Dwyer 616WL - Manual (Page 2)

2. Position: A vertical position, with the pressure connection pointing
down, is recommended. That is the position in which all standard models
are spanned and zeroed at the factory. They can be used at other angles,
but final spanning and zeroing must be done while transmitter is in that
alternate position.
3. Pressure Connections: Two integral barbed tubing connections are
provided. They are dual-sized to fit both 1/8˝ and 3/16˝ (3.2 and 4.8 mm)
I.D. tubing. Be sure the pressure rating of the tubing exceeds that of the
operating range. On ranges over 20 psi, we recommend use of a suitable
hose clamp to assure the integrity of the connection.
ELECTRICAL CONNECTIONS
CAUTION: Do not exceed specified supply voltage ratings.
Permanent damage not covered by warranty will result. This unit is
not designed for 120 or 240 volts AC line operation.
Electrical connections are made to the terminal block located on the inside
of the transmitter. Terminals are marked +, –. See Fig. B.
Wire Length - The maximum length of wire connecting transmitter and
receiver is a function of wire size and receiver resistance. Wiring should not
contribute more than 10% of the receiver resistance to total loop resis-
tance. For extremely long runs (over 1000 feet), choose receivers with high-
er resistance to minimize size and cost of connecting leads. Where wiring
length is under 100 feet, hook-up wire as small as 22 AWG can be used.
2-Wire Operation - An external power supply delivering 12-30 VDC with
minimum current capability of 40 mA DC (per transmitter) must be used to
power the control loop. See Fig. C for connection of the power supply,
transmitter and receiver. The range of appropriate receiver load resistance
(RL) for the DC power supply voltage available is expressed by the formu-
la.
RL Max = Vps - 12V
20mA DC
Shielded two wire cable is recommended for control loop wiring. If ground-
ing is required, use the negative side of the control loop after the receiver.
Otherwise, in the 2-wire operation it is not necessary to observe polarity of
control loop connections.
2-Wire Connections
Calibration Check - Each Series 616WL Transmitter is factory calibrated
in the vertical position to the range given in the model chart. To check cal-
ibration and adjust if necessary, the following procedure should be used.
For purposes of clarification in these instructions, range is defined as that
pressure which, applied to the transmitter, produces 20 milliamps of cur-
rent in the loop. Zero pressure is always assumed to be 4 milliamps.
1. With the transmitter connected to the companion receiver, insert an
accurate milliameter in series with the current loop. Full scale range
should be approximately 30 mA.
2. Connect a controllable pressure source to one leg of a tee with the other
two legs connected to the high pressure port of the
transmitter and the third leg to an accurate test gage or manometer, in
an appropriate range. The low pressure port should be vented to atmos-
phere. Calibration must be performed with the unit in the same position
in which it will be mounted.
3. Apply electrical power to the unit and allow it to stabilize for 15 minutes.
4. With no pressure applied to the transmitter, adjust ZERO control so that
loop current is 4 mA. Zero center units, ie. 1-0-1 in w.c. units, will out-
put 12 mA with no pressure applied. To calibrate zero center units an
accurate pressure source must be used to apply the minimum pressure
then adjust zero control to 4 mA. Use the increase/decrease
buttons located on left side. See Fig. D.
5. Apply full range pressure and adjust loop current to 20 mA using SPAN
control. Use the increase/decrease buttons located on the right side.
See Fig. D.
6. Relieve pressure and allow transmitter to stabilize for 2 minutes.
7. Zero and span controls are slightly interactive, so repeat steps 4 through
6 until zero and full range pressures consistently produce currents of 4
and 20 mA respectively.
8. Remove the milliameter from the current loop and proceed with final
installation of the transmitter and receiver.
MAINTENANCE
Upon final installation of the Series 616WL Differential Pressure Transmitter,
no routine maintenance is required. A periodic check of the system cali-
bration is recommended following the procedures explained under
Calibration Check. The Series 616WL Transmitter is not field serviceable
and should be returned, freight prepaid, to the factory if repair is required.
Please enclose a description of the problems encountered plus any avail-
able application information. Contact customer service to receive a return
goods authorization number before shipping.
Fig. B
CONN 1
+
+
Fig. C
616W
LOW PRESSURE
TRANSMITTER
1
2
POWER
SUPPLY
12 -35 VDC mA
RECEIVER
©Copyright 2008 Dwyer Instruments, Inc. Printed in U.S.A. 10/08 FR# 01-440886-02 Rev 2
ZERO ADJUST SPAN ADJUST
ZERO SPAN
Fig. D
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: [email protected]
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