Harsco Industrial MACH C1500GG Installation & Owner's Manual page 30

MACH® Gas-Fired Boiler
3.9.2 Test of Low Water Cut-off
The boiler is furnished with a probe-type low water cut-off in the outlet nozzle. Test as follows:
Push and hold the red "Push to test" button for at least 5 seconds. A manual lockout reset error displaying LOCKOUT
LOW WATER LEVEL on the display panel should occur. The LED indicator on the Low Water cut-off will no longer be
illuminated.
(Optional Test Method)
First turn the boiler off, and then turn the pump off. Isolate the boiler from the system. Drain the water level below the
low water cut-off probe. Turn the boiler back on. It should not operate, and a manual lockout reset error displaying
LOCKOUT LOW WATER LEVEL on the display panel should occur. The LED indicator on the Low Water cut-off will
no longer be illuminated.
Return the system to normal operation by refilling and restarting the boiler and pump.
3.9.3 Test of High-Limit Control
Fire the boiler and test the high limit control as follows:
With the main burner operating, turn down the temperature setting on the "high-limit" thermostat until the main burner
shuts off. A manual reset lockout displaying LOCKING HIGH LIMIT on the display panel will occur. The high-limit
switch must be manually reset prior to resetting the boiler at the display panel. Readjust the high-limit thermostat to
the desired setpoint.
3.9.4 Test of Gas Pressure Switches
Low Gas Pressure Switch
The boiler is furnished with two low gas pressure switches, one for both gas connections. The operation of these
switches must be checked by slowly closing the main gas cock while the burner is operating. This procedure should
be performed for each fuel, the Natural Gas and the Propane Gas. Each respective low gas pressure switch should
shut down the main burner. When the gas pressure switch opens, a manual reset lockout displaying LOCKING LOW
GAS PRESSURE on the display panel will occur. Upon re-opening the main gas cock, the LOCKING LOW GAS
PRESSURE will remain on until the display panel is manually reset.
High Gas Pressure Switch
The boiler is furnished with a high pressure switch that must be checked by closing the downstream gas cock with the
boiler off. When the boiler is started, it should enter its normal starting cycle and fail on high gas pressure when the
automatic gas valves open. The high gas pressure switch actuation is evident when a manual reset lockout
displaying LOCKING HIGH GAS PRESSURE on the display panel occurs. Upon re-opening the gas cock, the
LOCKING HIGH GAS PRESSURE indicator will remain on until the display panel is manually reset.
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