Rosegarden Branch Library



Electrical System

After re-designing the lighting system for the children’s computer, circulation and storytelling areas, the electrical system had to be re-designed as well. These are the new panel board schedules. All lighting fixtures were placed on the same schedules based on area and floor level: panelboard “L1” for the interior first floor and exterior, and panelboard “L2” for the interior second floor.

| | |

|  |Actual Load (kVA) |D.F. |New Load (kVA) |add 20% spares |Final Load (kVA) |

|General Lighting Load |7.10 |1.25 |8.88 |1.78 |10.65 |

|Rcptcl. First 10 kVA: |0.00 |1.00 |0.00 |0.00 |0.00 |

|Total Load: |8.10 |  |8.88 |1.78 |9.72 |

|  |

|Final Total Load (kVA): |9.72 |  |

| | |

|conclusion |There is a difference of 2.3 kVA in this panelboard. The change in VA is negligible and neither the breaker nor panelboard need to be resized. |

| | |

|Panel L2 |(lighting) |

|  |Actual Load (kVA) |D.F. |New Load (kVA) |add 20% spares |Final Load (kVA) |

|General Lighting Load |23.60 |1.25 |29.50 |0.20 |35.10 |

|Rcptcl. First 10 kVA: |0.00 |1.00 |0.00 |0.20 |0.00 |

|Total Load: |23.60 |  |29.50 |  |35.40 |

|  |

|Final Total Load (kVA): |35.40 |  |

| | |

|conclusion |There is a difference of 1.5 kVA in this panelboard. The change in VA is neglible and neither the breaker nor panelboard need to be resized. |

|  | |

|Panel R1 |(receptacles) |

|  |Actual Load (kVA) |D.F. |New Load (kVA) |add 20% spares |Final Load (kVA) |

|Other Loads |8.70 |1.00 |8.70 |0.20 |10.44 |

|Rcptcl. First 10 kVA: |11.60 |1.00 |11.60 |0.20 |13.92 |

|Total Load: |23.60 |  |20.30 |  |24.36 |

|  |

|Final Total Load (kVA): |24.36 |  |

|Panel R2 |(receptacles) |

|  |Actual Load (kVA) |D.F. |New Load (kVA) |add 20% spares |Final Load (kVA) |

|Other Loads |13.60 |1.00 |13.60 |0.20 |16.32 |

|Rcptcl. First 10 kVA: |11.60 |1.00 |11.60 |0.20 |13.92 |

|Total Load: |25.20 |  |25.20 |  |30.24 |

|  |

|Final Total Load (kVA): |30.24 |  |

For the feeder taps to each panel:

“L1”

General Lighting Load: 17,244 sqft at 1.2 VA/sqft = 20692.8 VA

Receptacle Load: 17,244 sqft at 0.5 VA/sqft = 8622.0 VA

Net computed load using demand factors from Table 12.2: 29314.8 VA at 100% = 29314.8 VA

Since it is a 208/120 V service:

Minimum Ampacity = 29314.8/(1.732 x 208) = 81.37 A

“L2”

General Lighting Load: 15,984 sqft at 1.2 VA/sqft = 19180.8 VA

Receptacle Load: 15,984 sqft at 0.5 VA/sqft = 7992.0 VA

Net computed load using demand factors from Table 12.2: 27172.8.0 VA at 100% = 27172.8.0 VA

Since it is a 208/120 V service:

Minimum Ampacity = 27172.8.0 /(1.732 x 208) = 75.43 A

For the main feeder:

Total computed load for six panels = 8.1 + 23.6 + 20.3 + 38.2 + 7.3 + 103.3 = 200.8 kVA

The Rosegarden Library, with its location in San Jose, California has its power supplied from PG&E. The connection is located in the exterior of north side of the building and the transformer is located in the Electrical Equipment room on the ground level. Refer to riser diagram above.

|New Conduit Schedule |

|Tag |Quantity |Conduit (IN) |Use |Remarks |

|1 |1 |2 1/2 |(4)#4/0+(1)#4G | |

|2 |3 |5 | |PG&E to install conductors |

|3 |2 |4 | |PG&E to install conductors |

Voltage drop calculations

To determine voltage drops, table 11.5 in S. David Hughes, Electrical Systems in Buildings was used.

Using 800 VA per common receptacle unit.

Use 120V Panelboards

X = length in ft.

System Type

The Rosegarden Library has a radial circuit arrangement. This building is composed of a main switchboard that branches out to the five control panels in the building. This system is the simplest of the circuit arrangements since there is only one primary feeder and one transformer through which the associated secondary bus is served. In order to leave it as simple as possible in order to avoid confusion with the maintenance and electricians, this system will be left the same.

Utilization Voltage

The Utilization voltage of this building is 208/120 V and it is used on both levels.

Transformer Configuration

Rosegarden Library uses Nema 3R, UON Transformer in exterior of building with a copper clad grounding rod. This is one of the best and most expensive kinds of system available. It is located on the northeast side of the building. This transformer is provided by PG&E, and they don’t give us the rating. When you ask for a certain rating, they usually give you less. So it will probably be according to one of the electrical engineers working on the project, and since it is a relatively small building a 300 kVA transformer (830 Amps) will probably be provided. The secondary voltage is 120/208V, 3 phase. The library does not have much control over this, since it is owned by the city of San Jose. It is a public building.

Emergency Power System

The emergency power system will not have automatic transfer switches since there is no emergency generator. There is a UPS in the telecom room though, which the library is providing for battery backup for the server. Emergency light fixtures have emergency ballasts incorporated, so there would be enough light in case of an emergency, for about 90 min. for most of them. These are all operated mainly in 120V. In addition, a shunt trip circuit breaker is provided for the elevator.

