Chroma 19032 - Page 28

Electrical Safety Analyzer 19032 User’s Manual
3-4
9. Confirm charging voltage has been completely discharged
The discharge time depends on the testing voltage and DUT characteristics. Assume that
the high voltage on the DUT is equivalent to the high voltage on a 0.01uF capacitor in
parallel with a 100MΩ resistance circuit. After turning off the power, the voltage on the
DUT will decrease to lower than 30V in approximately 3.5 seconds. When the test voltage
is 500V it takes approximately 2.8 seconds. To calculate the time required for the voltage
to decrease below 30V, use the formula below. (Refer to Figure 3-5.)
Formula: Vo
e
RCt /−
= VIL
Ex.: 1000V ×
e
RCt /−
= 30V
e
RC
t /
−
= 0.03
-t / RC = ln 0.03
∴
t = 3.5 Sec
Figure 3-5
10. Remote control of the analyzer
This instrument allows remote control of the high voltage output by an external control
signal. To prevent shock hazards, observe the following rules:
• Do not allow any unexpected high voltage output that may be dangerous.
• When the analyzer is putting out high voltage, do not permit the operator or other
personnel to contact the DUT, test cable, or probe output terminal.
11. Turning the power switch on and off
The analyzer should be positioned so that the power switch can be easily reached by the
operator during an emergency. When the power switch is turned off, wait a few seconds
before turning it back on. Do not turn it on and off continuously, especially during high
voltage output. Do not connect any object to the high voltage output terminal when
switching the power on or off.
12. Other safety items
Ensure the cover of the analyzer has been connected to earth ground before the high
voltage output terminal is short-circuited with the COMMON terminal.
13. Handling a dangerous event
Under any hazardous situation, such as shock, the DUT is burning, or the analyzer is
burning, follow the steps below to remove the danger:
• In the case of an emergency, turn OFF the POWER switch using a “hot stick” and
disconnect the AC power cord from the wall. DO NOT TOUCH THE INSTRUMENT
OR THE DUT.