Raypak 302A-902A manual Hydronic Heating, Temperature & Pressure Gauge, Pump Selection

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Failure to exceed 105ºF (41ºC) within 7 minutes may result in the premature failure of the hot surface ignit- er, remote flame sensor, burners and heat exchanger. It can cause operational problems, bad combustion, sooting, flue gas spillage and reduced service life of the vent system. The bypass allows part of the heater discharge water to be mixed with the cooler heater return water to increase the heater inlet temperature above 105ºF (41ºC). This precautionary measure should prevent the products of combustion from con- densing in most installations. Warranty claims will be denied when condensation occurs.

Cold water operation issues are applicable to both cold water start and cold water run applications. Cold water operation for 7 minutes or less on start-up is acceptable. Where cold water starts will last longer than 7 minutes or where cold water operation is con- tinuous, provisions must be made to mix higher tem- perature outlet water with the colder inlet water and thereby raise the inlet temperature to at least 105ºF (41ºC) within the 7-minute time limit.

Cold Water Starts

Frequent (more than once a week) cold water starts, wherein the inlet water temperature remains below 105ºF (41ºC) for more than 7 minutes, must have cold water start protection. Known protection methods con- sist of mixing heated outlet water with the inlet water with a bypass to raise the inlet to 105ºF (41ºC) or high- er. Once the system is heated up and has return water temperatures of 105ºF (41ºC) or higher, the mixing of outlet water with inlet water is no longer needed and the bypass can be shut off. If the bypass is not shut off as the system heats up, the outlet temperature may continue to climb and actuate the high limit, thereby

shutting down the heater. Thus an automatic valve system, such as a three-way proportional valve or a modulating two-way valve to control the bypass, should be utilized.

Cold Water Run

Cold water run differs from cold water start in that the system water entering the heater remains below 105ºF (41ºC) continuously. Typically, this is the case in swim- ming pool heating and water source heat pump appli- cations as well as some others. If the system water is kept in a narrow temperature range, a permanent manual bypass can be employed and manually adjust- ed to achieve an inlet temperature of 105ºF (41ºC) or higher. An injector pump arrangement may also be uti- lized to keep the heater loop at or above 105ºF (41ºC). An injector pump approach has the added value of being able to adjust to changes in the system water coming back to the heater take-off.

Temperature & Pressure Gauge

The temperature and pressure gauge is factory- mounted in the in/out header.

Hydronic Heating

Pump Selection

In order to ensure proper performance of your heater system, you must install a correctly sized pump. Ray- pak recommends using a 20°F ΔT as design ΔT. (ΔT is the temperature difference between the inlet and out- let water when the heater is firing at full rate). If a ΔT of larger than 20°F is necessary, see Table H and Table I for flow rate requirements.

 

Model

 

10°F

T

20°F

T

30°F

T

40°F

T

Min. Flow

 

Max Flow

 

 

 

No.

 

gpm

 

P (ft)

gpm

 

P (ft)

gpm

 

P (ft)

gpm

 

P (ft)

gpm

P (ft)

T

gpm

P (ft)

T

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

302A

 

50

 

3.1

25

 

0.8

N/A

 

N/A

N/A

 

N/A

20

0.5

25

90

9.8

6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

402A

 

67

 

5.5

34

 

1.4

22

 

0.6

N/A

 

N/A

20

0.5

34

90

10.0

7

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

502A

 

84

 

9.1

42

 

2.3

28

 

1.1

21

 

0.6

21

0.6

40

90

10.4

9

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

652A

 

N/A

 

N/A

55

 

4.1

36

 

1.8

27

 

1.1

27

1.1

40

90

10.8

12

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

752A

 

N/A

 

N/A

63

 

5.7

42

 

2.6

32

 

1.5

32

1.5

40

90

11.3

14

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

902A

 

N/A

 

N/A

76

 

8.3

50

 

3.8

38

 

2.2

38

2.2

40

90

11.7

17

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Notes:

1. Basis for minimum flow is 20 gpm or 40°F ΔT. Basis for maximum flow is 90 gpm. Flow switch will not operate if flow is less

 

 

 

than 20 gpm.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2.Rear-mounted pumps may provide higher flow rates on smaller models than the system requirements.

