5-5
MEGA3 NFPA Medical Gas Notification System
4107 9016 59.03
5.2.2 Install Gas-Specific Sensors
(Area or Combination alarms only)
Local Sensors
1. Install the MEGA3™ gas specific transduc-
ers following your records from the disas-
sembly.
NOTE:
If a DISS demand check valve is not
in place then one will need to be installed
to comply with NFPA 99.
9. Snap the I/O module adapter brack-
et (large bracket included with kit
4107220616) onto the standoffs at the
rear of the rough-in box (Figure 127).
Figure 126: MEGA3™ Adapter Bracket Mounting
Single
Power
Supply
I/O
Modules
Figure 127: MEGA3™ Double Adaptor
Bracket Mounting
Power
Supply
I/O
Modules
5. Install the gas specific transducer.
6. Tighten the DISS nut until you feel resis-
tance.
7. Repeat steps 2-6 until all of the gas spe-
cific transducers are installed.
8. Verify that the gas specific transducers are
in the appropriate places by referring to
your records from the disassembly.
9. Return pressure to each gas sensor, one
gas at a time and check for leaks. Make
any adjustments or corrections as needed.
CAUTION:
Ensure that the pressure on the
pipeline in the alarm area has been released
before removing any components from the
pipeline connection.
NOTE:
If the gas transducer needs to be
repositioned in the rough-in box or thread
size / fitting style is not compatible; use the
included fitting kits to adapt or relocate as
needed. Fitting/adapter kit needs to be in-
stalled upstream from the DISS connection
at the gas sensor.
2. Remove any existing fittings or adapters
from the gas tube in the rough-in box.
3. Install the gas specific DISS demand check
valve from the supplied tubing package
into the appropriate gas tube. To prevent
gas leaks, wrap Teflon tape a minimum
of three times around the fitting pipe
threads.
4. Tighten the adapter until you feel resis-
tance; then turn the fitting 2 full turns.
Remote Sensors
1. Sensors are packaged loose so they can
easily be installed remotely.
2. Remote sensors are installed directly to
the pipeline outside of the rough-in box.
Pipeline connections are to be made to
the top of the pipe.
NOTE:
If a DISS demand check valve is not
in place then one will need to be installed
to comply with NFPA 99.
