Middleby Cooking Systems Group Gas Oven PS770 - Manual (Page 14)

14
Certain safety code requirements exist for the installation
of gas ovens; refer to the beginning of Section 2 for a list of
the installation standards. In addition, because a the oven is
equipped with casters, the gas line connection shall be made
with a connector that complies with the Standard for Connectors
for Movable Gas Appliances, ANSI Z21.69 (in U.S.A.), as well
as a quick-disconnect device that complies with the Standard
for Quick-Disconnect Devices for Use With Gas Fuel, ANSI
Z21.41 (in U.S.A.).
D. PS770 Propane conversion
Four items have to be changed, to change the oven to LP:
1. Adjust internal burner air shutters.
2. Replace main Orifices
3. Replace (and adjust) the spring in the main valve (see LP
kit)
4. Adjust modulating valve bypass settings.
Disconnect the manifold unions closest to the main burner, and
remove the manifold assemblies (four screws each). Remove the
addition four screws holding the burner cores and slide out each
burner core (leaving the ignition and sense wires connected).
Adjust the internal air shutters fully open, and replace the cores.
Replace the main orifices on the manifold assemblies with the
LP units, and replace the manifold assemblies. Reconnect the
unions. Replace the valve spring with the LP spring, and adjust
the downstream pressure to get 7″ WC.
Adjust the bypass screws in the side of each modulating valve
to approximately 1/6 turn from fully closed. If this setting is too
low, the burners will shut off when trying to modulate. If it is
too open, the unit will tend to gradually raise up in temperature
at standby.
Figure 2-14 - Gas Burner/Blower Motor and Piping Assembly
Gas Burner Burner/Blower Motor