Master Alarm Wiring Conventions - BeaconMedaes MedPlus TotalAlert Operation And Maintenance

Master Alarm Wiring Conventions

Chapter 3: Theory of Operation

Master Alarm Wiring Conventions

The following section provides an overview of typical wiring conventions for
Master Alarm inputs and outputs (see figure 3-2 on page 3–9):
• To have the most reliable switch signalling, BeaconMedæs recommends
using input switches and relays having contacts that match the following
Master Alarm electrical characteristics:
•
•
•
Refer to the wiring instructions from the manufacturer for specific switches and
relays.
• To comply with the NFPA 99 standard, every switch and relay must have sep-
arate wiring to each Master Alarm.
• Polarity is determined by the indicators on the Master Alarm Breakout P.C.
Boards. Switches and contacts on signalling devices are not usually marked
with polarity indicators.
• When Master Alarms share input signals from the same pair of contacts on
switches or relays, polarity between each Master Alarm must be maintained.
• Low pressure sensing switches are typically wired from the normally open
and common contacts to each Master Alarm.
•
Normally open and normally closed refer to the state of the switch or relay in its
"shelf position" (the position of the switch or relay before the system is opera-
tional).
• High pressure sensing switches are typically wired from the normally closed
and common contacts to each Master Alarm.
•
• Switches sensing both high pressure and low pressure have independently
operating sets of contacts, one set for low pressure and one for high pressure.
Page 3-8
Low voltage (approximately 20V AC)
Low current (approximately 10 mA)
Dry circuit applications
Maintain polarity by wiring the normally open contact wire to the posi-
tive (+) terminal and the common contact wire to the negative (-) termi-
nal.
Maintain polarity by wiring the normally closed contact wire to the pos-
itive (+) terminal and the common contact wire to the negative (-) termi-
nal.
MedPlus TotalAlert® Alarm Network Operation and Maintenance Manual (205728)