One Power Supply (End-Connected) - Parker H Series Installation & Service Instructions Manual

4-22 Determine Power Requirements
Publication DNET-UM072C-EN-P - July 2004

One power supply (end-connected)

Example using thick cable
The following example uses the full calculation method to determine the
configuration for one end-connected power supply on a thick cable trunk line.
• Device 1 and Device 2 cause the same voltage drop but Device 2 is
twice as far from the power supply and draws half as much current.
• Device 4 draws the least amount of current but it is furthest from the
power supply and causes the greatest incremental voltage drop.
TR
TR = terminating resistor T = T-Port tap
PT = Power Tap D = device
1. Find the voltages for each device using the equation for thick cable.
SUM {[(L
D1
A.[(50 x (0.0045)) + (1 x (0.005))] x 1.00 = 0.23V
1.0A
D2
B.[(100 x (0.0045)) + (2 x (0.005))] x 0.50 = 0.23V
0.50A
C.[(400 x (0.0045)) + (3 x (0.005))] x 0.50 = 0.91V
D3
0.50A
D.[(800 x (0.0045)) + (4 x (0.005))] x 0.25 = 0.91V
D4
0.25A
2. Add each device's voltage together to find the total voltage.
0.23V + 0.23V + 0.91V + 0.91V = 2.28V
Since the total voltage does not exceed 4.65V, the system will operate properly
Results
(2.28V < 4.65V).
The percent loading is found by dividing the total voltage by 4.65V.
%Loading = 2.28/4.65 = 49%
power
supply
122 m
(400 ft)
30 m
(100 ft)
15 m
(50 ft)
PT T
D1
1.0A
x (0.0045)) + (N x (0.005))] x I
n t
244 m
(800 ft)
T T T
D2 D3 D4
0.50A 0.50A 0.25A
} < 4.65V.
n
TR
31514-M