SURENDRAN SOORAJ (IN)
SURENDRAN SREEHARI (IN)
| WO2020026258A1 | 2020-02-06 |
| US20140339900A1 | 2014-11-20 |
| I CLAIM: 1. A protected distribution board (PDB) integrated with low voltage load power distribution system in buildings with four levels of over cunent protection and three levels of ground fault protection for consumer building premise, said system comprising of: a mains grid source supply [1]; a second source supply [2] from solar /Uninterrupted Power Supply (UPS); an energy meter [ 18] of a meter board [17]; a Protected Distribution Board (PDB) box-1 [5]; a Protected Distribution Board (PDB) box-2 [30]; ~a 2 pole 63 A 300 mA earth-leakage circuit breaker (ELCB) [33]; and a 2 pole 63 A miniature circuit breaker (MCB) [34] in the meter board [17], wherein the PDB box-1 [5] comprises of: a 2 pole 63 A 30 mA earth leakage circuit breaker ELCB [6]; a 2 pole 63A miniature circuit breaker (MCB) [7]; four I pole MCB namely MCB-1 [10]; MCB-2 [11]; MCB-3 [12] and MCB -4 [13]; a 2 pole 3 position 40A change over switch [23]; a 2 pole 40A 30 mA ELCB [24]; and a 2 pole 40A MCB [25] for the second source supply [2], wherein the PDB box-2 [30] comprises of four, each 10mA leakage rated 2 pole residual current circuit breaker RCCBs [35, 36, 37, 38] which provides level-lground fault protection to external loads [19, 20, 21, 22], wherein the 2 pole 63A 30 mA ELCB [6] provides level-2 ground fault protection to the external loads [19, 20, 21, 22], wherein the 2 pole 63A 300 mA ELCB [33] on the meter board [17] provides level-3 ground fault protection to the external loads [19, 20, 21, 22], wherein the 1 pole MCB [10, 11 , 12, 13] provides level-1 phase fault protection to the external loads [19, 20, 21, 22] with rated demand current of each load circuit, wherein the 2 pole 63A MCB [7] rated to the rating of bus bar [9] provides level-2 face fault protection to the external loads [19, 20, 21, 22], wherein the 2 pole 63 A MCB [34] on the meter board [17] provides level-3 phase fault protection to the external loads [19, 20, 21, 22], wherein a fuse carrier [3] on the meter board [17] provides level-4 phase fault protection to the external loads [19, 20, 21, 22], wherein the second source supply [2] is selected using the changeover switch [23] and the corresponding external load [22] through 1 pole MCB [13] is protected by level- 1 overcurrent by 1 pole MCB [13] itself, level-2 by 2 pole MCB [25] and level-3 by the second source supply [2], wherein the 10mA rated 2 pole RCCB [38] provides level-I ground fault protection, the 2 pole 30 mA ELCB [24] provides level-2 ground fault protection, and the second source supply [2] itself provides level-3 ground fault protection, and wherein the system enables user to identify the type of fault in a consumer building premise as devices and faults are segregated in PDB box-1 [5] and PDB box-2 [30]. 2. The system as claimed in claim 1, wherein the PDB box-1 [5] and box-2 [30] are interconnected with wires [14.3, 81, 100, 110, 120, 30, 140]. 3. The system as claimed in claim I, wherein the second source supply [2] is directly connected to the 2 pole 40A 30 mA ELCB [24], then to the 2 pole 40A MCB [25] and then to the 2 pole 3 position 40A changeover switch [23]. 4. The system as claimed in claim 1 , wherein the 2 pole RCCB [35] operates for ground faults beyond 10mA in the load circuit of external load [19] including electric shock. 5. The system as claimed in claim I, wherein the three phase distribution of four wire grid source from the meter board [17] is converted to six wire system of three independent single phases at the meter board [17] and hence the fault level in the PDB box-1 [5], PDB box-2 [30] and the external loads [ 19, 20, 21 , 22] remain as 240V only. 6. The system as claimed in claim 1 , wherein each external loads [19, 20, 21, 22] are independently protected from phase fault through 1 pole MCBs [10, 11, 12, 13] and ground fault through the 2 pole RCCBs [35, 36, 37, 38] by which faulty circuit only will trip and isolate and eliminates blackout at consumer building premise. 7. The system as claimed in claim I ", wherein the 10mA leakage rated 2 pole RCCBs [35, 36, 37, 38] operate for ground fault as well as phase fault between two different phases and between phase and neutral of different circuits. 8. The system as claimed in claim 1 , wherein the external load circuits [19, 20, 21, 22] provided with the 10mA leakage rated RCCBs [35, 36, 37, 38] is less than the standard rating of 30 mA thereby providing an instantaneous energy saving of 20mA per consumer. |
| AMENDED CLAIMS, received by the International Bureau on 14 June 2023 (14.06.2023) I CLAIM: 1. A protected distribution board (PDB) integrated with low voltage load power distribution system in buildings with four levels of over current protection and three levels of ground fault protection for consumer building premise, said system comprising of: a mains grid source supply [1]; a second source supply [2] from solar /Uninterrupted Power Supply (UPS); an energy meter [18] of a meter board [17]; a Protected Distribution Board (PDB) box-1 [5]; a Protected Distribution Board (PDB) box-2 [30]; a 2 pole 63A 300 mA earth-leakage circuit breaker (ELCB) [33]; and a 2 pole 63A miniature circuit breaker (MCB) [34] in foe meter board [17], wherein the PDB box-1 [5] comprises of. a 2 pole 63A 30 mA earth leakage circuit breaker ELCB [6]; a 2 pole 63A miniature circuit breaker (MCB) [7]; four 1 pole MCB namely MCB-1 [10]; MCB-2 [11]; MCB-3 [12] and MCB-4 [13]; a 2 pole 3 position 40A change over switch [23]; a 2 pole 40A 30 mA ELCB [24]; and a 2 pole 40A MCB [25] for the second source supply [2], wherein the PDB box-2 [30] comprises of four, each 10mA leakage rated 2 pole residual current circuit breaker RCCBs [35, 36, 37, 38] which provides level-lground fault protection to external loads [19, 20, 21, 