Phoenix Contact PSR-CT Series, Руководство по эксплуатации, Страница: 35 / 69

Electrical connection
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4.4 Maximum cable lengths
Switch chains up to the maximum cable length as per Table 4-2 are permitted while observ-
ing the voltage drop due to the cable resistance. Also observe the maximum permissible
cable lengths between two safety switches.
Figure 4-1 Maximum cable length with n PSR-CT safety switches
Key:
Table 4-2 Maximum cable length
Number of switches in the
chain
Supply voltage at the first
switch
Maximum cable length
l
max

20 24 V DC 200 m

30 24 V DC 130 m
Maximum cable length between two safety switches I
n
: 100 m
Note that a high voltage drop at large load currents leads to low input voltages at the sen-
sor and evaluation unit.
PSR-CT 1 First switch in the switch chain
PSR-CT n Last switch in the switch chain
l
1
l
2
l
max
l
n
u
min
= 24 V DC
5 x 0,34 mm
2
5 x 0,34 mm
2
5 x 0,34 mm
2
PSR-CT n
i
out
PSR-CT n-1 PSR-CT 1
Phoenix Co
ntact Saf
ety R
ela
y