9
Model 580A Differential Pressure Switch
Section 2
Section 2—Installation
The instrument should be inspected at time of unpacking to detect any dam-
age that may have occurred during shipment.
IMPORTANT: The DPU was checked for accuracy at the factory. Do not change any of
the settings during examination or accuracy could be affected.
For applications requiring special cleaning/precautions, a polyethylene bag
is used to protect the instrument from contamination. This bag should be
removed only under conditions of extreme cleanliness.
Mounting/Piping/DPU Installation
Mount the instrument with four customer-supplied 5/16-in. (8-mm) bolts,
Grade 5 or greater, torqued to 17 ft/lbs. Mounting structures should be
designed to avoid resonance and/or minimize resulting amplification below
33 Hz. Response spectra at mounting surface of the instrument shall not
exceed those in the R3-580A-29 Qualification Report. Interfacing process
tubing and conduit shall be supported by the same mounting as the DP instru-
ment base in order to minimize relative motion of the DP instrument and
connections.
Dimensional drawings are provided on
Section 5—Dimensional Drawings,
page 33
.
See
Appendix A, page A-1
,
for Model 224 DPU installation and mainte
-
nance information.
Electrical Connection
Units are supplied with dual alarm switches. The direct-set switch contacts
are adjustable over 10% to 90% of the scale range.
The high switch and low switch set point adjustment procedures are covered
in
Changing Switch Set Point, page 20
.
For physical location of switches, see Figures 1.1 and 1.2,
page 4
.
Switch Use
Switch contact life is influenced by various application conditions such as
temperature, humidity, airborne contamination, vibration, amount of plunger
travel, cycling rate, and rate of plunger travel (and others), as well as by the
electrical (circuit) characteristics.