Eaton easySafety, Manual

Page: 60 / 695

Installation
56
02/16 MN05013001Z EN
In order to take appropriate precautions for a short-circuit,
follow the steps below:
X
Select the right F2 cable protection.
X
Use a power supply unit with enough output current .
Selecting the F2 cable protection
The cable protection chosen should have a maximum rated
operational current I
n
of 3.15 A. Since the maximum
permissible load current is 2.4 A (with 4 connected transistor
outputs at 0.5 A each and a tolerance of 20%), F2 will be
properly dimensioned with 3.15 A.
The cable protection chosen must have a rated operational
current I
n
with at least the following value; see
a
figure 18
,
page 53:
I
n
> I
L
= I
1
+I
2
+I
3
+I
4
; with I
L
at U
emax
Use an F2 cable protection of table 3 or types with the same
characteristic.
Selecting the power supply unit
The overload trip conditions (in the table below) that apply
will depend on the selected F2 cable protection. Make sure
to use power supply units with an appropriate output current
accordingly.
Table 3: Overload trip conditions for F2 in applications with two-
channel safety modules
Example:
Transistor outputs QS1, QS2, and QS3 each switch a
contactor with a rated pick-up current of 400 mA. The
maximum permissible rated operational voltage range limit
is:
F2 Trip condition
FAZ-B(
I
n
)/1; I
L
<
I
n
F 3A 7 x I
n
, 30 ms
FAZ-Z(
I
n
)/1; I
L
<
I
n
F 3A 4.2 x I
n
, 30 ms
FF(
I
n
); I
L
<
I
n
F 3.15 A 4 x I
n
, 50 ms