Dwyer 659RTD - Manual

659RTD-1 User Guide
1.0
DESCRIPTION
The head mounted 659RTD-1 connects to any standard Pt100 resistance sensor and
converts the linearised temperature to a 4 to 20 mA signal. The transmitter is a two wire
device, and is fully configurable by the user, over a wide temperature range, with the aid
of a simple push button. This new design incorporates additional configuration menus,
allowing the user to push button trim the transmitter output at both zero and span, ideal
for trimming out sensor errors. The transmitters advanced circuitry guaranties high
stability over the wide operating ambient temperature ranges experienced by head
mounted devices.
The 659RTD-1 features an LED which provides visual indication of sensor fault when in
normal operation and is also used to guide the operator through the simple menus during
configuration.
2.0 RECEIVING AND UNPACKING
Please inspect the packaging and instrument thoroughly for any signs of transit damage.
If the instrument has been damaged, please notify your supplier immediately.
3.0
SPECIFICATION @ 20 °C
INPUT
Sensor Type
PT100 100 R @ 0°C 2 or 3 Wire
Sensor Range (- 200 to +850) ° C (18 to 390) Ω
Sensor Connection Screw terminal
Minimum span (see note 1) 25 °C
Linearisation BS EN 60751(IEC 751) standard / JISC1604
Accuracy (see note 2) ±0.1 ° C±0.05% of Reading
Thermal Drift 0.0025 % / °C
Excitation current < 200 uA
Lead Resistance effect 0.002 ° C/ Ω
Maximum lead Resistance 20 Ω per leg
Note 1 Any span may be selected, full accuracy is only guaranteed
for spans greater than the minimum recommended span.
Note 2 Basic measurement accuracy includes the effects of
calibration, linearisation and repeatability
OUTPUT
Type
Two wire 4 to 20 mA sink
Limits Low >3.9 mA ; high 21.5 mA
Accuracy ±(mA out / 2000) or ±5 uA which ever greater
Loop Effect ± 0.2 uA / V measured @ 50 Hz 1 V (peak to peak)
Thermal Drift ± 1 uA / °C typical ; ±1.5 uA Max
Max Load [ (Vsupply – 10)/21 ] KΩ
GENERAL
Update Time
0.5 Seconds
Response Time 1 Second to reach 90% of final value
Start up time From power up typically 5 Seconds
Filter Factor Adaptive
Ambient Temperature (-40 to 85) °C
Connection Screw Terminal
Approvals BS EN 61326 ; 1998 – Electrical equipment for measurement
and control ANNEX A ; ANNEX F
Factory Default
(0 to 100) °C upscale burnout (0.0 °C user trim)
4.0
INSTALLATION AND WIRING
Figure 1
Mounting holes : two holes 5.5 mm diameter, 33 mm centers
Center Hole sensor wire entry : 4 mm
4.1 Mechanical
The transmitter has been specifically designed to fit inside a DIN standard probe head
enclosure, which provides adequate protection from moisture, dust, corrosive
atmosphere etc. All cable entries must be sealed using the correct size gland. Likewise
any probe assembly fitted must be sealed.
Care must be taken when locating the transmitter to ensure the working ambient
temperature range of (-40 to 85) °C is not exceeded. The enclosure has a hole allowing
the sensor wire to enter through the transmitter. This is applicable when the sensor is
mounted directly below the transmitter.
4.2 Electrical
Electrical connections to the transmitter are made to the screw terminal provided on the
top face. The sensor wires must be equal length and type for the lead compensation to
work correctly. The screw terminals allow for wires to enter either inner or outer direction.
The transmitter is protected against reverse connection and over voltage. If no sensor
(input) connection is made the transmitter will go into either up or down scale output
current, depending on configuration.
Figure 2 gives connection details, the output is shown connected to a 24 V supply. The
load symbol represent any other device connected in the loop, such as monitoring
equipment , panel indicators and loop isolators. The load value can range from 0 ohms to
the max loop load for given supply, refer to section 3 “Max load” for more information.
The transmitter conforms with EC directive BS EN 61326 : 1998 when correctly installed
in a termination head providing at least IP20 protection and with sensor wires less than 3
metres. Screened or twisted pair wires are recommended for output wires. Always ensure
the 4 to 20 mA loop is grounded at one point, this would normally be at the monitoring
equipment or loop power supply.
In normal operation the program LED acts as over-range LED.
Figure 2
33.0 mm
CENTERS
Ø 43.0 mm
21.0 mm
SIDE VIEW BASE VIEW
PUSH BUTTON
PT100
TEMPERATURE
TRANSMITTER
Power
Supply
U
-
+
Load
Pt 100
White
Red
Red
Every effort has been taken to ensure the accuracy of this
specification, however we do not accept responsibility for damage,
injury, loss or expense resulting from errors and omissions, and we
reserve the right of amendment without notice
MODEL 659RTD-1
DWYER INSTRUMENTS, INC.
MICHIGAN CITY, IN 46360 USA