22], wherein the 2 pole 63A 30 mA ELCB [6] provides level-2 ground fault protection to foe external loads [19, 20, 21, 22], wherein foe 2 pole 63A 300 mA ELCB [33] on the meter board [17] provides level-3 ground fault protection to foe external loads [19, 20, 21, 22], wherein the 1 pole MCB [10, 11, 12, 13] provides level-1 phase fault protection to the external loads [19, 20, 21, 22] with rated demand current of each load circuit, wherein the 2 pole 63 A MCB [7] rated to the rating of bus bar [9] provides level-2 face fault protection to the external loads [19, 20, 21, 22], wherein the 2 pole 63 A MCB [34] on the meter board [17] provides level- 3 phase fault protection to the external loads [19, 20, 21 , 22], wherein a fuse carrier [3] on the meter board [17] provides level-4 phase fault protection to the external loads [19, 20, 21, 22], wherein the second source supply [2] is selected using the changeover switch [23] and the corresponding external load [22] through 1 pole MCB [13] is protected by level- 1 overcurrent by 1 pole MCB [13] itself, level-2 by 2 pole MCB [25] and level-3 by the second source supply [2], wherein the 10mA rated 2 pole RCCB [38] provides level- 1 ground fault protection, the 2 pole 30 mA ELCB [24] provides level-2 ground fault protection, and the second source supply [2] itself provides level-3 ground fault protection, and wherein the system enables electricity user friendly by removing the known types of defects of Miniature Circuit breaker Distribution Board (MCBDB), and wherein the system enables user to identify the type of fault in a consumer building premise as devices and faults are segregated in PDB box-1 [5] and PDB box-2 [30]. 2. The system as claimed in clairp 1, wherein the PDB box-1 [5] and box-2 [30] are interconnected with wires [14.3, 81, 100, 110, 120, 30, 140]. 3. The system as claimed in claim 1, wherein the second source supply [2] is directly connected to the 2 pole 40A 30 mA ELCB [24], then to the 2 pole 40A MCB [25] and then to the 2 pole 3 position 40A changeover switch [23]. 4. The system as claimed in claim 1, wherein the 2 pole RCCB [35] operates for ground faults beyond 10mA in the load circuit of external load [19] including electric shock. 5. The system as claimed in claim 1, wherein the three phase distribution of four wire grid source from the meter board [17] is converted to six wire system of three independent single phases at the meter board [17] and hence the fault level in the PDB box-1 [5], PDB box-2 [30] and the external loads [19, 20, 21, 22] remain as 240V only. 6. The system as claimed in claim 1, wherein each external loads [19, 20, 21, 22] are independently protected from phase fault through 1 pole MCBs [10, 11, 12, 13] and ground fault through the 2\pole RCCBs [35, 36, 37, 38] by which faulty circuit only will trip and isolate and eliminates blackout at consumer building premise. 7. The system as claimed in claim 1, wherein the 10mA leakage rated 2 pole RCCBs [35, 36, 37, 38] operate for ground fault as well as phase fault between two different phases and between phase and neutral of different circuits. 8. The system as claimed in claim 1, wherein the external load circuits [19, 20, 21, 22] provided with the 10mA leakage rated RCCBs [35, 36, 37, 38] is less than the standard rating of 30 mA thereby providing an energy saving of 20mA per consumer. |
VOLTAGE LOAD POWER DISTRIBUTION SYSTEM
FIELD OF THE INVENTION
The present invention relates to a protected distribution board (PDB) integrated with low voltage load power distribution system. More particularly, the present invention relates to protected distribution board (PDB) integrated with low voltage load power distribution system in buildings with four levels of over cunent protection and three levels of ground fault protection. Advantageously, the system of the present invention enables the consumer to install renewable energy or uninterruptible power supply along with grid power source.
BACKGROUND OF THE INVENTION
Electricity is an inevitable power source in modem human living utilities. Domestic utilities are most prone for various electrical hazards and electrical fire accidents caused by short circuit Nowadays, frequent problem of short circuit in electric wires has led to an increase in the number of fire incidents occurring in the city areas. Short circuits occur during overloading or when two bare wires touch. A circuit is said to be overloaded when too much current flows thereby causing heat buildup or wiring to break down. This can lead to sparks and fire. So, short circuit becomes unknown phenomena causing danger to the users of electricity in building.
Conventional Single Phase Neutral Distribution Board (SPN-MCBDB) Referring to Figure 1, conventional Miniature Circuit Breaker Distribution Board also known as MCBDB [30] is mainly used for distributing electrical power to various electrical devices in building. The MCBDB comprises of grid source supply from 2 pole 40A isolator [5] of meter board [17] wired through wires [61, 62] into a 2 pole 40A isolator [6], then to 2 pole 40A 30 mA cunent operated earth leakage circuit breaker ELCB [7], then phase line to rigid bus bar [9] in which outgoing load circuit control and short circuit protection MCBs [10, 11, 12, 13] are attached and then phase lines connected to it from the loads [19, 20, 21, 22] through phase wires [19, 20, 21, 22] respectively. The neutral line from ELCB [7] through wire [81] and ail load circuit neutrals [82, 83, 84, 85] are wired to common rigid neutral link [8] with terminal connection. The earth line from each load circuit [El, E2, E3, E4] is wired to the common rigid earth bar [14] with terminal connection which is an extension of earth link [15] on the meter board [17], Earth link [15] is directly connected to the earth electrode [16] inside the external earth pit created with specification.
