Siemens-allis La3000a User manual

r

SIEMENS-ALLIS

----

-

~~-~

INSTRUCTIONS

TYPES

LA3000A

&

LA4000A

(UNFUSED)

AIR

CIRCUIT

BREAKERS'

WITH

MANUAL

OR ELECTRICAL

OPERATORS

..

-18X5689

MAY,

1977

(

INDEX-----------------------------------------------------------------------------------

WARRANTY

.•......

"

....

INSTALLATION

AND

INSPECTION

1.1.roduction

....•..........

Receiving

and

Inspection

for

Damage

Installation

..

Storage

....

Maintenance.

OPERATION

Description

.•

_

........

.

Manually-Operated

Breaker

..

Electrically·Operated

Breaker.

Drawout

Interlock

Racking

Mechanism

...

Lifting Bar & Rail

Extensions.

Spring

Discharge

Interlock

...

MAINTENANCE

AND

ADJUSTMENTS

Maintenance

..

Lubrication

....•

Maintenance

Closing

Handling

Instruction

ii

2

.

2-12

3

4

8

5

. . 6

6.21

· 6

..

17

Adjustments

.......

.

Trip-Latch

Engagement

Main

Contact

Make

..

ArCing

Contact

Make.

Contact

Replacement

..

Main

Contact

Fingers

.

Stationary

Arcing

Contact

..

Hinge

Contact

Fingers

....

Moving

Arcing

and

Main

Contact

Tripping

Actuator

..

Motor

Cutoff

Switch

.

Secondary

Oisc.

OPtion

.

Auxiliary

Switch

OpTion.

Shunt

Trip

Option

....

TRIPPING

TRANSFORMERS

Current

Sensors

...

Tripping

Tran

...

former

Table.

Bell Alarm

Switch

Option

Static

Trip

OPtion

....

UmiTrip

__

Undervoltage

Trip

Oevice

Option.

Lubricating

Instructions.

Instruction

Book

Ref

..

-

.......

7

8

9.10

.11

·

1'.

_

.11

.12

.11

.12

·

12

.11

·

21

.22

ILLUSTRATIONS---------------------------------------------------------------------------------

Fig.

1

Fig.2

F:g.3

Tyoical

LA-30aDA

Breaker

Outline.

T,,;,ical

LA-3000A-4000A

Operator

Typical

Wiring

Diagram -

Electrically

Operated

Breakers . _

..

Fig.4

Typical

RaCking Mechanism

and

Drawout

Interlock.

Fig.5

Maintenance

Closing

·

13

14

· 15

·

16

.18

Fig.6

Fig.7

Fig.8

Fig.9

Typical

Panel

Assembly

Secondary

Disconnect

Auxiliary

Switch

.

Shunt

Trip

...

Fig.

10

Undervoltage

Trip,

Fig, 11 Bell

Alarm

...

' .

·

19

.19

.20

TABLES----------------------------------------------------------------------------------------

Table

1

Operating

Procedure

-

Manually-

Table

3

Maintenance

Closing

.....

. 7

Operated

Breakers

........

. .

...........

3

Table

2

Operating

Procedure

-

Electrically·

Table

4

Trip

Rating

Table

-

Amperes

Static

Trip

11

•..••..••••

Table

5

Trip

Rating

Table

·

12

Operated

Breakers

.........

,

............

4

LimiTrip

,

.............

12

The

information

contained

within

is

intanded

to

assist

operating

personnel

by

providing

information

on

the

general

characteristics

of

equipment

of

this

type.

It

does

not

relieve

the

user

of

responsibility

to

use

sound

engineering

practices

in

the

installation,

application,

operation

and

maintenance

of

the

particular

equipment

purchased.

If

drawings

or

other

supotementary

instructions

for

specific

applications

.re

forwarded

with

this

manual

or

separately.

they

take

precedence

over

any

conflicting

or

incomplete

information

in

this

manual.

..

WARRANTY

Allis-Chalmers

"LA"

air circuit breakers are warranted to be free

of

defects

in

material and workmanship

for a period

of

one

year

from

date

of

initial operation

but

not

more

than

eighteen

months

from

date

of

shipment

by

company

_

This

warranty

is

limited to the furnishing

of

any

part

which

to

our

satisfaction has

been proven defective_Allis-Chalmers will

not

in

any case assume responsibility f

or

allied

equipment

of

any kind_(See Allis-Chalmers Warranty Form 5992.)

. . .

Typical Shipping Methods Used With

"LA"

Breakers

:

INSTALLATION AND INSPECTION

INTRODUCTION

The type

"LA"

air circuit breakers may be furnished for mounting

in

either

of

two ways. They may be

used

in

metal-enclosed switchgear

of

the

drawout type,

or

in

individual enclosures (drawout

tyre).

All

"LA"

breakers are completely assembled, tested, and calibrated

at

the

factory

in

a vertical posi :ion and

must be so installed

to

operate

properly. Customer's primary connections should be adequately braced

against

the

effects

bf

short

circuit currents

to

prevent overstressing

the

breaker terminals.

RECEIVING AND INSPECTION FOR DAMAGE

Immediately upon receipt

of

this equipment, carefully remove

all

packing traces and examine parts, check·

ing

them against

the

packing list and noting any damages incurred

in

transit. If such

is

disclosed, carrier in·

spection

must

be arranged for by consignee within 15 days

of

receipt

of

equipment.

If

equipment

shipped F.O.B. Shipping Point, consignee must file a claim with

the

carrier.

