Raypak 1005 Blower Check, Manifold Check, Model No Net Blower Suction Setting In. WC, Nat Pro

Blower Check

1.Check the net blower suction using a 6-0-6 U-tube manometer by connecting one end to the blower suction pressure tee (attached to the negative side of the air pressure switch, point “A” in Fig. 53) and the other end to the tracking pressure tee (attached to the positive side of the air pressure switch, point “B” in Fig. 53). Read the differential pressure with the heater firing at 100% input and compare to Table U.

2.Check the tracking pressure by removing the end of the U-tube manometer from the blower suction pressure tee (point “A” in Fig. 53). Replace the cap on the blower suction tee and check the track- ing pressure (at point “B” in Fig. 53) with the heater firing at 100% input. The tracking pressure pro- vides feedback to the gas regulator to compensate for various air ducting arrangements and changes in the pressure drop across the combustion air fil- ter. Initial readings with a clean air filter installed must be recorded on the “Start-up Checklist” locat- ed at the back of this manual. When the tracking pressure is more negative than -0.6 in. WC for 1005 and 1505 models or -0.8 in. WC on 2005 models and there are no obstructions to the air intake, replace the combustion air filter. If the air intake is obstructed, shut the unit off, clear the obstruction, re-start and check the tracking pres- sure as previously noted.

NOTE: Most commercially available amp probes are not accurate enough and/or are not shielded well enough to read accurately in the heater environment. Blower amp draw readings are for reference only.

4.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 net blower suction within the tolerances specified in Table U, contact the factory. The refer- ence 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. 51). This pressure should read per the values in Table W 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 No.	Net Blower Suction		Setting
	(in. WC)
			Tolerance
	Nat.	Pro.

B

A

1005	-4.8	-2.8	± 0.2 in. WC
1505	-3.5	-3.5	± 0.2 in. WC
2005	-4.6	-5.0	± 0.2 in. WC
Table U: XTherm Air Pressure Settings

AIR PRESSURE SWITCH

Fig. 53: Air Pressure Measurement Locations

3.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 V. The amp draw is measured with a clamp- on type amp probe clamped to the 14 AWG black power wire going into the blower.

Model No.	Amp Draw	Setting
		Tolerance
1005	4.8	+0.0/-0.2
1505	8.1	+0.0/-0.2
2005	13.0	+0.0/-0.5

Table V: XTherm Blower Amp Draw—Reference

Information

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