Installing An External Leakage Breaker; Installing A Circuit Protector - Yamaha SRCP User Manual

2-2 Connecting the Power Supply
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4
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CAUTION
The SRCP series controller does not have a power switch. Be sure to provide a power supply breaker (insulation)
of the correct specifications that will turn the power on or off to the entire system including the robot controller.
Power to EXT. CN must first be supplied before supplying power to the power supply terminal block. If this order
is reversed, an alarm (06: 24V POWER OFF) might be issued to prevent operation. (See "2.7 Connecting to the
EXT. CN Connector" in this chapter and Chapter 3, "I/O INTERFACE".)
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WARNING
Before beginning the wiring work, make sure that the power supply for the entire system is
turned off. Doing the wiring work while power is still turned on may cause electrical shocks.

2-2-3 Installing an external leakage breaker

To ensure safety, a leakage breaker must be installed in the power supply connection section of the
robot controller. Since the robot controller drives the motors by PWM control, leakage current flows
at high frequencies. This might cause the external leakage breaker to malfunction.
When installing an external leakage current breaker, it is important to choose the optimum sensitivity
current rating (IΔn). (Check the leakage breaker manufacturer's data sheets to select the optimum
product compatible with inverters.)
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CAUTION
1. Leak current was measured with a leak tester with a low-pass filter turned on (100Hz).
Leak tester: Hioki Electric 3283
2. When using two or more controllers, sum the leakage current of each controller.
3. Make sure that the controller is securely grounded.
4. Stray capacitance between the cable and FG may vary depending on the cable installation condition, causing
the leakage current to fluctuate.
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WARNING
Electrical shocks, injuries or fires might occur if the motor breaks down while the robot controller
is used without installing a leakage breaker.

2-2-4 Installing a circuit protector

To ensure safety, a circuit protector must be installed in the power supply connection section of the
robot controller. An inrush current, which might be from several to nearly 20 times higher than the
rated current, flows at the instant that the SRCP controller is turned on or the robot motors start to
operate.
When installing an external circuit protector for the robot controller, select a circuit protector that
provides optimum operating characteristics.
To ensure proper operation, we recommend using a medium to slow response circuit protector with
an inertial delay function. (Refer to the circuit protector manufacturer's data sheets for making the
selection.)
Example
SRCP
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WARNING
Electrical shocks, injuries or fires might occur if the motor breaks down while the robot controller
is used without installing a circuit protector.
Leakage current
SRCP 4mA (Max.)
Rated current Operating characteristics
Slow type with inertia delay
20A
300%
(
1000% 0.01 sec.
2 sec.
)