Percent Paramagnetic Oxygen Analyzer Part I: Control Unit
Part I: 3-7
Teledyne Analytical Instruments
Alarm Relays:
There are three alarm-circuit connectors on the alarm relays block
(under RELAY OUTPUTS) for making connections to internal alarm relay
contacts. Each provides a set of Form C contacts for each type of alarm.
Each has both normally open and normally closed contact connections. The
contact connections are indicated by diagrams on the rear panel. They are
capable of switching up to 3 ampers at 250 V AC into a resistive load
(Figure 3-6).
Figure 3-5: Types of Relay Contacts
The connectors are:
Threshold Alarm 1: • Can be configured as high (actuates when
concentration is above threshold), or low
(actuates when concentration is below thresh old).
• Can be configured as fail-safe or non-fail-safe.
• Can be configured as latching or nonlatching.
• Can be configured out (defeated).
Threshold Alarm 2: • Can be configured as high (actuates when concen-
tration is above threshold), or low (actuates when
concentration is below threshold).
• Can be configured as fail-safe or non-fail-safe.
• Can be configured as latching or nonlatching.
• Can be configured out (defeated).
System Alarm: Actuates when DC power supplied to circuits is
unacceptable in one or more parameters. Permanently
configured as fail-safe and latching. Cannot be de-
feated. Actuates if self test fails.
To reset a System Alarm during installation, discon-
nect power to the instrument and then reconnect it
Further detail can be found in chapter 4, section 4-5.