Raypak 503-2003 Model, Air Pressure, Setting in. WC, Amp Draw, Manifold Gas Pressure Setting

2.FOR REFERENCE ONLY: Measure the blower amp draw with the heater firing at 100% input and compare the measured value to the values in Table U. The amp draw is measured with a clamp- on type amp probe clamped to the 14 AWG black power wire going into the blower.

3.When firing at 100%, the desired heater combus- tion CO2 is between 8.5 and 9.0% for natural gas and 9.5 and 10.0% for propane with CO less than 100 ppm. If this combustion cannot be achieved with the blower suction within the tolerances spec- ified in Table T, contact the factory. The reference amp draw reading may help to indicate if there is a problem with the system or if blower adjustment is required.

Manifold Check

1.Check manifold gas pressure at the gas valve out- let pressure tap (connection “D” in Fig. 47). This pressure should read per the values in Table V for natural and propane gas.

2.If the pressure reading differs by more than ± 0.2 in. WC, STOP – Call the factory for directions on what to do next!

Model	Air Pressure	Setting
	Setting (in. WC)	Tolerance
503	-2.3	± 0.2 in. WC
753	-2.9	± 0.2 in. WC
1003	-3.0	± 0.2 in. WC
1253	-3.5	± 0.2 in. WC
1503	-4.0	± 0.2 in. WC
1753	-4.6	± 0.2 in. WC
2003	-4.1	± 0.2 in. WC
Table T:	MVB Air Pressure	Settings

Model	Amp Draw	Setting
		Tolerance
503	1.9	+0.0/-0.2
753	2.9	+0.0/-0.2
1003	4.8	+0.0/-0.2
1253	6.3	+0.0/-0.2
1503	8.1	+0.0/-0.2
1753	10.5	+0.0/-0.5
2003	13.0	+0.0/-0.5

Table U: MVB Amp Draw—Reference Information

Model	Manifold Gas Pressure Setting
	High Fire Values (in. WC)
	Natural Gas	Propane Gas
503	-0.1	-0.1
753	-0.4	-0.1
1003	-0.8	-0.2
1253	-1.6	-0.2
1503	-2.4	-0.6
1753	-0.4	-0.1
2003	-1.0	-0.5

Table V: MVB Manifold Pressure Settings

CAUTION: Special manifold and air settings may be required.

Finishing

1.Record all data on the “Start-up Checklist” located at the back of this manual.

2.Disconnect the manometers and reconnect the cap on the fan pressure switch tee and reinsert the sealing screws into the bleedle valves.

3.Start-up is complete and the heater should be operating properly.

Safety Inspection

1.Check all thermostats and high limit settings.

2.During the following safety checks leave manome- ters hooked up, check and record.

3.If other gas-fired appliances in the room are on the same gas main, check all pressures on the MVB with all other equipment running.

4.Check thermostats for ON-OFF operation.

5.Check high limits for ON-OFF operation.

6.While in operation, check flow switch operation.

7.Check the low gas pressure switch (if provided). (For proper adjustment, use the attached manometers, if available, to set pressure. The scales on the switch are approximate only.) Low

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