If

equipment

is

shipped F.O.B. -

Destination,

the

consignee must obtain the original of the carrier inspection report and notify Allis-

Chalmers immediately.

Two shipping methods are used with

"LA"

breakers:

1.

Individually skidded with protective covering for domestic shipments.

2.

Within a cubicle on

export

orders when part

of

a switchgear lineup. Breakers shipped

in

their cubicles

are blocked to prevent accidental tripping during shipment. Note

all

caution tags, remove blocking

bolts, and open breaker contacts before installation.

INSTALLATION

The

"LA"

air circuit breaker

is

completely adjusted, tested, and inspected before shipment,

but

a careful

check should be made

to

be certain

that

shipment or storage has

not

resulted

in

damage or change

of

ad·

justment. Circuit breakers should be installed

in

a clean, dry, well·ventilated area

in

which the atmosphere

is

free from destructive acid

or

alkali fumes. Before installing, make certain

that

the

breaker contacts are

in

the open position, and primary disconnect fingers are lubricated with Allis-Chalmers electrical contact lubri-

cant supplied with accessories.

1.

After

the

breaker

is

installed

in

position, close it manually by

the

maintenance closing method (see

MAINTENANCE AND ADJUSTMENTS, page

6)

to

check proper functioning

of

the

mechanism and

contacts.

CAUTION!!

MAKE SURE CIRCUIT

IS

NOT ENERGIZED.

During

the

closing operation, observe

that

the

contacts move freely

without

interference or rubbing

between movable arcing contacts and parts

of

the

arc chutes. Then refer

to

OPERATION, page 3 for a

detailed description

of

the

circuit breaker operating characteristics before putting

the

breaker

in

service.

2.

Trip units and accessory devices should receive a thorough check prior

to

placing the breaker

in

service

to

be certain

that

adjustments are proper and parts are

not

damaged. Refer

to

Static Trip

Dev·ice

In-

struction Book

18X4827·02

supplied with this equipment

or

to

LimiTrip Book 18X10107.

3. Breakers are equipped with a drawout interlock

to

prevent movement

of

a closed breaker into

or

out

of

the

connected position. See SPRING DISCHARGE INTERLOCK, page 5 for a description

of

the

interlock. Its

operation

should be checked before the breaker is energized.

4. Upon completion

of

the

installation inspection, the control wiring, if any,

is

checked and the insula·

tion

tested,

then

the

breaker

is

ready

to

be energized.

STORAGE

When

breakers are

to

be

put

into

storage, they should be wrapped

or

covered with a non-absorbent

material

to

provide

protection

from plaster, concrete dust, moisture

or

Qther foreign matter. Breakers

should

not

be exposed

to

the

action

of

corrosive gases

or

moisture.

In

areas

of

high humidity

or

tempera-

ture fluctuations, space heaters

or

the

equivalent should be provided.

- 1 -

MAINTENANCE

Occasional checking

and

cleaning

of

the

breaker

will

promote

long and trouble-free service. A periodic

in-

spection

and

servicing

on

an

annual basis should

be

included in

the

breaker

maintenance

routine

or

at

shorter

intervals if necessary

due

to

environmental

or

operating conditions.

If

the

circuit

breaker

is

not

operated

during

extended

periods,

the

breaker

should

not

remain

in

either

the

closed

or

open position

any

longer

than

six months. Maintenance opening and closing

operations

should be

made

to

ensure freedom

of

movement

of

all parts.

CAUTIONS TO

BE

OBSERVED IN

THE

INSTALLATION

AND

OPERATION

OF

"LA"

CIRCUIT

BREAKERS

1. Never

try

to

remove

the

breaker

from

the

compartment

or

reinsert

into

the

compartment

without

using

the

guide

rail

extensions

supplied. See page 17.

2. Read

the

Instruction

Book

before installing

or

making any changes

or

adjustments

on

the

breaker.

3.

As

the

closing springs

on

stored-energy breakers may be charged

with

the

breaker

contacts

in

either

the

open

or

closed

position.

extreme

care should be

taken

to

discharge

the

springs

before

working on

the

breaker.

4. When charging manually-operated breakers, always hold handle firmly until it

is

returned

to

the

normal

vertical position.

5. Check

current

ratings against single line diagram

to

assure

that

breakers are

properly

located

in

switch-

gear

at

installation.

6. Check

the

alignment

of

the

secondary

disconnect

fingers

to

ensure against misalignment due

to

possible

distortion

of

fingers

during

shipment

and handling.

7.

Once

the

breaker

is

energized, it should

not

be

touched,

except

for

operating, since

most

of

the

com-

ponent

parts

are also energized.

..

- 2 .

OPERATION

DESCRIPTION

The LA·3000A air circuit breaker has a maximum continuous

current

rating

of

3,000

amperes, and an

interruption rating

of

65,000

amperes

at

254, 508,

or

635 volts

60

Hz., when used with the short time

delay trip device. With instantaneous trip device, the interruption rating

is

85,000

amperes

at

254 volts,

65,000 amperes

at

508 volts, and 65,000 amperes

at

635 volts.

The LA-4000A air circuit breaker has a continuous current rating

of

4,000

amperes and an interruption

rating

of

85,000

amperes

when

used with the short time delay trip device. The interruption with instan·

taneous trip device

is

130,000

amperes

at

254

volts, 85,000 amperes

at

508 volts, and

85,000

amperes

at

635 volts.

All

currents are symmetrical amperes and voltages are maximum.

