Ashcroft GC52 Instruction Manual

Installation and Maintenance
Instructions for GC52
Differential Pressure
Transmitter
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AGENCY MARK ON
OUR PRODUCTS
© 2007 Ashcroft Inc. 250 East Main Street,
Stratford, CT 06614 USA
Tel: [phone], Fax: [phone], www.ashcroft.com
All sales subject to standard terms and conditions of sale.
I&M011-10160 -7/10/08
Version 5.0 10/07
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CONTENTS
CAUTION ............................................................................................ 4-5
1. PREFACE .......................................................................................... 5
2. OVERVIEW ........................................................................................ 5
3. FEATURES ........................................................................................ 5
4. SPECIFICATIONS.............................................................................. 6
5. MOUNTING........................................................................................ 8
5.1 Mounting Location ........................................................................ 8
5.2 Mounting Options ........................................................................ 8
5.3 Pressure Connection.................................................................... 8
6. PIPING .............................................................................................. 9
7. WIRING .............................................................................................. 10
7.1 Cable / Wiring Specifications........................................................ 10
7.2 Wiring Instructions........................................................................ 10
8. DISPLAY FUNCTIONS ...................................................................... 13
9. MODE CHANGES.............................................................................. 14
10. POWER-ON MESSAGE .................................................................... 14
11. MEASUREMENT MODE .................................................................. 15
11.1 Filter (Damping) .......................................................................... 15
11.2 Pressure Display Mode (Re-scaling in “inH20” units) .................. 15
11.3 Linear Display Mode
(Re-scaling in arbitrary user defined units) .................................. 16
11.4 Min/Max Display .......................................................................... 19
12. ZERO ADJUSTMENT MODE ............................................................ 20
13. SETTING MODE ................................................................................ 20
13.1 Setting Items for Pressure Display Mode
(Re-scaling in “inH20” units) ........................................................ 21
13.2 Setting Items for Linear Display Mode
(Re-scaling in arbitrary user defined units) .................................. 22
13.3 Setting Procedure ........................................................................ 25
13.4 Loop Check .................................................................................. 25
14. DIMENSIONAL DRAWINGS.............................................................. 26
15. Maintenance ...................................................................................... 27
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GENERAL:
A failure resulting in injury or damage may be caused by excessive
overpressure, excessive vibration or pressure pulsation, excessive in-
strument 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.
OVERPRESSURE:
Pressure spikes in excess of the rated overpressure capability of the trans-
mitter may cause irreversible electrical and/or mechanical damage to the
pressure measuring and containing elements.
Fluid hammer and surges can destroy any pressure transmitter and must al-
ways be avoided. A pressure snubber should be installed to eliminate the
damaging hammer effects. Fluid hammer occurs when a liquid flow is sud-
denly stopped, as with quick closing solenoid valves. Surges occur when flow
is suddenly begun, as when a pump is turned on at full power or a valve is
quickly opened.
Liquid surges are particularly damaging to pressure transmitters if the pipe is
originally empty. To avoid damaging surges, fluid lines should remain full (if
possible), pumps should be brought up to power slowly, and valves opened
slowly. To avoid damage from both fluid hammer and surges, a surge chamber
should be installed.
Symptoms of fluid hammer and surge’s damaging effects:
• Pressure transmitter exhibits an output at zero pressure (large zero offset).
• Pressure transmitter output remains constant regardless of pressure
• In severe cases, there will be no output.
FREEZING:
Prohibit freezing of media in pressure port. Unit should be drained to prevent
possible overpressure damage from frozen media.
STATIC ELECTRICAL CHARGES:
Any electrical device may be susceptible to damage when exposed to static
electrical charges. To avoid damage to the transmitter observe the following:
• Ground the body of the transmitter 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
transmitter body, and is not a suitable ground.

WARNING! READ BEFORE INSTALLATION
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USE IN LIFE SUPPORT DEVICES
Ashcroft Inc. products are not authorized for use as critical components in life
support devices or systems without the express written approval of the Gen-
eral Manager, Stratford Operations of Ashcroft Inc. As used herein:
Life support devices or systems are devices or systems which, (a) are in-
tended for surgical implant into the body, or (b) support or sustain life, and
whose failure to perform, when properly used in accordance with instructions
for use provided in the labeling, can be reasonably expected to result in a
significant injury to the user.
A critical component is any component of a life support device or system
whose failure to perform can be reasonably expected to cause the failure of
the life support device or system, or to affect its safety or effectiveness.
1. PREFACE
Thank you for purchasing the GC52 Rangeable Differential Pressure
Transmitter. Refer to the Ashcroft GC52 Data Sheet for product specifica-
tions and applicable operating conditions.
