1S25 Arc Fault Monitor. 1S25 Arc Fault Monitor 1S25 Arc Fault Monitor Electrical arc short circuits...

1S25Arc Fault Monitor


Electrical arc short circuits in metal clad switchgear may occur for many different reasons.

defective or ageing insulating materials

poor bus or cable connections

poor maintenance

human error

ingress of moisture, dust or vermin

abnormal service conditions

Arc FaultEffects and Consequences

ENERGY RELEASED BY ARC FAULTENERGY RELEASED BY ARC FAULT

PRESSURE

RISE

TEMPERATURE

RISE

VISUAL & ACCOUSTIC PHENOMENA

EFFECTS OF FAULT ARC

CONSEQUENCES FOR PLANT

MECHANICAL STRESSING OF ENCLOSURES

THERMAL STRESSING, MELTING, FIRE

VAPOURISATION

CONSEQUENCES FOR PERSONNEL

SHOCK WAVE, FLYING DEBRIS,

OPENING PANELS

U/V BURNS & EJECTION OF

FLAMES & HOT GASES & SMOKE

Switchgear FailureEffects and Consequences

Switchgear Internal FaultExample

FAULT TIME

PROTECTION

TRANSFORMER

2 secs

OC-relay

110/22 kV

30 MVA

Switchgear Internal FaultExample

FAULT TIME

PROTECTION

TRANSFORMER

0.07 secs

Arc protection

110/22 kV

30 MVA

Variable Speed DriveFault Example

PROTECTION

TRANSFORMER

Earth leakage

22 kV / 690V

Water CorporationWestern Australia

At approximately 0800 hrs on 25/2/07 No.2 VSD failed at Tamworth Pumping Station WA. The PSN electrician was called out to the fault later that same morning and found the main switch

compartment of the drive badly damaged.

The extent of damage is quite severe and was contained to the main switch compartment of the

variable speed drive.

The majority of damage appears to have been originated from the VSD main switch, then

spreading upon explosion to the upper and rear of the drive and also externally through the

ventilation ducts.


The earth leakage protection on the #2 VSD 22kV / 690V feeder tripped.

The O/C protection also detected a phase fault condition.

#2 22kV / 690V Transformer circuit breaker was found to be in the OFF position.

Judging by the extent of the damage the protection clearly did not respond quickly

enough.


OPERATOR HAZARD IN ADJACENT CORRIDOR


1S20 ARC FAULT PROTECTION INSTALLED AFTER EARLIER FAULT


SUBSEQUENT FAULT

As a result of this incident, RMS 1S20 Arc Fault Monitors and 1S30 Arc Flash Sensors

were installed.

Subsequently several months later another incident occurred, this time due to the failure

of the IGBT board.

As a consequence, the arc sensors were triggered by tripping the 22kV circuit breaker

and as can be seen by the photos the damage was insignificant.

1S30 ARC SENSOR

ARC FAULT


SUBSEQUENT FAULT

ARC FAULT


For moderate arc fault currents the trip

time of the over-current stage will be too slow:

For very low arc fault currents the

instantaneous trip stage of a standard

over-current relay cannot be set low

enough.


The degree of damage caused by arcing

depends principally on the duration of the arc.

~100ms Arc Fault Duration

The switchgear needs to be checked & the

insulation resistance measured before power

can be re-established.


The power supply will be interrupted; the

switchgear must be checked; power is re-

established only after minor repairs.


The degree of damage caused by arcing

depends principally on the duration of the arc.


The supply is interrupted, metal parts of the

switchgear are destroyed & poisonous gases

are emitted.

~1s Arc Fault Duration

Destroys most of the switchgear & may cause a

fire, injury to personnel & damage to property.


Arguably the greatest risk of arc fault damage

exists at the CB cable termination & in the CB

chamber itself due to the slow clearance times

of the IDMT feeder protection.

The problem of arc faults is most prevalent in

older metal clad switchgear, which already has

operational protection systems.

The CB cable termination is particularly at risk to

ingress of moisture & rodent damage.

