment manufacturers, follow their guidelines
.
Insulation Resistance Test Voltage
Insulation Resistance Values (IEEE 43-2000)
1.
Using the ON key or the MODE key from the keypad section to navigate to the display screen
(This is the main menu)
.
2.
Use the ◄►to highlight the INS icon from the display screen.
This
sets the ALL-TEST PRO® 31 up to measure insulation resistance to
ground.
3.
Connect
both
the Red lead & the Yellow lead to ground.
4.
Press the ZERO/OK key to select the Insulation Resistance Test.
This displays screen 8, the
insulation resistance test screen.
5.
View the insulation test voltage selected (
upper right hand corner of the insulation resistance
display screen). Refer to the insulation resistance test voltage table above for the correct voltage.
Motor Voltage Rating
Insulation Test Voltage
< 1000 Volts AC
500 V
1000 to 2500 Volts AC
1000 V
2501 to 5000 Volts AC
1000 – 2500 V
Application
Pass/Fail Value
Insulation systems prior to 1970
> 1 Meg-Ohm + 1 Meg-Ohm per kV rating of motor
Random Wound motors less than 600 V
> 5 Meg-Ohms
DC Armatures and Form Wound motors over 600 V
> 100 Meg-Ohms
