891 switchboard vs. 1558 switchgear

891 Switchboard vs. 1558 Switchgear

“The Rest of the Story II-While you where sleeping”

2

What happened since our last discussion?????

• Selective coordination went on steroids

• Arc Flash, Arc Resistant, and Arc Fault overtook the NEC

• New UL ratings for everything and nothing at the same time

• Mr. LEEDs is our new boss

3

TVSS SPD – Another UL? – 3 rd

addition

� The major differences are:

� Change in terminology from Transient Voltage Surge Suppressors to Surge Protective Devices

� UL 1449 3rd Edition is now an American National Standard (ANSI)

� Addition of Nominal Discharge Current to ratings and markings

� Duty cycle test at nominal discharge current

� Measured limiting voltage now performed at 6 kV/3 kA

4

TVSS 250 kA vs. 2 Billion kA

Based on available research, IEEE recommends using the 20 kV, 10 kA combination wave as the representative test for induced lightning surges at service entrance locations. Above this amount, the voltage will exceed BIL ratings causing arcing in the conductors or distribution system.

In summary, low voltage wiring (<600V) is not capable of conducting the lightning stroke currents.

5

UL Retrofits

6

Bolted Fault Arcing Fault

Systems must be designed However, the majority of faultsfor worst case conditions. will be arcing type.

Line-to-Line-to-Line Fault

7

What Can We Say About Arcing Ground Fault Current Values?

8

Fault Reduction

9

“Arc Mitigation” – What about the Standards?

1. UL recognizes switchgear tested in accordance with IEEE C37.20.7 as Arc Resistant Switchgear.

2. No ANSI or UL standards cover the testing or manufacturing of arc sensing relays or mitigation components.

10

ANSI C37.20.7

Type 1 - Arc resistant at front only

Type 2 - Arc resistant around the perimeter of the switchgear line-up

Appendix AType 1B or 2B - Arc resistant to type 1 or 2 with control door open.

Type 1C or 2C - Arc resistant to type 1or 2 plus between all adjacent compartments (Meets all requirements of type and suffix B in addition to the requirements of suffix C).

Type 1D - specifies Type 1 and applicable accessible sides

ARC Resistant Switchgear

11

Arc Resistant type 2CYou must have arc resistance from compartment 7 to the following compartments within this vertical section:

4,6,8

Additionally you must have arc resistance from this compartment 7 to the compartment 7 in the vertical section to the right and left of vertical structure shown.

In order to validate this you must initiate an arcing current in compartment 7, and have burn indicators placed in each of these adjacent compartments. You must pass all arc resistant test criterion

4

1

2

35

6

8

7

=Arcing fault in compartment 7

12

Remote Operation Solutions

13

Remote Operator(In Operation)

(1)

(2)

(3)

(4)

14

Mr. LEEDs; Good, Better, Best

15

Electronic vs. Thermal magnetic

Top 3 reasons

16

SD=0.5S

SD=0.3S

SD=0.3S

SD=0.3S

M1

F1 F2 F3X35kA fault current

Without ZSI = 0.5 S:

43.7 Cal/cm2

Greater than Cat. 4 PPE

DANGER!

With ZSI = 0.08 S:7.0 Cal/cm2

FR Shirt & PantsCat. 2 PPE

Safety (Wired for)Solution #1 – ZSI

Short time

GF

17

• ARMs features in white area of trip unit to separat e them from normal trip unit settings.

• Blue LED “Maintenance Mode”

• 2 Position Selector Switch: • ON = Local ON• O/I = OFF or External Control

• 5 Position Arc Flash Reduction Setting:• From R5 (Max) …. To R1 (Min) Reduction

• Remote Indication:• Power Relay Module Maintenance Mode Contact • Communications

• Remote Enable:

• Switchgear Mounted Logic Level Selector Switch• Switchgear Mounted Logic Level Ice Cube Relay

with Remote Mounted Control Switch• Via Communications: Using Infa-Red Mint &

PDA, PowerNet, Modbus mMINT, & BIM

• Lock-out/Tag-out

5 levels of protection allow the operator to pre-select the maximum arc flash reduction level

possible to avoid nuisance tripping during maintenance operations

SafetySolution #2 - ARMS

Switchgear and Switchboard

UL891=UL1558NEMA vs. ANSI

And 3 (of many) reasons why

20

UL1558 Switchgear vs. UL891 SwitchboardIsolation is beautiful!

21

UL1558 Switchgear vs. UL891 SwitchboardIsolation is beautiful!

