Middleby Cooking Systems Group PS870 Series manual Gas Burner/Blower Motor and Piping Assembly

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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 Connec- tors 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. PS870 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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Contents PS870 Series Gas Ovens Page Middleby Marshall Table of Contents Page Page Page QTY Description Page Standoff Installation Switching Photo Detector Resetting Direction JumperConveyor Belt Reversal Reversing the Conveyor BeltConnection PS870 Propane conversion 14 Gas Burner/Blower Motor and Piping AssemblyTemperature Control/Display Conveyor Time SettingMain On/Off Button Temp SetMain Screen on Main ScreenOven Temperature/Set Point/Indicator Screen Daily Shutdown ProcedureQuick Reference Touch Screen Controller Main Screen Energy ModesProblem Solution III. Quick Reference TroubleshootingPage Page Page Blower Belts IV. Maintenance Every 6 MonthsQTY Description