Download Motor Starters

LW’s What is it?
Three Phase Motor Starters
1
The coil connections on both NEMA and
IEC motor starters are typically identified
by the use of what letter and numbers?
2
The letter A and the numbers 1 and 2
This is an IEC diagram.
The coil connections are
identified as A-1 and A-2.
3
What protective element is
missing from this motor starter?
4
The heater element for L-1
Notice the
white
insulated
jumper
5
Where is the motor starter coil
on this diagram?
6
This is the symbol for the
motor starter coil
The designer did not include the coil identification
on this NEMA or American diagram.
7
How do you know when to stop tightening the
screws on these heater elements?
8
When they become flat
These washers have a
slight cup to them. When
they are properly torqued
they flatten out. They are
known as a disc spring or
Belleville washers.
When tightening fasteners
it is recommended that
you do so in three
stages or lifts.
9
What is this?
10
This is an IEC overload relay assembly
This is a Telemecanique brand overload relay assembly
designed to IEC standards.
11
What is this and what does it provide?
What do the letters H-1, H-3, H-2 and H-4 indicate?
These two
fuses protect
what?
What does
this fuse
protect?
What do the letters X2 and X1 indicate?
12
This transformer provides
control circuit power
The letters H-1, H-3, H-2 and H-4 indicate the primary
connections to the transformers
These two
fuses
protect the
primary
of the
transformer
This fuse
protects the
secondary
of the
transformer
The letters X2 and X1 indicate the
secondary of the transformer
13
On this 500 HP motor
what are these openings for?
14
These openings are for
ventilation-cooling air
15
With the motor running where would you
check for a voltage drop?
What does
this do?
How many
auxiliary
contacts does
this motor
starter have?
What is the
voltage to this
motor most
likely?
16
Voltage drop is checked at
L-1, L-2 and L-3 terminals
This is a surge
suppressor or an
RC network.
It suppresses
voltage spikes.
This motor
starter has
two auxiliary
contacts.
The colors brown,
orange and yellow
are typically used
for 480V.
17
To replace the magnetic coil
which four screws do you remove?
To inspect the
main power
contacts which
two screws do
you remove?
18
To replace the magnetic coil
you remove these four screws
To inspect the
main power
contacts you
remove these
two screws
19
What is missing?
20
The overload heater elements are missing
The wires
that connect
the motor
starter to
the motor
are missing
21
With the motor running how could you check the
condition of the main power contacts ?
22
With a voltmeter set to AC volts…
Test from
L-1 to T-1
Test from L-2 to T-2
Test from
L-3 to T-3
If the voltage
drop is more
than 0.25 volts
inspect the
contacts for
pitting and the
springs for
weakness
23
What is this and what does it do?
24
This is a Voltage Monitoring Relay
This setting dial is for the under voltage.
Range is 390 to 480 volts.
This setting dial
is for the
over voltage.
Range is
440 to 540 volts.
This setting dial is for the time delay.
Range is 1 to 30 seconds.
25
What is this?
What terminal
numbers
are for the
common
connections?
26
This is a pneumatic timer
The range is
adjustable from
0.5 to 5 seconds
The common
connection on
the left contact
set is # 5.
The common
connection on
the right contact
set is # 6.
27
Two of these are ____ and
one of these is a ____
28
These two are contactors and this one is a motor starter
The one with the overload relay is a motor starter
29
On a set of auxiliary contacts what do
the following numbers indicate?
13 & 14 =
43 & 44 =
21 & 22 =
31 & 32 =
30
The numbers indicate the
normal state of the contacts
13 & 14 = Normally open
43 & 44 = Normally open
21 & 22 = Normally closed
31 & 32 = Normally closed
31
All of the motor starters seen so far
have been what type?
I am not talking about brand name.
How do they start the motor?
32
Across the line full voltage
When a motor is started across the
line full voltage it will draw between
5 and 8 times its rated load amps.
33
What two labels should be on the
face of a motor starter enclosure?
34
An Arc Flash Warning and an
ARC Flash PPE required label
The upper WARNING label is required by the NEC.
The lower Arc Flash and Shock Hazard label is required by
NFPA 70-E the Standard for Electrical Safety in the Workplace.
35
Of the total cost of ownership
what is the largest?
Maintenance
or
Energy?
36
Electrical power accounts for 79% of the total
installed cost of a motor over its life span
Maintenance accounts for only 3% of
the total installed cost of a motor over
its service life.
By improving the efficiency of a motor
by 5% the total cost of maintenance
can be completely offset!
37
As the horse power of a motor increases the maximum
number of starts per hour increases or decreases?
38
As the horsepower of a motor increases the
number of starts per hour decreases.
Horse power
Max Start/Hr.
Min run time
between starts
in seconds
½
24
120
¾
24
120
1
15
75
1.5
13
76
2
12
77
3
9
30
5
8
83
7.5
7
88
10
6
92
15
5
115
39
What are these individual
parts known as?
40
These are the
moveable contacts
These
are the
contact
springs
These are the
fixed contacts
There are literally thousands of different types of
contact sets. Many look very similar to each other.
Replacement contacts must be ordered by starter
brand size and model only.
While
replacement
contact sets
can be
ordered for
NEMA motor
starters,
typically they
can not for
IEC starters.
41
How would you describe
these two coils?
This is a paper wrapped coil.
While replacement coils
are available for NEMA
starters, they are not for
IEC starters.
This is an epoxy molded coil.
Most coils today are made using
epoxy. They do a much better
job of keeping chemicals, dust
and moisture away from the
copper winding.
Some manufacturers use a color
to indicate the voltage of the
coil. Green indicates 230 VAC
for this mfg.
42
What is this?
43
These are overload heater elements for
NEMA motor starters
The heater
elements for IEC
starters are not
replaceable. The
entire overload
relay must be
replaced.
Overload
heater
elements
have a part
number on
them.
There are literally
thousands of different
types of heater elements.
They must be ordered by
brand, starter model and
heater number only.
44
How are IEC listed starters different from
NEMA starters?
45
IEC Starters have adjustable
heater elements
This element can be adjusted
over a range of 1 to 1.9 amps.
IEC listed starter overload
relays can be set to either
reset automatically or
manually.
There are
several other
differences
not covered
on this slide.
IEC overload relay have two sets of auxiliary contacts that change
state when the overload relay trips. Contacts 98-97 are NO and
95-96 are NC. NEMA overload relays have only one set of NC
contacts.
46
Are these IEC or NEMA
Motor Starters?
47
All of these are
NEMA listed motor starters
48
Can you identify these connections?
49
These connections are to the pilot duty
auxiliary contacts. They are NC.
These connections are for
the main power contacts.
50
In order to get the motor running again it is
necessary to push the red button
What does this most
likely indicate?
51
In order to get the motor running again it is
necessary to push the red button
What does this most
likely indicate?
•  The motor has been running
with an excessive load
•  There is a significant voltage
imbalance between the
phases
•  Motor or driven load bearings
are failing
52
The End
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