Three configurations of

the

operator

are available for charging the closing springs. These are:

(A)

manual charging,

(8.) electrical charging

(C.)

combination manual·electrical charging

All

operators are identical

except

for the means

of

supplying energy

to

the

closing springs.

A double-toggle, trip·free mechanism

is

used;

that

is,

the breaker

contacts

are free

to

open

at

any time, if

required, regardless

of

the

position of the mechanism.

(A.) Manually·Operated Breakers

The breaker has a

center·mounted

frame

so

many of the latches and links are arranged

in

pairs; for descrip·

tive purposes they

will

be referred to

as

single items. Refer

to

Figure 2 and Table

1.

Detail

"A"

shows the

position

of

the

trip latch

and

toggle linkage when the breaker

is

open and the closing springs are discharged.

Movement

of

the

charging handle downward rotates closing cam (204) against roller (168), thus pivoting

closing cam (159) clockwise

about

pin (215) and extending

the

closing springs thru link (163) and spring

hanger (157). Rotation

of

cam (159) allows roller (181)

in

toggle linkage to be moved into position shown

in

Detail

"8

".

Kickoff springs (199) move rollers away from stop block (171), then the toggle linkage

is

moved by torsion spring until latch (175) clears trip latch (153A). Spring (155) causes trip latch (153A) to

reset under latch (175).

Trip

flap (1538) should normally stop against

the

front surface

of

latch (175).

When

the

closing springs are fully charged, roller (168) engages latch (148). Charging'cam (204) engages

pawl

(146)

in

such a

manner

that

the charging cam must complete

the

charging stroke before it can return

to its normal position.

With

the charging handle in its normal upright position, the breaker can be closed.

8y

pressing firmly on

hood (149), latch (148) will disengage roller (168) and closing springs cause closing cam (159) to rotate

against

the

toggle rollers (181) moving

the

toggle into its upright position, shown

in

detail

"C".

The closing

cycle can be interrupted

at

any

point

by

operation

of

one

of

the

tripping means, which cause rotation of

trip latch (153A)

to

a position

that

releases latch (175) allowing toggle linkage

to

collapse

to

the position

shown in

detail"

A".

Manual opening

of

the

breaker

is

accomplished by pressing

in

manual trip bar (188). This bar engages the

top

oftrip

flap (1538) which

is

in turn arranged

to

disengage

the

trip latch (175).

TABLE 1 - OPERATING PROCEDURE -MANUALLY·OPERATED BREAKERS

Operation·

Charging Springs

Closing

Tripping

Procedure

Pull charging handle down

all

the way (approximately 120°) and return to normal

vertical position. (Engagement

of

pawl with

the

ratchet teeth prevents handle

re-

versal until

the

downward stroke

is

completed.)

Push

down

firmly

on

spring·release latch

hood

(149) after handle is returned

to

normal

vertical position.

Push in manual trip bar (188),

OR

..

If

shunt

trip is provided, operate remote trip

control

switch (CST). (See Figure 3.)

·3·

(B.) Electrically·Operated Breaker

The mechanism

of

the

electrically operated breaker

is

the

same as

the

manually operated breaker except

that

the manual charging

handle

is

replaced by a

motor

and gear system. Refer

to

Figure 1·2 and 4. With

power available

to

the

control

circuit, closing

the

motor

control switch (MI) will

start

the

automatic

charg.

ing cycle. The

motor

gear

box

pinion rotates gear (224) counterclockwise, cam follower (233) engages an

arm

of

wind and close cam (223) which rotates

the

cams

in

the

same

manner

as for

the

manually

charged.

breaker. When

the

wind

and

close cam (223) reaches its charged position,

the

back

of

the

cam engages

switch lever (229) rotating

the

lever away from

the

switch

operator.

Gear switch lever (231) will still be

holding

the

switch

in

the

operate

position, and the

motor

will

continue

to

run until

the

roll pins on

the

side

of

gear (224) lifts lever (231) clear. releasing

the

motor

cutoff

switch (MCO)' When

the

MCO

switch

opens,

the

motor

stops,

and

the

closing coil circuit

is

set up through

one

side

of

the

MCO

switch.

The breaker can now be closed by depressing the latch hood (149)

or

by

energizing

the

closing coil

(CC)

through

the

external close control switch (CSC). When

the

ClOSE

circuit

is

energized,

the

"Y"

relay

is

energized

and

opens

the

"Y"

contact

in

the

motor

circuit,

thus

preventing

"pumping"

or

repeated at·

tempts

to

charge

the

closing springs.

If

the

close circuit

CSC

switch

is

opened,

the

motor

will automatically recharge the closing springs, if

power

is

available for

the

motor

circuit. The close coil circuit

is

always interrupted by

the

motor

cut·off

switch

MCO.

Trip free

operation

of

the

mechanism, discharging

the

springs on a closed breaker

is

pre·

vented by completing

the

close coil circuit through auxiliary

contact

of

the

breaker.

TABLE 2 - OPERATING PROCEDURE -ELECTRICALLY·OPERATED BREAKERS

Operation

Charging Springs

Closing

Tripping

Procedure

Energize control circuit.

Move

motor control switch on

front

of

breaker

to

"ON"

position.

After

springs are charged, actuate remote close

control

switch (CSC).

OR

Push

down

firmly on spring·release latch

hood

(149).

Actuate

remote trip control switch (CST).

OR

Push in manual trip

bar

(188).

(C.) Combination

Operated

Breaker

The combination manually

and

electrically operated breaker includes

both

the motor·gear charging

system

as

well

as

the

manual charge handle. NOTE: Manual Handle

must

be

in

vertical position during

electrical charging.

