Coordinates for control building at any one corner, the plot boundary corners, anyone tower and transformer center lines should be marked in the plan layout. For this substation, if you see all the coordinates are marked for the plot corners, there's a point here. This is one of the corners, then this is one of the corners, then this is one corner. So all the four corners of the park boundary are marked then if you take the control building, so this is one coordinate, which is given Eastern North coordinates. Similar, this particular column central line, and this particular central line, and this particular central line. So all the coordinates are marked similarly, if you take the transformer central lines, the coordinates are marked here. Similar for the capacitor banks, the coordinate is marked for this capacitor bank, the coordinates are marked. So for C [FOREIGN] the coordinates are marked for these towers. Similarly here, every coordinate has been marked, similarly for 11 KV outgoing structures to post structure also the coordinates are marked. This particular substation, the lightning protection has been infused by means of spikes. This is called the spike, is 2m which is shown here this is called the lightning spike which is provided on top of the tower. So if you see the plan correspondingly, so this is there on all the towers. So calculations have been done to ensure there is a complete lightning protection covered for the whole area. That calculation is not a part of discussion of this particular topic. You should just know that lightning production spikes are provided and then calculations are made to verify, accordingly they are provided. So between these two power transformers, there is a firewall provided, the criteria is, this is a terminal transformer. This transformer definitely has got more than 2300liters of oil per transformer. If the clear distance between the two edges of the transformers is less than about 8m of this oil content then there is a firewall to be provided. If you see, based on the dimensions that have been provided here, this clear distance is less than 4m. So we provide a firewall between the two transformers. The criteria for dimension of the walls is also given, so that we will be seeing it subsequently as we progress along. This particular substation, there is no future space provision for any extension of the base, because no line or they cannot come this way already in the East West direction the space is limited. So there is no school for any future by extensions in this particular switch layout. Then, what are the minimum electrical clearances? Normally, it has been even in the table like this. So the minimum phase to phase clearance that I thought of the Kv is 320mm. The phase to earth clearance also is 320mm, the section clearance is 2,800mm, the ground clearance is 3700mm. So we will review these ground clearance and the sectional clearance aspects a little later, hope we can record these details. The same has been given for LAN cable system also. Only thing is normally in the LAN cable system. The phase to phase clearance is that we don't keep it around 150mm only, both phase to phase and they keep at 150mm only, we do not generally provide those parts of 280mm as part of the requirement. The important thing to be noted down is this, The height of the insulator bottom from the ground level should be kept at 2440mm as per the Indian electricity rules, what does it mean? So if you take, I'll just explaining the sectional layout, this is the top of the plant level. This is the insulator let us just say the bottom of the insulated is somewhere here. So this distance on top of the plant level to this insulated bottom which is this distance should be maintained minimum 2004 40mm. In any outdoor substation. If this is not maintained then the electrical inspectorate can call for a separate fencing of that particular equipment. This would be bad in mind. And normally if you see the sectional layout, the dimensions are marked from top of the plant alone. If you see this FGL means it is a finished ground level. Normally in a substation initially by the land it very much undulated and all so they had to cut some somewhere and then filled up somewhere and make it level ground. This that finished the ground level from the finished ground level. This is the top of the plant which is 300mm, all your heights are measured from top of print level. Normally in a substation initially by the land it very much undulated and all so they had to cut some somewhere and then filled up somewhere and make it level ground. But normally we mark here so that is 3800mm in this particular case which is ground clearance from here to the central bus bar which is strong, this is 5500mm like that. All the sensors are normally covered from the top of the current level and there is a gravel level from the finished ground level. The gravel level approximately 100mm from the top of finished ground level. So the difference between the top of it to the top of gravel be about 200mm that we can see clearly when we see the 3D movie layout. For LAN cable arrangement if you see we have a clear distance what I told before this 2440mm. So if that is required then there is no separate fencing is also required and then you can be very safely or to maintain. But if you have to work anything on this particular equipment in the 2 pole structure, the line, the particular