Now we're going to see the statutory clearances requirement. We will now study the clearance aspects which ought to be kept in mind. These are required from safety considerations on how to be approved by the electrical inspector prior to charging of the substation. Now let us go to section A-A for 33 kV line bay and 33 kV main bus. For easy reference, we have marked, for example, one denotes phase to Earth clearance. Two, denotes sectional clearance. Three, denotes phase to phase clearance. Now, let us see what are the phase to earth clearances involved in this section we're in. This is a 33 kV incoming line which is terminated on the gantry. There's a potter loop taken here for the lightening arrestor. Then there's a quarter loop taken through the suspension string with a PD isolated for further connections. This is the live part of the conductor. This is the beam. This corner of the beam to this live conductor, we must ensure minimum phase to get clearance. Similarly in this loop, but in this corner of the beam to this live conductor, this is the minimum phase to get clearance we must maintain. Similarly, if you see here, there is a current transformer and circuit breaker which are mounted on a common structure. In this level, you see there is a jumper connection from the current transformer to the breaker. Breakers will have two levels of terminals, what is upper terminal and lower terminal? If the connections are made this way, the lower terminal is getting connected to the CD. Then you'll see from this corner to this part of the structure of the CD to this left corner, we must maintain the phase to the Earth clearance. But had it been connected in a different way, for example, if the breaker had been rotated by 180 degrees, this current transformer terminal breaker can be connected like this. Then from here, breaker terminal to isolator lower level. This is what you will see in the 3D movie file. The connections there are a little different, we'll be able to appreciate it there. As per this going in for see, then you are to see their phase to earth clearance between this live jumper to this particular structure. Sectional clearance, we will see. Now, this is a third of the GAVI incoming line. This is a live part of the conductor. Now, suppose if this particular breaker has to be maintained, this breaker has to be opened. Then once this breaker is open, this isolator will be open. This end of the isolator will be live. It is possible to be in live condition. In this particular substation, this is the third of the GAVI incoming line which is live. If I want to maintain this particular circuit breaker, first, I will trip the circuit breaker, open this isolator. This is of course being only one incoming lines, so even if I open this isolator, the remote end of the line also can be open. But to explain the philosophy, let us just say this isolator is now open, this terminal will be live. When I'm working on this breaker, this live point to this baker, I should include minimum sectional clearance. Similarly, if AC, this is the bus bar. This bus bar, if they are having more incomers, if there are two incomers up there, this bus bar can be live, as we saw yesterday in a single line diagram. If I had to maintain this particular breaker, this is a live end. From here to this breaker, we should have the minimum sectional clearance, which is 2,800 in this particular case. This sectional clearance between two adjacent base, we will show it more clearly in the plan. This is one transformer bay. This is other transformer bay. For example, if you are working on this transformer or something, or this base under shutdown, but at this bay is still live, so these conductors are all in a live condition. This bay I have to maintain. If this end is live if am working here, this distance will be minimum section present should be maintained. That's what a mark does to here this distance. Similarly, when I'm working on this particular isolator, assuming the isolator has to be kept in the open position this open position of the isolator to disclose the position of this isolator because this is prose working. This I must enter a minimum sectional clearance here. This is how it should be checked. Then phase to phase clearances. Phase to phase clearance, now we will see the phase-to-phase clearance minimum phase-to-phase clearance aspects. We have seen Chapter 3 in this section layout. This is the conductor which has been strunk, and below, there is a bus bar running horizontal at 90 degrees. Between these two conductors, we must ensure minimum phase-to-phase clearance. This can be again, appreciated better in the plan. We will just see it in the plan. See these are the conductor which are running. This is the R phase of the conductor. This is Y phase, this is B phase. Similarly, there's conductors running below this. For example, let us take this as the B phase of the conductor, and this is R phase, this is Y phase. Between these two points here, at the top, because this conductor is running at 5.5 meter this conductor below is running at 3.8 meter, so considering sag and all you have to measure the clearance at this particular point on this particular point. This will be ensured. That's how we