Algas SDI VAPORAIRE M-Series, Руководство по эксплуатации и техническому обслуживанию

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Operation
SDI Operations & Maintenance Manual – 54264
4-23
EXAMPLE:
If the venturi is on at 4.5 PSIG and the mixed gas pressure setpoint should
be 5 PSIG, then the Mixed Gas Pressure Control Switch needs to be
adjusted. To increase the pressure setpoint, turn the screw clockwise (in).
Continue adjusting as needed until the venturi turns on when the mixed gas
pressure is at 5 PSIG. The Mixed Gas Pressure Control Switch has a fixed
deadband differential of approximately 0.5 PSIG. After the adjustments are
made, check the heating value of the LP gas-air mixture and adjust if
necessary.
HIGH MIXED GAS PRESSURE SAFETY SWITCH
The High Mixed Gas Pressure Safety Switch shuts down the mixer if there is a
Mixed Gas Pressure Control Switch failure. The High Mixed Gas Pressure
Switch is a mechanical switch located in the control box. The High Mixed Gas
Pressure Switch is wired normally closed and will open when High Mixed Gas
pressure setpoint is exceeded.
Adjusting High Mixed Gas Pressure setpoint ( Refer to data sheet for setpoint ).
Control box must be open to adjust.
1. To set, turn the adjusting wheel to the approximate setting shown on the
indicator scale on the switch. Indicator on the front of the switch is only a
guide; the pressure should be adjusted using a calibrated pressure gauge.
Turning the wheel counterclockwise decreases the pressure setting and
turning it clockwise increases the setting. The High Mixed Gas Pressure
Switch is set 3 PSI above the mixed gas operating pressure.
EXAMPLE:
8 PSIG Mixed Gas Pr 3 PSI = 11 PSIG High Mixed Gas
Pressure Setpoint.
LOW VAPOR PRESSURE SWITCH
The mixer requires a minimum vapor pressure for the proper operation of the
venturi. The Low Vapor Pressure Switch is wired normally open and is set to
close when there is adequate vapor pressure to operate the venturi. The vapor
pressure will close the Low Vapor Pressure Switch and activate the Mixed Gas
Pressure Control Switch. The Mixed Gas Pressure Control Switch will cycle the
venturi based on load. If vapor pressure decreases below the Low Vapor
Pressure Switch setpoint, the mixer will stop mixing and will remain in standby
until vapor pressure increases. The Mixed Gas Pressure Control Switch and
venturi solenoid valve are disabled until there is adequate vapor pressure to
operate the venturi.
Adjusting Low Vapor Pressure Switch Setpoint:
1. Put the system on a load so that the single venturi is cycling on/off. Slowly
throttle the LPG vapor outlet valve on the vaporizer outlet. This reduces the
LPG vapor pressure being sent to the mixer. Observe the LPG vapor
pressure gauge and note the pressure at which the venturi stops mixing, the
observed pressure is the Low Vapor Pressure Switch setpoint.
Compare
this value with the Data Sheet .
2. Repeat the throttling procedures to adjust the Low Vapor Pressure Switch
( Refer to Data Sheet for setpoint ) adjust by turning the adjusting wheel
until the Low Vapor Pressure Switch setpoint matches the value given on the
Data Sheet .