Over Current Protective Devices

There is an over current protection device which is a 1000 A, 3 phase circuit breaker. There is also a transformer assembly with two 40 VA transformers with separate secondaries in the relay panels. Transformers include internal over current protection with automatic reset and metal oxide varistor protection against power line spikes. 120 or 277 VAC as required, 60 Hz +/- 10%.

Location of switchgears, panelboards and motor centers

The main switchboard is located in the Electrical Equipment room (room 108 on the first floor). there are no switchboards in Rosegarden since they hold loads between 2000 – 5000 amps, and are more expensive. Switchboards are used in this building since we only need front access to it and since it is not that big, we just need it to hold 800-2000 (but could go up to 5000) amps. The mechanical equipment table will remain the same since no mechanical gear was changed.

Mechanical Equipment Table

|Mech Eq |Type |Service |Voltage |Phase |Hz |Full Load Amps |

|ACU 1 |Natural gas HTG Electrical|Library central area |208 |3 |60 |66 |

| |CLG Package Unit | | | | | |

|ACU 2 |Natural gas HTG Electrical|Library North Exposures |208 |3 |60 |73 |

| |CLG Package Unit | | | | | |

|ACU 3 |Natural gas HTG Electrical|Library South Exposures |208 |3 |60 |86 |

| |CLG Package Unit | | | | | |

|ACU 4 |Natural gas HTG Electrical|Library 1PstP floor community |208 |3 |60 |23 |

| |CLG Package Unit |room | | | | |

Typical lighting system

All the lighting systems in the building operate on 208/120V. The most common light fixtures in this library are the fluorescent light fixtures, either linear florescent or compact fluorescent. These lamps were chosen for their low power consumption and easy maintenance and repair.

All the ballasts in the light fixtures have a high power factor, CBM certified and bear the UL label. The electronic ballasts need to be high power factor, high frequency and suitable for lamps specified.

The library has a Smartwire relay lighting control system as well as DMX controls, in order to allow for color changing in the LED’s.

|Fixture |Lamps - total Input Watts |Volts |Description |Mounting |

|Code | | | | |

|A |1-42 |120 |5” Diameter, compact fluorescent downlight. |Recessed |

|C |1-5.5 |120 |12” color LED |Surface |

|T |(2x40,2x36) |120 |Direct/Indirect fluorescent pendant fixture. |Pendant |

| |232 | | | |

|AA |1-70 |120 |Metal Halide wall mounted fixture. |Surface |

|W |1-34 |120 |Compact fluorescent wallwasher |recessed |

|AD |1-100 |120 |Metal Halide Wall mounted fixture. |Surface |

|AJ |1-70 |120 |Metal Halide Bollard |Ballard |

The new lighting design loads have been placed on a 208v panelboard which would be fed from the panelboard. Since the loads have been reduced on the switchboard, it is going to be left as is. On the four spaces analyzed, there were not enough new fluorescent lighting to fill up a decent sized panelboard. The panel is going to be left unsized due to the fact that that only a portion of the total load can be applied to the panelboard without a full building analysis.

Mechanical Equipment Table

|Mech Eq |Type |Service |Voltage |Phase |Hz |Power factor |Full Load Amps |

|ACU 1 |Natural gas HTG |Library central |208 |3 |60 |0.9 |66 |

| |Electrical CLG Package |area | | | | | |

| |Unit | | | | | | |

|ACU 2 |Natural gas HTG |Library North |208 |3 |60 |0.9 |73 |

| |Electrical CLG Package |Exposures | | | | | |

| |Unit | | | | | | |

|ACU 3 |Natural gas HTG |Library South |208 |3 |60 |0.9 |86 |

| |Electrical CLG Package |Exposures | | | | | |

| |Unit | | | | | | |

|ACU 4 |Natural gas HTG |Library 1PstP floor|208 |3 |60 |0.9 |23 |

| |Electrical CLG Package |community room | | | | | |

| |Unit | | | | | | |

|EF1 |Centrifugal exhauster |Men/women restrooms|120 |1 |60 |.9 |5.8 |

|EF2 |Centrifugal exhauster |Men/women restrooms|120 |1 |60 |.9 |5.8 |

|EF3 |Centrifugal exhauster |Men/women restrooms|120 |1 |60 |.9 |9.8 |

| | |& public/staff | | | | | |

|EF4 |Centrifugal exhauster |Men/women restrooms|120 |1 |60 |.9 |5.8 |

| | |& public/staff | | | | | |

|GD1 | |Parking Garage |120 |1 |60 |.9 |9.8 |

|EV1 | |Elevator equip room|208 |1 |60 |.9 | |

Utility

The local utility used to distribute power to the building is Pacific Gas & Electric. PG&E will provide all the electricity for Rosegarden.

Controls

The controls used in this building were mostly DMX and iplayer 2.0 for the colored cove lights. This control along with the light system manager software, should provide enough and easy information in order for the library caretakers to program different views or environments in the children’s area of the library. These controls will allow for color changing through time. There will be various programmed “scenes” which will run through the day creating vibrant colors which will energize the space.

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3

Incoming service

2

UTILITY TRANSFORMER

SWITCHBOARD

1000 AMPS, 120/208 VOLTS, 3PHASE, 4 WIRE

M

PNL “R1”

225 AMPS

1

1

PROVIDE SHUNT TRIP CIRCUIT BREAKER FOR ELEVATOR

220 AMPS

3POLE

PNL “L2”

225 AMPS

PNL “L1”

225 AMPS

PNL “R2”

225 AMPS

400 AMPS

3POLE

225 AMPS

3POLE

225 AMPS

3POLE

225 AMPS

3POLE

225 AMPS

3POLE

PNL “M1”

400 AMPS

1

1

1

GROUNDING ROD

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