Emergency, Legally Required and Optional Standby Systems

CUPERTINO ELECTRIC

INTERNATIONAL ASSOCIATIONINTERNATIONAL ASSOCIATIONOFOF

ELECTRICAL INSPECTORSELECTRICAL INSPECTORS

2002 SOUTHWESTERN SECTION2002 SOUTHWESTERN SECTIONANNUAL MEETINGANNUAL MEETING

EMERGENCY, LEGALLY REQUIREDEMERGENCY, LEGALLY REQUIRED

ANDAND

OPTIONAL STANDBY SYSTEMSOPTIONAL STANDBY SYSTEMS

Rudy Bergthold, P.E.

CUPERTINO ELECTRIC, INC.

San Jose, California

CUPERTINO ELECTRIC

• Designers and Installers have become relaxed in using the terms emergency and standby.

• Any generator is an emergency generator.

• Any load connected to an alternative source of supply is an emergency load.

• Relaxed standards for the use of the terms emergency and standby can lead to confusion, added cost and failing to pass inspection.

CUPERTINO ELECTRIC

EMERGENCY VS. STANDBYEMERGENCY VS. STANDBY

CATEGORY EMERGENCY ARTICLE 700 LEGALLY REQUIRED STANDBY 701

OPTIONAL STANDBY ARTICLE 702

SCOPE Legally required and classified as emergency by codes or AHJ. • Egress lighting • Life safety systems • Fire alarm & communication • Fire pumps• Elevators• Essential VentilationPrimarily for artificial illumination in places of assembly - • Safe exiting• Panic control• Essential for safety of human life• Reference NFPA 101-1997 and NFPA 110-1996

Legally required and classified as legally required standby by codes or AHJ.• Permanently installed equipment • Smoke removal• Sewage Disposal• Industrial Processes• HVAC/Ventilation• Communication equipmentWhen stopped, could create hazards or hamper rescue or fire fighter.• Reference NFPA 110-1996 & IEEE 446-1995

• Intended to protect public and private facilities where life safety does not depend on the performance of the system. Only those systems that are permanently installed• Data processing• HVAC• Industrial Process

APPROVAL Approved for use on emergency systems.

Equipment approved for intended use.

Equipment approved for intended use.

TESTS Witness test of complete system and periodically afterward. • Tested on a schedule acceptable to AHJ.• Battery Maintenance Program required. • Written Record of tests and maintenance.• Means to test under load required.

Witness test of complete system.• Tested on a schedule acceptable to AHJ.• Battery Maintenance Program required.• Written Record of tests and maintenance.• Means to test under load required.

None

Based on 1999 NEC

CUPERTINO ELECTRIC

EMERGENCY VS. STANDBYEMERGENCY VS. STANDBYCATEGORY EMERGENCY ARTICLE 700 LEGALLY REQUIRED

STANDBY 701OPTIONAL STANDBY

ARTICLE 702

CAPACITY/ RATING

• Capacity to operate all emergency loads simultaneously.• May be used for peak load shed.• Portable/temporary required when generator is out of service for major maintenance or repair.• Highest priority if combined.• Selective load pickup/load shedding of legally required and optional standby.

• Allowed to supply legally required and optional standby loads.• Second priority if combined.• Capacity to operate all legally required standby loads simultaneously.• Selective load pickup/load shedding of optional standby.

• Lowest priority if combined • No mandatory loads

TRANSFER EQUIPMENT

• Automatic transfer identified for emergency use and approved by AHJ.• No inadvertent connection of sources.• Bypass/Isolation allowed. • Electrically operated, mechanically held.• Supply only emergency loads.

• Automatic transfer identified for standby use and approved by AHJ.• No inadvertent connection of sources.• Bypass/Isolation allowed.• Electrically operated, mechanically held.

• Suitable for intended use.• No inadvertent connection of sources.• Manual or automatic.