thing has to be taken and shut down only for any work on this W pole structure. Power supply has to be shut down. Then some of the other points which can be of note, If you see this is a 33Kv current transformer, this is a 33Kv circuit breaker. These two equipment are generally commonly known to run a common structure at the same level as we go up to the higher voltage levels. Each equipment will have its own separate structure, but at the end of the cable level, these two equipment can have a common structure. So if you see in this transformer bay, they are having a common structure and if you see the LAN bay also, they are there in that common structure only. And if you see the plan, the start of the circuit breaker when it comes, it will be generally the multiple spacing will be comparatively less than the normal spacing water adapt in the layout because these are type tested breaker. So the manufacturer maintains a certain distance but in pole to pole, so that's why you will see. These conductors will get skewed here, it will not be going parallel and all so the fall to post placing here will be less. So these conductors will get a little skewed here. Triple mechanically ganged breaker is not an individually operated breaker. That is why this much of skewing welcome at 33Kv. Then the other point, If you see in this country building, this is the 11Kv switch gear, the single and item which we saw sometime before, so there is a sufficient clearance has to be maintained. So in case if I had to draw out any particular breaker, I would have sufficient space to move the equipment. Normally, at least minimum 1.5m will be kept in front of 11Kv switchgear switchgear so that the breaker can be drawn out and taken for any maintenance work and all. And then similarly we can see it subsequently later we should maintain suffering clearance between the back of this panel to the edge of the wall. Since this cables are terminated at the bottom, people need to work on the backside so suffering clearances should be maintained. So these clearance aspects, we will see subsequently as we move along. Some of the other important points we will tell you this firewall will discuss, so the criteria for the firewall between the two transformers for the dimensioning aspect we will see now. So these are two transformers of 10MBA rating the oil capacity of each transformer is more than 2300liters under clear distance between the two transformers if we say it is about 4m. So we are providing a wall in between the two transformers, what should be the dimensions of this particular wall in terms of plan as well as in elevation. So if you see this is the center line of the transformer. So from this central of the transformer, if you see this access, this is not so direction. So there is one end of the radiator here, there's one radiator here. So from these extreme dimensions this wall should project at least 600mm beyond. So from here, if you see if they projected here, this distance should be minimum 600mm this side. Similarly on this side as they come here, they should project 600mm on this side. Similarly, the height when I talked to hide the bushing height of the transformer from the top of the bushing height, the wall should protect at least 600mm about. Let me see when they can show you two in there elevation. The wall is not here in this particular sections, I cannot show it to you here so please bear it in mind that the height of the wall should be such that it should project 600mm above the top of the 33Kv bushing. How to know the ROB phase sequence in the layout, there is a standard ROB phase sequence which we normally follow. For transformers for any transformer as you view from the high vaulted side to the low voltage side. The left hand side of the bushing should always be our face. So you see this particular transformer, this is 33Kv side, this is 11Kv side. So 33Kv this side 11Kv this side, decided they said so as I view it from this side, this face should be our face, this will be Y face, this will be B phase. So accordingly you see this is getting connected here. This will be our face this would be Y phase and there should be a B phase. So this has to be coordinated with the incoming line which is being coming from the authority. So serious master suppose this is RYB. Suppose if there's a change here, let us say this in our phase here B phase coming here and our phase coming here then what will you do this? This has to come here but this one this tapping should go here, so this is very essential to coordinate this ROB. Phase sequence in your layout with respect to the transformer and coordinate with their utility, how they are giving us the ROB phase sequence. So this trapping portion place a very critical role in violence in our layout. The statutory clearances for the phase to earth, the phase to earth. Under sectional clearances whatever we are marked here. So we will now review these aspects together. So we will review the layout considerations such as what is the ground clearance, what is bus bar height and what is bay width etcetera. Which has been adopted for this particular project. Say 3800mm let us see has been marked from from top of the plant level to the central end of the bus bar 3800mm. This is called as the ground clearance. So for any particular voltage level, there are certain criteria how to arrive at this particular distance continued in next part.
