Maintenance Procedure of
Motor
Maintenance of Motor
Activity
S.No Work Description
By
Each person involved in the maintenance should get a tool
1. Engineer
box
Verify that the feeder is isolated by removing the control
2. Electrician
and space heater fuses, turning the isolator/MCCB off.
3. Motor
In the field, physically compare the tag numbers on the
a. Electrician
authorization and the motor.
b. Verify the status of the motor emergency pushbutton. Electrician
Use a multimeter to test for voltage. Make sure there is no
c. Electrician
voltage.
d. Use a discharge rod to disconnect the motor and power cord. Electrician
e. Clean the motor canopy by removing it Electrician
f. Remove the fan cover. Clean the fan, and motor. Electrician
Verify the condition of the motor cables, terminal box, and
g. Electrician
motor/EPB earthing.
Check the condition of the motor shaft seals (e.g., V-ring or
h. Electrician
radial seal).
i. Check that Motor is good condition. Electrician
Open the terminal box of the motor. Check for any sign of dust
j. Electrician
/ moisture inside the terminal box.
Examine and make a note of the motor connection's terminal
k. Electrician
box.
Examine the device for any indication of lugs, cable ends, delta
links, internal leads, etc. for any burning smells. After
communicating with the in-charge Engineer, take the necessary
l. Electrician
action (such as re-lugging, re-taping, etc.). Additionally, examine
the terminal connections for any looseness and tighten them
with the proper pressure, being careful not to overtighten.
Check the tightness of the terminal connections and the health
m. Electrician
of the terminals by opening the terminal box.
With sealant and aluminium tape, secure the terminal boxes for
n. Electrician
the motor.
o. Clear the motor body completely of any accumulated dirt. Electrician
Make that the motor body is being earthed at two different
p. Electrician
positions.
q. Re-install the motor rain canopy. Electrician
From the feeder end, verify and record (in the checklist) the
4.
following:
a. Clean the cable and feeder chamber. Electrician
b. Check all the tools to make sure it is in good working order. Electrician
Inspect the tightness of the control wire at each connector and
c. component connection. Electrician
Inspect the current condition of electrical parts, such as the
d. contactors and relays. Replace as required. Electrician
Maintenance Procedure of
Motor
Maintenance of Motor
Activity
S.No Work Description
By
Check the Start and Stop push buttons are free to operate &
e. check the contact make & break using multimeter. If any Electrician
mislead, replace the contact element.
f. Check the Motor and Cable Insulation Resistance Electrician
Using a digital multimeter, check the resistance of the motor
g. Electrician
winding between each phase.
Check the tightness of the CT terminal. The secondary CT
circuit was measured as follows:
Measurement of Parallel Resistance (Ph-N).according to the
prescribed procedure. No interruption.
After opening the series links, measure the CT secondary
resistance (Ph-N).
After opening the series links, measure the load resistance (Ph-
h. N). Electrician
Series Resistance (link Open): Measure the resistance on the CT
secondary plus load side after opening the series links.
Link Resistance: After connecting a series link and a regular
connection.
After connecting the series link and regular connection,
measure the parallel resistance (Ph-N).
g. Check the condition by opening the power contactor. Electrician
5. Complete the checklist with all the required information. Electrician
6. Perform adequate housekeeping in the area. Electrician
Maintenance Procedure of
Motor
Maintenance of Motor
Checklist
MOTOR TAG NO: DATE OF COMMISSION:
Motor KW: FEEDER NO:
Motor Sr. No: MOTOR FLC:
1. PRECAUTIONS TO BE FOLLOWED BEFORE PM
a. The feeder has been isolated. Yes / No
b. Emergency The pushbutton has been Yes / No
pressed.
c. Using a multimeter, check for the existence No Voltage Present
of voltage.
d. The discharge motor and the power cord. Yes / No
2. IN INSPECTION FIELD
A. MOTOR
Clean the motor body, fan, fan cover, and terminal Yes / No
a.
box.
b. Connections to the motor body's earthing. Tight / Loose
The motor cables, terminal box, and motor / EPB Yes / No
c.
earthing are all in fine working order.