22

Comparison of StandardsEndurance UL 1066 and UL 489 (continued)

* Maintenance of contacts is allowed under UL 1066 M-13

Required Nos. of Operations *Electrical Mechanical

- - - -

- - - -

2,800 9,700

2,800 9,700

- - - -

800 3,200

- - - -

250 400Pick-up and TimeElements Tested:

• Long Time Delay• Instantaneous• Short Time Delay

1320 VMust be able to carry Current

Provides for inspection, cleaning, adjusting, lubricating

and tightening

O at 635V, 3-phase

FRAME SIZE

100 A150 A and 225 A

600 A

800 A

801 A - 2500 A

1600 A or 2000 A

2501 A - 6000 A

3000 A, 4000 A or 5000 A

Short Circuit Current Test

Post-Test Trip Device Calibration

Post-Test AC Dielectric Withstand V

Post-Test Condition of Circuit Bkr.

Maintenance

1240 - 2200 V

May not be able to CLOSE again

Internal servicing not permitted

O (2 - 60 min) - CO

One Pick-up and Time200% Trip out at 25ºC

Required Nos. of Operations *Electrical Mechanical

6,000 4,000

4,000 4,000

1,000 5,000

500 3,000

500 2,000

- - - -

400 1,100

400 1,100

UL 1066Sequence III

UL 489Sequence Y

Test Requirements

Switchgear and SwitchboardNumber 1 difference

Short time rating

NEMA vs. ANSI

24

Molded Case Circuit Breakers• Tested in accordance with UL489• Open Air Test - Rated @ 80%• Over Toggle Mechanism• Sealed Case - Not Maintainable

• Applied in Switchboards/Panelboards

Insulated Case Circuit Breakers• Tested in accordance with UL489• Open Air Test - Rated @ 80% or 100%• 2-Step Stored Energy Mechanism• Sealed Case - Not Fully Maintainable• Applied As Mains in Switchboards/MCC’s

Power Circuit Breakers• Tested in accordance with ANSI C37• Tested in the Enclosure - Rated @ 100%• 2-Step Stored Energy Mechanism• Open Access - Fully Maintainable

• Applied in Metal-Enclosed Drawout Swgr.

UL489 versus ANSI C37

Selective Coordination

27

True or False

� 100% Selectively Coordinating a system makes it more RELIABLE.

TRUE FALSE

28

True or False

� 100% Selectively Coordinating a system makes it SAFER.

TRUE FALSE

29

What devices are required to Selectively Coordinate?