Drawout Interlock

The breakers include

as

integral parts

the

mechanism

to

rack

the

breaker

in

or

out

of

the

cubicle compart·

ment, interlocking

to

prevent

racking a closed breaker into

or

out

of

the

connected position, and inter·

locking

to

prevent withdrawing a breaker from

the

cubicle while

the

closing springs are charged.

Racking Mechanism

Refer

to

page 17. With

the

breaker resting on

the

cubicle

rail

the

following sequence should be used

to

rack

the

breaker into

the

cubicle. .

CAUTION!! NEVER INSTALL OR REMOVE A BREAKER FROM THE COMPARTMENT WITHOUT

HAVING

RAIL

EXTENSIONS

IN

PLACE. SEE PAGE 17.

CAUTION!!

ON

ELECTRICALLY OPERATED BREAKERS,

BE

SURE MOTOR CONTROL SWITCH

ON

THE

FRONT

OF THE BREAKER

IS

OFF.

1. Push trip bar in, lower interlock slide

and

insert racking crank.

NOT~

Interlock slide

cannot

be open·

ed unless manual

trip

bar

is

pressed in. While

the

trip bar

is

pressed in,

the

breaker is in

the

TRlp·FREE

position and

cannot

be

closed.

·4·

2. With

the

racking crank,

rotate

the

racking screw (273) until

the

racking

shah

is

in

the

disconnected

position.

The

clevis can

now

engage

the

racking pins (E)

in

the

cubicle.

The

breaker should now be

pushed along

the

rail

into

the

DISCONNECTED position. Double

check

that

the

racking clevis does en-

gage

the

pins

in

the

cubicle.

3. Check

to

see

that

the

floor

interlock (Item 113)

is

clear

before

racking.

4. Counterclockwise

rotation

of

the

racking screw will rack

the

breaker

into

the

TEST

position.

At

the

TEST

position,

the

floor

mounted

interlock

is

clear and

the

cover slide interlock can be closed, allow-

ing

the

trip

bar

to

extend

and

the

breaker can be operated. Between

the

TEST

position and

the

CON-

NECTED position,

the

slide interlock will engage

the

stop pin

and

the

breaker will be tripped through

the

interlock mechanism,

and

the

cover slide

cannot

be closed.

In

the

CONNECTED position,

the

slide interlock will clear

the

stop

of

the

racking toggle and the

floor interlock

is

clear allowing

the

breaker

to

be closed. This prevents moving a closed breaker into

or

out

of

the

CONNECTED position.

5.

To

withdraw

the

breaker

from

the

CONNECTED position,

the

procedure

is

the

same

only

the

racking

screw

rotation

is

clockwise.

6. Before

attempting

to

operate

the

breaker,

the

position

of

the

device should be checked with reference

to

the

marking

in

the

cubicle,

to

be certain

that

it

is

fully

connected.

Two

stop

nuts

are provided on

the

racking screw

to

set

the

connected position. These are adjusted

by

setting

the

angle

of

the

racking

clevis, as shown

in

detail

"0"

of

Figure

1,

and by tightening

the

nuts

against

the

"L"

links (281) the

two

nuts

(278) should

be

then

locked against each other.

CAUTION!! TO AVOID DAMAGE TO THE RACKING MECHANISM,

DO

NOT ROTATE THE RACK-

ING

CRANK

IN

THE COUNTERCLOCKWISE DIRECTION

WHEN

IN

THE CONNECTED

POSITION.

Spring Discharge Interlock

When racking

the

breaker

out

to

the

DISCONNECTED position,

the

closing springs will automatically dis-

charge,

at

or

before reaching

the

disconnect position. The barrel

nut

engages

the

spring interlock. This

in

turn

connects

to

the

manual close

hood

which releases

the

closing springs.

CAUTION!!

ON

MANUALLY CHARGED BREAKERS, THE CLOSE HOOD

IS

INTER LOCKED TO

THE MANUAL CHARGE CAM, AND

MUST

BE

CLEAR BEFORE RACKING THE

BREAKER

TO

THE DISCONNECT POSITION.

NOTE:

Manual charge handle

must

be

in vertical position during racking

and

racking mechanism

must

be returned

to

the

test

position

before

closing springs can

be

charged while

breaker

is

removed from cubicle.

Note also

that

the

spring discharge interlock produces a TRIP-FREE

operation

in which all

of

the

stored

energy

of

the

springs

is

dissipated in

the

mechanism. It

is

preferable

to

turn

the

motor

control

switch

off

in

the

TEST

position, close

the

breaker normally in

that

position,

then

rack

out

in

the

normal manner.

..

MAINTENANCE

AND

ADJUSTMENTS

MAINTENANCE

Occasional checking and cleaning

of

the

breaker

will

promote long and trouble-free service. A

r:

~riodic

inspection

and

servicing, normally

at

intervals

of

one year, should be included

in

the

maintenar:e

routine.

Circuit breakers located

in

areas subject to acid fumes, cement dust,

or

other

abnormal conditi,ms, require

more frequent servicing.

After

a severe overload interruption, the breaker should be inspected.

If the Circuit breaker

is

not

operated during extended periods, it should

not

remain

in

either the closed

or

open position any longer

than

six months. Maintenance opening and closing operations should be made to

ensure freedom

of

movement

of

all

parts.

A suggested procedure to follow during maintenance inspections

is

given below.

1.