The order of power supply distribution in buildings from various utility companies in India is as below. The mains power source [I] from utility company to a building will first enter the tariff meter [18] on the meter board [17]. From tariff meter [18] phase line enters a re-wire able or HRC fuse unit [3] whereas the neutral will be connected to a neutral link [4]. As shown in Figure- 1 a single phase neutral (SPN) connection the phase from the fuse unit [3] and neutral line from the neutral link [4] will be wired to the 2 pole 40A isolator [5] of MCBDB [30] in the building.
The mains from meter board [17] is connected to a 2 pole 40A isolator [6] or equivalent rating of the ELCB [7] used. Isolator is not used for on-load switching. It is used for replacing the ELCB [7] during fault replacement. The MCBs [10, 11, 12, 13] are used for convenient switching in and switching out of each circuit and additionally protecting its circuit from over-current and short circuit. A 2 pole earth leakage circuit breaker ELCB [7] with 30mA minimum leakage current level is used for protecting all the phases and neutrals going out of the MCBDB [30] from ground fault The ELCB (7) is assigned for protecting the users and devices from ground electrical shock and ground faults respectively. A phase to ground fault, the tripping of ELCB (7) will be instantaneous. A neutral to ground fault tripping may or may not happen. The leakage current level is well below 30 mA, tripping will not happen and continue the leakage until the fault current reaches above trip level of 30mA. For any ground fault tripping blackout occurs in that building premise.
Practical experiments in consumer premise exposed that multiple neutrals are feeding leakage currents. Leakage current measured between different neutrals of a common neutral bus bar is such that one neutral with 5 mA leakage another one with 7 mA and another with 6 mA. 7 mA path is with the lowest fault resistance. If the resistance between the main earth and main neutral is very high or disconnected the multiple neutral earth leakage current will circulate between the faults and ELCB never will trip.
Three Phase Neutral Distribution Board (TPN-MCBDB)
Three Phase Neutral Miniature Circuit Breaker Distribution Board [TPN-MCBDB] is the 415 Volt version of the SPN-MCBDB in which the incoming source supply is 4- wire system Three Phase Neutral 415V 50 Hz. It is used for power distribution in buildings above minimum demand of 5kVA and above or as specified by the utility company. Referring to Figure-2 or Figure-3 or Figure-4, for the outgoing load circuit distribution is similar to Figure-1 SPN-MCBDB [30]. The mains form grid source [1] is a 4-wire system [1.1, 1.2, 1.3, 1.4] directly connected to TPN energy meter [18] on TPN meter board [17]. From the energy meter phases are wired to fuse units [3.1, 3.2, 3.3] and the neutral wired to neutral link [4], then phase and neutral connected to a 4 pole 40A isolator [5], The three phase neutral 4-wire system on the 4 pole isolator [5] is wired to another 4 pole isolator [6] on the TPN-MCBDB [30]. These isolators are used for the purpose of convenient off load switching during maintenance. From the 4 pole isolator [6] phases and neutral are wired to 4 pole 40A 30 mA current operated ELCB [7]. The outgoing from the ELCB [7] phases are connected to separate bus bars [9.1 , 9.2, 9.3] and the neutral to common neutral bus bar [8] with terminal connections for incoming and outgoing neutrals. The rest are equivalent to Figure- 1 of the SPN- MCBDB. The MCBs connected to red phase is [10.1, 11.1, 12.1, 13.1], yellow phase is [10.2, 11.2, 12.2, 13.2] and blue phase is [10.3, 11.3, 12.3, 13.3], Similarly, the external loads are named [19.1, 20.1, 21.1, 22.1] for red phase, [19.2, 20.2, 21.2, 22.2] for yellow phase and [19.3, 20.3, 21.3, 22.3] for blue phase. Neutral wires from all the loads are connected to common neutral bus bar [8] and earth leads from all the circuits connected to common earth bus bar [14].
Problems detected in MCBDB:
1. More than one incomer could be connected to the same bus bar and if two incomers connected to the same bus bar increase, the fault level above the designed level towards heat will rise in that bus bar during fault
2. If the combined capacities of the two incomings (as mentioned in point 1) are above the fault cunent level, then both incomers will share the fault current and tripping will not happen. In such situation electrical fire could be expected in that consumer premise.
3. Inside the MCBDB more than one MCB could be interlinked for two or more outgoing loads. In the case of a phase fault, all the MCBs involved must trip in order to isolate the fault. If the combined capacity is higher than the fault current or the fault current is less than the combined rated current, tripping will never happen and an electrical fire could be expected in that consumer premise.
4. The interlinking is possible between the phase lines at the load side also. In the case of a phase fault, all the MCBs involved must trip to isolate the fault. If the combined capacity is higher than the fault current or the fault current is less than the combined rated current, tripping will never happen and an electrical fire could be expected in that consumer premise.
5. MCBDB phase lines and neutral lines are not independently protected as in the case of high voltage system where each line is independently protected. 6. All the loads could be looped with one single neutral and that may lead to rise in heat in that neutral wire leading to electrical fire hazard.
