Dwyer Instruments 685 Series User manual

Series 685 Differential Pressure
Transmitter
Specications - Installation and
Operating Instructions
Bulletin P-685
The Series 685 Differential Pressure
Transmitter is used to measure differential
pressure and vacuum. The adjustable
pressure range and output signal make
it the ideal choice for installers and
maintenance professionals. It has a user-
congurable response time via a jumper
and can be mounted in any orientation.
Applications include building automation
systems, clean room monitoring, valve
and ap control, lter monitoring, and air
ow control. It has an adjustable pressure
range, a single button to zero, and can be
reset to factory settings with a long button
press. No additional reference pressure
sources or separate calibration devices
are necessary.
15 MM AF
0.787 [20.0]
0.217 [5.5]
0.374 [9.5]
1.772
[45.0]
1.614
[41.0]
1.102 [28.0]
0.236 [6.0]
2.598 [66.0]
0.118
[3.0]
0.098
[2.5]
0.472 [12.0]
1.083
[27.5]
0.866
[22.0]
0.394 [10.0]
P +P -
BENEFITS/FEATURES
• Cost effective and compact device
suitable for OEM applications where
space, simplicity, and value are key
• Single button to zero saves maintenance
time
• Factory restore to defaults with a long
button press
• User-adjustable response time provides
versatility for many applications
APPLICATIONS
• Building automation, air-conditioning and
clean room technology
• Valve and shutter control
• Filter, ventilator and fan monitoring
• Air-ow control
4-20 mA Output Wiring
Voltage Output Wiring
MAINTENANCE/REPAIR
Upon nal installation of the Series 685,
no routine maintenance is required. The
Series 685 is not eld serviceable and is
not possible to repair the unit. Field repair
should not be attempted and may void
warranty.
WARRANTY/RETURN
Refer to “Terms and Conditions of Sale” in
our catalog and on our website. Contact
customer service to receive a Return
Materials Authorization (RMA) number
before shipping the product back for repair.
Be sure to include a brief description of the
problem plus any additional application
notes.
©Copyright 2022 Dwyer Instruments, Inc.
Printed in U.S.A. 5/22
FR# 444682-00
2-WIRE
4... 20 mA
18... 30 VDC
2
1
LOAD
3-WIRE
GND
0... 10 V
18... 30 VAC
3
2
1
LOAD
11
10
9
8
7
6
5
4
3
2
1
0
0-10 V
U [V]
10.5 V
-50 050 100 p [%]
0.0 V
22
20
18
16
14
12
10
8
6
4
2
4-20 mA
I [mA]
21 mA
0
-50 050 100 p [%]
3.8 mA
DWYER INSTRUMENTS, INC
P.O. BOX 373
MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: [phone] Fax: [phone]
dwyer-inst.com
e-mail: [email protected]
®
DWYER INSTRUMENTS, INC
P.O. BOX 373
MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: [phone] Fax: [phone]
dwyer-inst.com
e-mail: [email protected]

MODEL DEPENDENT SPECIFICATIONS
Model
Pressure
Range Over Pressure
Burst
Pressure
Additional error with
temperature [% FS/10°C]
685-00(-V)
685-01(-V)
685-02(-V)
685-03(-V)
685-04(-V)
685-05(-V)
685-06(-V)
685-07(-V)
685-08(-V)
685-09(-V)
685-10(-V)
685-11(-V)
685-12(-V)
685-13(-V)
1 in w.c.
2 in w.c.
3 in w.c.
5 in w.c.
10 in w.c.
15 in w.c.
20 in w.c.
25 in w.c.
40 in w.c.
250 Pa
750 Pa
1250 Pa
2500 Pa
5000 Pa
60 kPa
75 kPa
75 kPa
85 kPa
85 kPa
85 kPa
85 kPa
85 kPa
85 kPa
60 kPa
75 kPa
85 kPa
85 kPa
85 kPa
100 kPa
125 kPa
125 kPa
135 kPa
135 kPa
135 kPa
135 kPa
135 kPa
135 kPa
100 kPa
125 kPa
135 kPa
135 kPa
135 kPa
± 0.7
± 0.5
± 0.5
± 0.3
± 0.3
± 0.3
± 0.3
± 0.3
± 0.3
± 0.7
± 0.5
± 0.3
± 0.3
± 0.3
SPECIFICATIONS
Service: Air and non-corrosive gases.