De·energize the primary

and

control circuits.

2.

Rack breakers to the disconnected position.

3. Install rail extensions.

4. Remove breaker from cubicle.

5. Remove arc chutes (Figure 1, Item 901) and examine for burned, cracked

or

broken parts. To remove

arc chutes, proceed

as

follows:

a.

Remove wing nuts from holding bar, remove bar and phase barriers.

b. Lift arc chutes vertically

to

clear arc runners.

6.

Wipe

the

contacts with a clean cloth saturated with a non-toxic cleaning fluid.

7.

Replace badly burned

or

pitted

contacts. (See Contact Replacement, Page 8, and Lubrication Instruc·

tions, Pages 6 and 21.)

8. Wipe all insulated parts with a clean cloth saturated with a non·toxic cleaning fluid.

9. Bearing pins and other sliding

or

rotating surfaces should be cleaned and then coated with a light film

of

grease. (See Lubrication chart page 21.:

10. Charge the breaker manually for maintenance closing

(see

Maintenance Closing belQw)

to

check

latch and linkage movement. (Rotate racking screw to the approximate

test

position to clear spring

dump interlock before

attempting

to change closing springs.)

11. Check breaker adjustments (see Adjustments,

Page

7).

LUBRICATION

Lubrication should be a

part

of

the

servicing procedure. Old grease should be removed from bearing pins

and

other

non-current carrying rotating

or

sliding surfaces, and they should be wiped with a thin film of

petroleum-oil-base precision·equipment grease, such

as

BEACON

P·290.

Greasing should be done with care so

as

to

avoid getting on insulating members, since it may affect the

dielectric strength. Faces

of

main and arcing contacts should

not

be lubricated. The rubbing surfaces

of

the

main

contact

fingers and hinge

contact

fingers are lubricated with coating

of

A-C

contact

lubricant,

15-171·370-002. If dust has accumulated, disassembly

is

necessary

to

clean and relubricate these points.

(See Contact Replacement, Page 8, and Lubrication Instructions,

Page

21).

MAINTENANCE CLOSING

During inspect:on prior to insta'lation and for routine maintenance inspections, the breaker contacts may

be closed slowly

to

check clearances,

contact

adjustments, and movement

of

links and latches. A manual

charging handle

is

used for maintenance closing the breaker.

Electrically-op~rated

breakers

do

not

have a marual charging handle,

but

it

is

available

as

a maintenance

item. Figure 5 shows the charging handle installed

in

an

electrically-operated breaker

after

removal

of

the front cover from the breaker. When

the

hole

in

t;e

charging handle assembly

is

aligned with

the

holes

in

the

operating mechanism frame,

the

pin which

is

attached

to

the

cam is inserted. This pin holds

the

assembly in place and acts as a pivot

point

for the cam. After installation

of

the

manual charging

-6-

l

..

handle assembly on the electrically-operated breaker, the actual maintenance closing operation

is

the

same for

both

the electrically-operated breaker and the manually-operated breaker_ Refer

to

Table 3

and Figure 5.

CAUTION!! THE PROCEDURE

IN

TABLE 3 SHOULD

BE

USED FOR MAINTENANCE CLOSING

ONLY. MAINTAIN A FIRM GRIP

ON

THE MANUAL CHARGING HANDLE DURING

THE CLOSING STROKE -THE BREAKER

MAY

SUDDENLY

LATCH

FULLY CLOSED

AND

APPLY UNEXPECTED FORCE

TO

THE CHARGING HANDLE.

TABLE 3 - MAINTENANCE CLOSING

Operation Procedure

Closing Contacts 1. Pull charging handle

DOWN

ALL THE

WAY

(approximate!y 120°),

2. Place blade

of

screwdriver between hood and spring release latch and hold it

in

this

position.

3. Slowly return handle to vertical position. Observe contact, touch, mechanical opera-

tion,

etc.

4. Remove screwdriver and pull charging handle

to

the fully charged position. Allow

spring release latch to hold closing springs. Move charging handle

to

the vertical

position.

5. Close breaker normally by pressing close hood.

Opening Contacts Push

in

manual trip rod.

NOTE:

Holding

the

spring release latch down prevents the stored-energy springs from propping

in

the charged posi-

tion. Thus, when the handle

is

slowly returned to the normal vertical position,

the

energy

in

the

springs

is

slowly released against

the

closing handle assembly cam face.

ADJUSTMENTS

During maintenance inspections,

the

following items should be checked

to

ensure

that

the

original settings

are maintained:

Trip Latch Engagement (Figure 2)

Toggle latch (175) should engage

the

full width

of

trip latch (153A) when

the

breaker

is

closed

in

the nor-

mal manner. The tension

on

spring (155) can be increased

if

required

by

bending spring tab on trip flap to-

wards the

front

of

the breaker.

Too

much tension

will

interfere with

the

capability of the tripping actuator

to

move

the

trip flap,

so

over-bending should be avoided.

Main

Contact

Make (Figure 6)

Compression

of

contact fingers

(5B)

should be between .093 inches and

.125

inches. This

is

the

difference

in

the

measurement from

the

breaker base to

the

tip

of

the finger

contact

surface when the breaker

is

open

and

the

measurement

in

the

same place when the breaker

is

closed. This

is

checked with a normal closing

operation -

not

maintenance closing. Adjustment

is

provided by positioning screws (85) after loosening

nuts (86). Counterclockwise rotation

of

screws (85) increases compression_ Care should be taken

to

retight-

en nuts (86) after adjustment. If

it

is

desired

to

check contact pressure, a push-type spring scale can be used

to

compress'contact fingers (58), with breaker open. Contact pressure should be between

20

to

30

pounds

on each finger.

