Page 793 - Med Plaza and Cancer Center

PROPRIETARY AND CONFIDENTIAL DRAFT 28/Feb/03

Medical Gas Alarm Network System Interaction
Chapter 3: Theory of Operation

• For the low pressure sensor, maintain polarity by wiring the normally
open contact wire to the positive (+) terminal and the common contact
wire to the negative (-) terminal.
• For the high pressure sensor, maintain polarity by wiring the normally
closed contact wire to the positive (+) terminal and the common
contact wire to the negative (-) terminal.
• Polarity should also be observed when wiring relays. When possible, use
relays that have a separate set of contacts for each output.

Output Relays on Master Alarms

There are two dry contact relays (MAIN ALARM and AUX ALARM) on the
Master Alarm Breakout P.C. Board that are available to provide signals to
outputs. These outputs can be wired to satisfy either normally closed or
normally open requirements from another system.

• MAIN ALARM RELAY
• When the Master Alarm is in alarm condition, this relay activates.
• When the Master Alarm is silenced, this relay deactivates.

• When the Master Alarm power is off, this relay activates until the
power comes back on.
• AUX ALARM RELAY

• When the Master Alarm is in alarm condition, this relay activates.
• When the Master Alarm is silenced, this relay stays activated.

• When the Master Alarm condition is remedied, this relay deactivates.

The Master Alarm also has an output relay that can be used to interface with a
building automation system.

Page 3 - 10 MedPlus TotalAlert™ Alarm Network Operation and Maintenance Manual (man291ra)