Enclosure 6N Pressure Switches
Page 6
CHAPTER
3
ADJUSTMENTS AFTER INSTALLATION
The factory-set setpoint or adjustable setpoint range is marked on the nameplate of the
switch. This section describes the adjustments needed after an Adjustable Pressure
Switch has been properly installed.
SETPOINT ADJUSTMENT
Disconnect the electrical power. Check for multiple circuits.
1.
Loosen the screws on the housing cover, and move it aside.
2.
Check the setpoints per paragraphs 4 and 5 below for precise adjustments.
3.
The adjustment nut can be rotated by hand or with an open-end wrench or similar
tool. The range scale is intended to be used only as an approximate guide; it indicates
the increasing setpoint.
4.
To check the increasing setpoint of a pressure switch, connect a pressure source and a
calibrated pressure gauge or transducer to the pressure port and slowly apply
increasing pressure (or vacuum on Model 180P) until the switch actuates. Actuation
can be noted by listening to the audible snap of the Belleville spring, or with an
ohmmeter across the appropriate free leads.
5.
If you want to check the decreasing setpoint, slowly decrease the pressure or vacuum after the
switch has actuated and note the value at which the audible snap or an ohmmeter indicates
deactuation. Deadband may be calculated if desired by subtracting the decreasing setpoint
reading from the increasing setpoint reading.
CAUTION
6. Replace the cover by moving it back into position over the top of the housing and
tightening the screws until the cover is snug against its gasket. Do not overtighten, as
this could damage the gasket.