Saia-Burgess Controls AG
Manual I/O-modules for PCD1 │ PCD2 series │ Document 27-600 – Release ENG09 │ 2019-05-01
A-10
Appendix
Installation direction and relays contact protection
A
The resistors used must withstand high voltages (pulse stability). With low resist-
ance values in particular, voltage flashovers can occur at the ground helical sec
-
tion produced in the manufacturing process. For this reason, composite carbon
resistors are often used in screening units. However, enamelled wire resistors or
cement resistors with a large helical pitch are suitable.
Dimensioning guide:
The value for C is the direct result of the switching current. The resistance value R can be established
by drawing a straight line through the corresponding points on the I and U curves and reading off the
resistance at the intersection with the R curve.
Load
Example:
U = 100 V
I = 1 A
C is direct result with 0,1
μF
R = 10
Ω (point of intersection with R scale)