Ohio Medical Corporation., 1111 Lakeside Drive, Gurnee, IL 60031-4099 (800/448-0770) www.ohiomedical.com
Medical Gas Alarm Manual
■
255098 (Rev.8) 07/08
Page 17
4.4 Master Alarm Connections from Source Equipment
Each Master Alarm Panel may accommodate up to 10 alarm inputs. Dry Contacts from
source equipment are connected directly to the Master Alarm Panel circuit board at positions
“MA1” through “MA10”. Each of these contact points is clearly marked on the circuit board
and includes both positive (+) and negative (-) terminals. The dry contacts from the source
equipment must be rated for at least 12 V
DC
.
WARNING — T
HE
EQUIPMENT
THAT
IS
CONNECTED
TO
THIS
INTERFACE
IS
NOT
CONSIDERED
TO
BE
PART
OF
THE
SYSTEM
CONFIGURATION
UNLESS
THE
EQUIPMENT
IN
QUESTION
COMPLIES
WITH
THE
STANDARD
FOR
HOSPITAL
AND
SIGNALING
AND
NURSE
CALL
EQUIPMENT
, UL 1069
The “Maintenance Mode” switch needs to be on to disable the audible alarm while wiring
contacts to the master alarm module. To make the Maintenance switch active, move the
switch at position “S11” on the Master Alarm Module toward the row of switches labeled “S1”
to “S10” as shown in Figure 8A. The maintenance lamp will be illuminated on the front of the
panel. Moving the switch away from the row of switches will restore the Master Alarm to
normal operation.
Switch settings on the Master Alarm Panel must be set to configure each alarm point for
normally open or normally closed operation. As shown on Figure 8A, the switches are on
the headers labeled “S1” through “S10”. The switches at position “S1” corresponds to the
alarm connected to the first pair of contacts “MA1”, “S2” to “MA2”, “S3” to “MA3”, and so on.
If one of the S1 through S10 switches is positioned toward the “S11” switch, the circuit loop is
normally open. It will cause an alarm when a closed contact is applied to the input terminal
strip (MA1-MA10). The switches at positions S1 & S3-S10 are shown in this position in
Figure 8A. This is the factory default setting. Any pair of contacts that are not connected to
source equipment should have their corresponding switch positioned toward the
maintenance switch.
If one of the S1 through S10 switches is positioned away from the S11 switch, the circuit loop
is normally closed. The contact will create an open circuit loop when an alarm condition
exists. The S2 switch is shown in this position in figure 8A. This is the setting for input
contact that is closed during normal operation but open during an alarm condition.
Per NFPA 99, information relayed from the source equipment is to be sent to two separate
master alarm panels at separate locations inside the medical facility. Wiring from the
source equipment is to be ran in parallel to each master alarm module and can not to be
slaved from one master alarm panel to the another.
