Middleby Marshall PS840 Series Connection, Gas Conversion, PS840 Propane Conversion

B. Connection

Figure 2-18. Flexible Gas Hose Installation

Check the oven’s gas supply requirements before making the gas utility connection. Gas supply requirement are listed on the oven’s serial plate and in Table 1-4. Gas Orifice and Pressure Specifications (in Section 1, Description).

Check the serial plate to determine the type of gas (Propane or Natural) to be used with the oven.

Refer to the instructions in the gas hose package (included in the Installation Kit) before connecting the gas line. One gas line connection method is shown in Figure 2-18; however, compliance with the applicable standards and regulations is mandatory.

Inlet, regulated, and pilot gas pressure readings can be taken using a digital tube manometer at the tap location shown in Figure 2-19. Figure 2-19 shows the burner assembly and Figure 2-21 shows the gas valve.

NOTE: The installation must conform with local codes or in the absence of local codes, with the National Fuel Gas Code, ANSI Z223.1-latest edition.

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 the oven is equipped with cast- ers, the gas line connection shall be made with a connector that complies with the Standard for Connectors for Movable Gas

1/2″ gas

pipe nipple

1/2″ gas line

tee with

pressure tap

Quick- disconnect device

3/4″-1/2″
gas pipe	To Gas
reducer
	Supply
	Pipe
3/4″ gas
pipe nipple
90°
Elbow

Full-Flow

Gas

Shutoff

Valve

Flexible	Individual gas
	connection for
Gas Hose
	each oven
	cavity

Appliances, ANSI Z21.69 (in U.S.A.), as well as a quick-discon- nect device that complies with the Standard for Quick-Disconnect Devices for Use With Gas Fuel, ANSI Z21.41 (in U.S.A.).

C. Gas Conversion

Where permitted by local and national codes, it is possible to convert ovens from natural to propane gas, or from propane 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 per- formed by a Middleby Authorized Service Agent.

D. PS840 Propane Conversion

Two items have to be changed, to change the oven to LP:

1.Replace main orifices.

2.Adjust main gas regulator per instructions below.

Disconnect the manifold union closest to the main burner, and remove the manifold assembly (four screws). Slide out the manifold assembly (leaving the ignition and sense wires con- nected). Replace the main orifices.

Replace the main orifices on the manifold assemblies with the LP units, and replace the manifold assembly. Reconnect the union.

E.Adjusting the Maximum Pressure Setting

1.Disconnect pressure feedback connection (if appcable).

2.Connect a suitable pressure gauge to pipe line or to outlet pressure tap of gas control concerned, to mea- sure burner pressure (measuring point must be as near to burner as possible).

Figure 2-19. Gas Burner Assembly

Gas Burner

Manifold Pressure Tap

3.Make sure that the appliance is in operation and the Moduplus® coil is energized with maximum current.

4.If maximum rate pressure needs adjustment, use an 8 mm wrench to turn adjustment screw for maximum pressure setting (clockwise to increase or counter-clockwise to decrease pressure), until the desired maximum outlet pressure is obtained.

5.Disconnect electrical connection of the Moduplus®.

6.Check minimum pressure setting and readjust if neces- sary. (See Adjusting Minimum Pressure Setting for proper adjusting procedure.)

7.Reconnect pressure feedback connection (if appcable).

8.If minimum and maximum pressures are set, wire the Moduplus® in circuit.

9.Close pressure tap screw.

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