7. Inside the MCBDB an external load could be connected to any one of the MCBs. If higher load is connected to low rated MCB, nuisance trip will happen whereas if lower load is connected to high rated MCB, tripping will not happen resulting in electrical fire during fault in that circuit.
8. A neutral break at some point in the circuit of an SPN-MCBDB, phase may back feed through the broken neutral and it may create accidents.
9. An accidental neutral breakage at some point in the circuit of a three phase neutral TPN- MCBDB, 240V rated building electrical devices may feed with 415V through other switched load in such a way that one load with lower voltage and the other with higher voltage and the devices with over voltage may bum and create electrical fire in that faulted premise.
10. In India all the building devices are maximum 240V rated single phase only. By using 415 V TPN-MCBDB, the fault level of that building electrical system dangerously increases to 415V level towards heat rise and related hazards.
11. Any outgoing load circuit involving phase and neutral are not independently protected. Therefore, external looping between phases and neutral are possible.
12. More than one outgoing phase wire could be connected to one MCB of the MCBDB. Usually, high rated MCB will be used. A high resistance leakage between one of the phase lines and neutral of one circuit continuously will feed fault leading to electrical fire hazard.
13. A ground fault in any phase line of a load circuit of the prior art MCBDB will create black out at that consumer premise. A ground fault in the neutral of a circuit may not trip and continue to feed fault current towards heat rise and electrical fire hazard. If the resistance between the main earth and main neutral is very high or disconnected the multiple neutral earth leakage current will circulate between the faults and ELCB never will trip. 14. MCBDB is unable to protect the operators and users of electrical devices in a building from electrical shocks below 30 mA level.
15. As per specification, the allowable leakage or energy loss per metered electricity consumer in India is 30 mA, and the consumer has to pay for the leaked energy coming to roughly INR 25 (as per current power tariff) in his monthly bill. In India, nearly 187 million homes are electrified and totally eligible to create an energy loss of 10026 million units per year.
16. Uninterruptible power supply (UPS) or solar supply is impossible to connect inside the conventional grid MCBDB of the building. Therefore, domestic and commercial consumers are using UPS or solar supply away from the conventional MCBDB without earthing and protection.
17. As per specification the rated voltage of the MCBDB is 240V and 415V. Therefore, accidental feeding of 240V rated devices with 415V and burning become legal.
18. As per specification of prior art MCBDB, another test at place of installation is not required. Therefore, commissioning without test at consumer building premise leaving the chances of detecting serious errors.
19. Described above are the reasons for short circuit in a metered building consumer premise. Short circuit is the reason for electrical fire at metered building consumer premise.
20. Any fault tripping inside prior art MCBDB requires service of a licensed electrician to find out the type of fault occurred, as the consumer is unable to identify the fault by himself.
21. Consumer is unable to identify and locate the type of fault and to restore his supply after black out if any, due to ground fault
US20160225562A1 discloses about an enhanced circuit breakers and circuit breaker panels and systems and method using the same. US9373952B2 talks about low fault current isolator system. WO2016171098 Al discloses about power supply device with over current protection. US 10476253B2 relates to power pedestal including adjustable ground fault protection. KR20170015913A discloses about DC fault protection in converter-based DC distribution system. However, none of the prior arts does not mention about use of conventional MCB or RCCB as an embodiment in the construction other than processor-based devices and technology.
Accordingly, there exists a need for a system that enables the consumers to identify the fault occurred at their premise by themselves and calls the right agency for fast rectification. There is a need for a protected distribution board integrated with low voltage load power distribution system to make electricity user friendly by removing known eighteen types of dangerous defects of Miniature Circuit Breaker Distribution Board.
OBJECTS OF THE INVENTION
One or more of the problems of the conventional prior arts may be overcome by various embodiments of the system and method of the present invention.
It is the primary object of the present invention to provide a protected distribution board (PDB) integrated with low voltage load power distribution system.
It is another object of the present invention to provide a protected distribution board (PDB) integrated with low voltage load power distribution system in buildings with four levels of over current protection and three levels of ground fault protection for eliminating one or more known types of dangerous defects of Miniature Circuit Breaker Distribution Board (MCBDB). It is another object of the present invention, wherein the protected distribution board (PDB) integrated with low voltage load power distribution system enables electricity user friendly by removing the known types of dangerous defects of Miniature Circuit Breaker Distribution Board (MCBDB). •
It is another object of the present invention to provide a single phase neutral protected distribution board (SPN-PDB) integrated with low voltage load power distribution system.
It is another object of the present invention to provide a three phase neutral protected distribution board [3SPN-PDB] integrated with low voltage load power distribution system.
It is another object of the present invention, wherein the system comprises of two protected distribution board (PDB) boxes.
It is another object of the present invention, wherein one of the protected distribution boards (PDB) box-1 includes a load circuit over current protection and isolation system and the other protected distribution board (PDB) box-2 includes ground fault level- 1 protection and isolation system to enable users or consumers to identify the fault occurred at their premises.
