Rev. 11/10/00
4
Power Formulas
Like Ohms law, power formulas use several variants of a formula to calculate
power. Voltage, current, and resistance can be used to calculated power when two
of these three values are known. Power, in electrical terms, is expressed as Watts
using the letter W as its symbol in measurements and the letter P in formulas.
The formula variants are: P = IE, P = E²/R, P = I²R. This means that power is
directly proportional to the current multiplied by the voltage. Power can also be
calculated by dividing the voltage squared by the resistance or by multiplying the
current squared by the resistance. If the power is known, then using the formulas
can help in determining the voltage or current or resistance values.
CONNECTING TO OUTSIDE PLANT
The Sidekick comes with three test leads; red, black and green. The red test
lead is connected to the Ring wire of a twisted pair, the black lead to the Tip wire
of the twisted pair, and green to ground. It is extremely important to have a good
ground connection. Erroneous test readings may occur when a good ground is not
present.
Verify that the test connections are good before starting a test. Make sure the
test lead clips are securely connected to the wires and that the ground clip is
connected properly to a good ground. When disconnecting the test lead clips,
always squeeze to open the clips before removing them from the wire.
Do not
forcibly pull the clips off the wires or ground connections.
Damage to the test
lead and wires can occur.
Typical outside plant places the Central Office (CO) battery on the Ring
line and ground on the Tip line. The customer’s line is connected between Tip
and Ring. The line circuit is the CO battery running through the Ring line to the
telephone and through Tip to ground. When the customer’s telephone is on-hook
(hung up), the circuit is incomplete and current can not flow. When the phone is
picked up (receiver off hook) the path is complete and current can then flow to
ground.
FAULT TYPES
Faults are caused by many factors including materials and workmanship. Care
must be exercised when performing any repairs or installations. Construction
work near buried or overhead cables can easily lead to damaged lines.
