Switch installation procedures

Two types of switches are generally used in the solar home system. First type is wall mount switch, which is fixed permanently on to the wall of the house by using the mounting screws. Second type is bed switch or hanging switch, which is not fixed on to the wall but instead hanged with the help of wires. The quality of latter one should be of better one other wise there is possibility of frequent failure.

Figure 7.7.1. Types of switch

Switch should be installed on the predetermined location marked initially during wire layout design. Use screw to fix the switch on the wooden wall. If the wall is made from mud or brick use wooden or nylon grip for holding screw.

Hanging

switch Wall mount

switch

The wiring of the switch starts with the cutting of the red wire in the middle of the loop provided by using the wire cutter. Use the wire stripper to remove the ½ inch of the wire insulation from the cut ends of the wire. During removing insulation make sure that no piece of wire get broken or no stain from the stripper be made o the wire. If the insulation removed wire is very flexible, twist 1-2 turns. Then remove the screw from the wire holding holes inside the switch by using screwdriver and insert the insulation removed wire ends into two different holes. Do not insert the insulation containing part of the wire inside the wire gripping holes of the switch. Tighten the screw to grip the wire end inside the holes and test the gripping of wire by pulling the wire slightly.

In some lamps switch is already included in the lamp itself as shown the figure 7.4.2. For these type of lamps there is no need for the installation of the switch on the wire passing through the lamp but care should be taken to determine the position of lamp so that switch is easily accessible.

Figure 7.7.2. Solar lamps with inbuilt switch 7.8 Power socket installation procedures

For the operation of television and cassette player, the power needs to be given through the battery. For supplying the power to these appliance three-pin socket will be used. The location of the socket should be in that place where usually family gathering take place such as living room. For the installation of the socket mark the position in the wooden pillar or wall for the housing the socket. Extend the 3/22 grade wire from the junction box to the socket. Remove the insulation from the end of the extended red and black wires and insert it into the holes in the terminal of the socket. Screw the holes containing the

inserted wires inside the terminals of the socket. For the uniformity in the wiring connection use (+) red wire on the left side of the socket and (-) black wire on the right side when viewed from front side as shown in the figure 7.8.1.

Figure 7.8.1. Wiring connection for socket

If there is switch also in the socket then use the wiring method as shown in the figure 7.8.2.

Figure 7.8.2. Wiring connection for socket with switch 7.9 Components assembly of Solar Home System

During the installation of the solar home system each components of the system must be tested and installed separately followed by joining each other as following,

a) Connection of the wire going towards the battery to charge controller b) Connection of the wire coming from charge controller to the battery

c) Check the functioning of the indicator in the charge controller showing condition of the battery

d) Connection of the wire coming from the solar module to the charge controller

Red Red

Back side view Front side view

Switch

Black

± —

Black Red

e) Check the functioning of the indicator in the charge controller showing the charging of the battery from the module

f) Connection of the wire coming from junction box to the charge controller

7.9.1 Connection of the wire going towards the battery to charge controller

Wire for connecting charge controller with the battery is generally supplied separately by the SHS manufacturer. This wire is generally thicker than the one used for connecting the lamps and it contains cable shoe at one end for connecting it to the battery as shown in the figure 7.9.1.

Figure 7.9.1 Wire for connecting charge controller with battery

The other side of this wire does not contain cable shoes. The insulation of about ½”

should be removed from this free end and its red wire should be connected to the terminal of the controller printed with battery (+). During connection of the wire to the terminal , the wire should be inserted into the hole of the terminal and screw should be tightly used to fix it properly. The length of the bare wire inserted into the terminal should be equal to the thickness of the terminal only and cut the wire if extend beyond that to prevent short circuit. Follow the same procedure for the black wire by connecting its free end with the battery (-) printed terminal of the charge controller.

7.9.2 Connection of the wire coming from charge controller to the battery

This connection should be done very carefully. If mistake occurs this might damage the charge controller. For connecting it, first identify the positive (+) terminal of the battery.

