www.miinet.com
Moore Industries-International, Inc.
- 11 -
User’s Manual
225-748-01L
February 2017
Programmable Current/Voltage Safety Trip Alarm
STA
HLPRG
SEC
TION 1
Failsafe Alarms
are de-energized when tripped, energized when the process input is at a
non-alarm level. Non-failsafe alarms are energized whenever tripped, de-energized when the
process input is at a non-alarm level. The relays in the STA are failsafe only. Normal is the term
used to describe the “shelf-state” of relay contacts. The contacts of a Normally Open relay are
open (infinite resistance) when the relay is not energized. The contacts of a Normally Closed
relay are open when the relay is energized (closed when not energized).
Note:
Sometimes a non-alarm input level is referred to as being in a “normal” condition. This
practice is intentionally avoided in this manual. Do not confuse the term “normal”, as in Normally
Open or Normally Closed, with a non-alarm input condition. In this manual, “normal” is an
exclusive reference to the shelf state or quiescent state of an alarm’s relay contacts, whether
open or closed.
