LF30 Pressure Switch

The LFAS employs a differential pressure to actuate a precision snap switch at chosen pressure setting. This may be the difference between atmospheric and a negative or positive pressure or between any two given pressures. When a change of pressure occurs between the negative pressure chamber and the positive pressure chamber the main diaphragm activates the snap switch at a pre-determined value.

The LFAS pressure cut-off switch is manufactured from selected compound derivatives of polycarbonate & PBT offering exceptional thermal and dimensional stability at elevated temperatures up to 105°C when used in contaminated atmospheres of air, products of combustion, L.P. or natural gas. It has been designed to meet the low pressure, high-temperature specifications of future generations of fanned gas and similar appliances where differential pressures form part of an integrated control system.

Typical Applications:

Detects airflow in forced draught appliances

Signals either positive, negative or zero air movement

Shut down burner in blocked flue conditions

Guards against poor or hazardous combustion

Indicates dirty or inefficient filters

Model	LF30 (LFAS)
Medium	Air, products of combustion, L.P. or natural gas
Mounting /Fixing	4 screws with maximum penetration depth of6.3mminto appropriate mounting holes, or fixed with optional bracket.
Mounting Position	The LFAS is position sensitive. It may be mounted in most positions provided it has been calibrated.
Field Adjustable Range	0.4mbar to 8.0mbar make on positive or negative pressure rise. Minimum upper switching pressure 0.4mbar. Minimum lower switching pressure 0.2mbar.
Switch Differential	Not less than 0.1mb and not greater than 0.3mb depending on pressure settings.
Maximum Operating Pressure	10mbar Pmax=50mbar.
Operating Temperature Range	105?Maximum
Electric Rating	125V,250V,5Asingle pole on-off or single pole change over. Other ratings are available on request.
Contact Arrangement	SPDT or SPST
Terminals	6.3 or4.88 mmmale Q.C. Optional insulation cover available as necessary.
Calibration	LFAS switches are normally calibrated at their lower switching pressure in accordance with customer requirements. Ramp rate at switch point=0.03mb/second
Calibration Tolerance	Standard production tolerance at ambient temperature is ± 0.10mb or ± 5% of setpoint, whichever is the greater.
Pressure Connections	6mmO.D. push on or "Permifix" tubing. The lower (negative) connector may be supplied in any one of four positions for ease of installation.