Arcing

Contact

Make (Figure 6)

With movable arcing

contact

(73) in

anyone

phase touching the mating"stationary

contact

when the break-

er

is

closed

by

the

maintenance closing method (See Table

3,

Fig. 5).

the

phase-to-phase variation should

not

exceed

_062

inches. Adjus:ment may be made by positioning screws (85)

as

in

the

previous paragraph,

..

but

it

is

essential

that

the main

contact

compression be maintained within

the

tolerance listed

in

the

pre-

vious paragraph. Arcing

contact

pressure should be between

20

and

30

pounds when checked with a pull-

type spring scale

at

the

base

of

the arcing contact tip insert with the breaker contacts closed. Measure each

blade separately.

Contact Replacement

(F

igu

re 6)

The

contact

structure consists

of

main current carrying contacts and arcing contacts arranged so

that

initial

contact make and final

contact

breaker

is

by means of the arcing contacts. The actual

contact

surfaces are

clad with an alloy facing which greatly reduces mechanical

w~ar

.and arc erosion.

When

inspection

of

the

alloy facing indicates that the contacts should be replaced, it should be noted

that

hinge

contact

fingers (66, 67) main

contact

fingers (70) and arcing contacts (73) are spring loaded. There-

fore, care

must

be exercised

in

removal and installation of any

of

the contacts.

Main

Contact

Fingers (Figure 6)

With

the

breaker contacts open and the stored-energy springs discharged, main

contact

fingers (58) may be

removed by loosening screws (75) enough to relieve the compression on springs (54, 57). There are two

springs behind each finger and it

is

important that they be positioned properly upon reinstallation.

If

diffi-

culty

is

experienced

in

correctly positioning these springs, the upper and lower primary disconnects (902,

Figure

1)

may be removed from each phase and the breaker inverted

to

rest on the ends

of

connectors (52)

and (62).

Stationary Arcing Contact (Figure 6)

The stationary arcing

contact

is

part

of

connector (52) and may be replaced by proceeding

as

above.

In

this

case, screws (60) must be removed.

Hinge

Contact

Fingers (Figure 6)

Hinge

contact

fingers can be replaced by removing lower connector and removing fingers individually.

Moving Arcing

and

Main

Contact

(Figure 6)

Either moving arcing

contact

(73)

or

main contact (70) or both may be removed and replaced

as

follows:

Remove

two

screws on each side

of

lower connector. The complete movable

contact

assembly may now be

brought

to

a bench_ The location

of

spacers should be noted,

in

disassembly.

CAUTION!! EXTREME CARE SHOULD

BE

TAKEN

TO

HOLD

THE ASSEMBLY FIRMLY TO

RE-

TAIN SPRING GUIDE (80)

AND

SPRING

(82,83)

UPON REMOVAL OF THE SCREWS.

The moving arcing

contact

or

the

main contact may now be easily repli'lced. The reverse procedure

is

fol-

lowed for re-installation. Care should be taken

to

replace spacers correctly. Check alignment and adjust-

ment

of

contacts

upon

reassembly.

T ripping

Actuator

When

the

static trip device senses a circuit condition

that

requires

the

circuit breaker

to

open,

it

produces

an

output

that

is fed

to

the

tripping actuator. This device then causes

the

circuit breaker contacts

to

open

and isolate

the

circuit.

Mounted

on

the

circuit breaker,

the

tripping actuator

is

held

in

a charged position

by

a permanent magnet.

It contains a coil

that

is

energized

by

the

output

of

the

static trip device. When energized,

the

coil causes

the

magnetic flux

to

shift

to

a new

path,

releasing the stored energy

of

a spring located inside the tripping

actuator. The spring provides

the

energy

to

trip the breaker moving

the

trip flap clear

of

the

toggle latch.

If

the

spring loaded armature does

not

reset during trip operation as explained above, spacer washers may

be added

to

obtain positive reset

of

the

armature. ..

If

adding spacers does

not

allow

the

armature

to

be reset,

the

tripping actuator should be replaced (if break-

er mechanism

is

not

at

fault)_

_R -

NOTE:

Do

not

attempt

to

disassemble

the

tripping

actuator

as

this may

destroy

the

magnetic field set-up by

the

permanent

magnet

and

will render

the

actuator

latch inoperative until remagnetized.

When replacing a tripping actuator,

the

coil leads must be connected

to

the

terminal block

of

the

static

trip in

the

correct

polarity relationship.

The black lead

of

coil

must

be

connected

to

terminal 7 (negative)

and

the

red lead

of

coil connected

to

terminal 8 (positive)

of

the

static trip device.

When

the

tripping

actuator

has been replaced,

the

circuit breaker should be given a FUNCTION TEST

to

ensure

proper

operation

of

all

components.

Refer to Allis-Chalmers Instruction Book 18X4827-02 for

the

procedures

of

the

FUNCTION TEST.

Motor

Cutoff

Switches

The

function

and

adjustment

of

the

motor

cutoff

switches

on

electrically-operated breakers

is

described on

Page

10_

..

Position 1.

Position 2.

BOTTOM

VIEW

Springs discharged; motor

in

stop position. Note

that

spring position lever (1)

is

forward actua·

t;:,g both switches. Motor/gear position (2)

Iner

is

retracted. Motor

cutoff

switch

(3)

is

c osed. Application

of

power

at

this time

will

cause

the

motor

to

start

thereby charging the

closing springs.

