AU8937601A - Protective power supply interface - Google Patents

Description

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S&FRef: 577855

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Actual Inventor(s): Address for Service: Majdi M M Basheti 6/11-13 Eighth Ave Campsie New South Wales 2194 Australia Moh'd Ali S. Ammouri Spruson Ferguson St Martins Tower,Level 31 Market Street Sydney NSW 2000 (CCN 3710000177) Protective Power Supply Interface Invention Title: The following statement is a full description of this invention, including the best method of performing it known to me/us:- Documents received on: S2 INOV 2a01 5845c PROTECTIVE POWER SUPPLY INTERFACE This invention relates to improvements in equipment for protective power supply units.

Serious electrical accidents can happen to any one, not necessarily Just those who are inexperienced, but often to wellI trained professionals.

Everyday, many people must work with or near, potentially dangerous electrical circuitry. Often circumstances make it difficult to maintain adequate safety measures. This situation is common for construction workers, service crews, firemen and countless others who may not realize they are in danger.

Not only that, but many people also and on daily bases, tend to use electrical appliances of any sort most every where, such as refrigerators, freezers, washing machines etc.

Be it in homes, hotels, restaurants, hospitals and in many other places.

These appliances may very well, at one time or another, have an insulation fault due to age, or being installed in damnp areas, or due to a slight mechanical accident, causing a law undetected current leakage.

Such law leakage cannot be felt because they are well below the threshhold of human sensation.

However, each law leakage even in micro amps will slowly evolve and cause heavy damage and probably a fatal electric shock.

Taken from the symposium on electrical risk in medicine held in Paris 1981 on currents passing through the organism will cause: mA very little sensation.

01*010 mA muscular contraction.

mA respiratory paralysis.

0 75 mA irreversible cardiac fibrillation.

I mA cardiac arrest.

A leakage of few millianips can produce a spark and start a fire but not enough to blow a fuse or trigger the safety device, contrary to this invention.

3o People tend to rely on earthing systems and or earth leakage relay, also known as ground fault interrupters for protection yet, when a rated leakage current occurs, the relay trips off, and power is interrupted at the time when it is most needed, contrary to this invention.

-2- As for earthing, it was first designed for protection against lightning yet, for maximum safety and protection, ungrounded current supply Is most recommended by all standards, because when an insulation fault occurs in the system, most of the capacitive currents passing through conductors are very little. Thus, a single pole protection breaker will not trip, so isolated power) recommended will continue to provide safe and monitored current.

Early detection of insulation fault and repair are much less costly than partial or complete replacement.

Earth leakage relay an Electro-mechanical sensing device normally senses Iacurrent leakage in the range of 30 mA up and, then break the circuit.

Such a value or even less, may very well cause a muscular contraction and possible respiratory paralysis to a human touching this current, this is a disadvantage see electrical risks above This invention, referred to here as the Device can sense a leakage current as law as few micro-amps and warns by light and sound indicating the leakage value through the indicating panel mount meter on the device while maintaining the load, as indicated on the amp-meter and will continue to provide safe power supply when a single pole earth fault occurs, allowing the consumer reasonable time for checking and repair.

If the isolation resistance, on both poles, falls below a minimum value and/or an over-load occurs, the circuit breaker will trip. Hence, observation is recommended.

Just fit the Protective Power Sup ply Interface Device between the local power source and the electric equipment to be protected and, switch the breaker on.

S Earth line must be connected between the Device and the other equipment.

Another advantage of this Device is self monitoring; In case of a weak insulation in the Trans and a leakage of a very small current occurs, within the Device, warning signals will come on. Just plug the Device to the power source and turn the breaker on to check and to find out.

Thus avoiding any earth fault complication between the Device and the protected equipment.

Isolation earth faults being sensed, detected and monitored through the solid state printed circuit board within the Device.

-3- To assist with understanding the invention, reference will now be made to the accompaning drawing which show one example of the invention, In the dr-awing: FIG. I shows one example of the protective power supply interface according to this invention' Referring to FIG. I it can been seen that the protective power supply interface Device according to this invention comprises a metal case I consisting of two part mild steel cases for portable or bench top.

Top cover provide protection for front and rear panels.

Ventilation lourvers on sides aid cooling and with a built in miniature piezo electric buzzer, chassis mounting, with wide operating voltage 1-16 vdc. Both parts of the metal case are fixed together by 4 screws, 2 on each side or as necessary.

2 is a rubber foot, one on each corner for soft placing.

1< 3 is a double pole circuit breaker, thermo-inagnetic, panel mount.

Rated to match the transformers load.

4 a green power on indicating light, panel mount 240/1 20 vac.

a panel mount MA indicating meter 0- 100 A.

6 SPST. push button switch, panel mount.

7 momentary push button switch.

8 a red indicating light panel mount, 240/120 vac.

9 a panel mount Ampere-meter to indicate the applied load, 10 space for label to indicate brand name or trade name.

I I space for label to indicate technical specifications.

The rear view 15 shows another label 14 to indicate instruction, 12 are 3-pin socket out lets, panel mount, rated to correspond with the applied load.

13 is a strain relief bush holding the electric cord with a plug next to a panel mount load matching fuse in series with the cord connected to the primary of the Iso-Trans former.

FIG. 2/A is the PCB enclosed in a plastic mould 16 covered with an acid proof :9 non conductive resin for protection against moisture, dust ambient temperature and unnecessary tampering. PCB connected to a ten way terminal block 17.

18 space for a label to illustrate proper connections between PCB and components on front panel.

&4 The Device requires a built in Iso. Trans, shielded and of a desired capacity for small or medium application with most popular voltages 240/120 vac. 50/160 c/s on primary and secondary for single phase.

Size of the Device is determined by the size of Trans. used.

Other load complying components such as elect. Cords, plugs, fuses, outlets, main circuit breakers and their connecting conductors will comply with international specifications.

Suggested Trans. capacities up to 10 KVA.

FIG. 2/B illustrates the general wiring connections.

Connection from transformer secondary to the out put sockets LOAD) via the load amp.-meter, 4 in FIG. I insulated copper conductors size will comply with total load.

PCB connections and functions: 1t Terminal 1,2 are connected to the main load conductor. Terminal 1 is also connected to each via the push button switch 7 in FIG. 1 Terminal 3,4 connected to green power indicating light 4 in FIG.1 Terminal 5,6 connected to the buzzer via SPST push button 6 in FIG.1 Terminal 7,8 connected to the red light indicator 8 in FIG.1 to indicate earth S leakage when occurred.

Terminal 9,10 connected to the micro-meter 9 to indicate earth leakage value.

Terminal 10 is also earthed to the chassie as in terminal 1 and the out put load sockets 12 in FIG.1, rear view.

Size of connecting electric insulated wires from terminal block to components is mm. Sq.

Function: Plug the Device to power supply and turn the circuit breaker on, the green indicating light come on thus power is on.

If the read indicating light also comes on, then an internal isolation fault in the Device has occurred, and that is very seldom.

Turn switch 6 FIG. I on and press test push button 7 FIG. red indicating light will come on and the buzzer will sound, indicating that PCB is Ok. The Device is ready.

Turn circuit breaker off, plug the equipment to be protected in socket 12 FIG.I, eo turn the circuit breaker on, now the system is in operation.