Relief Valve
RELIEF VALVE
Figure 4-1_Relief Valve
This appliance is supplied with a relief valve(s) sized in
accordance with ASME Boiler and Pressure Ves
sel Code,
Section IV (“Heating Boilers”). The re
lief valve(s) is
mounted directly into the heat ex chang er inside the header
(see FIG. 4-1). To pre
vent water damage, the dis
charge
from the relief valve shall be piped to a suit able floor drain
for disposal when relief occurs. No reducing couplings or
other restrictions shall be installed in the discharge line. The
discharge line shall allow complete drainage of the valve and
line. Relief valves should be manually operated at least once
a year.
CAUTION
Avoid contact with hot discharge water.
Water Flow Switch (if equipped)
FLOW SWITCH
FLO
W
Figure 4-2_Water Flow Switch - Top Connections
A water flow switch is available as a factory sup plied option on
all heating boilers (see FIG. 4-2). The flow switch should be
wired between terminals X and B. Remove the jumper between
the X and B terminals on the terminal strip. This wiring
connection installs the flow switch in the 24 VAC safety cir cuit
to prove water flow before main burner ig ni tion. A flow switch
installed with the fac to ry sup plied minimum adjustment setting
requires a spe cif ic minimum flow to make the switch and start
burner operation. The flow rate required is a function of the
diameter of pipe and tee used for installation. Ensure that the
pump installed on the boiler will supply adequate flow to make
the flow switch con tacts and operate the boil er.
A water flow switch meets most code re quire ments for a low
water cut off device on boil ers requiring forced cir cu la tion for
operation.
4
Water connections
23
Installation & Service Manual
Содержание CBN045
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