U TIL ITY A

M A I N A

M SG -A

M S G -TI E

U TI LITY B

M A IN B

M S G -B

A TS -EQ N O RM A T S-C R N O RM A T S- L S N O R MC H IL LE R F D R

G EN # 1 M A I N

G E N S W G R

A T S- EQ E M E R A TS -C R EM E R A TS -L S E M E R

G E N # 1

G E N # 2 M A I N

G E N # 2

EN

A T S- EQ

EN

A TS -C R

EN

A TS -L S

C B L-A T S EQ N C BL -A T S C R N C BL -A TS L S N C BL -0 00 5 C B L-0 0 06 C BL- 00 0 7

C B L -E Q 4 80 V P N L C BL -C R 4 8 0V PN L C BL -LS 4 80 V P N L

E Q 4 80 V P N L

EQ X F M R P R I

C B L -E Q X F M R P R I

S

P

E Q X F M R

C B L -E Q 2 08 V P N L

EQ 2 0 8V P N L M A IN

E Q 2 08 V P N L

EQ 2 0 8V B R A N CH

C R 4 8 0V PN L

C R X FM R P R I

C BL -C R X F M R P R I

S

P

C R X FM R

C BL -C R 2 0 8V PN L

C R 20 8 V P N L M AIN

C R 2 0 8V PN L

C R 20 8 V BR A N C H

L S 4 80 V P N L

L S X FM R P R I

C BL -LS X F M R PR I

S

P

L S X F M R

C BL -LS 2 08 V P N L

L S 2 0 8V PN L M A IN

L S 2 08 V P N L

L S 2 0 8V BR A N C H

C H ILL E R

C BL- C H ILLE R

D IS T R P N L FD R

C BL- D IST R P N L

D IS T R P N L

4 80 V LT G P N L F D R

C BL - 48 0V LT G P N L

48 0 V LT G P N L

LT G BR A N C H

4 80 V LR G S T

1. Load side of any Emergency System ATS

2. Emergency source to the line side ATS

3. Normal source to the line side of the ATS???

30

U TIL ITY A

M A I N A

M SG -A

M S G -TI E

U TI LITY B

M A IN B

M S G -B

A TS -EQ N O RM A T S-C R N O RM A T S- L S N O R MC H IL LE R F D R

G EN # 1 M A I N

G E N S W G R

A T S- EQ E M E R A TS -C R EM E R A TS -L S E M E R

G E N # 1

G E N # 2 M A I N

G E N # 2

EN

A T S- EQ

EN

A TS -C R

EN

A TS -L S

C B L-A T S EQ N C BL -A T S C R N C BL -A TS L S N C BL -0 00 5 C B L-0 0 06 C BL- 00 0 7

C B L -E Q 4 80 V P N L C BL -C R 4 8 0V PN L C BL -LS 4 80 V P N L

E Q 4 80 V P N L

EQ X F M R P R I

C B L -E Q X F M R P R I

S

P

E Q X F M R

C B L -E Q 2 08 V P N L

EQ 2 0 8V P N L M A IN

E Q 2 08 V P N L

EQ 2 0 8V B R A N CH

C R 4 8 0V PN L

C R X FM R P R I

C BL -C R X F M R P R I

S

P

C R X FM R

C BL -C R 2 0 8V PN L

C R 20 8 V P N L M AIN

C R 2 0 8V PN L

C R 20 8 V BR A N C H

L S 4 80 V P N L

L S X FM R P R I

C BL -LS X F M R PR I

S

P

L S X F M R

C BL -LS 2 08 V P N L

L S 2 0 8V PN L M A IN

L S 2 08 V P N L

L S 2 0 8V BR A N C H

C H ILL E R

C BL- C H ILLE R

D IS T R P N L FD R

C BL- D IST R P N L

D IS T R P N L

4 80 V LT G P N L F D R

C BL - 48 0V LT G P N L

48 0 V LT G P N L

LT G BR A N C H

4 80 V LR G S T

What devices are required to Selectively Coordinate?

3. Normal source to the line side of the ATS???

Is this Zone importantfor continuity of service?

This bus sees an unnecessary outage. ATS transfers into a fault. Gen feeds a fault. Normal ATS breaker must be reset for ATS to transfer back

31

2010 CEC

32

Why .1 seconds?

� “Operating records show that the majority of electric faults originate as phase-to-ground failures.” IEEE std. 141-1993, page 187. (Red book)

� “It should be recognized, however, that actual short circuits often

involve arcing, and variable arc impedance can reduce low-voltage short-circuit current magnitudes appreciably.” IEEE std. 141-1993, page 113. (Red book)

� Looking at TCC’s, fault currents that cause operation of OCPD’s in the sub 6 cycle range have been found to be rare occurrences for systems that have already been safely energized.

33

Selective Coordination Discussion – Protective Devices

35

Ground Faults on low-voltage systems

� “Arcing faults are the more destructive type of fault because the arc limits the fault current.”

� “Selectivity can be typically achieved only by including more than one level of ground fault relays.”

� IEEE std. 142-2001, page 626. (Buff book)

36

How GFP Effects Coordination

� From NEC 517-17: (a) Feeders “ Where GFP is provided for operation of the service disconnecting means ----an additional step of GFP shall be provided in the next level of feeder disconnecting means downstream toward the load.”

� This is a healthcare requirement.

37

More from NEC 517-17

� (b) Selectivity . “ GFP for operation of the service feeder disconnecting means shall be fully selective such that the feeder device and not the service device shall open on ground faults on the load side of the feeder device. A six cycle minimum separation between the service and feeder GF tripping bands shall be provided.”

� Why 6 cycles? (OCPD opening time).

� Note: only GFP is referenced here.

Specific Application Circuit Breakers

Motor Starting

Motor Circuit Protectors

�Motor Starting Considerations

� National Electrical Code 430-52

�Maximum instantaneous setting 13x FLA

� First peak may be 17-18x FLA or higher

on energy efficient motors

� HMCP size 0-4 transient inrush trip suppressor

- Sustain high inrush for first cycle

- Provide sensitive, adjustable short-circuit protection

Specific Application Circuit Breakers

HMCP

Motor Circuit

Protectors

Adjustable Trip Settings�Multiples of continuous

current rating

� Field adjustable

� Close coordination

with motor

characteristics

42

Thermal MagneticOverload Protection (Thermal)

Short-Circuit Protection (Magnetic)

43

Know your fault current!

44

Bolted Fault Arcing Fault

Systems must be designed However, the majority of faultsfor worst case conditions. will be arcing type.

Line-to-Line-to-Line Fault

45

Why .1 seconds?


� “It should be recognized, however, that actual short circuits often

involve arcing, and variable arc impedance can reduce low-voltage short-circuit current magnitudes appreciably.” IEEE std. 141-1993, page 113. (Red book)

� Looking at TCC’s, fault currents that cause operation of OCPD’s in the sub 6 cycle range have been found to be rare occurrences for systems that have already been safely energized.

46

Does .1 Seconds make Sense -Types and Frequencies of Faults


� “It should be recognized, however, that actual short circuits often involve arcing, and variable arc impedance can reduce low-voltage short-circuit current magnitudes appreciably.” IEEE std. 141-1993, page 113. (Red book)

891 switchboard vs. 1558 switchgear

Engineering