Connect the red wire with cable shoe coming from battery (+) printed terminal of the charge controller to the (+) terminal of the battery. Then connect the black wire with

Cable Shoe

cable shoe coming from battery (-) printed terminal of the charge controller to the (-) terminal of the battery carefully.

Figure 7.9.2 Positive (+) and negative (-) sign printed in the battery

After connecting the wire to the battery observe whether the battery condition-indicating indicator of the charge control light. If the indicator light properly then connection is considered as correct. If the indicator does not light properly, examine the connections made at the battery and charge controller once again. If the connections are found perfect, apply petroleum jelly, grease, or Vaseline at both terminals of the battery. If the connections done to the battery and charge controller are OK but battery condition indicating indicator is not functioning correctly then there is the possibility faulty in of either charge controller or battery. In this case first replace charge controller if this does not work then replace battery.

7.9.3 Connection of the wire coming from the solar module to the charge controller

Before joining the wire coming from solar module to the charge controller check the wire if there is proper voltage generated from the solar module. For this adjust the selector switch of the multimeter to DC 50V range and connect the red probe of the multimeter to the (+) terminal and black probe to the (-) terminal of the solar module. Remove ½” long insulation from the red and black wire coming from the solar module. Connect the red probe of the multimeter to the red wire coming from (+) terminal of the solar module and black probe of the multimeter to the black wire coming from (-) terminal of the solar module. The voltage should read between 12 – 22 V if the voltage coming from the module if functioning well. If the meter shows negative value then check the wire connected to the junction box of solar module (connection of red and black wire may be interchanged). If every things goes well connect the red wire coming from the (+) terminal of the module to the terminal of the charge controller printed (+) below the solar module sign. Follow the same procedure for the black wire coming from the (-) terminal of the module by connecting (-) terminal of the module to the terminal of the charge controller printed (-) below the solar module sign. Cover the solar module with cloth

+ +

during connecting it to the charge controller to prevent electric shock. If the connection goes well then indicator in the charge controller showing the charging of the battery by solar module will light.

7.9.4 Connection of the wire coming from the junction box to the charge controller Before connecting the wire coming from junction box to the charge controller, switch off all the light and loads connected to junction box. Then connect the red wire coming from (+) terminal of the junction box to the respective positive connector of the charge controller with (+) printed below sigh of lamp. Now carefully connect black wire coming from (-) terminal of the junction box to the respective negative terminal of the charge controller with (-) printed below sigh of lamp. If there is short circuit inside the connections of the junction box with red and black wire coming from load touching each other then the fuse of the charge controller might goes off or the spark might occur burning wire. If this happens, disconnect the wire joining the junction box with charge controller and check the connections at the junction box. Check the short circuit along the length of the wire joining the junction box with charge controller by using multimeter. If every thing goes well then connect red wire first and just touch the bare end of the black wire coming from the junction box to the respective terminal of charge controller. If it connections and wire condition are OK then it should not give spark. Connect the black wire to the controller if every thing goes well.

7.9.5 Connection of the DC/DC Converter

To connect the input of the DC/DC converter to the power socket join the wire coming from (+) and (-) terminal of the converter to the respective connector of the three pin plug. Then connect the plug to the socket and switch ON the converter. If there is power indicator in the converter then it should light. Then measure the output voltage of the converter. If multimeter shows proper voltage reading then installation of the converter is considered as done correctly.

7.9.6 Connection of the DC/AC Inverter

For connecting the DC/AC inviter to the system, first of all connect the required length of wire to the three pin plug taking into consideration of the polarity of the three pin socket i.e. (+) and (-) terminals. Then connect the other end of the wire to the respective (+) and (-) DC input terminals of the inverter. The inverter main switch and socket switch must be switched OFF before these connections. After finishing the connection, switch ON the socket switch followed by inverter main switch. Measure the AC volt output from the inverter. If the reading shows around 220 V then installation of the inverter is considered as done correctly.