Conduit sizing

Conduit sizing

The conduit fill is the amount of areas in square inches, of conductors inside section of conduit. Conduits fill is necessary for dissipation of heat, pulling of wires, potential high cost change orders when the conductors that you specified do not fit inside the conduit. We require conduit fill when we installing new conduit & conductors or adding new conductors to existing conduit run. The maximum allowable fill for new conduit is 26% & for old 40%. Some necessary instructions are remember:

·        Always put extra conduit in crossing roads.

·        If the conduit crossing is for illumination or power supply, put in a spare 2” conduit.

·        If the conduit crossing is for signal conduits at an intersection put in a spare 3” conduit. If the crossing is not at the intersection put in a spare 2” conduit.

·        A 2” conduit should be the minimum size used for all crossings.

·        Install a spare 2” conduit into a service cabinet.

·        Install a spare 2” conduit between all transformers and the improvement the transformer is serving.  (ITS cabinet, VMS cabinet, etc.)

·        Always best try to not use too many different sizes of conduits. Stick with even sizes of conduits. (1”, 2”, 3” or 4”).

·        Leave room for future conductors. Running 2” conduit nears the service or where there is potential for future expansion usually provides plenty of future room.

·        The conduit from the luminaries pole to the adjacent junction box  5’–10’  away shall be 1”. This is usually the only place you would ever run a 1” conduit in grade  (except the grounded electrode conductor)

Here two types of conduits are designed with illustrations.

1.     Rigid Metal Conduit: Type RMC

2.     Rigid Nonmetallic Conduit: Type RNC ( PVC schedule 40, PVC schedule 80 & HDPE schedule 40)

PERFORMANCE REPORT OF 1MW THIN FILM SOLAR POWER PLANT

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PERFORMANCE REPORT OF 1MW THIN FILM SOLAR POWER PLANT

Dated: 17-01-2013

M/s Conflux infratech Pvt. Ltd, Village: khirva, Tahsil –Falodi, Dist: Jodhpur, State: Rajasthan(India)

 The above1MW thin film Solar Power Plant is situated at village Khirva between Falodi and Bap road, about 22km from Falodi. The geographical coordinate of Falodi are Latitude: 27.23N & Longitude: 72.36E . The environmental temperature varies from 0° to 48° degrees centigrade’s. The solar insolation in December is 4.12 KWh/M^2/day  and in May is 6.97 KWh/M^2/day. The average solar insolation is 5.55KWh/M^2/day. In December month Solar panels starts to produce energy from 8.00AM to 4.00PM (8.00 hours) & in June month from 6.30Am to 5.30PM.( 11.00 hours) The Solar power available in AC form after deducting losses i.e module mismatching loses, high temperature loses, dirt & dust loses, wiring loses, DC to AC conversion loses. So the conversion factor is assumed 0.77.  So annual production of1MW power plant will be = 1000x365x5.55x0.77 = 1559827KWh .The power performance can be improved by minimize above loses.

The said unit has 21.00 bigha land. It consists of 8550 Nos. 85watt & 3600Nos. 77.5watt  thin film solar cell modules of First solar company from USA. All modules are UL approved. These modules are south faced, mounted on 135 fix axis supporting structure, 6 strings in each structure. From 135 structures 14 are not working. The solar power via combiner boxes goes to two 500KW inverters, after inversion it goes to 1.2 MVA step up transformer to grid. Suitable disconnects are also available.

1.    Nos. of  85 Watt First Solar thin film modules           8550     Power – 726.750KW

2.     Nos. of 77.5 Watt First Solar thin film modules       3600      Power – 279.000 KW

                                                                                         Total    Power -1005.750KW

Less :1  Broken Modules:  85 Watts                            144       Power- 12.240Kw

              Broken module    77.5Watts                           167       Power- 12.942KW

                                                                                      Total                 25.182KW

Net available power :   980.568 KW   or 0.980568MW,  Say .98MW   

       

Conflex infratech Pvt, Ltd, Village: Khirva, Tahsil: Falodi, Dist: Jodhpur

(Comparison table between estimated & actual energy harvesting)

Sn.	Months	Insolation- KWh/M^2/day	Estimated Power generation /MW	Actual power generation	Shortage	% Short /Excess
1	Mar16-2012	6.04	74413	53650	20763	27.90
2	April-2012	6.73	155463	126997	28466	18.31
3	May-2012	6.97	166374	70945	85429	57.31
4	June-2012	6.55	151305	98885	52420	34.65
5	July-2012	5.46	130330	114700	15630	11.99
6	Aug-2012	5.42	129375	71136	58239	4502
7	Sep-2012	5.85	135135	91407	43728	32.36
8	Oct-2012	5.31	126750	122267	4483	03.54
9	Nov-2012	4.99	115269	113071	2198	01.91
10	Dec-2012	4.12	98344	114586	-16242	-16.52
11	Jan17-2013		56418	56262	156	00.28
KWh	Average	5.55	1339176	1033800	305270	22.80

                                          I have inspected this unit on 17^th January, 2013 at 3.00PM during sun peak hours. Unfortunately it was cloudy day so available power up to 3.00PM was only 2542.00KWh. This energy is developed by 0.98MW power module instead of 1.005MW power module. The total energy, 1033.800MWh is generated from 16^th March,2012 to 17^th Jan-2013 ( Ten months). If the broken modules are replaced, than 2% (1033800x0.02= 20676KWh) energy can be harvest more. Then it will be 1054.476MW. But still there is gap of (1339.176-1054.476=284.700MWh). From above table about 20% less energy is sold. There may be some mistakes in data logger reading and actual delivered energy to the PPA agency.

The Plant started since 16^th March,2012. During this half month energy harvested was 53650KWh, which is 20763KWh less than estimated energy 74413KWh.  The % loss is 27.9. In May month % lose is 57.3, it show improper communication with PPA agency. August & September are rainy season months. October & November  it harvested better energy. In month of December 16% energy harvesting is more. This situation may be due to sunny days and full supply to grid.  During Jan17,2013 the energy harvesting is to the estimated level.

Findings:  There is no technical problem in Plant Machinery & erection. Lose of harvesting power is due to manual mistakes & communication gap between PPA authority.

Suggestions: 

1.    Broken modules should be replaced as soon as possible.

2.    Regularly clean modules from dirt & dust.

3.    Proper communication with electricity board to dispatch maximum harvested energy.

4.    By 2% extra modules for future breakages or for personal use.

5.    Single axis tracking can be used to improve the efficiency.

6.    One extra 1.2MVA  should be purchased in case of failure of plant transformer.

Enclosed: Insolation chart of Falodi

Preparedby:-

Chandanmal Jain +91 9829930553

B.E(Mechanical)

cmjain735@gmail.com,   chandan735@gmail.com

Solar Energy Consultant & Approved Valuer (P&M)

 Mahaveer Circle, Juna keradu marg

Barmert (Rajasthan)- India