Low Voltage Protection

Trip on arc fault <10ms

1S 25

HEALTH Y

Z ONE 2

Z ONE 3

Z ONE 4

Z ONE 1

Cus tom te xt

Cus tom te xt

Cus tom te xt

Cus tom te xt

FAIL

FAIL

FAIL

FAIL

T RIP

T RIP

T RIP

T RIP

RESET/T EST

CO MMO N TRIP

ALARMO UTPUTS

System Integration

With current check using high speed starter element

A R C FA U LT TR IP IN IT IATE

CB ARC FAULT

M O NITORSENSOR

OVER-CURRENT RELAY3 P o le O C + E F

H E A LT H Y

Z O N E 2

Z O N E 3

Z O N E 4

Z O N E 1

C u s to m te x t

C u s to m te x t

C u s to m te x t

C u s to m te x t

F A IL

F A IL

F A IL

F A IL

T R IP

T R IP

T R IP

T R IP

R E S E T/T E S T

Single Line DiagramCable box only

Trip only if over current starter picked up

ZONE 1ARC PROTECTION

COMMONALARM

OUTPUT

1S2550/51

Single Line Diagram

Cable box and CT chamber


CO MMO NALARM

O UTPUT

1S 2550/51

HEALTH Y

Z ONE 2

Z ONE 3

Z ONE 4

Z ONE 1

Cus tom te xt

Cus tom te xt

Cus tom te xt

Cus tom te xt

FAIL

FAIL

FAIL

FAIL

T RIP

T RIP

T RIP

T RIP

RESET/T EST

Single Line Diagram

Protect multiple breakers with a single 1S25

ZONE 1ARC PROTEC TIO N

COMMO NALARM

O UTPUT

1S 2550/51

HEALTH Y

Z ONE 2

Z ONE 3

Z ONE 4

Z ONE 1

Cus tom te xt

Cus tom te xt

Cus tom te xt

Cus tom te xt

FAIL

FAIL

FAIL

FAIL

T RIP

T RIP

T RIP

T RIP

RESET/T EST

TRIP

Single Line Diagram

Cable box, CT and CB chamber


CO MMO NALARM

O UTPUT

1S 2550/51

HEALTH Y

Z ONE 2

Z ONE 3

Z ONE 4

Z ONE 1

Cus tom te xt

Cus tom te xt

Cus tom te xt

Cus tom te xt

FAIL

FAIL

FAIL

FAIL

T RIP

T RIP

T RIP

T RIP

RESET/T EST

ZONE 2 TR IPUP STREAM

BREAKERZONE 2

ARC PROTECTION

ZONE 1 TR IP

Single Line Diagram

Cable box, CB and BUS chamber

ZONE 1



ZONE 2, 3 & 4 TRIPUP STREAM BR EAKER


CO MMO N ALARM O UTPUT

1S 25

HEALTH Y

Z ONE 2

Z ONE 3

Z ONE 4

Z ONE 1

Cus tom te xt

Cus tom te xt

Cus tom te xt

Cus tom te xt

FAIL

FAIL

FAIL

FAIL

T RIP

T RIP

T RIP

T RIP

RESET/T EST

50/51

Single Line Diagram

BUS chamber

ZONE 1 & 3TRIP CO MMO N

ALARMO UTPUT

50/51 1S 25

HEALTH Y

ZONE 2

ZONE 3

ZONE 4

ZONE 1

Cus tom te xt

Cus tom te xt

Cus tom te xt

Cus tom te xt

FAIL

FAIL

FAIL

FAIL

TRIP

TRIP

TRIP

TRIP

RESET/TEST

ZONE 2 & 3TRIP

50/51ZONE 1

TRIP

ZONE 3TRIP

ZONE 2TRIP

ZONE 3TRIP

ZONE 1 ZONE 3 ZONE 2

ZONE 1TRIP

ZONE 2TRIP

1S30 Optical Sensors

1S30Arc Sensor

Mounted in each segregated switchgear chamber

Sensitivity linear in forward direction through 180º

Detects reflected arc light - mounting position not critical

Burden 2.5mA (quiescent)

Optional rear facing sensor

1S30Arc Sensor Installation

Mounting position of the Sensor is not critical.

High sensitivity in direction of ‘View’

1S25 System Testing

Use camera flash to check operation of arc sensor and pick up of 1S25 trip contact.

Typical operating range of flash to arc sensor is 50 to 300mm

1S25 System Testing

CRO trace showing nominal operation time of the trip contacts. First contact touch at 6.25ms and fully closed by 7.25ms.


1S30 shown mounted on the outside of a switchgear panelDetector oriented to ‘look’ through a hole into the switchgear

S w itchgearpanel

2 x M 4self th read ing

m oun ting sc rew s(S upp lied )

S ea led cab les tress re lie f

O p tica l detec torp ro trud ing th rough

ho le in pane l


1S30 shown mounted on the inside of a switchgear panelDetector oriented to ‘look’ out into the switchgear compartment

2 x M 4self th reading

m ounting screw s(S upp lied )

O p tica l de tec to rfac ing aw ayfrom panel


The dual optical detector version can be panel mountedto monitor two adjacent switchgear compartments simultaneously.

