the Electrical Distribution Systems for Hospitals - Part Two

in the previous Topic; the Electrical Distribution Systems for Hospitals - Part One, we talk about types of Electrical Distribution Systems for Health Care Facilities and we mentioned that the Essential electrical system will include the following two sub-system: 

1- Emergency system: which include the following two branches: (see fig.1)

• Life Safety Branch.
• Critical Branch.

2- Equipment System/branch.

I explained in this previous topic the Life Safety Branch and Critical Branch. 

You can review the following previous topics for more information and good following:

• the Electrical Design Requirements for Health Care Facilities – Part One
• the Electrical Design Requirements for Health Care Facilities – Part Two

Today, i will explain the second branch of Essential electrical system which is Equipment System/branch as follows.

fig.1

2- Equipment System/Branch:

Definition: A subsystem of the essential electrical system consisting of The feeder conductors and equipment used to supply electrical power to the equipment branch of the essential electrical system.

the Equipment that fed from Equipment System/Branch will be divided into three ttypes as follows:

1. Equipment Branch Non-Delayed Automatic Connection.
2. Equipment Branch Delayed-Automatic Connection.
3. Equipment for Delayed Automatic or Manual Connection.

1- Equipment Branch Non-Delayed Automatic Connection

it include the following generator accessories which must be arranged for non-delayed automatic connection to the alternate power source:

• Electrically operated louvers 
• Other generator accessories essential for generator operation 
• Transfer fuel pump 
• Equipment Branch Delayed-Automatic Connection 

2- Equipment Branch Delayed-Automatic Connection:

This equipment shall be arranged for delayed automatic connection to alternate power source. This means an outage to this equipment can exceed 10 seconds.

• Vacuum pumps and oral evacuation pumps serving medical and surgical functions, including controls.
• Sump pumps and other equipment required to operate for the safety of major apparatus, including associated control systems and alarms.
• Medical and dental air compressors, serving medical and surgical functions, including controls (such systems may be connected to the Critical Branch; the A/E shall coordinate with the Chief Engineer at the facility).
• Smoke control and stair pressurization.
• Kitchen hood supply and/or exhaust systems, if required to operate during a fire in or under the kitchen hood.
• Uninterruptible Power Supply (UPS) equipment serving other than telecommunications equipment.
• Medical and laboratory refrigerators and freezers as required.
• Oxygen storage control panel.
• Fire pump, jockey pump, and make-up pump for water-based fire protection systems; lighting and selected receptacles in fire pump room.
• Autoclaving equipment (shall be permitted to be arranged for either delayed-automatic or manual connection to the alternate source).
• Administrative Areas: Task illumination and selected receptacles in the hospital Director’s, Engineering, and Security and Communications Suites.
• Closed-loop water chilling equipment for linear accelerator.
• Domestic Water Pumps: Equipment, control system, light fixture and receptacle near the pump.
• Electric tape for heat tracing of piping requiring freeze protection.
• Heating, ventilating and air-conditioning (HVAC) systems: 

1. Air-conditioning equipment, lubricating oil pumps for centrifugal compressors, control air compressors, air dryer and absorption machine refrigerant pump to draw down lithium chloride before crystallization (omit for machines accomplishing this manually).
2. Chillers, chilled water circulating pumps, fans, and controls for surgical suites, recovery rooms, intensive care, and coronary care units.
3. Chillers, chilled water circulating pumps, fans and controls for animal research facilities.
4. HVAC equipment for Bone Marrow Transplant (BMT) areas.
5. HVAC equipment for Magnetic Resonance Imaging (MRI) Suites and Computerized Topographic (CT) Scanners.
6. HVAC equipment serving emergency areas in outpatient clinics in seismic and high-risk hurricane areas.
7. HVAC equipment for Main Computer Room and Telephone Equipment Room, Telephone Console Room, and Head End Room.
8. Exhaust fans serving Autopsy Rooms, reagent-grade Water Treatment Rooms, Orthotic Laboratory special exhaust systems, battery charging areas, flammable storage rooms and illustration rooms (Medical Media).
9. Supply, return and exhaust ventilating systems for Infection Isolation Rooms, Protective Environment Rooms and exhaust fans for laboratory fume hoods and nuclear medicine areas where radioactive material is used. These systems are permitted on delayed automatic system only and shall not be served via manual system. Some systems may be placed on Critical Branch. Coordinate with VA.
10. Ventilation, cooling and control equipment for electrical rooms.
11. Ventilation, cooling and control equipment for elevator machine rooms.