Based on 1999 NEC

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ARTICLE 702

SIGNALS • Audible and Visual where practicable• Derangement (BKR open, low fuel)• Carrying load• Not functioning (battery charger fail)• Ground fault (Alarm not trip) posted instructions

• Audible and Visual where practicable • Derangement• Carrying load• Not functioning (battery charger)

• Audible and Visual where practicable.• Derangement• Carrying load

SIGNS • At service entrance indicate type and location of onsite emergency power sources.• At grounding location if remote from emergency source.

• At service entrance indicate type and location of legally required standby power sources.• At grounding location if remote from standby source.

• At service entrance indicating type and location of standby sources.• At grounding location if remote from source.

WIRING • Boxes, enclosures, transfer switches, generators, panels, etc. permanently marked as emergency.• Wiring kept independent except in transfer equipment, at exit/emergency fixtures, at unit equipment.• Locate circuits to minimize hazards; flood, fire, ice, vandalism.• In high rise/life safety or assembly occupancies over 1000 people:

a. Circuits in fully sprinklered spaces or 1 hours resistive circuit construction.

Permitted to occupy the same raceway, cable, box or cabinet as general wiring.

No special restrictions.

Based on 1999 NEC

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ARTICLE 702

WIRING b. Listed thermal barrier for electrical components.

c. Minimum 2” of concreted. Listed cable assemblye. Equipment in sprinklered space or 1

hour rating.

SOURCES OF POWER

Transfer within 10 seconds Transfer within 60 seconds No transfer time specified.

STORAGE BATTERY

• 1.5 hours to 87.5 percent of normal voltage• Sealed battery OK need not be transparent.• Wet cell needs to be transparent • No automotive batteries• Automatic charging.

• 1.5 hours to 87.5 percent of normal voltage• Sealed battery OK need not be transparent• Wet cell needs to be transparent• No automotive batteries.• Automatic charging.

Not applicable.

GENERATOR SET

• Automatic start.• Time delay retransfer 15 minutes provided• Two hour fuel supply (8 hours UBC) on premise• Two sources of fuel and cooling if served from public utility system. • Automatic fuel source transfer.• Start battery needs independent charger.

• Automatic start.• Time delay retransfer 15 minutes provided• Two hour fuel supply on premise.• Two sources of fuel and cooling if served from public utility system.• Automatic fuel source transfer.• Start battery needs independent charger.

Not applicable.

Based on 1999 NEC

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ARTICLE 702

GENERATOR SET • Battery charger and dampers connected to generator.• Fuel transfer pumps powered from generator.

UNINTERRUPTIBLE POWER SUPPLIES(Lighting Inverter)

• May be used but refer to batteries and generator above.

• May be used but refer to batteries and generator above.

Not applicable.

SEPARATE SERVICE

• If acceptable to AHJ• Per Article 230• Widely separate electrically and physically from normal.

• If acceptable to AHJ• Per Article 230• Widely separate electrically and physically from normal.

Not Applicable.

UNIT EQUIPMENT • Rechargeable battery and battery charger.• Local and/or remote lamps.• Relay to energize lamps.• 1.5 hours to 87½ percent battery output.• 60% light output for 1.5 hours• Permanently fixed in place.• Flexible cord and plug connection permitted if not over 3’ long.

• Rechargeable battery and battery charger.• Local and/or remote lamps.• Relay to energize lamps. • 1.5 hours to 87½ percent battery output.• 60% light output for 1.5 hours.• Permanently fixed in place.• Flexible cord and plug connection permitted if not over 3’ long.

Not applicable.

Based on 1999 NEC

CUPERTINO ELECTRIC

EMERGENCY VS. STANDBYEMERGENCY VS. STANDBYBased on 1999 NEC

CATEGORY EMERGENCY ARTICLE 700 LEGALLY REQUIRED STANDBY 701

OPTIONAL STANDBY ARTICLE 702

UNIT EQUIPMENT

•Circuit also feeds normal lighting in space or, if 3 circuits used in space may be on separate circuit from same panel and locked on.• Clearly mark circuit at panel.