The motor shaft seals (e.g., V-ring or radial seal) are Yes / No
d.
in good condition.
e. Main TB Power Cable Connection Tight /Loose/Overheat
Indication of moisture, dust, or contaminants into Yes / No
f.
the TBs
Look for any indications of abnormalities or Yes / No
g.
overheating.
Yes / No
h. TBs have been sealed.
Yes / No
i. The Motor Canopy has been reassembled.
Connection Diagram for Motor Terminal Box: R Y B
j.
3. MOTOR HEALTHINESS CHECK
a. In connection to the earth, check the motor's _____ MΩ
I.R. value. (Make sure the field's motor
terminal box is closed.)
b. Inspect the resistance of the motor windings. RY : ____ Ω
Maintenance Procedure of
Motor
Maintenance of Motor
YB : ____ Ω
BR : ____ Ω
c. Check the setting for the bimetal overload _____ A
relay.
d. Considering the FLC and load current, the Ok / Not Ok
setting for the overload relay is good.
4. FUSE CONDITION CHECK
a. Check fuses: (R) Phase : _____ A Ok / Blown Out
(Y) Phase : ______ A Ok / Blown Out
(B) Phase : ______ A Ok / Blown Out
b. Check control fuse / MCB : ______ A Ok / Blown Out
c. Check D.C. fuses (if any): ______ A Ok / Blown Out
5. MCC FEEDER
a. Cleaning the Feeder and Cable box. Yes / No
b. Checked each of the devices to make sure Ok / Not Ok
they are in good working order.
c. All wire was checked for wear & cuts and Ok / Not Ok
was found to be okay.
d. Petroleum jelly is used to clean and lubricate Yes / No
contacts.
e. Feeder was inspected for signs of Ok / Not Ok
overheating, arching, or insulation failure
and confirmed to be in good condition.
f. Telescoping rails and racking screws are Yes / No
greased.
A. POWER CABLE CIRCUIT
a. Connectivity of power cables at cable alley's Tight / Loose / Over-Heat
outgoing terminals.
b. Outgoing jaw connectors on power cables Good / Over-Heat
terminate inside the module.
c. Power termination at the power contactor's Good / Over-Heat
incoming and outgoing terminals.
d. Power contactors (contacts) and arc chute Ok / Not Ok
condition
e. Continuity of every pole of the power Ok / Not Ok
contactor after maintenance is completed
f. Power contactor Coil Resistance __________ Ω
g. The condition of the power contactor's Ok / Not Ok
auxiliary contact
h. Continuity of each overload relay pole after Ok / Not Ok
maintenance is completed
Maintenance Procedure of
Motor
Maintenance of Motor
B. CONTROL CIRCUIT
a. All control wires' connection tightness at fixed and Tight / Loose
moving contacts
b. All control wire connections at auxiliary and power Tight / Loose
contactors are required to be tight.
c. Tightness of the wire connections at the Tight / Loose
overload and numerical relay
d. Tightness of the control wire connections at control Tight / Loose
and neutral connections
e. Tightness of the cable connections at metering Tight / Loose
and protection CT
f. Tightness of the control wire connections at the earth Tight / Loose
leakage relay and CBCT
g. Tightness of the control wire connections at the Tight / Loose
indicator bulb and push buttons
h. Control the testing process in Test mode with the Ok / Not Ok
Test Push Button.
i. Overload resetting works. Ok / Not Ok
j. The feeder's overall cleanliness Ok / Not Ok
k. Control contactor / relay coil resistance:
Contactor Number: Resistance (Ω)
l. CT The secondary circuit is in satisfactory condition Ok / Not Ok
and is not open. Resistance was tested as shown
below & determined to be adequate.
R Y B
Resistance in parallel (Ph-N)
CT Resistance (Ph-N)sec
Load Resistance (Ph-N)
Resistance in series (open link)
Resistance of the link (after connect)
REMARKS:
Maintenance Procedure of
Motor
Maintenance of Motor
Note:
PM – Preventive Maintenance
TB – Terminal Box
MTB – Main Terminal Box
MCC – Main Circuit Chamber
Ph – Phase
N - Neutral
Electrician Signature Engineer Signature
(Name with Date) (Name with Date)
