Patterson-Kelley TBIG-03 - Manual (Page 17)

Maintenance
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propane
connection
manual
shutoff
natural gas
connection
manual
shutoff
regulator
low gas
pressure switch
motorized gas valve
(propane)
low gas
pressure switch
motorized gas valve
motorized gas valve
(natural gas)
high gas pressure
switch
pressure tap
burner
secondary
shutoff, manual
pilot
shutoff
regulator
pilot regulator and
solenoid valve
mechanical link
to control air
(Lo-Hi-Lo only)
Items with symbol must be
vented to outside. Refer to the
drawings packed with your
boiler for additional information.
leak test
valves
n.o. vent valve
(I.R.I. only)
Figure 7-1 Piping Schematic for the Twin-Fuel Gas Train
7.0 M AINTENANCE
7.1 G
ENERAL
Warning! High voltage! Shock hazard. Properly lock-
out/tagout the electrical service and all other energy
sources before working on or near the machine.
For testing control circuits only, the service power
shutoff switch (located inside the auxiliary panel) may
be used to de-energize the system in lieu of normal
lockout/tagout procedures. Use extreme caution
when using this alternative.
service power
shutoff switch
Figure 7-2 Service Power Shutoff Switch
(located inside the auxiliary panel at the back of the boiler)
Maintenance of the twin-fuel gas boiler is similar to
that of the standard model. Refer to pages 11 through
14 of the “Installation and Owner’s Manual - TBIG.”
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