In terna l pa rtitionbe tw een sw itchgea r

com partm en ts

O p tica l de tec to rp ro trud ing th rough

com partm en t d iv ide rin to ad jacent

sw itchgea r cham ber

O p tica l de tec to rw indow fac ing aw ayfrom com partm en t

d iv ide r


Right angle mounting off a surfaceMount off floor or walls within switchgear / BUS bar chamber

R igh t ang lem ountingb racke t

O p tica l de tec to rw indow fac ing aw ay

from right anglem ounting b racke t

S ing leop tica l de tec to r

D ua lop tica l de tec to r


Flush mount reinforcing plate1.2mm zinc plated mild steel

2 x M 4self th read ing

m ounting screw s(S upp lied )

F lush m oun tre inforc ing

p la te


SENSOR LOCATIONS

Cable Box Arc Fault

13.1kA (50mS)

Fault created in Cable Box by connecting three bushing connectors with fuse wire.

Sensor fitted to side of box.

Cover after testCover as new

Cable Box Arc Fault

Lower portion of Coverstrengthened

Cable Box Arc Fault

Sensor location

CB Chamber Arc Fault

CB chamber fault at 13.1kA (50mS)

Fault initiated by connecting 3 phases of circuit side of CB with fuse wire

- typical of test leads used during maintenance.

One ARC sensor fitted.

CB Chamber Arc Fault

General views after test

1S25Does it Work

WILL IT OPERATE UNDER DYNAMIC CONDITIONS? --- YES

HOW FAST DOES IT REMOVE AN INTERNAL FAULT? --- 50-75ms

IS IT EFFECTIVE IN ALL SWITCHGEAR CHAMBERS? --- YES

HOW MUCH DAMAGE IS CAUSED TO THE SWITCHGEAR? --- Minimal

DOES IT IMPROVE SAFETY? --- YES, Significantly

1S30Arc Sensor

measured current( increase 1*In ==> 10*In)

arc detection

overcurrent detection

trip output contact

Up to 8 arc sensors in 4 independent zones

5 high speed tripping duty arc sense output contacts

<10ms arc fault tripping time

Self supervision with fail alarm contact

Push button reset & self test

1S30 Arc sensor continuous supervision

Compact, economic design

Simple panel mounting for retrofit applications

1S25 Summary

Front Panel Indication

HE ALT HY

ZO NE 2

ZO NE 3

ZO NE 4

ZO NE 1

Custom text 1

Custom text 2

Custom text 3

Custom text 4

S ENS OR FA IL

S ENS OR FA IL

S ENS OR FA IL

S ENS OR FA IL

TRIP

TRIP

TRIP

TRIP

RE SE T/TE S T

Mounting

Front v iew15

2 ho les o f 3 .7

Ind icativepos ition

S ide v iew

S ize 2M 28-Sdraw out case

D raw ing un its : m m

Term ina l layout P ane l cut out

S uits flush pane l m ounting &4U h igh 19 inch rack fram e

14

1 2

27 28

1S25Configuration Settings

Switch ON OFF

C1 Latching trip contacts Self reset trip contacts

C2 Segregated trip outputs Common trip outputs

C3 Apply volts to BLOCK Remove volts to BLOCK

C4 DC only status inputs AC/DC status inputs

O NO NO NO N

O FFO FFO FFO FF

S w itch 1S w itch 2S w itch 3S w itch 4

B A N K

A

Bank A & B configuration switches are used to set the number of 1S30 arc sensors connected.

1S25Wiring Termination

1

3V x P ow er sup p ly ,C PU & se nso r

fa il a larm

R em o te re set

A rc fau lt BL O C K in pu t

Configuration sw itches(Primary PCB)

Z one 1A rc s ens or inp ut

1S 30A rc F au lt Se nso rs




2

Z one 1 T rip

Z one 2 T rip

Z one 3 T rip

Z one 4 T rip

C om m o n Trip

Switch 1Switch 2Switch 3Switch 4

B AN K

AB AN K

BB AN K

C

27

25

23F ail

H ea lthy

A la rm c om m o n

S igna l p rocess ingand log icfunc tions

O N O N O N

A rc s ens or fa u lt s igna l

1S25 Ordering Code

ORDER CODE The order code determines the production build in the factory & cannot be changed in the field.

Generate the required order code as follows: e.g. 1S25 BA

Order

Code General Type 1 2

1S25 -

1 AUXILIARY SUPPLY RANGE

A 20 - 70V DC B 40 - 300V DC & 40 – 275V AC

2 CUSTOM ENGRAVED TEXT

A Not required No engraving - factory default B Required Complete the custom text details at left

1S30 Ordering Code

Generate the required ordering code as follows: e.g. 1S30 A

1 DETECTORS

A Single through hole panel detector B Dual detectors

2 SPECIFY OPTIONS (Only if required)

F Flush mount reinforcing plate required L 20m shielded cable required

1 2

1S30

1S25Additional Information

Technical Bulletin User Guide Price & Availability

www.rmspl.com.au/1s25.htm

Test Manuals

www.rmspl.com.au/search.asp

Other Products

www.rmspl.com.au/products.htm

1S25 Arc Fault Monitor. 1S25 Arc Fault Monitor 1S25 Arc Fault Monitor Electrical arc short circuits...

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