Dwyer Instruments 641RM Operating Manual

Bulletin E-66-RM
Series 641RM Air Velocity Transmitter
Specifications - Installation and Operating Instructions
1-5/8 [41.28] WITH LED
1/2 NPT
1-39/64 [40.88]
4-31/32
[126.21]
Ø5/16
[Ø7.94]
Ø13/64
FOR A STANDARD 12˝ PROBE
[Ø5.16]
1-3/32 [27.78] WITHOUT LED
43/64
[17.07]
14-21/64
[53.07]
6 FT
[152.40]
The Series 641RM Air Velocity Transmitter uses a heated mass flow sensor technology. It has 8 user selectable ranges from 250 FPM to 15000 FPM with corresponding metric ranges of 1.25 MPS to 75 MPS. The Series 641RM Air Velocity Transmitter provides an isolated 4-20 mA out­put proportional to the velocity. With the optional 1/2˝ 4-1/2 digit LED display, the Series 641RM Air Velocity Transmitter will provide a highly visible local readout of the velocity.
INSTALLATION Location: Select a location where the temperature will be
within 32 to 140°F (0 to 60°C) to mount the enclosure. The transmitter may be located any distance from the receiver provided that the total loop resistance does not exceed 600 ohms. The probe should be located where conditions are representative of the overall environment being monitored. Avoid locations where turbulence, stagnation, or rapidly fluctuating velocities or temperatures are present as these conditions may affect the readings. The filter setting may be used to average velocity readings in turbulent conditions.
Position: The transmitter is not position sensitive and may be mounted in any orientation.
1-25/32 [45.24]
31/64
[12.30]
SPECIFICATIONS Service: Air and compatible, non-combustible gases. Accuracy:
3% FS Process gas: 32 to 122°F (0 to 50°C). 4% FS Process gas: -40 to 32°F & 122 to 212°F (-40 to 0°C & 50 to 100°C). Response Time: Flow: 1.5 seconds to 95% of final value (out­put filter set to minimum). Temperature Limits: Process: -40 to 212°F (-40 to 100°C). Ambient: 32 to 140°F (0 to 60°C).
Pressure Limit: 100 psi (6.89 bar) maximum. Humidity Limit: Non-Condensing. Power Requirements: 12–35 VDC, 10–16 VAC. Output Signal: 4-20 mA, isolated 24V source, 3 or 4-wire
connection.
Output Filter: Selectable 0.5 –15 (seconds). Loop Resistance: 600 ohms max. Current Consumption: 300 mA max. Electrical Connections: Screw terminal. Mounting Orientation: Unit not position sensitive. Probe must
be aligned with airflow.
Weight: 13.2 oz (374.26 g). Cable Length: 6 ft (1.82 m). Probe Length: 12˝ (30.48 cm) standard. Probe Diameter: 5/16˝ (0.79 cm).
Probe Orientation: Dots on the probe indicate the direc-
tion of the calibrated airflow. Align these dots toward the source of the process air.
Airflow: The Series 641RM Air Velocity Transmitter is intended for use with clean dry air. Particulates in the air may cause sensor damage. Dust accumulation may impair the velocity measurement and will require probe cleaning.
OPTIONAL DISPLAY VERSION: Display: 4-1/2 digit 1/2˝ Red LED. Resolution: 1 FPM, 0.01 MPS
(10 FPM @ 10,000 and 15,000 FPM ranges).
Weight: 13.9 oz (394.16 g).
Agency Approvals: CE
The following standards were used for CE approval: IEC 61000-4-2: 2001 IEC 61000-4-3: 2002 IEC 61000-4-4: 1995
TO READ DISPLAY UNIT MUST BE MOUNTED HORIZONTALLY AS SHOWN ABOVE. DISPLAY CAN BE TURNED 180° SO CON­DUIT OPENING CAN BE POSITIONED TO THE RIGHT OR LEFT.
IEC 61000-4-5: 2001 IEC 61000-4-6: 2003 IEC 55011: 1998 IEC 61326: 2002 89/336/EEC EMC Directive
DWYER INSTRUMENTS, INC.
Phone: 219/879-8000 www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: 219/872-9057 e-mail: info@dwyer-inst.com
Y
Page 2
NOTE: Where conduit connections are not made, a 1/2˝
NPT cable seal should be used to prevent contaminants from entering the case. Where conduit connections are made, make sure that any possible condensation within the conduit will not flow into the transmitter housing.
