AC Power Source Connections

The Hot, Neutral, and Ground wires from the

20 VAC power source or L1, L2. and

Ground wires from the 240 VAC power source connect to the system through the top three

terminals of the terminal strip on the front of the power supply.

DC Power Source Connections

Connect the + and – wires from the

25 VDC (nominal) power source to the top two

terminals on the terminal connector.  These connections are not polarity-sensitive on an

AC/DC input power supply.  (However, the DC Input-only type supplies, which are

discussed later in this chapter, are polarity sensitive.)

Input Overvoltage Protection Devices

This information applies to all Series 90-30 power supplies except IC693PWR322

and IC693PWR328.  The overvoltage protection devices for this power supply are

connected internally to pin 4 on the user terminal strip.  This pin is normally connected to

frame ground (pin 3) with the supplied jumper strap which is installed at the factory.  If

overvoltage protection is not required or is supplied upstream, this feature can be disabled

by  removing the jumper strap from pins 3 and 4.