Mrcartool B530 - Circuit Breaker; Work Mode

There are four modes to diagnose the electrical
systems, which can be accessed by depressing
the mode button and cycling through each one.
The tool is short-circuit protected, its internal
circuit breaker will trip if it becomes overloaded,
the circuit breaker is a valuable test tool as well
as a safety measure to protect the tool from
overload.
When circuit breaker tripped, the LCD will
display as below (Figure 1). All other functions of
the tool are still active, which means you can still
probe a circuit and observe the voltage reading.
When the circuit breaker is tripped, the tool will
not be able to conduct battery current to the tip
even when the power switch is pressed.
Intentionally tripping the breaker and using the
tool to probe can be considered an added
precaution against accidental pressing of the
power switch.
Circuit Breaker
Work Mode
(Figure 1)
Circuit Break
V V
0.0
While the tool in this mode, contact the probe tip
to a circuit, then the LCD display will read the DC
voltage with a resolution of 0.1 volt (Figure 2).
DC Voltage:
While the tool in this mode, contact the probe tip
to a circuit, then the LCD display will read the
max voltage, the min voltage, frequency and
duty cycle (Figure 3).
AC Voltage:
While the tool in this mode, contact the probe tip
to a circuit, then the LCD display will read the
resistance between the tip and auxiliary ground
lead (Figure 4).
Resistance:
When the tool is in this mode, the tone can be turned on or off with a quick press
of the mode button. When you press (quickly press and release) the mode
button quickly, a short high pitched sound is heard which indicates that audio
is on. However, if a short low beep is heard, then the audio is off (Figure 5).
This function can be particularly useful when working in areas where the LED
illumination is not sufficient. The audio function can also be turned off as
Tone On/OFF:
(Figure 3)
V V
Max
Min Duty
Freq
12.3V 0.6Hz
49%
0.3V
(Figure 4)
V V
735Ω
(Figure 2)
V V
12.0
3