Raypak 902B, 302B Electrical Power Connections, Gas Supply Pressure, Field-Connected Controllers

6.Reinstall the pipe cap on the left-hand end of the main gas line.

7.Remove plastic cap from the right-hand side panel and reinstall into the standard main gas opening located on the left-hand side of the heater.

8.Remove the rubber grommet from the left-hand- side panel and reinstall into the standard main gas opening, located on the right-hand side of the heater.

9.Install a coupling, nipple, union and sediment trap onto the right-hand end of the main gas line and then install the gas line, making sure that a manu- al shut-off valve has been installed within 10 ft of the heater.

10.Replace the left and right front panels on the heater.

Gas Supply Pressure

A minimum of 5.0 in. WC and a maximum of 10.5 in. WC upstream gas pressure is required under load and no-load conditions for natural gas. A minimum of 11.0 in. WC and a maximum of 13.0 in. WC is required for propane gas. The gas pressure regulator(s) supplied on the heater is for low-pressure service. If upstream pressure exceeds 14.0 in. WC, an intermediate gas pressure regulator, of the lockup type, must be installed.

When connecting additional gas utilization equipment to the gas piping system, the existing piping must be checked to determine if it has adequate capacity for the combined load.

The gas valve pressure regulator(s) on the heater are nominally preset at 3.5 in. WC for natural gas, and

10.5in. WC for propane gas. The pressure at the gas valve outlet tap, measured with a manometer, while in

Fig. 17: Gas Valve

operation should be 3.5 ± 0.1 in. WC for natural gas and 10.5 in. ± 0.1 in. WC for propane gas. If an adjust- ment is needed, remove the adjustment screw cover and turn the adjustment screw clockwise to increase pressure or counter-clockwise to lower pressure.

CAUTION: For proper operation, no more than a 30% drop in gas supply pressure from no-load to full- load conditions is acceptable. Under no circumstances should the pressure be outside the listed operational range.

Electrical Power Connections

Installations must follow these codes:

•National Electrical Code and any other national, state, provincial or local codes or regulations hav- ing jurisdiction.

•Safety wiring must be NEC Class 1.

•Heater must be electrically grounded as required by the NEC.

•In Canada, CSA C22. 1 C.E.C. Part 1.

The heater is wired for 120 VAC, 8 amps in its basic configuration. Additional options may increase the amp draw of the unit. The voltage is indicated on the tie-in leads. Consult the wiring dia-gram shipped with the heater in the instruction packet. The remote tank control stat, thermostat, or electronic heater control (as applicable) may be connected to the stage selector terminal (See wiring diagram). 24 VAC is supplied to this connection through the heater trans-former. DO

NOT attach any voltage to the stage selector termi- nals. Before starting the heater check to ensure proper voltage to the heater and pump.

Install a separate disconnect means for each load. Use appropriately sized wire as defined by NEC, CSA and/or local code. All primary wiring should be at least 125% of minimum rating.

If any of the original wire as supplied with the heater must be replaced, it must be replaced with 105°C wire or its equivalent.

Field-Connected Controllers

It is strongly recommended that all individually-pow- ered control modules and the heater should be supplied from the same power source.

NOTE: Field-supplied isolation relays should be installed when field-connected controllers are mounted more than 50 equivalent feet (18 Ga) from heater.

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