Electrical Systems: Designing electrical rooms J oin oi n the the dis c us s i on about about thi thi s Webc as t on Twitt Twi tter er at at #C S E electri c alroom lroo m
Sponsored by:
Presenters: Brian Martin, PE, Portland Electrical Department Manager CH2M Hill Portland, Ore.
Brian Rener, PE, LEED AP, AP, Associate SmithgroupJJR, Chicago, Ill.
Moderator: Jack Smith, Consulting-Specifying Engineer and Engineer and Pure Power , CFE Media, LLC
Presenters: Brian Martin, PE, Portland Electrical Department Manager CH2M Hill Portland, Ore.
Brian Rener, PE, LEED AP, AP, Associate SmithgroupJJR, Chicago, Ill.
Moderator: Jack Smith, Consulting-Specifying Engineer and Engineer and Pure Power , CFE Media, LLC
Electrical Systems: Designing electrical rooms Brian Martin, PE, Portland Electrical Department Manager CH2M Hill Portland, Ore. Brian Rener, PE, LEED AP, AP, Associate SmithgroupJJR , Chicago, Ill.
Presentation scope • NFPA 70 (NEC) 2014 • International Building Code (IBC) • 800 A and Above • Primary services • No hazardous locations • Good engineering practices
Electrical room design • Needs a coordinated team: • Electricals • Architects • Structural • Mechanicals • Fire protection
Room types • Primary service rooms • Electrical rooms • UPS or battery rooms • Generator rooms • Computer rooms • Utility vaults
Design issues • • • • • • • •
Working vs. dedicated spaces Dedicated spaces and foreign systems Fire protection Fire ratings Ventilation Structural Building occupancy Lighting
Working vs. dedicated spaces • Different spaces – Worker vs. equipment
Working vs. dedicated spaces • Different spaces – Worker vs. equipment
Working space • Applies to: – “Equipment operating at 600 V, nominal, or less, to ground and likely to require examination, adjustment, servicing, or maintenance while energized.” NEC Article 110.26(A) • Switchboards • Switchgear (Added in 2014) • Motor control centers • Panelboards • Disconnect switches • Circuit breakers • Controllers • Controls for HVAC equipment • Transformers sometimes fall into this category
Working space: table
Working space: elevations
Nonelectrical parts “Where rear access is required to work on nonelectrical parts on the back of enclosed equipment, a minimum horizontal working space of 30 in. shall be provided.” NEC Article 110.26(A)(1)a
Dedicated spaces • Applies to: • “All switchboards, switchgear, panelboards, and motor control centers shall be located in dedicated spaces and protected from damage.” NEC Article 110.26(E) • Switchboards • Switchgear (Added in 2014) • Panelboards • Motor control centers
Dedicated spaces and foreign systems • Can you have foreign systems (mechanical ducts and/or plumbing) in your electrical room? – Yes and no • Understand dedicated space
Foreign systems (MP) • NEC: above, if protected
• What about sprinklers? •
NEC: okay in dedicated space
2014 NEC change • Outdoor spaces – New requirement now calls for the same basic dedicated equipment or electrical space for outdoor installations that has been in effect for indoor installations – This space above and below the electrical equipment should be dedicated
Primary equipment • Switchboard vs. switchgear • Switchboards: UL 891 – Front access – Rear access – Primarily fixed mounted
Primary equipment • Switchboard Vs Switchgear • Switchgear - ANSI C37 – Rear Access – Primarily Drawout Construction
Access • 1200 amps & 6 feet in width – Two doors on opposite ends – Doors 6’ 1/2’’ x 24” – One door if working clearance doubled – Doors Swing Out
• 800 A (New to NEC 2014) – Listed Panic Hardware on Doors
Access: plan examples
Beyond NEC: working space and access • • • • •
Doors: at least 36 in. wide or double 36 in., 9 ft. high Access to drawout devices Would you want to work in only 3½ ft? Breaker truck access NFPA 70E: Standard for Electrical Safety in the Workplace - arc flash zones • Arc flash gear, venting • Height above switchboards • Space planning: work with your architect
Fire protection • Sprinklers – NFPA 13: yes, or 2 hr rating – Some cities: preaction
• Fire detection – Smoke detectors in electrical rooms – Recommend heat and flame detection in generator rooms
Fire ratings • Do electrical rooms need to be fire rated? – NEC • Not if sprinklered
– What about dry type transformers? • 112.5 kVA, 155 C or higher insulation
• Emergency systems (NEC Article 700) – NEC high rise or high occupancy • Approved fire suppression •
2-hr systems
Fire ratings • NFPA 110 – EPS installed in a separate room for Level 1 systems – Room must have a 2-hr rating
• Know your local codes – Example: City of Chicago • Generator room rating: 3 hr • Fuel storage: 550-gal limit • Not located more 2 floors up or down from grade.
• Insurance carrier requirements
Ventilation • • • •
Required? General rating of equipment: 104 F Recommend: 86 F Electrical rooms – Without transformer: 1 cfm/sq. ft. – With transformer: 1.0% to 2.0% of kVA (3 cfm/kVA)
• Generator rooms – Cooling vs. combustion air – After engine shuts down – Remote radiator – 2,500 Btu/hr/kVA
Ventilation • Battery/UPS rooms – Keep temperature around 77 F – What about hydrogen? • Flooded (vented) batteries • Valve regulated, sealed • Conflicting codes: NEC, UFC, IFC
– Safe rules • 1 cfm/sq. ft. • Fan failure relay
Structural • Often overlooked – – – – – –
Switchboards and switchgear Generators Vibration isolation Computer rooms Raised floors Miscellaneous • • • •
Pads Penetrations Fire sealing Path of delivery
Lighting • Recommended lighting levels – IES and NFPA 70E: 30 foot-candles
• Emergency lighting – 1 foot-candle is not enough
• Switching – Must include nonautomatic means
Miscellaneous room issues • EMI • Noise
Codes and Standards References from Today’s Webcast • NFPA 70 (NEC) 2014 • International Building Code (IBC) • UL 891 • ANSI C37 • NFPA 70E: Standard for Electrical Safety in the Workplace • NFPA 110 • IES
Presenters: Brian Martin, PE, Portland Electrical Department Manager CH2M Hill Portland, Ore.
Brian Rener, PE, LEED AP, Associate SmithgroupJJR, Chicago, Ill.
Moderator: Jack Smith, Consulting-Specifying Engineer and Pure Power , CFE Media, LLC
Webcasts and Research • Smart Electrical Systems: Meters, submeters and smart meters
• 2013 Electrical and Power study
