Middleby Marshall PS360WB-U English, E. Checking the Gas Supply Inlet Pressure, Volumetric Method

Models: PS360-L PS360WB-U

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E.Checking the Gas Supply (Inlet) Pressure

ENGLISH

SECTION 2 - INSTALLATION

E.Checking the Gas Supply (Inlet) Pressure

1.Remove the supply (inlet) pressure cap screw from the multifunction gas valve. Attach a manometer to the stud.

2.Depress the machinery compartment safety switch to allow the oven to operate.

3.Open the main gas supply valve. Switch the circuit breaker/ fused disconnect to the ON ("I") position.

4.Start the oven and adjust the temperature controller to the maximum setting (288°C).

5.Measure the supply (inlet) pressure.

6.Switch the oven off. Close the main gas supply valve, and switch the circuit breaker/fused disconnect to the OFF ("O") position. Remove the manometer, and replace the cap screw onto the multifunction gas valve.

7.Compare the measured supply (inlet) pressure to the nominal pressures shown in the Gas Orifices and Pressure Specifications table.

If the supply pressure is lower or higher than the nominal pressure, the reason should be investigated and the gas supplier contacted.

For natural gas ovens, if the measured supply pressure is lower than 17mbar, or higher than 25mbar, contact the gas supplier. DO NOT OPERATE THE OVEN or adjust the oven controls.

F.Adjusting the Orifice (Manifold) Pressure and Heat Input

To use the orifice pressure method, you must know the specific gas type and quality used. If using the orifice pressure method, you should double-check the input using the volumetric method.

To use the volumetric method, you must know the heat value (HuB) of the gas used. This information is available from your gas supplier.

During these measurements, do not operate any other appliances that use the same gas meter as the oven.

1.Orifice (Manifold) Pressure Method

a.Check that the main gas supply valve and the circuit breaker/fused disconnect are in the OFF ("O") position.

b.Remove the regulated (manifold) pressure cap screw from the multifunction gas valve. Attach a manometer to the stud.

c.Remove the cap screw from the pressure adjustment screw (governor) on the multifunction gas valve.

d.Depress the machinery compartment safety switch to allow the oven to operate.

e.Open the main gas supply valve. Switch the circuit breaker/fused disconnect to the ON ("I") position.

f.Start the oven and adjust the temperature controller to the maximum setting (288°C).

g.Adjust the pressure adjustment screw as necessary to match the correct pressure for the oven's specific gas type. Refer to the Gas Orifices and Pressure Specifications table. Turning the adjustment screw clockwise increases the flow, while turning it counterclockwise reduces the flow.

h.Switch the oven off. Close the main gas supply valve, and switch the circuit breaker/fused disconnect to the OFF ("O") position. Remove the manometer, and replace the cap screws onto the multifunction gas valve.

2.Volumetric Method

a.Determine the time of 0.1m3 (100 liters) of gas usage as follows.

Consumption (m3/hr.) =

 

NB (Rated input in kW)

HuB (Heat [Calorific] value

 

 

 

 

 

of gas in kW/m3)

Time (in minutes) of

=

 

6

 

0.1m3 of gas usage

 

Consumption

 

 

b.Check that the main gas supply valve and the circuit breaker/fused disconnect are in the OFF ("O") position.

c.Remove the cap screw from the pressure adjustment screw (governor) on the multifunction gas valve.

d.Depress the machinery compartment safety switch to allow the oven to operate.

e.Open the main gas supply valve. Switch the circuit breaker/fused disconnect to the ON ("I") position.

f.Start the oven and adjust the temperature controller to the maximum setting (288°C).

g.Adjust the pressure adjustment screw as necessary to match the calculated volume using the time (in minutes) of 0.1m3 of gas usage. Turning the adjustment screw clockwise increases the flow, while turning it counterclockwise reduces the flow.

h.Record the reading obtained from the gas meter and calculate the obtained gas flow. Compare this value to the information in the Gas Orifices and Pressure Specifications table.

i.Switch the oven off. Close the main gas supply valve, and switch the circuit breaker/fused disconnect to the OFF ("O") position. Replace the cap screw onto the multifunction gas valve.

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Middleby Marshall PS360WB-U, PS360-L English, E. Checking the Gas Supply Inlet Pressure, Orifice Manifold Pressure Method