◇
33
接地检测输出
高压测试输出
TH9201
系列仪器
待测设备
高压测试点
接地测试点
其他外壳接点
1. Ground connection test
Ground connection is used in testing device
，
now the low test terminal is connected to
the ground terminal
（
shell
）
, which is used to judge the reliability of ground connection.
If the low terminal connection is not reliable, the shell of
DUT takes high voltage in the process of testing; it will
cause the accident shock.
Instruction
：
High voltage test terminal is connected to the ground
terminal of DUT.
Test low terminal is connected to the ground connection
terminal of shell.
Ground check terminal is connected to other terminals
of shell
（
screw
）
.
Set ground connection test
，
test time is set by user.
Start
test
，
instrument firstly executes ground check
：
output current from ground check
，
and flows back to test
low terminal shown as the figure.
If the test circuit connection is normal within the set time
（
if circle resistance<1ohm, it is normal
），
the ground
check is passed and test continues.
If test circuit is not available
（
if circle resistance >1ohm, it is abnormal
），
the
instrument will quit testing, and displays connection error
（
GR FAIL
）
.
Note
：
ground breakover parameter is the GR CONT in
SYSTEM1
interface.
1. Electric wall function
Electric wall is used to check the ground current and avoid shocking in the process of
testing. When outputting high voltage
，
the current from voltage output terminal will be
back to shell through body, it will cause a serious result.
Instruction
：
When starting electric wall, if ground current is larger
than 0.5mA, it judges as shock.
When electric wall is closed, if ground current is larger
than 30mA, it judges as shock.
When the judge is shock, the instrument will output high
voltage within 0.3S
，
and quit test status, as well as
display GFI FAIL.
Note
：
when ground current reaches to 30mA
，
it is so serious
that it will cause the operator coma or death. It is suggested
高压测试输出
TH9201
系列仪器
待测设备
