Datasheet

70 Kanthal Appliance Alloys Handbook
General formulas
Combining equations [9] and [10] gives:
Rating
I
2
.
R
U
.
I
PI
UR
P
.
R
I
.
R
U
2
R
U
R
P
U
P
R
P
I
U
I
U
2
P
P
I
2
Current
Voltage Resistance
Combining equations [2], [6], [9] and [10]
gives:
Definition:
Cross sectional area q [mm
2
] or [in
2
]
A) Round wire
Combining equations [1], [6], [7] and [12]
gives the wire diameter, d:
A
C
R
20
U = R
T
· I [V]
[9]
P = U · I
[W]
[10]
[11]
=
A
C
R
20
I
2 ·
C
t
p
[cm
2
/Ω] or [in
2
/Ω]
q =
[12]
π
4
· d
2
[mm
2
] or [in
2
]
d = 3
[13]
4
π
2
ρ · P
·
p · R
20
The ratio , used for determining wire,
strip or ribbon size, is tabulated for all alloys
in the Kanthal Handbook.