Fluid Components International FLT Series Rack Mount - Manual (Page 11)

Doc. No. 06EN003250 Rev. N/C 1 - 1 FLT  Series FlexSwitch  Rack Mount
CHAPTER 1 - GENERAL INFORMATION FLUID COMPONENTS INTL
•
Operating Pressure:
Hydrostatically proof pressure
tested to 3500 psi (241.3 bar) at
70
° F (21.1 ° C). De-rated with
temperature, the maximum
recommended operation service is
2350 psi (162 bar) at 500
° F (260
° C). Higher ratings available with
special construction and test
certification.
•
Signal Output:
Buffered voltage output available
as a standard for temperature and
either flow or level/interface. The
minimum load impedance is
10 Megohms.
•
Control Circuit:
Part Number: 5495
3U, 19 inch rack (according to
ANSI/IEEE 1101, DIN 41494
part 5).
Mating Connector (DIN 41612,
type F, 48 pins, female).
•
Heater Power:
Field Selectable for specific fluid
service requirements at 0.75,
1.75, and 2.5 watts.
•
Relay Rating (Each
Channel):
Dual SPDT or single DPDT field
configurable 6 amp resistive at
115 VAC or 24 VDC.
•
Enclosure:
NEMA type 7. NEMA type 4x
optionally available.
•
Input Power:
24 VDC (-3.5, +6). 500mA
maximum for 2 channels.
•
Repeatability:
±0.5% of monitoring reading.
Up to ±0.05 inch (±0.13 cm) of
level depending on model.
±1.0°F, (±0.56°C) of temperature.
1. General Information
Description
The FLT

Series uses FlexSwitch

technology. The FLT Series models are multipurpose measurement
instruments. They are individual instruments that are capable of detecting fluid flow and temperature. They are
also able to detect liquid level or fluid interfaces. The instruments have two adjustable set-point alarms as well as a
built-in calibration circuit. Relay contacts are the primary output, but the analog and fluid temperature signals can be
monitored also.
The model control circuit is designed to interface with the FLT series sensing elements. It is packaged as a rack
mounted 3U Eurocard configuration which conserves space when installing several sensing elements. The control
circuit has two channels for two independent sensing elements. Each channel provides two alarm outputs for each
channel. The first voltage output represents the signal developed from the flow or level condition of the media. The
other signal represents the temperature of the media. Each channel has a calibration circuit that is useful when
setting an alarm switch point. Other options are available with plug-able jumpers. These options will be discussed
later in the manual.
Theory of Operation
The FLT models are a fixed position, single-point flow, level, interface, and temperature switch. The operation of
the FLT sensing element is based upon the thermal dispersion principle: A low-power heater is used to produce a
temperature differential between two resistance temperature detectors (RTDs). The RTD temperature differential
varies as a function of forced convection for flow measurement and as a function of fluid thermal conductivity for
level and interface measurement. The measurement of the fluid's temperature is obtained from the non-heated RTD.
The FLT control circuit converts the sensing element's RTD temperature differential into an analog DC voltage
signal. Dual comparators monitor the sensing element signal and activate relay alarm circuits if the signal exceeds an
adjustable set point value.
Technical Specifications
•
Process Connection:
3/4 in. male NPT standard. 1 in.
BSP, 1 in. male NPT, or flange
mounting optionally available.
•
Insertion Length:
1.13 in. (2.87cm) standard. 2 in.
(5.1cm), 4 in. (10.2cm), 6 in.
(15.2cm), 9 in. (22.9cm), 12 in.
(30.5cm), 18 in. (45.7cm), or
other customer specified
lengths optionally available.
•
Material of Construction:
All wetted surfaces are 316
Stainless Steel, all welded. Other
corrosion resistant materials are
optionally available.
•
Operating Temperature:
Ambient: -40
°
to 140°F (-40° to
60°C) Process (standard
temperature Sensing Element):
-40° to 250°F (-40° to 121°C).