ELECTRICAL CONNECTION
The Series 641RM Air Velocity Transmitter has been designed for easy and flexible connection to power and loop receivers. Electrical connection is made inside the body of the device with a “Euro” style terminal block. The device features a current loop that is fully isolated from the power source. The current loop has an internal 24V isolat­ed supply so no external loop power is required. With full isolation, loop grounding is not a concern. The input power requirements are also very flexible. The device may be pow­ered from either an AC or DC power source.
3 or 4-Wire Connection
POWER SUPPLY
AC OR DC
RECEIVER
4-WIRE
DC SUPPL
ONLY
(EITHER
POLARITY)
RECEIVER
3-WIRE
RECEIVER NEGATIVE
COMMON
DC SUPPLY
ONLY
(EITHER
POLARITY)
RECEIVER
3-WIRE
RECEIVER POSITIVE
COMMON
CAUTION: Do not exceed the specified supply voltage rat­ing. Permanent damage not covered by the warranty may result. Do not use an external power source on the current loop connection.
Receiver-Transmitter Connection — The Series 641RM Air Velocity Transmitter is designed as a three or four wire 4­20 mA device. The current loop output is isolated from the power supply input and provides an internal 24-volt loop supply. With a DC power supply, a three or four-wire con­nection may be used. Do not use a three-wire connection with an AC power source. In a three-wire connection either power supply wire may be used as the common. The total loop resistance should not exceed 600 ohms.
CAUTION: Do not use transformers with a secondary volt­age rating greater than 16 VAC RMS.
Wire Type and Length — The wire selection for an instal­lation is often overlooked or neglected and may contribute to improper or even intermittent operation. In all cases ensure that the connection meets all applicable national and local electrical codes. Although the 4-20 mA current loop systems are relatively immune to wire or wiring related problems, selection of the wire for some installations will be an important factor in ensuring satisfactory system opera­tion. Twisted conductors will usually be immune to most stray electric and magnetic fields and to some extent elec­tromagnetic fields, such as interference from RF transmit­ters. With twisted pair wiring the current loop and the power connections should be separate pairs. Avoid using flat or ribbon cable that has no regular conductor twist. Where interference is possible, it is recommended that shielded wire be used. The shield must not be used as one of the conductors and should be connected to ground at only one end, generally at the power supply. Similarly, if the installation uses conduit, the conduit should be connected to protective ground as specified by the applicable code and the signal wiring must not be connected to the conduit at more than one point or as specified by the code. The maximum length of wire connecting the transmitter and receiver is a function of the wire resistance and receiv­er resistance. The total loop resistance must not exceed 600 ohms, including the receiver resistance and wire resis­tance. The power supply connection must be designed so that the worst case voltage drop due to wire resistance will not cause the power supply voltage at the transmitter to drop below the specified value. Provided the power supply voltage is maintained within the specified voltage range, the Series 641RM Air Velocity Transmitter is not affected by variations in power supply voltage.
TRANSMITTER SETUP
The Series 641RM Air Velocity Transmitter has been designed for easy setup. It has five configuration parame­ters that may be adjusted by the user. These parameters are Output Filter, Range (in English or Metric), span, 4 mA set-point and 20 mA set-point. All of these may be adjust­ed at any time in the field. These adjustments may also be easily returned to factory default.
Interior Label Diagram
CAUTION: Do not use a receiver with an internal power
supply or use an external supply in the current loop. The current loop is powered from within the Series 641RM Air Velocity Transmitter. Connecting an external supply to the current loop may destroy the transmitter. Using an external supply voids the warranty.
Power Supply Connection — The power supply may be either AC or DC. The DC power may be from 12 to 35 volts. The power connection is not polarity sensitive so the posi­tive and negative connections may be made to either power terminal. The AC connection may be from 10 to 16 VAC RMS. Do not exceed 20 VAC. When selecting a transformer please note that the specified output for transformers is at some specified current. With a load current less than the specified current transformer output may be significantly higher than the specified voltage. Transformers with sec­ondary voltages of 10 to 16 VAC are recommended.
A set of controls and indicators are provided within the unit consisting of the select button, enter button, adjustment control, and six LED indicators. When operating normally, only the RUN LED indicator will be illuminated. During the setup operation the LED indicators will indicate the para­meter selected, when it is being adjusted, and status of the adjustment process. If the unit is left in the setup mode for several minutes without any activity it will return to the normal operating mode.
Loading...
+ 2 hidden pages