Electrical Safety Devices for Hospitals
By Ikyatha Yerasala
To provide electrical safety in industries to a greater extent, some new devices need to be adopted. Ikyatha Yerasala talks to architect Raja Arjun, who reveals more.
While catering to electrical safety of hospitals, it’s important to keep track of the latest technologies and equipment that have hit the market or have been developed. Raja Arjun, Founder, Office of Cognitive Design (OCD) and Director of Strategy ACE Group Architects), throws light on the recent developments in protective devices that one needs to be aware of to ensure electrical safety in the healthcare sector.
RCCB
A residual-current device (RCD), or residual-current circuit breaker (RCCB), is a device to quickly disconnect current to prevent serious harm from an ongoing electric shock. Injury may still occur in some cases, for example if a person falls after receiving a shock. The device is more commonly known as a ground fault circuit interrupter (GFCI), ground fault interrupter (GFI) or an appliance leakage current interrupter (ALCI). In India these are better known by their initials RCD, and a combined RCD+MCB is known as a RCBO (residual-current circuit breaker with overcurrent protection). In Australia, they are sometimes known as safety switches or a RCD. An earth leakage circuit breaker(ELCB) may be a residual-current device, although an older type of voltage-operated earth leakage circuit breaker also exists. These electrical wiring devices disconnect a circuit when it detects that the electric is not balanced between the energized (line) conductor and the return (neutral) conductor. In normal circumstances, these two wires are expected to carry matching currents, and any difference usually indicates that a short circuit or other electrical anomaly is present. Even a small leakage current can mean a risk of harm or death due to electric shock if the leaking electric current passes through a human; a current of around 30 mA (0.030 amperes) is potentially sufficient to cause cardiac arrest or serious harm if it persists for more than a small fraction of a second. RCCBs are designed to disconnect the conducting wires quickly enough to prevent serious injury from such shocks. (This is commonly described as the RCD being "tripped".)
AFCIs
An Arc Fault Circuit Interrupter (AFCI) is a type of duplex receptacle or circuit that breaks the circuit when it detects a dangerous electrical arc, in order to prevent electrical fires. An AFCI distinguishes between a harmless arc that occurs incidental to normal operation of switches, plugs and brushed motors and an undesirable arc that can occur, for example, in a lamp cord that has a broken conductor in the cord. AFCI breakers have been required for circuits feeding electrical outlets in Patient rooms / suites of hospitals by the electrical codes of Canada and the States since the beginning of the 21st century; since 2014, U.S. code has required them for outlets. This has been proposed to be implemented in hospitals in India. Arc faults in spaces is one of the leading causes for electrical wiring fires. Conventional circuit breakers only respond to overloads and short circuits; so they do not protect against arcing conditions that produce erratic, and often reduced current. An AFCI is selective so that normal arcs do not cause it to trip. The AFCI circuitry continuously monitors the current and discriminates Between normal and unwanted arcing conditions.
GCDs
A Glowing Connection
Can develop anywhere electrical connections are made
Is currently difficult or impossible to detect until it's too late
Is particularly likely in older buildings with aging wiring
Can NOT be detected by a conventional circuit breaker
Can NOT be detected by a Ground Fault Circuit Interrupter
Can NOT be detected by an Arc Fault Circuit Interrupter
HFFR Cable
Recent developments have produced a prototype detector, capable of detecting intermittent series arcing as well as a glowing connection. The device consists of a small electronics package that is carried room-to-room, and individually plugged into the outlets. A series of LEDs indicate if any series arcing, or a glowing connection, is found. An electrician can use the device to isolate the circuit, or sometimes even the outlet, which harbours the hazard. With this information, an electrician can make Repairs, or replace faulty equipment or wiring before a disaster occurs.
Linear Heat Sensing Cable
Linear Heat sensing (LHS) cable is a very commonly used method of fire detection.
It can detect a fire anywhere along the length of the cable, and can be of lengths in excess of a kilometer
Applications can range from building fire alarm systems to mobile plant machinery.
Linear Heat Sensing (LHS) cable is essentially a two-core cable terminated by an end-of-line resistor (resistance varies with application).
Thermography surveys
Thermography can help you see heat and potential Electrical equipment failures before they become issues, helping you manage equipment costs, increase fire safety, and look for energy reduction opportunities.
A single critical fault (defined as a temperature delta of >75F above norm) can mean additional energy costs of apx.Rs. 55,000 annually and average repair or replacement costs of Rs.2,50,000, including components and labour.
On average, each thermography survey reveals five to eight faults, highlighting the relative affordability of this predictive service. Thermography surveys offer a low-cost, predictive maintenance tool to find and correct heat-related issues before more costly failure happens.