Sensor Type: Piezoresistive pressure sensor.
Output Signal: 2-wire: 4-20 mA; 3-wire: 0-10 V.
Supply Voltage: 2-wire: 18-30 VDC; 3-wire: 18-30 VAC/DC.
Loop Resistance: 2-wire: 500 Ω max; 3-wire: ≥ 1 kΩ (≤ 10 mA).
Maximum Current Draw: 2-wire: 21 mA; 3-wire: 40 mA.
Accuracy*: ≤ ±0.5% RSS (BFSL), ± 1Pa.
Thermal Effects*: See model-dependent specications table.
Long-Term Stability*: ≤ ±1% FS per year.
Temperature Limits: -4 to 158°F (-20 to 70°C).
Humidity Limits: 0 to 95% RH, non-condensing.
Response Time: 1 s (default) or 200 ms (user selectable).
Pressure Connections: 6 mm hose connection.
Electrical Connection: Spring connector for cable and leads up to 1.5 mm2.
Cable Conduit: Cap nut conduit, 15 mm (across ats), made of polyamide.
Mounting: Screw fastening with sheet metal screws.
Housing Material: ABS.
Housing Dimensions: Ø 66 x 28 mm.
Enclosure Rating: IP54.
Weight: 1.6 oz (46 g).
Compliance: CE, UKCA.
*Accuracy specications are based on measurements at 73°F (23°C).
Installation
Location
Select a clean, dry mounting location
free from excess vibration where the
temperature will remain between -4
and 158°F (-20 and 70°C). The tubing
supplying pressure to the instrument can
be practically any length required, but long
lengths will increase response time slightly.
Position
The 685 differential pressure transmitter
can be mounted in any position. The zero
compensation eliminates errors due to
positioning.
Pressure Connections
Pressure hoses may not be bent or
damaged during installation. Leaking hoses
and hose connections will cause errors on
the device or inaccurate measurements.
Tubing should have an inner diameter
≤ 3.5/5.5 mm for optimal clamping.
Electrical Connections
Electrical connections are made to the
terminal block located under the cover of
the transmitter. Terminals are marked 1, 2
and 3 as shown below.
Determine which of the following circuit
drawings applies to your application
and wire accordingly. Shielded cable is
recommended. Ground the shield at the
power supply end only.
Do not exceed specied
supply voltage ratings.
Permanent damage
not covered by warranty will result. This
unit is not designed for 120 or 240 VAC line
operation.
NOTICE
Response Time Adjustment
The response time is selectable between
1 seconds (default) and 0.2 seconds.
The response time of the output signal is
congured using the jumper on the circuit
board under the cover. If the jumper is in
place the response time is 1 second. If the
jumper is removed, the response time of
the output signal is 0.2 seconds.
Pressure Range Adjustment
The end of the measuring range can be
set between 50% to 100% of its factory set
full scale value. Make sure the negative
pressure port marked “-” is open, then
apply the designated end of pressure range
to the positive pressure port marked “+”. To
conrm, press the button under the cover
for 5 to 10 seconds. The LED will ash to
conrm the adjustment. The output signal
(0-10 V or 4-20 mA) now corresponds to
the new measuring range.
Zero Adjustment
The zero point can be adjusted by pressing
the zero button for 0-5 seconds. If this is
performed without an applied pressure,
this compares to a zero pressure offset
calibration. If performed with an applied
pressure ”x”, the entire pressure range will
be shifted by this pressure “x”. The LED will
light up to conrm the adjustment. Offset
calibration is recommended for initial start-
up or change in position.
Factory Settings Reset
This feature provides the ability to reset
the transmitter to the original factory
settings and calibration. If the button
under the cover is pressed for longer than
10 seconds, all settings (zero point and
measuring range end) are reset on the
device. The LED will go OFF to conrm the
unit has been reset.
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