Guys for Support

2
Anchoring and Providing Guys for supports : Normally the guys are provided to the supports at the following places : 1. Angle locations 2. Dead and locations 3. Tee-off points 4. Steep gradients location to avoid uplift on the pole. Sometimes storm guys are provided along the straight run at equal intervals where wind pressure is more than 50kg/M2. The installation of guy will involve the following works. 1. Excavation of pit and fixing of stay rod 2. Fastening of guy wire to the support 3. Tightening guy wire and fastening to the anchor. The marking of the guy pit for excavation, the excavation of pits and setting of the anchor rod must be carefully carried out. The stay rod should be placed in a position such that the angle of inclination of the rod with the vertical facr of the pit is 35o/45o as the case may be. The concreting of the stays at the bottom should then be carried out. The back filling and ramming must be well done thereafter and allowed to set for at least 7 days. The free end of the guy wire is passed through the eyes of the anchor rod, bent back parallel to the main portion of the guy and bound after inserting the GI thimble. The loop is projected by the GI thimble where it bears on the anchor rod where the existence of the guy wire proves hazardous, it should be protected with a suitable asbestos pipe, fitted with concrete about 2 Mt. length above the ground level, duly painted with white and black stripes so that it may be visible at night. The turn buckle shall be mounted at the pole end of the stay and guy wire so fixed that the turn buckle is half way in the working position, thus giving the maximum movement for tightening or loosening. Guy insulators are placed to prevent the lower part of the guy from becoming electrically energised by a contact of the upper part of the guy when the conductor snaps and tail on them or due to leakage. Guy insulator shall be located at 2/3 of its length from the ground. The minimum breaking load of guy insulator shall be 9900 Kv. for 11 KV and 4000 kg for LT lines. Fixing of cross Arms and Insulators : After the erection of supports and providing guys the next step would be to amount the cross arms on the support. The practice of fixing of cross arm before the pole is erected is followed in some states. In case the cross arm is mounted after the support is erected, the lineman should climb the support having requisite

description

anchoring and guys for electrical support

Transcript of Guys for Support

Anchoring and Providing Guys for supports : Normally the guys are provided to the supports at the following places : 1. Angle locations 2. Dead and locations 3. Tee-off points . !teep gradients location to avoid uplift on the pole. !ometimes storm guys are provided along the straight run at e"ual intervals where wind pressure is more than #$%g&'2. The installation of guy will involve the following wor%s. 1. ()cavation of pit and fi)ing of stay rod 2. *astening of guy wire to the support 3. Tightening guy wire and fastening to the anchor. The mar%ing of the guy pit for e)cavation+ the e)cavation of pits and setting of the anchor rod must ,e carefully carried out. The stay rod should ,e placed in a position such that the angle of inclination of the rod with the vertical facr of the pit is 3#oo as the case may ,e. The concreting of the stays at the ,ottom should then ,e carried out. The ,ac% filling and ramming must ,e well done thereafter and allowed to set for at least - days. The free end of the guy wire is passed through the eyes of the anchor rod+ ,ent ,ac% parallel to the main portion of the guy and ,ound after inserting the ./ thim,le. The loop is pro0ected ,y the ./ thim,le where it ,ears on the anchor rod where the e)istence of the guy wire proves ha1ardous+ it should ,e protected with a suita,le as,estos pipe+ fitted with concrete a,out 2 't. length a,ove the ground level+ duly painted with white and ,lac% stripes so that it may ,e visi,le at night. The turn ,uc%le shall ,e mounted at the pole end of the stay and guy wire so fi)ed that the turn ,uc%le is half way in the wor%ing position+ thus giving the ma)imum movement for tightening or loosening. .uy insulators are placed to prevent the lower part of the guy from ,ecoming electrically energised ,y a contact of the upper part of the guy when the conductor snaps and tail on them or due to lea%age. .uy insulator shall ,e located at 2&3 of its length from the ground. The minimum ,rea%ing load of guy insulator shall ,e 22$$ 3v. for 11 34 and $$$ %g for 5T lines. Fixing of cross Arms and Insulators : After the erection of supports and providing guys the ne)t step would ,e to amount the cross arms on the support. The practice of fi)ing of cross arm ,efore the pole is erected is followed in some states. /n case the cross arm is mounted after the support is erected+ the lineman should clim, the support having re"uisite tools with him. The cross arm is then tied to a hand line and pulled up ,y the ground man through a pully till the cross arm reaches the lineman. The ground man should station himself well to one side so that if any material drops from the top of the pole it may not stri%e him. All the materials re"uired should ,e lifted or lowered ,y means of the hand line. /n no case the material or the tools should ,e dropped or thrown from the pole top. Insulators : The pin insulators are fxed in the holes provided in the cross arms and the pole top brackets. The insulators are mounted in their places over the pins and tightened In the case of strain or angle supports, where strain fttings areplaced over the cross arm. The nut of the straps is so tightened that the strapcan move freely in horizontal directions, as this is necessary to fx the strain insulator.