Initial Starting; Regular Operation - Mitsubishi Electric SF-PR Series Instruction Manual

(6) Protection device
This motor does not have a protection device. Installation of an overload protection device is mandatory under
the Electrical Equipment Technical 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 Ω or more for the low voltage motor.) Never touch the
terminals with bare hands when measuring the insulation resistance. Failure to observe this could lead to
electric shocks.
b. Are any screws loose?
c. Rotate the shaft by hand and confirm that it rotates freely without catching. (Remove the shaft protection clamp
first.) Take care not to cut your hand on the keyway.
d. Is an adequate fuse installed?
e. Are the power supply and grounding connections secure?
f. 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 if a skew fan is used. Be sure to refer to the outline dimension drawings for more details.
g. Is the connection with the machine correct? (Refer to Section 5. COUPLING WITH MACHINE.)
h. When using a star delta ( -Δ) 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 number 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. Be aware that leaving the power ON
may cause unexpected motor behaviors and subsequent personal injuries such as follows: Depending on the load,
the load may be too heavy for the motor to start up, causing the motor electrical devices to burn or the motor to start
operating unexpectedly.
f. Never go near or touch the rotating parts (shaft, etc.) during operation. Failure to observe this could lead to
entanglement or injures. Also, do not insert your fingers or objects such as a screwdriver into the fan cover
or bracket openings. 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 in Table 8.
– 9 –