Raypak Hi Delta 302A-902A Installation And Operating Instructions Manual

46PreparationCheck Power SupplyWith multi-meter at incoming power, check voltagebetween:Hot - Common (≈120 VAC)Hot - Ground (≈120 VAC)Common - Ground (< 1 VAC)Attach Manometers to Measure Pressures1. Turn off main gas valve.2. Attach 24” scale manometer to the first main gasshut-off valve pressure tapping.3. Attach (1) 12” scale manometer to the outlet sideof the second main gas shut-off valve pressuretapping.4. Attach (1) 12” scale manometer near the fan-prov-ing switch. Pull black cap from air pressure switchtee and connect the manometer. NOTE: Retaincaps for reinstallation later.Check Gas Supply Pressure1. Slowly turn on main gas shut-off valve.2. Read the gas supply pressure from the manome-ter; minimum supply pressure for natural gas is 5.0in. WC, recommended supply is 7.0 in. WC, mini-mum supply pressure for propane gas is 11.0 in.WC (dynamic readings, all stages firing).3. If the pressure is > 14.0 in. WC, turn off the valve.4. Check if the service regulator is installed and/oradjust the service regulator.WARNING: Do not turn on gas at this time.WARNING: If Common - Ground is > 1 VAC,STOP: Contact electrician to correct ground failure.Failure to do this may burn out 120V-24V trans-former, or may cause other safety control damage orfailure.Start-UpBlower Adjustment1. Turn off power.2. Unplug cap at pressure switches and connect ma-nometer(s) to the tee.3. Close all manual firing valves.4. Turn power on.5. Check manometers attached to fan pressureswitch. The reading should be 1.4 ± .1 in. WC forpropane gas and natural gas. If not, adjust the airshutter on the blowers to attain the correct value.6. Turn power off.7. Reconnect this cap.Main Burner Adjustment1. Turn off unit.2. Open manual firing valves.3. Turn on the unit, wait 15 seconds, and the ignitershould glow. Look into sight glass located at eachend of the heater to check igniter operation. Gasvalves should open in 45-60 seconds.4. If burner does not light on first trial. It will retry, upto three times.5. Main burner ignition: Check manifold gas pressureat gas valve outlet pressure tap. This should read3.5 ± 0.1 in. WC for natural gas and 10.5 ± 0.1 in.WC for propane gas.6. If the pressure reading differs by more than ± 0.1in. WC, remove screw cover from the gas pres-sure regulator and adjust main burner manifoldpressure. Replace the screw cover. Repeat steps2 to 5 on other valves as necessary.CAUTION: Special manifold and air settings maybe required. Verify rating plate and blower housing.