Middleby Marshall PS220, PS570, PS360, PS200 123, VII. GAS Leak Test VIII. Inlet Pressure Check

SECTION 3 - SERVICING COMPONENTS

Appendix - Instructions for All Gas Conversion Kits

for Ovens with Wayne Burner, Natural Gas to Propane, 8/00

VII. GAS LEAK TEST		VIII. INLET PRESSURE CHECK
1.	Restore the electrical and gas utility connections to the	1. Using a manometer, check the inlet pressure at the inlet
	oven.	pressure tap. See Figure 6. An inlet pressure of 11-14”
2.	Paint all gas pipe connections from the union to the	W.C. (27.4-34.9mbar) is recommended for propane
		operation.
	venturi mounting plate, as well as the pilot tubing,
	bypass tubing, and pressure tap plug, with a rich	2. If the inlet pressure is:
	solution of soap and water (2/3 soap, 1/3 water is	• HIGHER THAN 14” W.C. (34.9mbar) - This pressure
	recommended). Any visible bubbles indicate a gas	may damage the combination gas control valve
	leak.	(safety regulator). The gas supply pressure should
3.	If a gas leak is detected, tighten the affected joints and	be decreased.
	connections. If tightening the connection(s) fails to stop	• LOWER THAN 11” W.C. (27.4mbar) - It may be
	the leak:	necessary to increase the supplied gas pressure.

• Turn off the electric power supply to the oven.
• Turn off the gas supply at the service valve behind	CAUTION
	IF IT IS NECESSARY TO ADJUST THE GAS LINE
the oven.
	PRESSURE, HAVE THE CUSTOMER CONTACT THE
• Replace the affected component(s).
	GAS UTILITY SUPPLIER.
• Repeat the gas leak test.

WARNING - FIRE/EXPLOSION HAZARD
HIDDEN GAS LEAKS CAN CAUSE A FLASHBACK	IX. PILOT PRESSURE ADJUSTMENT
IN THE MACHINERY COMPARTMENT. THIS
	1.	Unscrew the cap plug from the pilot pressure tap (pilot
CAN CAUSE SEVERE INJURY OR DEATH.
		tee), and attach a manometer to the tap. See Figure 6.
STAND WELL CLEAR WHEN SWITCHING ON
THE HEATING CIRCUIT.	2.	Remove the pilot adjustment cap screw from the
4. If no leaks are detected by the test, depress the safety		combination gas control valve.
switch(es) and switch on the oven. Then, switch on the	3.	Turn the oven on, and allow it to heat to temperature.
heating circuit to ignite the burner.		Make a note of the customer’s set point temperature.
5. With the burner in operation, paint all gas pipe joints with	4.	After the oven has heated, adjust the set point of the
the solution of soap and water.		oven far lower than its current (operating) temperature.
6. If any further gas leaks are detected, shut down the		This ensures that the pilot flame will be at its lowest level

oven. Reseal and tighten the affected joints and	for some time.
	Continued...
connections. If tightening the connection(s) fails to stop
the leak:

•Turn off the electric power supply to the oven.

•Turn off the gas supply at the service valve behind the oven.

•Replace the affected component(s).

•Repeat the gas leak test.

Figure 6

Adjust manifold pressure here (under cap screw)

Measure inlet	Measure
	manifold
pressure here
	pressure here

ENGLISH

Measure pilot pressure here

(under cap plug)Adjust pilot pressure here

(under cap screw)

5

123