•Circuit also feeds normal lighting in space or, if 3 circuits used in space may be on separate circuit from same panel and locked on.• Clearly mark circuit at panel.

BRANCH CIRCUIT LOADS

• No appliances and no other lamps on emergency lighting circuits.• Automatic transfer required for power branch circuits that supply emergency equipment.

Not applicable. Not applicable.

EMERGENCY ILLUMINATION

• Emergency illumination includes required means of egress.• Single lamp out cannot cause total darkness.• HID sources need emergency lamp on until normal illumination restored.• Include all required means of egress lighting, exit signs, and other lights necessary.• No single lamp failure leaves space requiring illumination in darkness.• Operate HID fixtures until normal restored. (Quartz restrike)

If acceptable to AHJ• Not tapped within service disconnecting means.• Separate physically.

Not applicable.

CUPERTINO ELECTRIC

EMERGENCY VS. STANDBYEMERGENCY VS. STANDBYBased on 1999 NECCATEGORY EMERGENCY ARTICLE 700 LEGALLY REQUIRED


ARTICLE 702

LIGHTING CIRCUITS

Supplied from alternate source when normal power interrupted.• Independent supply with means to automatically transfer.• Two or more systems with independent power supply where only one is required.• Automatic switching unless both systems normally in service.• May be part of general lighting system.



SWITCHING Authorized persons have control.• When two single throw switches in parallel, one accessible only to authorized personnel.• Additional switches to turn lights on but not off.• No 3 way or 4 way.• No switches in series.

No special restriction. Not applicable.

SWITCH LOCATIONS

• Convenient to authorized persons only• In places of assembly (i.e. theater) – switch convenient in lobby. • No switch in projection booth unless to only turn lights on.• Exterior lights may by turned off by photo cell.

No special restriction. Not applicable.

CUPERTINO ELECTRIC

EMERGENCY VS. STANDBYEMERGENCY VS. STANDBYBased on 1999 NECCATEGORY EMERGENCY ARTICLE 700 LEGALLY REQUIRED


ARTICLE 702

OVERCURRENT PROTECTION

• Accessible to authorized persons only.• Coordinated system (fully rated vs. integrated).

• Accessible to authorized persons only.

Same as general building supply system.

GROUND FAULT PROTECTION

Tripping not required, indication only. Tripping not required, indication only. Tripping required if more than 150 volts to ground and 1000 AMPS.

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TYPICAL TRANSFER SYSTEMS

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TYPICAL EQUIPMENT CONFIGURATIONS

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TYPICAL SYSTEM WITH A SINGLE GENERATOR SERVICE ALL LOADS. MAY EMPLOY LOAD SHED.

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TYPICAL SYSTEM WITH OPTIONAL LOADS USING UNIT EQUIPMENT FOR EGRESS LIGHTING.

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TYPICAL SYSTEM WITH BOTH EMERGENCY AND OPTIONAL STANDBY ALTERNATE SOURCES.

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TWO TYPES OF ALTERNATE SOURCES, FOUR TYPES OF TRANSFER.

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MEDIUM VOLTAGE SYSTEM WITH LOW VOLTAGE EMERGENCY LOADS.

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TYPICAL THREE POLE TRANSFER SWITCH CONNECTIONS.

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TYPICAL FOUR POLE TRANSFER SWITCH CONNECTION.

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TYPICAL UNIT EQUIPMENT CONNECTION. BATTERY SERVES LOAD FOR 90 MINUTES WHEN NORMAL SUPPLY TO GENERAL ILLUMINATION FAILS.

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SWITCHABLE UNIT EQUIPMENT. BATTERY SERVES LOAD FOR 90 MINUTES WHEN NORMAL SUPPLY TO GENERAL ILLUMINATION FAILS.

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SEPARATE CIRCUIT FOR EGRESS LIGHTING WHEN ROOM/AREA SERVED WITH 3 OR MORE CIRCUITS.

