2 Overhead Distribution 2 Poles - 2 Pole Framing and Guying Flashcards
What is the main function of the utility pole?
The main function of utility pole Is to support conductor and other unitality equipment.
What are the aspects that need to be considered when choosing the type of pole construction?
- it has to be able to support the weight of the construction and the pulling force of the cables.
- it must maintain the proper spacing between cables to provide the right amount of electrical clearance
- it should allow enough clearance to allow the line man work safely.
- it must allow room for other equipment like transformers
- it must have available room for other utility’s such as telephone and TV.
The conductors exert two basic forces on the pole. Name them.
One is the weight of the wire, this force acts straight down.
The other force is strain or pull put on the conductor to provide clearance below.
This force acts in the same direction as that wire/conductor.
The forces that one conductor can exert on a pole are dependent on several effects. Name all of them.
- the angle that conductors are made with the pole
- the length of the conductors
- the wight of the conductors.
In what way do conductors exert the least force on the pole?
When they are installed in the straight line as the pole they are installed on.
Since this way the strain from opposite side of the conductor would cancel each other out.
What is the lateral strain on the pole?
When conductors are installed with a bent on direction, the lateral strain happens on the pole structure.
The more sharper turn between the spans would make a grater force on the pole structure exponentially.
Sharp turn conductors puts too much strain on the pin insulators, what kind of insulator can be used instead of pin insulator to support sharp turn conductors ?
One way is to use disk dead end insulation and use jumpers to connect to the other side. This way incoming and outgoing wires can be connected in the straight line to the insulators and thereby reducing the lateral force on the insulators.
Name 3 basic pole construction types.
- cross arm
- arm lees
- vertical
What is the trough bolt on the Cross arm Pole?
It’s the bolt that connects the cross arm to the pole.
What are the purposes of the braces on the cross arm pole?
They are there to balance the cross arm to be straight.
What is double cross arm?
When the forces of conductors are greater then capacity of one cross arm an extra cross arm is installed and this type of installation is called double cross arm.
On double cross arm there would also be two sets of insulator to support conductors.
When installing double cross arm how is the distance between the two cross arms are made?
By installing spacer bolts between the two cross arms.
Why are conductors sometime installed in the side of the insulators such as the one shown in the photo with the special pin?
This is done to resist the lateral strain exerted on the pin insulator when the conductors are ran in angle to the pole and insulator.
Note this technique should only be used when downward stain on the insulator is not great enough to pull the insulator downward.
When are ally arms used instead of cross arms?
One of the examples is shown in this photo. As shown if the cross arm where to use then there would be more stress on pole cross arm and pin insulators since the wires had to be pushed all the way to the pole. However as you can see the ally arm is in more straight line then cross arm would have been therefore less stress is on the pole, cross arm and insulators.
Name the equipment shown in the photo and its use.
This is the chicken wing bracket. Its type of armless structure.
Name the type of structure shown in this photo.
this is the running corner pole structure.
It is used for sharp turns conductors.
What type of insulator is this?
This is called the suspension insulator it will grab the wire as shown on the photo to instead of grabbing the end like the dead end insulators.
Why are the top of the poles cut in angle as shown on the photo?
This is to reduce the amount of snow collecting on top of the pole.
Why are the top of the poles cut in angle as shown on the photo?
This is to reduce the amount of snow collecting on top of the pole.
What is the slab roof on the pole.
Its one sided cut that helps to reduce the amount of snow collecting on the pole top.
What is the gable roof on the pole?
Its the two sided cut on top of the pole to reduce the amount of snow collecting on top of the roof.
What is this cut on the pole and what is it used for?
This is called a gain cut. It is used for cross arm to be installed on pole.
On the gain cut for pole top. How deep should the cut be?
It should be no longer then one inch deep.
What is a patent gain?
Its type of bracket that is used instead of gain cut to support cross arm.
What is the name of this bolt shown on the photo.
This is called a carriage bolt.
What is the name of this bolt shown on the photo.
This is called a lag screw
Name what you see in the photo and explain its use
This is a insulator pin. Which is a trough bolt that insulator can be installed on it.
Name the nut that has been pointed at it.
This is called a pal nut. Its shaped to fit over the surface of the main nut to prevented form getting loos.
What is the construction print?
It’s a blueprint of pole installation. It Gieves the specific location and requirement for the pole that needs to be installed.
How to choose the right size through bolt?
Add all the objects that trough bolt should go through and two more for nut and bolts.
For example the pole diameter could be 8 inches + patent gain adds one more inch + 4 inch for cross arm.
8+1+4+2 = 15ich for this particular pole
Where are the down guy used mostly ?
