Ashcroft IXLdp User manual

MODEL IXLdp TRANSDUCER
INSTRUCTION SHEET
WARNING! READ
BEFORE INSTALLATION
1. GENERAL:
A failure resulting in injury or damage
may be caused by excessive overpres-
sure, excessive vibration or pressure pul-
sation, excessive instrument temperature,
corrosion of the pressure containing parts,
or other misuse. Consult Ashcroft Inc.,
Stratford, Connecticut, USA before installing
if there are any questions or concerns.
2. OVERPRESSURE:
Pressure spikes in excess of the rated over-
pressure capability of the transducer may
cause irreversible electrical and/or
mechanical damage to the pressure mea-
suring and containing elements.
3. STATIC ELECTRICAL CHARGES:
Any electrical device may be susceptible to
damage when exposed to static electrical
charges. To avoid damage to the transducer
observe the following:
• Ground the body of the transducer
BEFORE making any electrical connections.
• When disconnecting, remove the ground
LAST!
Note: The shield and drain wire in the cable
(if supplied) is not connected to the trans-
ducer body, and is not a suitable ground.
DESCRIPTION
The Industrial Low Pressure Differential
Transducer consists of a silicon diaphragm
supported between two layers of metallized
glass. The Si-Glas technology combines the
inherent high sensitivity of a variable capaci-
tance trans ducer using a micro-machined, sin-
gle crystal diaphragm which provides excellent
stability and repeatability.
The transducer should be used with clean, dry
air or other dry non-corrosive gases. Both
unidirectional (e.g. 0/1.0 in. W.C.) and bidirec-
tional (e.g. +/– 5.0 in. W.C.) pressure ranges
are offered as well as a wide selection of out-
put signals.
The storage temperature limits of the trans-
ducer are –40 to 210°F. The unit can operate
between –20 and 185°F and is temperature
compensated between 0 and 160°F.
MOUNTING
The unit should be mounted with #8 or #10
screws using the three mounting feet provided
(see Fig. 1). Easy access to the covers may
be a consideration when mounting. The trans-
ducer can be mounted in any orientation with
virtually no effect on calibration. Any minor

zero pressure offsets that are encountered
can be adjusted using the zero adjust poten-
tiometer. (See the Calibration section for more
details on the zeroing procedure.)
PIPING
The “high” and “low” pressure connection ports
are plugged to avoid debris entering the unit.
The plugs should be left in place until the tub-
ing and fittings are connected. The two 1⁄4˝ NPT
pressure connections should be sealed to the
transducer housing using teflon tape. The use
of a dope-type sealant should not be used
since it may cause measurement errors
because of outgassing.
WIRING
Voltage Output:
The IXLdp requires 12-36 VDC excitation for
operation and will draw less than 5 mA. Warm-
up is typically less than 15 seconds.
Current Output:
The voltage required for a 4-20mA output is
dependent upon the loop resistance of the
circuit (see Fig. 2). The voltage required is
proportional to the load (loop resistance)
being driven. Figure 2 shows the minimum
supply voltage (Vmin) required for a given
loop resistance. Warm-up is typically less
than 15 seconds.
The field wiring terminals can be accessed by
unscrewing the four cover screws and remov-
ing the terminal block access cover (see Fig.
1). Once the cover is removed, make sure no
contaminants, (e.g. water, oil, chemicals,
grease, dirt, etc.), enter the inside of the
enclosure. Feed the cable from the conduit
through one of the conduit attachment holes
into the terminal area. Connect the conduit to
the conduit connection threaded hole on the
side of the transducer. Attach the cable wires
to the appropriate terminals. The unused con-
nection hole should be closed with a suitable
conduit plug.
The transducer should be wired with a multi-
conductor shielded cable. Figures 3 and 4
show how the current and voltage output
transducers should be wired. The transducer
housing should be earth grounded at the
ground screw using one of the cable’s conduc-
tors as shown in Figures 3 and 4.
When the cover is reinstalled, make sure the
gasket is seated correctly and all four screws
are properly engaged and tightened.
CALIBRATION
The zero adjustment for the transducer can be
accessed by unscrewing the four cover screws
and removing the zero pot access cover (see
Fig. 1). Once the cover is removed, make sure
© 2011 Ashcroft Inc., 250 East Main St., Stratford, CT 06614-5145, U.S.A. Tel: [phone], Fax: [phone], email: [e-mail], www.ashcroft.com
All sales subject to standard terms and conditions of sale. I&M011-10062 (250-2985) Rev. A 5/11
no contaminants, (e.g. water, oil, chemicals,
grease, dirt, etc.), enter the enclosure. The
zero adjustment range is approximately ±10%
of span.
The offset or zero adjustment potentiometer is
shown in Figure 1. A hole is provided in the
fiber insulation board to access the pot adjust-
ment screw. Before you adjust, make sure a
short tube is connected from the “low” port to
the “high” port of the transducer. This connec-
tion will ensure that both ports are at the same
pressure. A clockwise rotation raises the output.
DO NOT ADJUST THE SPAN
ADJUSTMENT POTENTIOMETER
Proper span calibration requires a pressure
standard three to five times more accurate
than the accuracy of the transducer.
When the cover is reinstalled, make sure the
gasket is seated properly and all four screws
are properly engaged and tightened.
SERVICE
There are no user serviceable parts inside the
transducer. Servicing should only be carried
out by factory-trained personnel. Service prob-
lems encountered in the field might be
mechanical or electrical in nature.
Mechanical problems might be attributed to
plugged or leaking pressure lines, or faulty
pressure sources.
Electrical problems might be attributed to
improper wiring, bad connections (e.g. open,
shorts, etc.), malfunctioning or improper power
supply.
PHYSICAL
Weight: approx. 2 lbs.
NEMA 4X rated enclosure
OPTIONAL FEATURES
Variable Damping
A third potentiometer, placed to the left of
the zero potentiometer, allows the user to
adjust the unit’s response time.
Multiple Range
By relocating the shunt jumper, the user can
“re-range” the unit. The unit can be re-
ranged by a 1⁄2, 1⁄3, 1⁄4and a 1⁄5. For example, a
unidirectional 5 in. W.C. unit can become a
2.5 in. W.C., 1.67 in. W.C., 1.25 in. W.C. or a
1.0 in. W.C. range.

