Rapid 2005, Installation, Operation & Service Manual

Page: 87 / 162

SECTION 16: G
AS
P
IPING
77 of 147
16.4 Gas Pipin g
The gas manifold extends thro u gh the side of the
control cabinet for models 2005 - 2030. The factory
piping terminates
w ith a female pipe connection in
the man u al gas v al v e. The man u al main gas sh u toff
v al v e is shipped loose for field installation. A u nion
m u st also be installed (s u pplied by others) bet w een
the s u pplied man u al gas v al v e main and the first tee
pipe. Be s u re that the f u el s u pply pipe connected at
this point is large eno u gh to ens u re the proper gas
flo w and line press u re at the inlet of the air handler.
The piping m u st comply w ith:
United States: Refer to NFPA 54/ANSI Z223.1 - latest
re
v ision, National F u el Gas Code.
Canada: Refer to CSA B149.1 - latest re v ision,
Nat u ral Gas and Propane Installation Code.
Gas s u pply piping m u st conform to best b u ilding
practices and local codes. D u ring installation of the
gas piping, be s u re that no piping restricts
accessibility to the air handler or its remo v able
access doors.
Lockable man u al sh u t-off v al v e m u st be added by the
installer in compliance w ith Occ u pational Safety and
Health Administration (OSHA) reg u lations.
16.5 Pressure Test Ports
There are 1/8" (3.2 mm) and 1/4" (6.4 mm) press u re
test ports located on the manifold. The test ports are
a
v ailable to meas u re the manifold inlet gas press u re
and the b u rner gas press u re d u ring b u rner set u p.
16.5.1 Manifold Inlet Gas Pressure
The press u re port for meas u ring manifold inlet
press u re is located on the inlet side of the first safety
sh u toff v al v e. Refer to the u nit rating plate for the
acceptable inlet gas press u re.
16.5.2 Burner Gas Pressure
A press u re tap is u sed to meas u re negati v e airflo w at
the b u rner and to set high fire gas press u re. On air
handlers eq u ipped w ith a M611 mod u lating v al v e
(Model 2005), the press u re tap is located on a tee
bet w een the M611 v al v e and the b u rner. See Page
77, Figure 36 and Page 123, Figure 81 . On air
handlers eq u ipped w ith the MR212 mod u lating v al v e
(Models 2010 - 2030), the press u re tap co u ld be
located on the do w nstream side of the MR212 v al v e,
on a T-fitting coming off the o u tlet press u re tap on the
MR212 v al v e or bet w een the MR212 v al v e and the
b u rner. See Page 77, Figure 37 and Page 122,
Figure 79 .
FIGURE 36: Plu g Tappin g (2005)
FIGURE 37: Plu g Tappin g (2010 - 2030)
16.6 Line Pressure Test - Leak Testin g
The air handler and its indi v id u al sh u t-off v al v e m u st
be disconnected from the gas s u pply piping systems
d u ring any press u re testing of that system at test
press u res in excess of 14 in w c (34.9 mbar). The air
handler m u st be isolated from the gas s u pply piping
system by closing its indi v id u al man u al gas v al v e that
is located immediately u pstream of the safety sh u t-off
gas v al v e.
Burner
Modulating Valve
Manual Gas Valve (Burner)
Plugged Taping
To Measure Burner Pressure
Burner
Modulating Valve
Manual Gas Valve (Burner)
Plugged Taping