Raypak 302B High Limit Manual Reset, Low Water Cut-OffOptional, Flow Switch, Operating Control

High Limit (Manual Reset)

The heater is equipped with a manual reset high limit temperature device. Push the reset button and adjust the setting to 40 - 50°F above desired operating tem- perature.

Low Water Cut-Off (Optional)

The low water cut-off automatically shuts down the burner whenever water level drops below the level of the sensing probe. A 5-second time delay prevents premature lockout due to temporary conditions such as power fluctuations or air pockets.

Fig. 30: High Limit (Manual Reset)

Flow Switch

This dual-purpose control, mounted and wired in series with the main gas valve, shuts off heater in case of pump failure or low water flow.

Fig. 32: Low Water Cut-Off

High and Low Gas Pressure Switches

The low gas pressure switch (optional) connection mounts upstream of the gas valve to ensure that suffi- cient gas pressure is present for proper regulator performance. The low gas pressure switch automati- cally shuts down the heater if gas supply drops below the recommended setting of 5.0 in. WC for natural gas, and 10.0 in. WC for propane gas.

The high gas pressure switch (optional) connection mounts downstream of the stage-1 gas valve. If the gas pressure regulator fails, the high gas pressure switch automatically shuts down the burner. The high gas pressure switch automatically shuts down the heater if gas manifold pressure rises above the recom- mended setting of 5.0 in. WC for natural gas, and 11.5 in. WC for propane gas.

Fig. 31: Flow Switch

Operating Control

The heater may be equipped with different types of
operating controls. Consult the individual control data
sheets supplied with your heater paperwork. See the
General Safety Section for safety precautions con-	Fig. 33: High/Low Gas Pressure Switch
cerning domestic hot water applications.

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