NetApp DS4243 User Manual

V
LOAD
= I R
TEST
I = V
LOAD/
R
TEST
V
OC
= V
SOURCE +
V
LOAD
V
OC
= IR
S +
V
LOAD
R
S
= V
OC -
V
LOAD
I
R
S
= (V
OC -
V
LOAD
)
V
LOAD
/R
TEST
R
S
= V
OC -
V
LOAD
V
LOAD
=
48V - 47.5V
47.5V
= 0.105
R
TOTAL
= R
CABLE
+ R
SOURCE
R
CABLE
= R
TOTAL
- R
SOURCE
R
CABLE
= 0.233 - 0.105
= 0.128
Solution
V
DROP
= I
MAX
R
TOTAL
2
= 8.6 R
TOTAL
R
TOTAL
= 2/8.6
R
TOTAL
= .233
x
R
TEST
x 10
For example, if you have a 12-gauge wire, solid strand, at room temperature, you use the following
calculation:
Total cable length =
Total cable length = = 75 ft
R
CABLE
DC resis.
1
.128
.0017 /ft
AWG
Strand DC resistance
1
[Ω/ft.] Total cable length
2
[ft]
25°C 75°C 25°C 75°C
12 Solid .0017 .0020 75 64
DS4243, DS2246, DS4486, and DS4246 Installation and Service Guide 66
Recommended power line sizes

NetApp DS4243 Specifications

General

Brand	NetApp
Model	DS4243
Category	Storage
Language	English