It is another object of the present invention, wherein the system enables the consumers or users to install renewable energy or uninterruptible power supply along with grid power source. SUMMARY OF THE INVENTION
Thus, according to the basic aspect of the present invention there is provided a protected distribution board (PDB) integrated with low voltage load power distribution system in buildings with four levels of over current protection and three levels of ground fault protection for consumer building premise, said system comprising of: a mains grid source supply; a second source supply from solar /Uninterrupted Power Supply (UPS); an energy meter of a meter board; a Protected Distribution Board (PDB) box-1; a Protected Distribution Board (PDB) box-2; a 2 pole 63A 300 mA earth-leakage circuit breaker (ELCB); and a 2 pole 63A miniature circuit breaker (MCB) in the meter board, wherein the PDB box-1 comprises of a 2. pole 63 A 30 mA earth leakage circuit breaker ELCB; a 2 pole 63 A miniature circuit breaker (MCB); four 1 pole MCB namely MCB- 1; MCB-2; MCB-3 and MCB-4; a 2 pole 3 position 40A change over switch; a 2 pole 40A 30 mA ELCB; and a 2 pole 40A MCB for the second source supply, wherein the PDB box-2 comprises of four, each 10 mA leakage rated 2 pole residual cunent circuit breaker RCCBs which provides level- 1 ground fault protection to external loads, wherein the 2 pole 63 A 30 mA ELCB provides level-2 ground fault protection to the external loads, wherein the 2 pole 63A 300 mA ELCB on the meter board provides level-3 ground fault protection to the external loads, wherein the 1 pole MCB provides level- 1 phase fault protection to the external loads with rated demand current of each load circuit, wherein the 2 pole 63A MCB rated to the rating of bus bar provides level-2 face fault protection to the external loads, wherein the 2 pole 63 A MCB on the meter board provides level-3 phase fault protection to the external loads, wherein a fuse carrier on the meter board provides level-4 phase fault protection to the external loads, wherein the second source supply is selected using the changeover switch and the corresponding external load through I pole MCB is protected by level- 1 overcurrent by 1 pole MCB itself, level-2 by 2 pole MCB and level-3 by the second source supply, wherein the 10mA rated 2 pole RCCB provides level- 1 ground fault protection, the 2 pole 30 mA ELCB provides level-2 ground fault protection, and the second source supply itself provides level-3 ground fault protection, and wherein the system enables user to identify the type of fault in a consumer building premise as devices and faults are segregated in PDB box-1 and PDB box-2.
It is another aspect of the present invention, wherein the PDB box- 1 and box-2 are interconnected with wires.
It is another aspect of the present invention, wherein the second source supply is directly connected to the 2 pole 40A 30 mA ELCB, then to the 2 pole 40A MCB and then to the 2 pole 3 position 40A changeover switch.
It is another aspect of the present invention, wherein the 2 pole RCCB operates for ground faults beyond 10mA in the load circuit of external load including electric shock. It is another aspect of the present invention, wherein the three phase distribution of four wire grid source from the meter board is converted to six wire system of three independent single phases at the meter board and hence the fault level in the PDB box- 1 , PDB box-2 and the external loads remain as 240V only.
It is another aspect of the present invention, wherein each external loads are independently protected from phase fault through 1 pole MCBs and ground fault through the 2 pole RCCBs by which faulty circuit only will trip and isolate and eliminates blackout at consumer building premise.
It is another aspect of the present invention, wherein the 10mA leakage rated 2 pole RCCBs operate for ground fault as well as phase fault between two different phases and between phase and neutral of different circuits.
It is another aspect of the present invention, wherein the external load circuits provided with the 10mA leakage rated RCCBs is less than the standard rating of 30 mA thereby providing an instantaneous energy saving of 20mA per consumer.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1: illustrates single phase neutral metering board and single phase neutral distribution board in building according to prior art
Figure 2: illustrates three phase neutral metering board and three phase neutral distribution board in building according to prior art
Figure 3: illustrates three phase neutral metering board and three phase neutral distribution board in building according to another prior art
Figure 4: illustrates three phase neutral metering board and three phase neutral distribution board in building according to yet another prior art Figure 5: illustrates single phase neutral metering board and single phase neutral distribution board in building according to present invention.
Figure" 6: illustrates three phase neutral metering board and three phase neutral distribution board in respect of Red phase according to present invention.
Figure 7: illustrates three phase neutral metering board and three phase neutral distribution board in respect of Yellow phase according to present invention.
Figure 8: illustrates three phase neutral metering board and three phase neutral distribution board in respect of Blue phase according to present invention.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO
THE ACCOMPANYING FIGURES
The present invention as herein described relates to a protected distribution board (PDB) integrated with low voltage load power distribution system in buildings with four levels of over current protection and three levels of ground fault protection.
Construction of Single Phase Neutral Protected Distribution Board (SPN-PDB) The present invention relates to a single phase 240 Volts 50 Hz two wire system of incoming and outgoing feeders to achieve two levels of over current and two levels of ground fault protection for electrical circuits in building with the aid of conventional MCB and RCCB connected with two hard wires at the incoming source and another two hard wires in the load circuit to create independent phase and independent neutral between all outgoing circuits.
