Application manual for PSRclassic and PSRmultifunction, and the modular safety relay system
26 / 136
PHOENIX CONTACT 102597_en_03
3.4 Safe isolation
Depending on the version, the PSR safety relays from Phoenix Contact have safe isolation
between input and output and between the contacts. Applications with 250 V AC low voltage
(typical) can be switched reliably and safely.
Insulation between input
circuit and enabling
current path
Typically, the PSR safety relays provide safe isolation, reinforced insulation, and 6 kV
between the input circuit and the enabling current paths.
According to the standards, safe isolation is required if SELV/PELV and low voltage are
switched together or led directly next to one another in a device.
Due to the internal structure and the insulation properties between the input and the contacts
in Phoenix Contact PSR safety relays, 250 V AC, for example, can be switched without any
limitations. The output contacts (13-14, 23-24, …) are isolated using basic insulation or rein-
forced insulation, depending on the type.
Basic insulation between
enabling current paths
Rated surge voltage: 4 kV
A mixture of SELV/PELV and low voltage is strictly prohibited. Only switch 250 V AC at one
of the enable contacts if the adjacent contact carries the same potential.
Reinforced insulation
between the enabling
current paths
Rated surge voltage: 6 kV
Reinforced insulation (e.g., thanks to greater air clearances and creepage distances
between conductive paths) is designed for one overvoltage category higher than basic insu-
lation. This means that SELV/PELV circuits of U 25 V AC or U 60 V DC and circuits with
higher voltages can be mixed.
To Next Page
Loading...
Need help?
General
