Initial Starting; Regular Operation - Mitsubishi Electric JR Series Instruction Manual

(5) Precautions for - starting method
Always observe the following precautions as if the motor is installed in a dusty and humid
environment and the voltage will always be applied when the neutral point is cut off during motor
stopping, the insulation may deteriorate and burn.
(a) when selecting the - starter, select one with a magnetic switch (3-conductor type) on the
primary side, and prevent the application of the voltage onto the motor wiring during stopping.
(b) If not using the primary side magnetic switch, always open the power side switch when stopping
the motor.
(6) Protection device
This motor does not have a protection device. Installation of an overload protection device is
mandatory under Electrical Facility Technology Standards. Installation of a protection device
(leakage breaker, etc.) besides an overload protection device is recommended.
If switching surge may be caused by operating a circuit breaker, switch or magnetic valve, install a
protection device for limiting surge.
(7) Terminal box
(a) The direction of the terminal box can be changed in 90° steps by loosening the screws in the
box. When changing the direction of the terminal box, make sure that the inner lead wires are
not caught. Apply a waterproof sealing agent to the mounting screws of the terminal box seat of
the outdoor type motor.
(b) Running the motor with the terminal box cover removed could lead to electric shocks. Always
return the terminal box cover to the original position after work is completed.

8. INITIAL STARTING

Check the following points before turning the switch ON to run the motor for the first time.
a. Is the insulation resistance above the specified value when the motor has been subjected to moisture
during shipment or storage? (Insulation resistance must be 1M or more for the low-voltage motor.)
Never touch the terminals with bare hands when measuring the insulation resistance.
b. Are any screws loose?
c. If the motor has been stored for a long time, remove any dust or foreign matter collected inside.
(For drip-proof type.)
d. Rotate the shaft by hand and confirm that it rotates freely without catching.
Take care not to cut your hand on the keyway.
e. Is an adequate fuse installed?
f. Are the power supply and grounding connections secure?
g. Check the motor as a single unit first if there may be a problem when the machine rotation direction
is reversed. In this case, remove the key installed on the shaft.
If the rotation direction must be changed, interchange two of the three power wires connected.
Note that the rotation direction is fixed when using a skew fan, etc., so refer to the outline drawing
for details.
h. Is the connection with the machine correct? (Refer to Section 5. COUPLING WITH MACHINE.)
i. When using a star delta ( -) starter or start compensator, confirm that the handle is at the start position.

9. REGULAR OPERATION

a. Keep the load as light as possible when turning the switch ON, and apply the load after the full
speed is reached.
b. Use an ammeter to check that the load is adequate. Adjust the load so that it is lighter than the
value noted on the nameplate. If a current exceeding the current value on the nameplate is flowed,
overload operation will occur and may lead to burning of the coil.
c. The motor may be damaged if the starting time is too long or if the No. of continuous starts is too high.
d. Check that there is no abnormal noise in the bearings.
e. If a power failure occurs during operation, always turn the switch OFF. IF the power is left ON, the
state with the load applied will be entered when the power is restored. This could cause starting to
be prevented due to the load being too heavy, to damage or to unforeseen accidents due to the
motor starting unexpectedly.
f. Never approach or touch a rotating part (shaft, etc.) during operation. There is a risk of
entanglement or injury. Do not insert your fingers or objects such as a screwdriver into the fan
cover or bracket openings while the motor is running. If the rotary sections such as the fan is
contacted, a hazardous state leading to injuries or damage could occur.
g. The motor surface will become hot during operation. Touching these with your fingers or body
could lead to burns.
h. The temperature rise limits for the coils and bearings are as shown below. (Table 8)
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