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GENERATOR SIZING EXAMPLEGENERATOR SIZING EXAMPLE

Notes: (1) Running Load = 150KVA (180A @ 480V 3Phase). See Sheet B for calculation.

(2) Refer to Sheet C for Generator Sizing for Combination Loads.

(3) Refer to Sheet D for Total Load Generator Sizing.

DESCRIPTION LOAD(KW)

CLASSIFICATION OF LOAD GENERATOR LOAD DURING:

EMERGENCYLEGALLY

REQUIRED STANDBY

OPTIONAL STANDBY

ROUTINE OUTAGE

OUTAGE WITH

FA/LSS

OUTAGE WITH FA &

PUMP

OUTAGE WITH

EQUIPMENT IN

OPERATION

Egress Lighting 100 100 100 100 100 100

Fire Alarm/LSS 50 50 50 50 50 50

Smoke Control 200 200 200 200 200

Fire Pump 125 125 855 (1) 855 (1)

Computer Room 400 400 400 400

Elevator 100 100 100 100 100 100

Garage Exhaust 100 100 100 100 100 100

Walk-in Refrigerator 25 25 25 25

TOTALS 1100 475 300 425 775 550 971 (2) 1100 (3)

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GENERATOR SIZING EXAMPLEGENERATOR SIZING EXAMPLE

FIRE PUMP STARTINGFIRE PUMP STARTINGSHEET B

Fire Pump = 150 Hp, 480V 3Ph, Code G Squirrel Cage Motor Started Across the Line.

TABLE 430 – 150: 150Hp = 180 Amps @ 480V.

TABLE 430 – 7(b): Code G = 5.6 – 6.29 KVA/Hp.

Starting KVA = 6.29 x 150Hp = 943.5 KVA = 1135 Amps.

NFPA 20 limits Starting Voltage Drop to 15%.

Approximation of Voltage Drop equals Ratio of Starting Current to Maximum Available Fault Current.

AmpsCircuit Short Required AmpsStarting

0.1515%

7567Amps0.151135

0.15 AmpsStarting

AmpsCKT Short Required

The Normal Source Impedance for 480V Diesel Generators is between 10% and 17% or 0.1pu and 0.17pu

Normal Source FLA = Short CKT Amps x Source Impedance pu

= 7567 x 0.17

= 1286 Amps

480V 3Phase Generator KW = 0.8pf x Normal FLA x 0.48 x 1.732

= 0.18 x 1286 x 0.48 x 1.732

= 855KW

Normal Starting Requirement (Generator KW) is 4 to 6 times Fire Pump Horsepower.

pu Impedance SourceFLA Source Normal

AmpsCircuit Short

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SHEET C

From Sheet B

Fire Pump starting required Short Circuit Amps = 7576

Total of Connected Loads = 675KW.

New Combination Required Short Circuit Amps = 7576 + 1014

= 8590 Amps


= 8590 x 0.17

= 1460 Amps


= 0.18 x 1460 x 0.48 x 1.732

= 971 KW

GENERATOR SIZING FORGENERATOR SIZING FOR

COMBINATION OF LOADS WITH FIRE PUMPCOMBINATION OF LOADS WITH FIRE PUMP

1014Amps1.732 x 0.48 x 0.8

675 Loads Other of AmpsLoad Running

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SHEET D

From Sheet B

Fire Pump starting required Short Circuit Amps = 7576

Total of Running Loads = 1100 KW.

New Combination Required Short Circuit Amps = 7576 + 1654

= 9230 Amps


= 9230 x 0.17

= 1569 Amps


= 0.18 x 1569 x 0.48 x 1.732

= 1043 KW

Minimum Size = Connected Load when Minimum Starting Calculation is less than Connected Load.

= 1100 KW

GENERATOR SIZING FORGENERATOR SIZING FOR

TOTAL OF ALL LOADSTOTAL OF ALL LOADS

Amps16541.732 x 0.48 x 0.8

1100 Loads Other of AmpsLoad Running

Engineering

Emergency, Legally Required and Optional Standby Systems