Electrical Distribution Systems for Nursing Homes and Residential Custodial Care Facilities


in the previous Topic; the Electrical Distribution Systems for Hospitals - Part Twowe talk about the Equipment system/ branch and  Electrical Design types according to size of hospital.

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



Today, i will explain the Electrical Distribution Systems for another type of health care facilities which is "Nursing Homes and Residential Custodial Care Facilities" as follows. 


second building type: Electrical Distribution systems for nursing homes and residential custodial care facilities:


In nursing homes and residential custodial care facilities, usually the Essential Electrical System type will be Type 2-ESS.

The essential electrical system is subdivided into two systems as follows:
  1. The emergency system. 
  2. The critical system. 

1- The emergency system:


Emergency system In these cases is limited to those loads defined for the life safety branch for hospitals, plus sufficient illumination to exit ways in dining and recreation areas. These emergency system circuits are required to be installed separately and independently of non-emergency circuits and equipment. The NFPA standards require that this emergency system branch be designed to permit automatic restoration of electrical power within 10 s of power interruption.

The emergency system shall supply power for lighting, receptacles, and equipment as follows:
  • Illumination of means of egress.
  • Exit signs and exit directional signs.
  • Alarm and alerting systems, including the following: 
  1. Fire alarms.
  2. Alarms required for systems used for the piping of nonflammable medical gases.
  • Communication systems, where used for issuing instructions during emergency conditions 
  • Sufficient lighting in dining and recreation areas to provide illumination to exit ways of a minimum of 5 ft-candles 
  • Task illumination and selected receptacles at the generator set location 
  • Elevator cab lighting, control, communication, and signal systems 

Note: No function other than those listed above shall be connected to the emergency system


2- The critical system:


The critical system shall be so installed and connected to the alternate power source that equipment listed in below shall be automatically restored to operation at appropriate time-lag intervals following the restoration of the emergency system to operation. Its arrangement shall also provide for the additional connection of equipment listed as follows:

a- AC Equipment for Nondelayed Automatic Connection:
Generator accessories, including but not limited to, the transfer fuel pump, electrically operated louvers, and other generator accessories essential for generator operation, shall be arranged for automatic connection to the alternative power source.



b- Delayed-Automatic Connections to Critical System:
The following equipment shall be permitted to be connected to the critical system and be arranged for delayed-automatic connection to the alternate power source:

  • Task illumination and selected receptacles in the following: 
  1. Patient care areas.
  2. Medication preparation areas.
  3. Pharmacy dispensing areas.
  4. Nurses’ stations (unless adequately lighted by corridor luminaires).
  • Supply, return, and exhaust ventilating systems for airborne infectious isolation rooms.
  • Sump pumps and other equipment required to operate for the safety of major apparatus and associated control systems and alarms.
  • Smoke control and stair pressurization systems.
  • Kitchen hood supply and/or exhaust systems, if required to operate during a fire in or under the hood.
c- Delayed-Automatic or Manual Connections to Critical System.
The equipment in below shall be permitted to be connected to the critical system and be arranged for either delayed-automatic or manual connection to the alternate power source as follows:



1- Heating Equipment to Provide Heating for General Patient Rooms.
Heating of general patient rooms during disruption of the normal source shall not be required under any of the following conditions: 
  • The outside design temperature is higher than −6.7°C (+20°F). 
  • The outside design temperature is lower than −6.7°C (+20°F) and, where a selected room(s) is provided for the needs of all confined patients, then only such room(s) need be heated. 
  • The facility is served by a dual source of normal power.

2- Elevator Service.
In instances where interruptions of power would result in elevators stopping between floors, throw-over facilities shall be provided to allow the temporary operation of any elevator for the release of passengers.

In addition, connect the following items to the Critical Branch, arranged for delayed-automatic connection to the alternate power system:
  • Nurse Call System.
  • Patient Bedrooms: Bathroom light, an alcove or lavatory mirror light, night light, and one receptacle per bed wall.
  • Electrical Rooms and Closets: 50 percent of lighting and one receptacle.
  • Main Computer Room, Telephone Equipment Room and Telecommunications Rooms: UPS equipment, 50 percent of lighting, all receptacles and telecommunications equipment.
  • Mechanical Rooms: Task illumination and one receptacle.


Electrical Design types according to size of Nursing House:

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

1- Small 
Nursing House case:

the electrical single line diagram will be as follows:


Electrical Single Line diagram for Small Nursing House

1- Large Nursing House case:

the electrical single line diagram will be as follows:

Electrical Single Line diagram for Large Nursing House

Alternate Source of Power for nursing homes and residential custodial care facilities: 

The alternate source of power shall consist of a diesel engine-driven generator set.



third building type: Electrical Distribution systems for other health care facilities:


Note: other health care facilities excluding hospitals, nursing homes, and residential custodial care facilities where the facility administers inhalation anesthetics or requires electromechanical life support devices.

In other health care facilities, usually the Essential Electrical System type will be Type 3-ESS.

In other health care facilities, the Essential electrical system consists of one system supplying a limited amount of lighting and power considered essential for life safety and orderly cessation of procedure whenever normal electrical service is interrupted for any reason. The type of system selected should be appropriate for the medical procedures performed in the facility.

The Essential Electrical System for other health care facilities shall comply with the Type 3 system as defined in NFPA 99 as follows:
  • The emergency system shall have an alternate source of power separate and independent from the normal source that will be effective for a minimum of 1.5 hours after loss of the normal source. 
  • The emergency system shall be so arranged that, in the event of failure of normal power source, the alternate source of power shall be automatically connected to the load within 10 seconds. 

Note: If electrical life support equipment is required or critical care areas are present in the facility, the Essential Electrical System shall comply with the Type 1 system as defined in NFPA 99. If a Type 1 system is required, connect the functions/items listed in the topics for hospital design to the Essential Electrical System.


Alternate Source of Power for other health care facilities:


The alternate source of power for the system shall be specifically designed for this purpose and shall be a generator, battery system, or self-contained battery integral with the equipment.



in the next Topic, I will explain the Common power system architecture for Health care facilities. so, please keep following.




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