Raypak 751 - Manual

7 GENERAL SAFETY To meet commercial water use needs, an externaloperating control for this hot water boiler is adjustableup to 210°F. However, water temperatures over 125°Fcan cause instant severe burns or death from scalds.The preferred starting point for setting the control forsupplying general pu...

Equipment Base The boiler should be mounted on a level, structurallysound surface. The boiler is approved for and can beinstalled on a combustible surface but must NEVERbe installed on carpeting. Gas fueled equipmentinstalled in enclosed parking garages must be locatedat least 18 inches above the fl...

9 Outdoor Installations Raypak Advanced Design Boilers are design certifiedby CSA for outdoor installation. Roof water drainagemust be diverted away from boilers installed underoverhangs. Combustion and Ventilation Air Indoor Units The boiler must be supplied with sufficient quantities ofnon-contami...

11 Conventional Combustion AirSupply U.S. Installations All Air from Inside the Building If all combustion air is drawn from the air inside thebuilding (the mechanical equipment room does notreceive air from outside): 1. The mechanical equipment room must be provid- ed with two permanent openings co...

of 1 million BTUH. This opening(s) shall be eitherlocated at or ducted to a point neither more than18 inches (450 mm) nor less than 6 inches (150mm) above the floor level. The duct can also"Goose Neck" through the roof. The duct is pre-ferred straight down 18 inches from floor, but donot pla...

HYDRONIC HEATING Pump Selection In order to ensure proper performance of your boilersystem, you must install a properly sized pump.Raypak recommends using a 20°F ΔT as design ΔT.(ΔT is the temperature difference between the inletand outlet water when the boiler is firing at full rate). Ifa ΔT larger...

19 POOL HEATING The ADB unit is equipped with an external pump andbypass arrangement that blends outlet water with theinlet to increase the inlet water temperature, therebyreducing the likelihood of condensation forming on theheat exchanger. The pump also serves to circulatewater through the heater ...

22 Fig. 16: Connections Gas Supply Connection The boiler must be isolated from the gas supply pipingsystem by closing the manual shutoff valve during anypressure testing of the gas supply piping system attest pressures equal to or less than 1/2 PSIG. Relievetest pressure in the gas supply line befor...

23 Gas Pressure Regulator The gas pressure regulator is nominally preset to theoutlet values shown in Tables T and U, within +.1 in.WC. If an adjustment is needed, turn the adjustmentscrew clockwise to increase pressure or counterclock-wise to lower pressure. Venting of Diaphragm GasComponents Boile...

34 Ver tical Direct Venting SystemInstallation These installations utilize the boiler mounted blower todraw combustion air from outdoors and uses the natu-ral buoyancy of the heated flue products to create athermal driving head that expels the exhaust gasesfrom the flue. The negative draft must be w...

40 e) A venting system shall terminate at least 3 feet above any forced air inlet located within 10 feet. f) Adjacent brick or masonry surfaces must be pro- tected with a rust-resistant sheet metal plate. g) Multiple Outdoor Vent installations require a four (4) feet clearance between vent caps. The...

41 CONTROLS Central Point Wiring (CPW) Central Point Wiring is an advanced control integrationtechnique that provides complete boiler diagnosticcapability and greatly simplifies troubleshooting. At theheart of CPW is the Operations Status Center, whichis comprised of two different circuit boards: th...

43 U-2 Diagnostics Board The U-2 Diagnostics board is a solid-state electronicfault indicator that has been engineered to enhancesafety, simplify troubleshooting and minimize equip-ment down time. The U-2 safety board is the centralpoint for wiring, operations monitoring, and fault indi-cation for t...

46 Low Water Cut Off (Optional) The low water cut off automatically shuts down theburner whenever water level drops below the level ofthe sensing probe. A 3 second time delay preventspremature lockout due to temporary conditions suchas power fluctuations or air pockets. High and Low Gas PressureSwit...

48 ADB INITIAL START-UP Tools Needed • One 8-0-8 , 16” scale manometer (or larger) • Four 4-0-4, 8” scale manometers (or larger) • “T” fitting • 7/16” and 1/2" open end wrenches • Small and large flat-head screwdrivers • Volt meter • Amp probe • Elec. Dual reading thermometer with strap on sen-s...

50 Main Bur ner Adjustment 1. Turn on the unit; about 45 seconds later, the pilot should light. If the pilot fails to light, repeat pilotadjustment. 2. Turn the top manual valve on, Location (2). The inner burner will fire. 3. Make sure that the supply gas manometer reads between 7 – 14 in. WC (dyna...

51 burners should reignite after pre-purge time delay. 8. Test limit control: While burner is operating, move indicator on high limit control below actual boilerwater temperature. Burner should go off whileblower circulator continues to operate. Raise set-ting on limit control above boiler watertemp...

53 10. Connect the flue vent (Category IV venting, UL 1738 Certified Venting Material) to the 15° elbowof the CHX flue outlet. 11. Connect the PVC pipe (not supplied) for conden- sate water disposal (check with local authorityregarding condensate disposal). 12. Replace the shroud.13. Allow the silic...

54 APPENDIX Inside Combustion AirContamination: All boilers experience some condensation during start-up. The condensate from flue gas is slightly acidic. Inmost cases the pH level is not harmful to vents ordrains. When combustion air is contaminated byvapors from products in areas listed below, the...