EUCHNER CET-AR Series User Manual

Operating Instructions
Transponder-Coded Safety Switch CET.-AR-…
22
(Translation of the original operating instructions) 2110788-13-03/20
10.5.1. Determining cable lengths using the example table
Example: Six switches are to be used in series. Cabling with a length of 40m is routed from a safety relay in the control
cabinet to the last switch (#6). Cables with a length of 20m each are connected between the individual CES-AR/CET-AR
safety switches.
CET-AR # 6
Sicherheits-
relais
Safety Relay
CES-AR # 5CES-AR # 3
CES-AR # 2CES-AR # 1
CET-AR # 4
l
1
= 40 ml
2
= 5 x 20 m
l
= 140 m
l
n
= 20 m
u
n
= min. 19,2 V
i
OA/OB
= min. 75 mA
Figure 3: Circuit example with six CES-AR/CET-AR
A safety relay is connected downstream that consumes 75mA at each of the two safety inputs. This operates over the
whole temperature range with a voltage of 19.2V (corresponds to 24V -20%).
All the relevant values can now be determined using the example table:
1. Select the corresponding section in the column n (max. number of switches). Here: six switches.
2. In column I
OA/OB
(possible output current per channel OA/OB), nd a current greater than or equal to 75mA. In this case:
100mA.
¨ It is then possible to determine the maximum cable length from the last switch (#6) to the control system from column
l
1
. In this case, a length of 50m is permitted.
Result: The desired cable length l
1
of 40m is below the permitted value from the table. The overall length of the switch
chain l
max
of 140m is less than the maximum value of 200m.
¨ The planned application is therefore functional in this form.

EUCHNER CET-AR Series Specifications

General

Brand	EUCHNER
Model	CET-AR Series
Category	Switch
Language	English