Referring to Figure 5, the single phase neutral protected distribution board comprises of mains grid source supply [1]; an energy meter [18] of a meter board [17]; a fuse carrier [3]; a neutral link [4]; a Protected Distribution Board (PDB) box- 1 [5]; a Protected Distribution Board (PDB) box-2 [30]; a 2 pole 63A 300 mA earth-leakage circuit breaker (ELCB) [33]; and a 2 pole 63A miniature circuit breaker (MCB) [34], The Protected Distribution Board (PDB) box-1 [5] comprises of a 2 pole 63 A 30 mA earth leakage circuit breaker ELCB [6]; a 2 pole 63 A miniature circuit breaker (MCB) [7]; four I pole MCB namely MCB-1 [10]; MCB-2 [ 11]; MCB-3 [12] and MCB-4 [13]; a 2 pole 3 position 40A change over switch [23]; a 2 pole 40A 30 mA ELCB [24]; and a 2 pole 40A MCB [25],
The Protected Distribution Board (PDB) box-2 [30] comprises of four, each 10mA leakage rated 2 pole residual cunent circuit breaker RCCBs [35, 36, 37, 38] dedicated one for each outgoing load circuit [19, 20, 21 , 22], The external load circuit phase and neutral wires [91-92, 93-94, 95-96, 97-98] are wired to each RCCB’s [35, 36, 37, 38] terminal-2 and terminal-4. Earth wires [El, E2, E3, E4] are connected to a common earth bus bar [32], The PDB box- 1 [5] and box-2 [30] are interconnected with wires [14.3, 81, 100, 110, 120, 130, 140],
The mains grid source supply [I] is directly connected to the energy meter [18] of the meter board [17] through phase line [1.1] and neutral line [1.2]. From the energy meter (18) the phase line [1.1] is connected to the fuse carrier [3] and the neutral line [1.2] to the neutral link [4], The phase line [1.1] and neutral line [1.2] from the fuse carrier [3] and neutral link [4] are wired to the 2 pole 63A 300 mA earth-leakage circuit breaker (ELCB) [33], The phase line [1.1] and neutral line [1.2] outgoing from the ELCB [33] are connected to the 2 pole 63A miniature circuit breaker (MCB) [34]. Another embodiment on the meter board [17] is an earth link [15] connected through an earth wire [15.1] to an external earth electrode [16] inside a created earth pit The incoming earthed neutral [1.2] of the energy meter [18] is connected to the earth link [ 15] to remove stray voltages between the neutral and ground of the consumer premise. The meter board [17] is connected to the PDB box-1 [5] with hard insulated copper conductor phase and neutral wires [61 , 62] respectively. The outgoing load circuit [19, 20, 21, 22] phase, neutral, and earth wire are connected to the PDB box-2 [30] interconnected with wires [81, 100, 110, 120, 130, 140] between PDB box-1 [5] and PDB box-2 [30].
Terminal- 1 of the 2 pole 63A 30 mA ELCB [6] is connected with the phase wire [61] and terminal-3 of the 2 pole 63A 30 mA ELCB [6] is connected with the neutral wire [62] coming from the meter board [ 17]. Terminal-2 and terminal-4 of the 2 pole 63 A 30 mA ELCB [6] are connected to terminal- 1 and terminal-3 of the 2 pole 63A MCB [7]. Phase terminal-2 of the 2 pole 63A MCB [7] is wired to a rigid bus bar [9] and neutral terminal-4 of the 2 pole 63A MCB [7] is wired to a neutral link [8] through wire [8.4]. A second source supply [2] from solar/UPS is directly connected to terminal-1 and terminal-3 of the 2 pole 40A 30 mA ELCB [24] through phase line [2.1] and neutral line [2.2] and terminal-2 and terminal-4 of the 2 pole 40A 30 mA ELCB [24] are linked to terminal- 1 and terminal-3 of the 2 pole 40A MCB [25]. Terminal-2 and terminal-6 of the 2 pole 3 position 40A changeover switch [23] wired from bus bar [9] to terminal-1 of the MCB [10] and neutral link [8] through wire [26] respectively. Terminal-4 and terminal-8 of the changeover switch [23] are connected to terminal-2 and terminal-4 of the 2 pole MCB [25] through wire [29] and [31] respectively. Terminal- 1 and terminal- 5 of the changeover switch [23] are connected through bus bar [9.4] to terminal- 1 of the MCB [13] and neutral link [28] through wire [27], The external load circuit I pole MCBs -1, 2 and 3 [10, I I, 12] are connected from the rigid bus bar [9] and I pole MCB-4 [13] connected from the bus bar [9.4], An earth link [14] connected to an external earth electrode [39] through earth wire [14.1] and another earth wire [14.2] as provision for earth connection to the second source supply [2], Another earth wire [14.3] from the earth link [14] is interlinked to the PDB box-2 [30] through an earth terminal bar [32]. Construction of Three Phase Neutral Protected Distribution Board [3SPN-PDB] Referring to Figures 6 to 8, the three phase neutral protected distribution board [3SPN- PDB] is tiie 415 Volt version of the SPN-PDB in which the incoming source supply is 4 wire system three phases and neutral 415V 50 Hz. It is used for power distribution in buildings above minimum demand of 5kVA and above or as specified by the utility company. The outgoing load circuit distribution is similar to Figure-5 of SPN-PDB. Tiie three phase neutral protected distribution board comprises of main grid source [ 1]; fuse units [3.1, 3.2, 3.3]; a neutral link [4]; a TPN energy meter [18] on a TPN meter board [17]; an earth link [15]; three 2 pole 63A 300 mA ELCB [33. 1, 33.2,33.3]; three 2 pole 63A MCBs [34.1 , 34.2, 34.3]; a Protected Distribution Board (PDB) box-1 [5]; and a Protected Distribution Board (PDB) box-2 [30].
The Protected Distribution Board (PDB) box-1 [5] comprises of a 2 pole 63 A 30 mA earth leakage circuit breaker ELCB [6.1]; a 2 pole 63A miniature circuit breaker (MCB) [7.1]; four 1 pole MCB namely MCB-1 [10.1]; MCB-2 [11.1]; MCB-3 [12.1] and MCB-4 [13.1]; a 2 pole 3 position 40A change over switch [23.1]; a 2 pole 40A 30 mA ELCB [24]; and a 2 pole 40A MCB [25].