MOUNTING
FOOT
➤
➤
➤
➤
➤
➤
➤
ø 0.2
1.4
4.31
➤
➤
➤
➤
➤
0.2 TYP
2) PLACES
MOUNTING FOOT
2.68
ACCESS COVER (TERMINAL BLOCK)
➤
➤
MOUNTING FOOT
SPAN POT
ZERO POT
LOCATION
➤
➤
➤
➤
➤
➤
2.7
4.6
➤
➤
0.7
➤
➤
5
➤
1/2 NPSM THREAD TYP BOTH
SIDES FOR CONDUIT PIPING
ACCESS COVER
(ZERO AND SPAN POTS)
3
➤
➤
➤
➤
2.5
➤
➤
➤
➤
➤
➤
➤
➤
0.8 1.34
3.0
0.7
HIGH LOW
1/4 NPT
PRESSURE
FITTINGS
➤
➤
Figure 1.
General Dimensions (INCHES)
MODEL IXLdp TRANSDUCER
INSTRUCTION SHEET
OPERATING
REGION
LOOP SUPPLY VOLTAGE (VDC)
V
01012 20 30 36 40
1250
1045
1000
750
500
250
0
LOOP RESISTANCE (OHMS)
LOAD LIMITATION 4-20mA OUTPUT ONLY
F
Figure 2. Loop Supply Voltage vs. Loop Resistance
Figure 3.
Current (4-20mA) Output Wiring
EARTH
GROUND POWER
SUPPLY
V+
V–
F
RS
(LOAD)
EARTH
GROUND
SIGNAL
OUT
+
–
V+
V-
F
POWER
SUPPLY
V
min
= 12 + (.022A x R
L
)
R
L
= RS+ R
R
L
= Loop Resistance (ohms)
R
S
= Sense Resistance (ohms)
R
= ire Resistance (ohms)
*INCLUDES A 10% SAFETY FACTOR
Figure 4.
Voltage Output Wiring
© 2011 Ashcroft Inc., 250 East Main St., Stratford, CT 06614-5145, U.S.A. Tel: [phone], Fax: [phone], email: [e-mail], www.ashcroft.com
All sales subject to standard terms and conditions of sale. I&M011-10062 (250-2985) Rev. A 5/11