• Hot Water Circulatory and Steam Condensate Return Pumps: Equipment, controls, and light fixture and receptacle near the pumps.
• Hot Water Generator: Equipment, controls, and light fixture and receptacle near the generator.
• Kitchen: Illumination and minimum equipment to feed patients during extended outage; freezers and refrigerators.
• Laboratory Air Compressors and Vacuum Pumps: Equipment, controls, and light fixture and receptacle near the compressors and pumps.
• Animal Ward lighting.
• Mortuary Refrigerator or Cold Room: refrigeration equipment and task illumination 
• Radiology Suite: Task illumination, one automatic X-ray film processor, and one X-ray unit.
• Refrigerated Medical Storage: refrigeration equipment.
• Sewage Pumps: Equipment, controls, and light fixture and receptacle near the pumps 
• Supply, Processing, and Distribution (SPD): 

1. Task illumination and selected receptacles in the following areas: core, sterile storage, non-sterile storage, preparation, and decontamination.
2. One ultrasonic cleaner, one ethylene oxide gas sterilizer, one steam sterilizer, one washer sterilizer, one gas generator.
3. Equipment in warehouse areas needed to preserve subsistence drugs and X-ray film materials that may be subjected to damage from infestation, humidity or temperature.

• Water and Sewage Treatment Plant: Lighting, receptacles and equipment needed during emergency.

3- Equipment for Delayed Automatic or Manual Connection:

This equipment shall be arranged for either delayed automatic or manual connection to alternate power source. As mentioned for delayed automatic connection, an outage to this equipment can exceed 10 seconds.

• Heating equipment to provide heating for operating, delivery, labor, recovery, intensive care, coronary care, nurseries, infection/isolation rooms, emergency treatment spaces and general patient rooms. 
• An elevator(s) selected to provide service to patient, surgical, obstetrical and ground floors during interruption of normal power. 
• Supply, return and exhaust ventilating systems for surgical and obstetrical delivery suites, intensive care, coronary care, nurseries, infection/isolation rooms, emergency treatment spaces and exhaust fans for laboratory fume hoods, nuclear medicine areas where radioactive material is used, ethylene oxide evacuation and anesthesia evacuation. 
• Hyperbaric facilities. 
• Hypobaric facilities. 
• Automatically operated doors. 
• Minimal electrically heated autoclaving equipment shall be permitted to be arranged for either automatic or manual connection to the alternate source. 
• Selected controls. 

Electrical Design types according to size of hospital:

the electrical design will vary according the the size of the hospital, you can know and extract the differences by yourself from reviewing the electrical single line diagrams in both cases ; small and large hospital as follows:

11- Small hospital case:

the electrical single line diagram will be as follows:

Electrical Single Line diagram for Small hospital 

2- Large hospital case:

the electrical single line diagram will be as follows:

Electrical Single Line diagram for Small hospital 

Alternate Source of Power for Hospital Buildings ( Type 1 - ESS):

The alternate source of power shall be one or more diesel-engine-driven-generator sets with applying the following points:

• you must Provide physical space for one additional generator; paralleling switchgear shall be appropriately provisioned. 
• Generator remote alarm annunciator(s) must be used in Energy Center control room, and the Security office or Telephone Operator office (whichever is continuously staffed).

in the next Topic, I will explain the Electrical Distribution systems for nursing homes and residential custodial care facilities. so, please keep following.