Raypak HD101 Flow Switch, High and Low Gas Pressure Switches Optional, Low Water Cut Off Optional

The optional adjustable auto reset high limit is located behind the front panel (see Fig. 3). Adjust the setting to approx. 20°F (10°C) above desired outlet tempera- ture.

Fig. 26: High Limit — Auto Reset (Optional)

Flow Switch

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

NOTE: Flow switch will not operate if flow is less than 12 gpm.

Fig. 27: Flow Switch

High and Low Gas Pressure Switches (Optional)

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 per- formance. The low gas pressure switch automatically shuts down the heater if gas supply drops below the recommended setting of 4.0 in. WC for natural gas, and 9.0 in. WC for propane gas.

The high gas pressure switch (optional) connection mounts down-stream of the gas valve. If the gas pres- sure 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 recommended setting of 4.0 in. WC for natural gas, and 10.5 in. WC for propane gas.

Fig. 28: Gas Pressure Switch

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. 29: Low Water Cut Off

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