The down guy is used mostly on dead end poles to balance the from the previous pole.
When installing the guy wire, what does One To One Ratio Means?
If there is enough room usually the guy is installed in a distance to the pole as the high of the point where the guy is connected to the pole and this is called the one to one ratio.
Sometimes there is a down guy installed on the straight line pole. Why is that.
One reason could be the difference in length between the two spans. If one span is longer than other it would make it so that longer span would pull more on its side, therefore a guy is installed to balance the extra force and keep the pole in balance.
What are the storm guys?
Storm guys are set so that in the event of storm that brings the possibility of broken poles the guys would prevent the pole to fall in the street and therefore it prevents danger to human life and property.
When are pole Guys used?
Pole guys are used when anker for down guy cannot be used for some reason.
What is the Span guy?
Span or overhead guy is when a guy is running on top of the two poles between each other
What is the stub pole?
Stub pole is a pole that its purpose is to support other poles by being connected with span or overhead guy wire.
What is an advanced guy?
In advanced guy system one guy is connected to another pole and another one were the force is
Distributed between several poles. This is done if there is no possibility of for putting an anker down.
What is the Arm guy?
When a guy wire is connected from cross arm to another pole.
As shown in the photo below there is a strain on the cross arm from two lines that are connected to the cross arm. The Arm Guy offsets the forces of the lines.
How are the guy wires connected to the pole or cross arms.
Most guy wires are secured with barkers that are supported with trough bolts.
What are strain insulators?
Strain insulators are thin fiberglass rods that are used to protected guy wire from unwanted voltage to the guy wire.
What is the part show in this photo and what is it used for?
This is a type of stain insulator or guy insulator. It mechanically and electrically separates the two half of the guy wire so that unwanted voltage would not be present to the rest of the guy wire.
Why is the guy wire attached to the extended wood on top of the pole as shown on the photo?
This is to protect the guy wire from unwanted voltage to the guy wire.
What is the part shown in this photo and how does it work?
This is a expansion anker.
It has metal leaves that expands when the anker is in the ground and secures a strong hold in the ground.
When the anker is in the hole to the distance desired, the anker will get pound by the operator with a pipe or other devices and with that the leaves would open.
Name the part on the photo and explain what is it used for.
This is called a guy wrap. It is used to connect the end of the guy wire to the anker.
What does making up the guy means?
When rapping the guy rap around the end of the wire and anker, the process is called making up the guy.
What is automatic dead-end?
Automatic dead-end is a U shape part that allows the guy wire trough it in one direction but it does not allow the wire to go back from that direction. It is a kind of zip tight method.
What is the push guy?
Push guy is when a guy supports a pole by pushing on it, instead of pulling on it like a down guy. Post push guys are made of wood as shown on the photo.
Why are sometimes a push guy is used instead of the down guy?
On situations where there is no room for the down guy such as near the roads a push guy is used. As you can see on the photo if the down guy where to be used it would have to be installed on the road, which is not possible.
How is the push guy connected to the pole?
The push guy is usually connected to the pole by a hinge bracket as shown on the photo.
Name the part shown in the photo and its use?
This is a screw anker.
It does not need a hole, this peace would be drilled in to the ground on its own.
Note: when drilling the anker to the ground a certain pressure must be kept to make shore the drilling action would not make a churning.
What does churning mean when drilling in to the ground?
While drilling if there is not enough pressure the ground becomes soft and therefore it would not support holding the anker as it should.
Name the part shown in the photo and explain its use.
This is called a bound coil.
It holds the guy wire in the coil and allows the line man to take as much as he needs without letting go of the whole wire.
When taking guy wire out of bound coil, what is the most important rule that needs to be considered ?
Keep it under control.
When unwinding the guy wire out of bound coil, you must with one and hold the coil to make sure the wire does not uncoil rapidly and with the other hand pull out the guy wire slowly. In case of uncontrolled unwind the guy wire can heat someone or if it is opened on to of the pole it can jump to the primary and make a devastating fault.
When cutting a guy wire, it is recommended to tape the part where the cut is being done. Why is that?
The taping is done to prevent the strains of the guy wire to be separated and cause problems.
How is the tension on the guy wire set?
It is set with ratchet hoist.
One end is connected to the eye of the anker and the other side of the hoist has a wire grip that grips the guy wire, then the line man can put tension on the wire by ratcheting the hoist.
Why is a guy rap used on the guy wires?
On situations such as down guy. The guy wire is not easily visible therefore there is a danger of someone running in to it. The guy wire rap is used to make it easily visible to prevent the accident.
