Middleby Marshall PS638 Series, Руководство владельца по эксплуатации и установке

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22
GAS CONVERSION
Where permitted by local and national codes, it
is possible to convert ovens from natural gas to
propane/ULPG or from ULPG to natural gas.
Use the appropriate Middleby Gas Conversion
Kit for the specific oven model.
CAUTION: The terms of the oven’s warranty
require all start-ups, conversions and service
work to be performed by a Middleby Authorizes
Service Agent.
PROPANE/ULPG CONVERSION
To convert the oven from natural gas to
ULPG/propane gas three items must be changed.
1. Replace the main gas orifices (3 pieces)
2. Replace the by-pass orifice (1 piece)
3. Change the combination gas control valve
regulator spring and make the proper gas
pressure adjustment.
ULPG orifice conversion procedure
1. Disconnect the gas supply to the oven.
2. Disconnect the manifold union closest to the
gas burner manifold.
3. Remove the four screws securing the burner
manifold assembly to the burner box (Retain
these screws they will be needed for
reassembly).
4. Remove the burner manifold from the burner
box.
5. Remove the existing main burner orifices and
replace them with the main orifices supplied in
the Middleby propane/ULPG kit. (1.75 mm)
6. Replace the burner manifold into the burner box
and secure the burner manifold to the burner
box with the four screws removed in step 3
above.
7. Tighten the union connection that was loosened
in step 2 above.
(For steps 8-11, See page 20, Figure 2-21:
ByPass Tube and Orifice Location
drawing)
8. Remove the two compression nuts on the ¼”
(6.35mm) diameter aluminum tubing. Inside of
the ¼” (6.35mm) diameter tubing (Located in
the tee above the union) will be a small orifice.
9. Remove the by-pass orifice from the ¼”
(6.35mm) diameter tube.
10. Insert the by-pass orifice from the Middleby
propane conversion kit (#55 drill, 0.052”
diameter, 1.321 mm) into the same position in
the ¼” (6.35mm) diameter tube where the
previous orifice was removed.
11. Reconnect the ¼” (6.35mm) tubing with the
compression nuts that were removed in step 8
above.
ULPG Pressure Spring Replacement
1. Locate the cap covering the
pressure regulator adjusting screw on the
combination gas control valve.
2. Remove the cap to expose the pressure
adjustment screw.
3. Using a 5/16” wide (7.9mm) flat blade
screwdriver (or a T40 Torx if available)
remove the pressure adjuster screw by turning
counter-clockwise.
4. Gently insert a thin screwdriver into the center
of the regulator barrel and lift the Natural gas
spring out of the regulator.
5. Insert the new spring supplied in the Middleby
ULPG/propane conversion kit. The spring
range is 5” – 7” water column (1.25 to 1.75
KPa) (12.4 to 17.4 mbar) (
Ignore the Natural
Gas Reference on the Honeywell paperwork
)
6. Install the new plastic adjuster (that was
supplied in the Middleby propane conversion
kit) and thread it in until the plastic adjuster top
face is flush with the surface of the regulator
housing.
7. Turn the plastic adjuster screw clockwise 10 full
turns. This will be approximately the desired 6”
water column (1.5 KPa, 14.9 mbar) setting
required for propane/ULPG.
8. Reconnect the gas supply to the oven.
9. Using an electronic gas sniffer or liquid leak
check solution, check the gas train piping
connections for any possible gas leaks. If any
leaks are found secure the pipe such that the
leak has been eliminated. If no leaks are found
continue onto step 10.
Pressure
Adjustment
Screw
Regulator
Spring