5. CHECK AND TROUBLESHOOTING
Check points before inspection
1) Prepare thoroughly
Check the first aid method, arrangements around the job location and safety of the equipment and machine
2) Review based on the circuit diagram
When the electricity is connected to the power system, check various power sources, the status whether current
is flowing in the 1st side of circuit breaker, and the installed condition of ground wire.
Check whether it is possible to communicate with the pertain departments closely and firmly.
4) Check zero voltage condition and safety measures
Review the following details for safety when checking the main circuit.
A) Open the pertain circuit breakers and disconnecting switches, to make the main circuit voltage zero.
B) Use electroscope to check the zero voltage condition and ground the locations as necessary.
C) Take out the circuit breaker so that it is disconnected and attach "Inspection now in progress" sign.
D) Operate the disconnecting switches after interrupting the power.
E) Especially for the panels where power is connected circuitously such as 'distribution panel of the consumer,
auto control and MCC panel, take actions of above C) and D) for the switches of the other party.
5) Be careful of current and voltage
When checking connecting parts of condensers and cables, discharge the residual charge and ground the wires.
6) Prevention of mal-operation
Interrupt the power supply and attach caution sign.
7) Preparation of protective insulation devices
Wear safety gear suitable for the rated voltage including insulation gloves, safety hat, insulation boots, safety suit, etc.
8) Measures for intrusion of rats or insects
Establish appropriate measures to prevent rats, insects and snakes intruding the panels.
Check items after inspection
1) Final checking
a) Check whether any worker is inside the control panel.
b) Check whether the removal of the makeshift structures set up for the inspection is delayed.
c) Make sure not to forget to fasten the bolts.
d) Check for abandoned tools.
e) Check whether rats or insects intruded inside the panel.
2) Recording the inspection
In inspection, it is recommended to record the key points of inspection or repair, failure conditions and the date.
This can be used as reference for the future inspection.
- In a routine inspection, make a plan for effective examination for the loads of the machines in operation, Opera-
tion hours and conditions.
- The inspection cycle suggested in this manual is just for general guidance. You should establish a specific inspec-
tion plan considering the machine load and frequency of use.
- Do not conduct insulation resistance test on the 2nd phase of the transformer supplying the power to controller or
for other control purpose.
- Do not conduct insulation resistance test on devices (sensors, switches, etc.) connected to the controller.