System Manual HS3A-H21M4
13
Notes about UL, c-UL
Important!
For use and operation as per the UL, c-UL requirements
1)
, a power supply
with the feature “for use in class 2 circuits” must be used.
Alternative solutions must comply with the following requirements:
a) Electrically isolated power supply unit with a max. open-circuit voltage of
30V DC and a limited current of max. 8A.
b) Electrically isolated power supply unit in combination with fuse as per
UL248. This fuse should be designed for max. 3.3A and should be in-
tegrated into the 30V DC voltage section.
For use and applications as per the requirements of UL, c-UL
1)
, a connec-
tion cable listed under the UL category code CYJV2 or CYJV must be used.
1) Note on the scope of the UL approval: The devices are tested according to the requirements of UL508 and CSA/ C22.2 No. 14
(protection against electric shock and fire).
Safety in case of faults
The operating voltage U
B
is reverse polarity protected.
The safety outputs are short circuit proof.
A short circuit between the safety outputs is detected by the switch.
A short circuit in the cable can be excluded by laying the cable with protec-
tion.
Fuse protection for power supply
The power supply must be provided with fuse protection depending on the
number of switches and current required for the outputs. The following rules
apply:
Max. current consumption of an
individual switch I
max
I
max
= I
UB
+ I
OUT
+ I
OA+OB
I
UB
= Switch operating current (80 mA)
I
OUT
= Load current of monitoring outputs (max. 200 mA)
I
OA+OB
= Load current of safety outputs OA + OB (2 x max. 400 mA)
Max. current consumption of a switch chain
Σ
I
max
Σ
I
max
= I
OA+OB
+ n x (I
UB
+ I
OUT
)
n = Number of connected switches