Table H: Heater Rates of Flow and Pressure Drops

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Contents Installation and Operating Instructions Page Contents Pay Attention to These Terms Before Installation Product ReceiptModel Identification Ratings and CertificationsComponent Locations Component Locations BackModel # Burners per Stages Fire at Valve General InformationModel # Burners Valve Firing Per Valve Staging Time/Temperature Relationships in Scalds General SafetyWater Time to Produce Serious Temp Burn Installation Installation CodesEquipment Base StackingOutdoor Installations Indoor InstallationsClearances Installations1 Canadian Installations2 Combustion and Ventilation Air Indoor UnitsReversing Air Filter Direct VentInstallations Conventional Combustion Air SupplyTruSeal Combustion Air All Air from Inside the BuildingCanadian Installations Water PipingGeneral Reversing Water ConnectionsRelief Valve Piping Hydrostatic Test Cold Water OperationTemperature & Pressure Gauge Hydronic HeatingPump Selection Min. Flow Max Flow GpmPressure Drop in Feet of Head Feedwater Regulator PipingAir-Separation/Expansion Tank Three-Way ValvesPotable Water and Space Heating Pool HeatingAutomatic Chlorinators and Chemical Feeders Winterizing Your HeaterGas Supply Pool/Spa Water Chemistry Water HardnessPH of Water Total Dissolved SolidsReversing Gas Supply Connection Gas Supply ConnectionTable J Maximum Equivalent Pipe Length Electrical Power Connections Check the Power SourceGas Supply Pressure Field-Connected ControllersField Wiring Connection Making the Electrical ConnectionsWiring Connections Venting Appliance CategoriesSupport of Vent Stack Vent Terminal LocationDirect Venting Horizontal Through Stainless SteelCanadian Installations InstallationsChanging the Flue Outlet Venting Installation Tips Venting ConfigurationsInstallation Natural Draft Vertical Venting CategoryTermination Common Venting SystemModel Venting Vent Size Height Intake Pipe Max. Length Min MaxHorizontal Through-the-Wall Venting Category Horizontal Through-the-Wall Venting CategoryMax. Length Venting Vent Size Equivalent Intake Pipe Direct Vent Horizontal Through- the-WallMaterial Direct Vent Vertical Controls Outdoor InstallationFreeze Protection Heater Sequence of Operation Models 302A, 402A, 502A, 652A, 752A and 902AExternal Lights Color Indication Auto Reset High Limit Red Auto reset optionInternal Lights Color Indication Ignition Module Code ConditionHigh Limit Manual Reset Flow SwitchHigh and Low Gas Pressure Switches Operating ControlHigh/Low Gas Pressure Switch 87%-Efficiency Boilers Special Instructions Water Piping Venting Appliance CategoriesModel 10F 20F 30F Min. Flow Max Flow Gpm Direct Venting Horizontal Through AL29-4CVent Terminal Location Vertical Venting CategoryCondensate Management Certified Maximum Combustion Air Air Inlet Model Venting Material Vent Length100’ Ducted 40’ 752AE Combustion Air 902AE 30’ 80’Direct Vent Horizontal Through- the-Wall Direct Vent Vertical Certified Vertical Venting Combustion Air Air Inlet302A 100’ 402A Galvanized Steel 502A 75’ Category 25’ 100’ 40’ 752A 902AWiring Diagram START-UP Pre Start-upMain Burner Adjustment Blower AdjustmentStart-Up Safety Inspection Leak Test Procedure Dual-Seat Gas ValvesFollow-Up Pilot Turn-Down TestPost Start-Up Check Leak TestLighting Instructions OperationTo Turn Off Gas To Appliance Troubleshooting StepSuggested Minimum Maintenance Schedule MaintenancePreventive Maintenance Schedule Weekly Semi-AnnuallyAnnually As RequiredAppendix Inside Air ContaminationLimited Parts Warranty HI Delta Types H and WH Limited Parts Warranty HI Delta Type P

302A-902A specifications

The Raypak 302A-902A is a highly regarded pool and spa heater, known for its efficiency and reliability in delivering warmth to residential and commercial aquatic applications. This heater stands out due to its robust design, advanced technology, and user-friendly features.

One of the key characteristics of the Raypak 302A-902A is its dual fuel capability, which means it can run on either natural gas or propane. This flexibility allows users to choose their preferred fuel type, contributing to operational efficiency and cost-effectiveness. With a BTU output ranging from 302,000 to 902,000, the Raypak heater is capable of quickly heating large volumes of water, making it ideal for pools, spas, and hot tubs.

The heater incorporates advanced technology such as a stainless steel heat exchanger, which not only ensures excellent thermal conductivity but also promotes durability against corrosion. This is especially advantageous in harsh environments, where exposure to chemicals can significantly impact the lifespan of traditional copper heat exchangers. The Raypak 302A-902A's heat exchanger is designed to withstand the rigors of constant use while maintaining high performance levels.

Another prominent feature of the Raypak 302A-902A is its digital display control system, which simplifies the operation and monitoring of the heater. Users can easily set and adjust temperatures, as well as access diagnostic information, all through an intuitive interface. This digital control not only enhances user experience but also aids in the timely maintenance of the unit.

Energy efficiency is another major selling point of the Raypak 302A-902A. The heater is designed with environmentally friendly practices in mind, utilizing a low NOx burner that minimizes harmful emissions. This not only meets environmental regulations but also makes it a greener alternative for heating needs.

In terms of installation, the compact design of the Raypak 302A-902A allows for versatile placement options, whether in a residential backyard or a commercial environment. Its user-friendly installation process ensures that homeowners and businesses alike can enjoy the benefits of heated water with minimal hassle.

Overall, the Raypak 302A-902A is an exemplary choice for anyone seeking a high-quality, efficient, and flexible pool and spa heating solution. Its combination of robust engineering, advanced technology, and user-focused features solidifies its position as a leader in the market, promising effective heating for years to come. Whether for personal enjoyment or commercial use, this heater delivers exceptional performance that meets diverse heating needs.
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