Commercial Pool Heaters
INSTALLATION Continued
Figure 29 shows a typical pool heater gas train.
The manifold pressure is preset at the factory and adjustment is not usually required. If you must adjust regulator pressure, follow the instructions under Gas Manifold Pressure Adjustment, page 30.
Venting of Combination Gas Valves
The combination gas valve/regulator used on these pool heaters is equipped with an integral vent limiting orifice per ANSI Z21.78. The vent limiter ensures that the volume of gas emitted from the valve in the event of a failed gas diaphragm does not exceed the maximum safe leakage rate allowed by agency requirements. Combination gas valve/regulators equipped with integral vent limiters are not required to have vent or relief lines piped to the outdoors.
Figure 29 – Typical Pool Heater Gas Train Drawing
TABLE-J
Suggested Gas Pipe Size for Single Unit Installations
Btu/hr |
| Distance From Meter (in feet) | ||||||
Input | ||||||||
500,000 |
| 1 1/2" |
| 2" |
| 2" |
| 2 1/2" |
1 1/4" |
|
|
| |||||
|
|
|
|
|
|
|
|
|
650,000 | 1 1/2" | 2" |
| 2" |
| 2 1/2" |
| 2 1/2" |
|
|
|
|
|
|
|
|
|
750,000 | 1 1/2" | 2" |
| 2" |
| 2 1/2" |
| 3" |
|
|
|
|
|
|
|
|
|
990,000 | 2" | 2" |
| 2 1/2" |
| 2 1/2" |
| 3" |
|
|
|
|
|
|
|
|
|
1,260,000 | 2" | 2 1/2" |
| 2 1/2" |
| 3" |
| 3" |
|
|
|
|
|
|
|
|
|
1,440,000 | 2 1/2" | 2 1/2" |
| 3" |
| 3" |
| 3 1/2" |
|
|
|
|
|
|
|
|
|
1,800,000 | 2 1/2" | 3" |
| 3" |
| 3 1/2" |
| 3 1/2" |
|
|
|
|
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|
|
|
2,070,000 | 2 1/2" | 3" |
| 3" |
| 3 1/2" |
| 4" |
|
|
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|
|
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|
|
|
Combination Gas Valves
These pool heaters fire in a single stage of operation.
Note: This pool heater incorporates a “soft start” feature which lights approximately half of the burners before lighting the remaining burners. Each combination valve consists of a gas regulator and two valve seats to meet the requirements for redundant gas valves. The valve has a gas control knob that must remain in the open position at all times when the pool heater is in service. The gas control valve has pressure taps located on the inlet and discharge sides of the valve. Manifold pressure is adjusted using the regulator located on the valve. A manifold gas pressure tap for each burner stick is located on the discharge side of the valve.
Checking Gas Supply Pressure
Use the following procedure to check gas supply pressure.
1.Turn the main power switch to the “OFF” position.
2.Turn gas valve knobs to the “OFF” position.
3.Shut off gas supply at the
4.Remove the 1/8" hex plug, located on the “inlet” side of any gas valve. You may also use a tapping on the field- installed main manual gas cock or gas piping. Install a fitting in the inlet pressure tapping suitable to connect to a manometer or magnahelic gauge. Range of scale should be 14" w.c. or greater to check inlet pressure.
5.Turn on gas supply at the manual gas cock, turn on L.P. gas at the tank if required.
6.Turn the power switch to the “ON” position.
7.Turn the gas valve knobs to the “ON” position. Set the temperature control to call for heat. See Operating Temperature Control on page 40 for programming instructions.
8.Observe the gas supply pressure as all burners are firing. Ensure that inlet pressure is within the specified range. See Connecting To Gas Supply, page 26 for minimum and maximum gas supply pressures.
9.If gas pressure is out of range, contact gas utility, gas supplier, qualified installer or service agency to determine necessary steps to provide proper gas pressure to the pool heater.
10.If gas supply pressure is within normal range, turn the power switch to the “OFF” position.
11.Turn gas valve knobs to the “OFF” position.
12.Shut off gas supply at the manual gas cock in the gas piping to the pool heater. If fuel supply is L.P. gas, shut off gas supply at the tank.
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