Hardware Manual

Saia-Burgess Controls AG

Hardware Manual PCD 1 / PCD 2 Series│Document 26 / 737│Edition EN 15│2008-07-22

Appendix A

A

A-9

Installation direction and relays contact protection

The resistors used must withstand high voltages (pulse stability). With low resistance

values in particular, voltage flashovers can occur at the ground helical section pro-

duced 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 �F

R = 10 Ω (point of intersection with R scale)