Raypak NH - Manual (Page 25)

whenever the pilot flame is interrupted. Pilot flame is
automatically lit when the device is powered. Unit
performs its own safety check and opens the main
valve only after the pilot is proven to be lit.
LOW WATER CUT-OFF (OPTIONAL)
The low water cut-off automatically shuts down
burner whenever water level drops below probe. 90-
second time delay prevents premature lockout due to
temporary conditions such as power failure or air
pockets. Flush float type devices at beginning of each
heating season.
HIGH AND LOW GAS PRESSURE
SWITCHES (OPTIONAL)
These switches sense either high or low gas pres-
sures and automatically shut down burners if abnormal
pressures exist.
HIGH LIMIT
The heater is equipped with a manual reset High
Limit. Push the reset button and set the limit(s) to
30 °F - 40 °F above desired operating temperature.
Maximum setting is 210 °F.
FLOW SWITCH
This dual-purpose control shuts off the heater in
case of pump failure or low water condition and is
strongly recommended. It is mounted and wired in
series to the main gas valve.
NOTE: The flow switch is a safety device and not a
control. Do not operate the heater with flows less than
the minimums stated in this manual.
100% PILOT SAFETY
Models 514-4001 employ electronic devices which
close the main gas valve within 8/10 of a second
LIMIT CONTROLS
MECHANICAL MODULATING VALVE LOCATION
MODELS 0724-1336
MOTORIZED GAS VALVE LOCATION
MODEL 3001
25
Fig # 9332
Fig # 9333.1