Springs charging;

motor

not

yet cutoff.

Wh

ile

the springs are charging the motor/gear position

e e

lever (2) moves forward applying pressure to

the

switch actuating leaf. The spring position

lever

(1)

retracts

as

the springs reach full

charge.

The.motor

cutoff

switch

(3)

is

closed

and the

motor

is

running.

Position 3. Springs charged;

motor

stopped. The springs have reached charged position. The motor/gear

lever (2) has been retracted by roll pins on the

large gear

as

the

cam follower (233, Figure 2)

on

the large

spur

gear has disengaged from the

wind and close cam (223). The

motor

cutoff

switch (3) has opened, stopping

the

motor, and

the

closing coil switch (4) has closed. Upon

application

of

power

to

the

closing circuit the

breaker will close. Switches then return

to

No.1

position.

NOTE 1

In

position 3 there

is

clearance between both levers and the switch actuating leaf. Clearance may

be minimal (appx. 1/64)

or

up

to

1/16

inch. It

is

important

to

completely remove pressure from

the

switch actuating leaf

to

be sure

that

the

switches are free

to

actuate. Adjustment

is

made by

carefully bending

the

levers as indicated by arrows (Items 1 and 2). Do

not

bend

the

switch actu-

ating

leaf_

NOTE 2 CAUTION!! If

the

motor

cutoff

switch (3) does not open,

the

motor

will continue

to

run and the

cam follower (233) will re-engage wind and close cam (223, Figure 2) jamming

the

entire mech-

anism, possibly stripping gears

in

the

gear motor, blowing the control fuse,

or

damaging

the

motor.

To

free a jammed mechanism

it

is

necessary

to

remove

the

gear

m~or.

CAUTION!! The springs

will

discharge and

the

breaker close when

the

gear

motor

pinion is dis-

engaged from

the

spur

gear.

-

10-

(

'-...

ACCESSORIES

Tripping Transformers -Static Trip

II

There are several tripping transformer ratings available, each with seven calibrated pickup settings (Page 12).

The tripping transformers are mounted on the lower connector and mounted with the polarity mark facing

the breaker panel.

Current

Sensors -LimiTrip

The

current

sensors provided with the optional LimiTrip device are integrated units containing two cores

with four terminals. Proper polarity

is

established when the terminals face away from the panel. LimiTrip

sensors should never be subjected to primary current with the LimiTrip device disconnected from the

sensor.

OPTIONAL DEVICES

Secondary Disconnect Assembly Option

The electrical

attachments

are wired

to

the

terminals

of

a secondary disconnect assembly (See Figure 7).

which

is

mounted

on

the

left side

of

the

breaker. Three blocks

of

ten terminals each can be mounted on

the breaker.

The

secondary disconnect assembly

is

accessible from

the

front of the breaker and aligns with

a stationary

unit

in

the

cubicle. The stationary contact strips should be lubricated with a light film

of

con·

tact grease which

is

furnished with

the

switchgear.

Atfxiliary Switch

Option

The auxiliary switch (See Figure

8)

is

of

the rotary type and functions by direct connect

to

the

breaker

mechanism.

The

contacts are factory set for

"a"

(open when the breaker

is

open) and

"b"

(closed when

the breaker

is

open) position,

but

each rotor (955) may be adjusted individually

in

steps

of

30

degrees. This

adjustment

is

made by removing cover (962) and lifting the entire

rotor

assembly

out

of case (950) after

disconnecting arm (957) from

the

linkage. Cotter pin and bearing (956) are removed to permit

reo

moval

of

rotors (955) from shaft (954). To change rotors (955) from

"a"

to

"b"

position,

the

rotor should

be

rotated 60°

in

the

clockwise direction after removal and replaced on the shaft

in

this new position.

Shunt

Trip

Option

Each electrically·operated breaker

is

equipped with a

shunt

trip attachment for tripping from a remote

location. (See Figure 9). Since the

shunt

trip coil

is

designed for a momentary

duty

cycle, an

"a"

auxiliary

contact switch

is

used

to

interrupt

its circuit immediately after

the

breaker

is

tripped. Energization

of

the

coil causes

the

armature

to

pick up and rotate the trip latch

to

trip

the

breaker. A compression spring (808)

returns

the

armature

to

its normal position.

Undervoltage Trip Device Option

The undervoltage

trip

device (Figure 10) automatically trips the breaker on loss of voltage. Either instan·

taneous

or

time·delay operation can be supplied. A .06 inches

gap

should be maintained between flap ex·

tension and pull link (738) when

the

device

is

energized with the breaker closed. Pick·up and drop-out

is

set so

that

the

device picks up

at

a voltage of 85%

or

less

of rated value and drops

out

between 30% and

60%

of

the

rated value.

NOTE:

Pick-up and

drop-out

are

not

individually adjustable.

Bell

Alarm Switch

Option

The bell alarm switch

option

(See Figure 11) functions

to

operate a switch. A single pole double

throw

or

a double pole

double

throw

switch

is

available. The switch operator

is

connected

to

and

is

operated by the

tripping

actuator.

The

switch operator remains tripped even when

the

actuatorJs reset

by

the

breaker. The

switch

operator

must

be reset either manually,

or

by an additional optional electrical reset solenoid.

The

contacts

of

the

bell alarm switch can be connected

in

series with

the

hreaker closing coil,

to

provide a

lockout feature

to

prevent reclosing after a fault.

