Series 631 Differential Pressure Transmitter
R
5
[127.00]
DWYER INSTRUMENTS, INC. MICHIGAN CITY, IN 46360, USA.
4-45/64
[119.46]
3-13/32
[86.52]
13/32
[10.32] TYP
3/16
[4.76]
1/4 FEMALE NPT LOW
PRESSURE CONNECTION
(LIQUID)
(4) #6-32 X 3/8 [9.53] DP
HOLE ON A 4-11/32 [110.33]
BOLT CIRCLE
1/4 FEMALE NPT HIGH
PRESSURE CONNECTION
(LIQUID)
1/4 FEMALE NPT LOW
PRESSURE CONNECTION
(AIR OR GAS)
1/4 FEMALE NPT HIGH
PRESSURE CONNECTION
(AIR OR GAS)
3/4 [19.05] TYP
DWYER INST. INC
MICH CITY, IND
46360 U.S.A.
35° TYP
Specifications - Installation and Operating Instructions
Bulletin E-114
Series 631B
The Series 631 Differential Pressure Transmitter monitors differential
pressure of air and compatible gases and liquids. The design employs
converting pressure changes into a standard 4-20 mA output signal for
two wire circuits. Digital push-button, zero and span adjustments are
easily accessed on the front cover. The Series 631 Differential Pressure
Transmitter is designed to meet NEMA-4X (IP66) construction.
SPECIFICATIONS
Service: Compatible gases & liquids.
Wetted Materials: Brass, silicone, 300 SS.
Accuracy: Transmitter Output: ±2% F.S. (includes linearity, hysteresis
and repeatability). Gage: ±3% of full scale at 70°F (21.1°C).
Stability: ±1% F.S./yr.
Temperature Limits: 20 to 120°F (-6.67 to 48.9°C).
Pressure Limits: -20˝ Hg to 500 psig. (-0.677 bar to 34.4 bar).
Thermal Effect: Greater than 1˝ ranges: ±0.025%/°F (±0.045%/°C); 1˝
range: ±0.045%/°F (±0.081%/°C); 0.5˝ range: ±0.09%/°F (±0.162%/°C).
INSTALLATION
1. Location: Select a location where the temperature of the unit will be
between 20 and 120°F. Distance from the receiver is limited only by total
loop resistance (see electrical connections). The tubing feeding pressure
to the instrument can be practically any length required, but long lengths
will increase the response time slightly. Mount the instrument in a
location that will not be subject to excessive temperature, shock or
vibration.
2. Position: A vertical position is recommended (pressure connections
pointing vertically) since that is how all standard models were originally
spanned and zeroed at the factory.
Power Requirements: 10-35 VDC.
Output Signal: 4 to 20 mA.
Response Time: 50 msec.
Loop Resistance: 0-1250 ohms maximum.
Electrical Connections: M-12 circular 4 pin connector.
Process Connections: 1/4˝ female NPT high and low pressure taps,
duplicated - one pair top for air and gas, and one pair bottom for
liquids.
Enclosure Rating: Designed to meet NEMA 4X (IP66).
Mounting Orientation: Diaphragm in vertical position. Consult factory
for other position orientations.
Weight: 8 lb, 4 oz (3.74 kg).
Agency Approvals: CE.
3. Pressure Connection: Dual 1/4˝ female NPT pressure connections
are provided. Use pipe thread sealant tape or other suitable pipe joint
compound when making connection to the pressure source. Avoid
excess sealant which could block the pressure passage. When
monitoring liquid pressures, air trapped in the lines can cause incorrect
readings. Bleed fittings or similar mechanisms should be used to bleed
off any trapped air.
Phone: 219/879-8000 www.dwyer-inst.com
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: 219/872-9057 e-mail: info@dwyer-inst.com
ELECTRICAL CONNECTIONS
1/4 (6.35) HOLES IN PANEL
FOR BLOWOUT PASSAGE
3/4 (19.05) HOLE IN PANEL
FOR ELECTRICAL CONNECTION
42° - TYP 2 PLACES
35°
(4) 3/16 (4.76) HOLES IN PANEL
EQUALLY SPACED ON A
4-11/32 (110.33) B.C.
SURFACE MOUNT HOLE PATTERN
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 volt AC line operation.
Bulletin E-114
MOUNTING OPTIONS
+
4
1
3
2
–
Fig. A
Wire Length - The Maximum length of wire connecting transmitter and
receiver is a function of wire size and receiver resistance. Wiring should
not contribute to more than 10% of receiver resistance to total loop
resistance. For extremely long runs (over 1000 ft.), choose receivers
with higher resistance to minimize size and cost of connecting leads.
When the wiring length is under 100 feet, lead wire as small as 22 AWG
can be used.
Current (4-20 mA) Output Operation - An external power supply
delivering 10-35 VDC with minimum current capability of 40 mA DC (per
transmitter) must be used to power the control loop. See Figure B for
connection of the power supply, transmitter, and receiver. The range of
the appropriate receiver load resistance (RL) for the DC power supply
voltage available is expressed by the formula:
RLMax = Vps – 10
20 mA DC
Shielded two wire cable is recommended for control loop wiring. If
grounding is required use negative side of control loop after receiver, see
Figure B.
MAINTENANCE
Upon final installation of the Series 631 Differential Pressure Transmitter
SERIES 631
PRESSURE
TRANSMITTER
1
2
RECEIVER
+
mA
+
–
POWER
SUPPLY
10-35 VDC
–
and the companion receiver, no routine maintenance is required. A
periodic check of the system calibration is recommended. The Series
631 Differential Pressure Transmitter is not field serviceable and should
be returned if repair is needed (field repair should not be attempted and
may void warranty). Be sure to include a brief description of the problem
plus any relevant application notes. Contact customer service to receive
Fig. B
a return goods authorization number before shipping.
MULTIPLE RECEIVER INSTALLATION
An advantage of the standard 4-20 mA DC output signal provided by the
Series 631 Differential Transmitter is that any number or receivers can
be connected in series in the current loop. Thus, an A-701 digital
readout, an analog panel meter, a chart recorder, process controlling
equipment, or any combination of these devices can be operated
simultaneously. It is necessary only that each be equipped with a
standard 4-20 mA input and proper polarity of the input connections be
observed when inserting the device into the current loop. If any of the
receiving devices displays a negative or downscale reading this
indicates that the signal input leads are reversed.
©Copyright 2011 Dwyer Instruments, Inc. Printed in U.S.A. 2/11 FR# 01-443311-00 Rev. 4
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: 219/872-9057 e-mail: info@dwyer-inst.com
Phone: 219/879-8000 www.dwyer-inst.com