The Protected Distribution Board (PDB) box-2 [30] comprises of four, each 10 mA leakage rated 2 pole residual cunent circuit breaker RCCBs [35.1, 36.1, 37.1, 38.1] [35.1, 35.2, 35.3], [36.1, 362, 36.3], [37.1, 37.2, 37.3] in respect for each red, yellow and blue phases and common for both sources RCCBs [38.1 , 38.2, 38.3] with reference to Figure-6, Figure-7 and Figure-8. A second source supply [2] is connected 2 pole 30 mA ELCB [24], then wired to 2 pole 40A MCB [25] and interconnected to each phases changeover switches [23.1, 23.2, 23.3]. The external load circuits [19.1, 19.2, 19.3, 19.4], [20.1, 20.2, 20.3, 20.4], [21.1, 21.2, 21.3, 21.4] and [22.1, 22.2, 22.3, 22.4] are each connected to one RCCB with wires [ 41-42, 43-44, 45-46, 47-48], [51-52, 53-54, 55-56, 57-58], [61-62, 63-64, 65-66, 67-68] respectively and earth wires from each load connected to corresponding earth links [8.1, 8.2, 8.3]. The PDB box-1 [5] and box-2 [30] are interconnected with wires [81, 101, 111, 121, 131, 141], [82, 102, 112, 122, 132, 142], [83, 103, 113, 123, 133, 143]. The PDB box-2 [30] is connected to an earth link [32] through wire [14.3] to PDB box-1 [5] earth link [14] and earthed through wire [ 14.1 ] connected to an external earth electrode [39] inside a created earth Pit- .
The mains form grid source [1] is a4 wire system [1.1, 1.2, 1.3, 1.4] directly connected to the TPN energy meter [18] on the TPN meter board [17]. The source neutral [1.4] is connected to the energy meter [ 18] and to the earth link [15] on the meter board [17] and wired through a wire [15.1] connected to an earth electrode [16] inside a created earth pit. From the energy meter phases are wired to the fuse units [3.1, 3.2, 3.3] and the neutral wired to the neutral link [4]. The three- phase four wire system 415V enters the fuse units [3.1, 3.2, 3.3] and neutral while going out as 3 numbers single phase or six wire system of 240V 50 Hz. Three phase grid phases from the fuse [3.1, 3.2, 3.3] are directly connected to terminal-1 of the 2 pole 63A 300 mA ELCB [33.1 , 33.2, 33.3] and terminal-3 of each wired from neutral link [4]. Terminal-2 and terminal-4 of each 2 pole 300 mA ELCBs [33.1, 33.2, 33.3] are directly connected to terminal-1 and terminal-3 of the 2 pole 63 A MCBs [34.1, 34.2, 34.3], Terminal-2 and terminal-4 are wired through wires [71-72, 73-74, 75-76] to the PDB box- 1 [5] 2 pole 30 mA ELCBs [6.1, 6.2, 6.3] terminal- 1 and terminai-3. Terminal-2 and terminal-4 of the 2 pole 30 mA ELCBs [6.1, 6.2, 6.3] are wired to the 2 pole 63A MCB [7.1, 7.2, 7.3] terminal-1 and terminal-3. The outgoing from the 2 pole MCBs [7.1, 7.2, 7.3] phases are connected to separate bus bars [9.1, 9.2, 9.3] and the neutral to common neutral bus bar [8.1, 8.2, 8.3], The rest are equivalent to SPN-PDB drawing shown in Figure-5 in respect of Red phase, Yellow phase and Blue phase. The load circuit MCBs connected to red phase bus bar [9.1] is [10.1, 11.1, 12.1] and [9.4] is [13.1]. The load circuit MCBs connected to yellow phase bus bar [9.2] is [10.2, 11.2, 12.2] and [9.5] is [13.2], and the load circuit MCBs connected to blue phase bus bar [9.3] is [10.3, 11.3, 12.3] and [9.6] is [13.3],
Working of Single Phase Neutral Protected Distribution Board (SPN-PDB)
The mains from grid single phase supply [ 1] feeding in to the load circuit of a building consumer premise is completely protected by the SPN-PDB with 4 levels of over current, short circuit protection and 3 levels of ground fault protection to each load circuit going out of an SPN-PDB.
For illustration:
Referring to Figure-5, consider outgoing load circuit [19] from PDB box-2 [30] and the explanation for all other loads from the SPN-PDB is same. The first level of over current and short circuit protection is provided by the single pole MCB-I [10] in PDB box-1 [5]. The single pole MCB-I [10] is the first one to operate for any overcurrent fault in the load circuit [19]. The rating of the MCB-1 [10] will be equal to or above maximum current demand level of that circuit. If due to any reason, the MCB-1 [10] becomes dysfunctional, the 2 nd level device is the 2 pole MCB [7] of the box-1 [5] that will operate and isolate the fault. Similarly, 3 rd level device is the 2 pole MCB [34] on the meter board [ 17] and the 4 lh level of over-current protection is provided by the fuse carrier [3] in the meter board [17] and work as upstream stand by protection to the MCB-1 [10],
Referring to Figure-5, the outgoing load circuit [19] from PDB box-2 [30] is protected from level- 1 ground fault by the 2 pole RCCB [35]. The rated leakage level of the 2 pole RCCB [35] for trip is I OmA and the operation on phase earth fault or neutral earth fault will be instantaneous or less than 100 milli seconds. If the 2 pole RCCB [35] becomes inoperative due to some reason, the upstream backup protection device level- 2 is the 2 pole 63A 30 mA ELCB [6] on the PDB box-1 [5] with a leakage rating of 30 mA will operate and isolate the fault. Another level-3 upstream ground fault protection device 2 pole 63 A 300 mA ELCB [33] with a leakage rating of 300 mA on the meter board [18] also will detect the fault and will operate on the failure of the level-2 ground fault device ELCB [6]. Nowadays the electricity utility companies are insisting the consumers to install the energy meter on the boundary wall, for easy access for meter reading. In such scenario underground cable will be used for inter connection between the meter board [ 18] and SPN-PDB box-1 [5]. The leakage rating of the ELCB [33] is as high as 300 mA to make sure that it operates only on fault in cable or at a worst situation as backup operation.
