Setra System Model 542 - Manual (Page 5)

High Temperature Pressure Measurement : Possible using a length of piping or a "syphon" to
isolate the instrument from the hot media. Since there is no flow, the temperature drop along the tubing
is considerable and usually a relatively short length is sufficient to bring the pressure media temperature
within acceptable limits for the instrument. Alternatively a temperature isolator, part number GA33, can
be fitted (G¼ connection only). Pressure media must not be allowed to solidify in the tube and/or
pressure port.
ELECTRICAL INSTALLATION
All types include suppression devices providing transient protection to EN 61000-4-2 and EN 61000-
4-4.
For all types conformity with the requirements of the CE mark only applies when
connection is made with Setra Systems approved cable, See APPROVED CABLE
section, and the shield of that cable is connected to a reliable ground point at the
instrumentation end.
Types 540 / 542 Water Submersible Cable (IP68 rated): These types are capable of being
immersed to a maximum depth of 200m WG.
Types 540 / 542: To combat the effects of lightning strike these types are fitted with suppression
devices providing surge immunity to IEC 801 Part 5. To protect the ‘receiving’ equipment it is
recommended the end user fits a Lightning Protection Unit (LPU) at the instrumentation end close to the
point of cable entry into the building, installed as recommended by the LPU manufacturer, to protect
against the likely high current surge resulting from lightning strikes.
Types 540 / 542 Weatherproof Cable ( IP66): These types employ a weatherproof (IP66 rated)
cable assembly.
Types 540 / 541 / 542 10-6 Bayonet Connector: These types are fitted with a MIL-C size 10,
6 pin receptacle. The mating socket (not supplied) must conform to MIL-C-00264872.
APPROVED CABLES
Setra Systems uses cable comprising 6 color-coded wires, with a central vent tube, enclosed by an
aluminium/polyester shield where the screen is in intimate contact with a separate drain wire. The outer
sheath can be of various material, depending upon application and operating temperature, e.g. Exar
(non-immersible, +150°C max), PTFE (non-immersible, +200°C max), Polyurethane (immersible,
+70°C).
OPERATION
Having installed the transducers as instructed they are ready for use. The transducer should not be
removed while the system is at pressure. Before applying power, check that the correct polarity and
excitation levels are being applied. See ELECTRICAL REQUIREMENTS.