accordingly arrive at the heights of these structures and all that. Now, we will go to the Section BB, which is for the 33kV main bus on the transformer bay. Item marked as one is the Phase 2 that clearance between the breaker live terminal to the CT tank, which we have already discussed. Section of clearance between the isolator and the breaker. If I am to maintain this particular breaker, this isolator arm will be live because it is fed from the bus bar. From here to this, I must ensure minimum sectional appearance of 2,800mm. Please note that there is no requirement of isolator in the transformer bay after the current transformer because once there is an interpreter being vicinity is provided we didn't thought of the kV breaker and the associated 11 kV breaker. When 33 kV breaker trips, the 11 kV breaker trips, that breaker can be closed only when this particular breaker is closed. There is no battery which is going to come from this side. That is why there is no requirement of any isolator here after the current transformer in the transformer bay. As we have discussed, the layout if this transformer I were to take out for any maintenance aspect, this particular structure which is supporting the cable and the lightning arrester, they will have to be dismantled. That only the transformer can be taken hold for any maintenance. We now see the typical 11 kV outgoing line bay to a pole structure arrangement. See the Section CC, which is 11 kV, outgoing line base. From the 11kV switchgear, from the control where the cable is coming, this cable is getting terminated here. From here it is going into the isolator terminal and then it goes to the line and it gets connected to the lightning arrester also. We will now see the typical 11kV outgoing line beam. From the 11kV switchgear panel, you see the cable is getting terminated on this tuple structure. This is a cable supporting structure. From this, there's a jumper connected to the isolator. Then it is getting connected to the line and we're also getting connected to the lightning arrestor. As we discussed, minimum phase-to-earth clearance will be maintained between this point to the live conductor. Similarly for this isolator also, this is a live conductor. This is the frame of the isolator. We should maintain that minimum phase-to-earth clearance. Then whenever you are going to work on this particular pole structure, the 11kV freighter has to be shut down. You can see that more clearly in this particular view. This is the isolator. The cable is coming here. It is getting connected to the lightning arrestor, jumper and then the line is going like this. This height is kept at 7,500 a month for the 11kV outgoing line. We have seen that there is one 11kV switchgear bay has been kept for the auxiliary transformer of 100kVA. If we refer to this particular Section F-F and Section E-E, you can see this transformer is monitored on the tuple structure itself. There's a beam provided here wherein resistor kept here. If you see, the height has been kept minimum 2,440 mm. There is this AB switch drop-off fuse arrangement then the station transformer is given, the connections are made. If I told you how to do any work on this particular thing, the 11kV switchgear panel, that freighter has to be shut and then operate the drop-off fuse and then you can work on this. The fuse has been basically provided for isolation as far as for the protection. Having seen the clearances, some of the aspects in the outdoor switch chart, what are the clearances that we should see in the control building which is housing the 11kV switchgear? Let us just see that. You will see the 11kV switchgear panels here. This is vacuum switchgear, route tape of switchgear panels. We need to draw out the panels for any maintenance like this. Minimum distance of at least about 1.5 meters should be available in front of this switchgear so that I can record this panel and then take it to a convenient place and then do the maintenance work. Once the maintenance work is finished, then we can put it inside and then we can operate the system. Since all these 11kV switchgear panels, are outgoing freighters, and incoming freighters are all terminated by a cable from the backside terminations, this denotes cable terminations at the back, we need clear working space behind these panels. As per the Indian electricity rules there are certain criteria, how much should be the space which should be available? 150 mm should be available. Either it should be less than 200 a month if there is no requirement of any work, or it should be minimum of 750 a month or more than 750 a month. It should be available here. Accordingly, the clearance is kept here. If I'm working with 150 minimum and all there's a passageway. The clear height also should be available so that there's no obstruction. That passageway height should be at least 1,800 a month so that a person will be able to freely move without any obstruction in-between. This aspect has to be checked well presenting this dimensioning of the panels and all that. Now we can go through the 3D movie file for more clarity on the layout part of it. Whatever we have seen now is on a two-dimensional platform. We will see the same layout in a 3D form.