The load circuit [22] could be fed from either grid source [I] or solar/UPS source [2] through the selections of the change over switch [23]. When selected for grid source [1], the protection for load circuit will be as explained for load circuit [19], and when selected for solar/UPS the upstream protection devices will shift to the 2 pole 40A 30 mA ELCB [24] and the 2 pole 40A MCB [25], but the downstream protection devices MCB-4 [13] on the PDB box-1 [5] and the 2 pole RCCB [38] on the PDB box-2 [30] will remain the same.
The external source supply [2] from solar or UPS device is directly connected to the 2 • pole 40A 30 mA ELCB [24] on the PDB box-1 [5] will work as the main earth leakage protection for the whole source supply [2]. The outgoing load circuit [22] from the PDB box-2 [30] first level of over current and short circuit protection is provided by the single pole MCB-4 [13] in the PDB box - I [5]. The single pole MCB-4 [13] is the first one to operate for any over-current fault in the load circuit [22]. The rating of the MCB-4 [13] will be equal to or above maximum current demand level of that circuit In case due to any reason, if MCB-4 [13] becomes inoperative the 2 nd level device is the 2 pole MCB [25] of the PDB box-1 [5] which will operate and isolate the fault. Similarly, 3 rd level over-cunent device is the solar/UPS equipment itself. The outgoing load circuit [22] from the PDB box-2 [30] is protected from level -1 ground fault by the 2 pole RCCB [38] of box-2 [30]. The rated leakage level of 2 pole RCCB [38] for trip is 10mA and the operation on phase earth fruit or neutral earth fault will be instantaneous or less than 100 milli seconds. In case of the 2 pole RCCB [38] on the PDB box-2 [30] becomes inoperative due to any reason the upstream backup protection device is the level-2 ELCB [24] on the PDB box-1 [5] with a leakage rating of 30 mA wilt operate and isolate the fault. Another level-3 upstream ground fault protection is provided by the solar/UPS device itself.
Working of invented Three Phase Neutral Protected Distribution Board [3SPN- PDB]
The working of three-phase neutral protected distribution board [3SPN-PDB] is similar to the working of SPN-PDB. 3SPN-PDB means three numbers SPN-PDB. Referring to Figure-6 or Figure-7 or Figure-8, the 4 wire three-phase 415V system is converted into 6 wire three numbers single phase 240V 50 Hz system in the meter board [17] itself. Every outgoing single phase load circuit has its own RCCB and will provide independent circuit protection. Therefore, phase mixing or neutral mixing will cause tripping of those RCCBs and isolation of those circuits involved. Testing and commissioning of every SPN-PDB and 3SPN-PDB after site installation is mandatory to compare with factory test results and test results should be maintained for future references during periodical service and maintenance. This way PDB will ensure electrical safety and protection at building consumer premise throughout its life.
Advantages of the system of the present invention are as follows:
1. The system eliminates short circuits caused by either phase faults or ground faults. The system arrests or removes electrical fire chances from the building premise. 2. Electrical shock while using or operating building electrical devices will never sustain beyond 10mA ground fault current level.
3. The fault level inside the protected distribution board (PDB) of the present invention and electrical circuit inside the consumer building will never increase beyond 240 V level.
4. The system eliminates complete power failure or blackout inside the consumer building premise due to phase fault or ground fault in the load or load circuit.
5. Other than grid source, a second source supply from solar or battery powered UPS could be connected to the protected distribution board (PDB) and simultaneously use the power in such a way that higher loads always through grid source and lower loads (through Grid supply or through UPS supply) in either or manner.
6. With respect to energy savings, by using protected distribution board (PDB) of the present invention with 10mA leakage level in India, an energy saving of 7053. 0167 million units per annum could be achieved. (The approved energy leakage level as per BIS specification per metered consumer in India is 30mA equivalent to a total energy loss of 10579.525 million units per annum)
7. Every phase line going out of the protected distribution board (PDB) is independently protected and if a mixing between any two phases lines occurs, the circuit involved in the mixing will trip and isolate by taking load current
8. Every neutral line going out of the protected distribution board (PDB) is independently protected and if a mixing between any neutral occur, the circuit involved in the mixing will trip and isolate by taking load current
9. Every circuit involving phase and neutral of the protected distribution board (PDB) are independently protected and if a mixing between the circuits or phases of the circuits, or between the phase of one circuit and neutral of the other circuit occur, the circuit involved in the mixing will trip and isolate while taking load current 10. At the load side of the protected distribution board (PDB) any electric shock between two different phases or between face and neutral of different circuits will never sustain beyond 10mA.
11. The system enables the consumer to identify the type of load circuit fault that occurs at the consumer premise.
12. The system enables the utility company to identity the fault at a consumer premise by telephone call or video call or through questionnaire while registering complaint and the remedial measure could be offered before sending emergency team to the site.