TABLE 4 - TRIP RATING TABLE -AMPERES

STATIC TRIP

II

Breaker Tripping Long Time Element Ground Element

Type and XFMR Calibrated Pick-Up Settings

Max_

Calibrated Pick-Up

Frame Rating E Cont_ Settings

Size (Primary) A C D E F G Rating 15%

25%

50% 100%

LA-3000A 2000 Amps 1000 1250 1500 1750 2000 2250 2500 2500

300

500

1000 2000

LA-30OOA

3200

Amps 1600 2000 2400 2800

3200 3600

4000

3000

480

800

1600 3200

LA-4000A

4000

Amps

2000

2500 3000

3500

4000 4500

5000

4000

600

1000 2000 4000

TABLE 5 - TRIP RATINGS -AMPERES.

LlMITRIP

Breaker Tripping Long Time Element

Type and XFMR Calibrated Pick-Up Settings Max.

Frame Rating Cant.

Size (Primary) A B C D E F Rating

LA-3000A

2000

Amps 1000 1250 1500 I 1750 2000 2250 2500

LA-3000A

3200

Amps 1600 2000 2400

2800

3200

3600

3000

LA-4000A

4000

Amps 2000 2500

3000

3500

4000

4500

4000

Static Trip

Option

The optional tripping devices are covered

in

detail under their own instruction books which are referenced

on the last page. Several

types

are available

that

provide a range

of

tripping functions.

The Static Trip

II

device

mounts

onto

a slide type bracket

on

the

circuit breaker.

To

remove trip device,

the terminal block cover located above the trip device should be removed, exposing

the

terminal block

screws. The lower row

of

screws can be loosened with a screwdriver, allowing

the

terminal block fanning

strip from

the

static

trip

to

be

removed from

the

terminal block. Removal

of

the fanning strip exposes a

mounting screw. This screw can be removed allowing the static trip device

to

be removed from the breaker

by pulling the

trip

device towards

the

front

of

the

breaker.

_

1")

_

273

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I 902

DETAIL

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LH

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VIEW

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VIEW

C

Fig. 1 - LA·3000A Circliit Brenl<er

240

241

~

FRONT

VIEW

A

SECTION "AA"

k

241

240

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DETAIL

"A"

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DETAIL

"US"

DETAIL

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11

171

1538

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149

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,

204

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DETAIL G -

157

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223

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FF

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224

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AUX. SWITCH

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<>sv

7

o-:-v

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SEC. DISC.

SYMBOLS

CC

-

CIRCUIT

BREAKER CLOSING

COIL

TC -

CIRCUIT

BREAKER

TRIP

COIL

Y -

AUX.

CLOSING

RELAY·

ANTI

PUMP

MCO -MOTOR CUTOFF SWITCH

88 -SPRING CHARGING MOTOR

CSC

-CONTROL SWITCH· CLOSE

CONTACT

CST -CONTROL SWITCH· TRIP

CONTACT

R - RED INDICATING LAMP

G -GREEN INDICATING LAMP

• -

AUX,

SWITCH·

OPEN

WHEN

8R'KR.

IS OPEN

b -

AUX.

SWITCH -CLOSED WHEN

BR'KR.

IS OPEN

MI -

MECHANICAL

INTERLOCK

CT

-CURRENT TRANSFORMER .

STD -STATIC TRIP DEVICE

AL

-

ALARM

DEVICE

RC -

ALARM

DEVICE ELECT. RESET

COIL

TA

-

TRIP

ACTUATOR

~

UV

-UNDERVOLTAGETRIPCOIL

CLASS C WIRING

NO. 14 WIRE, (SISI

00·557·286·341

Mca

BL

1

tJ

~

1~

~1P

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<S2

2

Fig, 3 - Typical Wiring Diagram -Electrically Operated Breakers

Lift Bar

and

Rail Extensions

The

lifting

bar

connects as

shown.

Always lift with extreme caution

to

prevent damage

to

breaker.

In

parti·

cular, watch

that

the

secondary

disconnects clear the

rail

extension. References: Lifting bar assembly:

18

727·837

·501. Extension rail: 18·193·732-502. See

Page

4.

-~~

"

1----1"

..

,)

,;

LIFTING

BAR

--

__

I

LIFT

HERE

MECHANICAL

INTERLOCK

SIDE

VIEWS

FRONT

VIEW

A

266

SECTION

BB

DETAIL

"A"

Fig. 4 - Typical Racking Mechanism

and

Drawout

Illterloc'<

.

16

.

HANDLING

INSTRUCTIONS

I

INSERTING

CIRCUIT

BREAKER

1. Mount extension rails (A) as shown. Tighten catches

(8) to secure rails.

2. Lower circuit

breaker

onto

rails, checking wheel align-

ment

to

rails.

3. Roll breaker

to

disconnect

position

and

remove exten-

sion rails. Safety

lock

(e)

prevents accidental removal

of

breaker from cell.

4.

Use

crank

to

rack

breaker

into

cell.

5. Check panel

shutters

(0)

for

free movement before

closing panel.

REMOVING

CIRCUIT

BREAKER

1.

Mount

extension

rails

to

unit

as

described under,

"in-

serting Circuit Breaker,"

2. With

circuit

breaker

in

disconnect position, release

breaker i

nterlock

and pull breaker

out.

3. Pull on safety lock handle

to

fully release breaker from

cell.

4.

Roll breaker

out

onto

extension rails and

lift

free

of

unit.

Siemens-Allis LA3000A User manual

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