2-7
MEGA3 NFPA Medical Gas Notification System
4107 9016 59.03
2.3.7 B4X Relay Output Board
A Master or Combination alarm can contain
multiple relay output boards; up to a maxi-
mum of 4 boards with 16 relay outputs each.
The B4X boards (B40, B41, B42, B43) utilize
normally closed dry contact relay outputs.
The outputs on the B4X boards are labeled
Y01 through Y16.
Identify each pair of field installed relay
output signal wires inside the alarm rough-in
box. Route each pair of relay output wires as
shown in Figure 25 to the appropriate termi-
nals on the relay board. Connect each pair of
signal wires to the terminal blocks, noting the
correct polarity (+,-).
Refer to NFPA Mas-
ter/Combination Wiring Diagram (Section
3.1/3.3).
NOTE
:
Each pair of terminals labeled on the signal
board connector is labeled “+” and “-”. Ensure
that when a source equipment dry contact is
wired to two master panels, the same side of
the dry contact is connected to the same termi-
nal at both panels. For example, if the source
equipment’s normally closed contact is wired to
the “+” of the first master panel, ensure it is also
connected to the “+” terminal of the second
master panel.
Figure 25: B4X Board Wire Routing