2. OVERVIEW
The GC52 is a 4-20mA loop powered (two-wire) differential pressure trans-
mitter with integral display incorporating Ashcroft’s proven SiGlas silicon
based variable capacitance sensor with stainless steel media isolation di-
aphragms and silicone pressure transmission fluid. The device was designed
to offer the user small size and user adjustable ranging for applications such
as tank level measurements and gas / liquid flow measurements.
3. FEATURES
(1)Media Compatibility: Wetted materials consist of 316 stainless steel,
alumina ceramic and viton to handle a wide range of media with the
ability to offer ranges as low as 4˝ W.C. F.S. (URL).
(2)Linear Scaling Function: The linear (scaling) function allows the user
to adjust zero and span values providing a corresponding
4-20mA output signal.
(3)Digital Filter Function: User adjustable damping of the output signal
by means of internally calculated moving average to provide a stable
output signal in applications where the user wants to reduce the pulsat-
ing of the display and / or output signal.
(4)LED Back Light: To supplement the LCD display when conditions re-
quire (dark area, night etc.).
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(5)Loop Check Function: Allows the user to output an analog signal cor-
responding to differential pressure without applying pressure, simplify-
ing system maintenance and troubleshooting.
(6)Zero and Span Adjustment: The adjustment of the Zero (4mA) and
Span (20mA) reading via internal push buttons.
(7)IP65 / NEMA 4X Environmental Rating: Enclosure environmental rat-
ing suitable for indoor and outdoor installation, depending upon operat-
ing temperature range.*
(8)CE Compliance: EN613261 1997, A1/1998, A2/2001 (Heavy Industrial).
*Display not to be mounted in direct sunlight.
Gas or liquid compatible with 316SS, viton and alumina
ceramic (isolation fluid is silicone oil). Media tempera-
ture range: –10 to +70°C
Static (Line) Pressure: 300psi all ranges
Singe Side (Differential) Limits:
• Pressure Ranges <8˝W.C., ±4˝W.C.; 30psid
• Pressure Ranges >20˝W.C., ±8˝W.C.; 100psid
12-32Vdc
4-20mAdc (two wires, Output range: 3.2 to 20.8mAdc)
Response Time: 100ms (with “0” filter setting)
Resolution: 0.1%F.S.,
Load resistance: 500Ωmax.
±0.5% F.S. (URL) at 73°F (23°C); includes the effects of
non-linearity, hysteresis and non-repeatability)
±0.50% F.S. (URL) + 1 digit at 23°C
Zero: –10 to +110% FS
Span: –10 to + 110% FS
Character height: 10mm, with LCD display with LED
backlight
Pressure / linear display: (4) LCD digits max.
Display update: 500 ms
4. SPECIFICATIONS
1. Media/Wetted Parts
2. Overpressure
(Proof)
3. Supply Voltage
4. Output
5. Accuracy
6. Display Accuracy
7. Rangeability /
Adjustment
8. Display
ITEM DESCRIPTION
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9. Units
10. Setting Adjustments
11. Enclosure
12. Pressure Connection
13. Electrical
Termination
14. Memory Protection
15. EMC Directive
16. Operating
Temperature
17. Storage
Temperature
18. Vibration
19. Shock
20. Insulation
Resistance
21. Weight
Pressure Units: inH2O (2), (1) arbitrary
Internal key switches (Mode, T, S)
Scaling function: Linear output
Filter function: User adjustable output damping select
from 0, 2, 4, 8 and 16 (None, 2, 4, 8, and 16 (s)).
Loop check function: User adjustable output for loop/
system check and troubleshooting, 4-20mA.
Material: Aluminum die cast
Environmental Rating: IP65 / NEMA 4X
1⁄4NPT female pressure ports w/equalizing valve
Cable Gland (Optional): Cable diameter 0.35 to 0.47˝
(9-12mm)
1⁄2 NPT Female Conduit Adapter (Optional)
Terminal Block: 14-22 AWG (stranded or solid wire)
Permanently stored by EEPROM (nonvolatile memory)
CE Compliance: EN61326/1997, A1/1998, A2/2001
–10 to 60°C (14 to 140°F)
–20 to 70°C (–4 to 158°F)
5g’s, 150Hz
10g’s, 16ms
50Vdc, 100MΩor more
Approx. 670g (1.5lbs)
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5. MOUNTING
5.1 General
The GC52 was designed to be mounted using the bracket supplied.
Pressure connections via the (2) 1⁄4 NPT female pressure ports. Al-
though the display can be rotated in 90 degree increments by remov-
ing the display cover it is preferable to orientate the electrical
termination downward, particularly in applications where protection
from the environment is required.
5.2 Mounting Orientation
It is preferable to orientate the unit with the pressure ports either
downward or upward. If mounting with pressure ports to the side an
“orientation effect” will be seen at zero pressure as the pressure gen-
erated by the silicone oil fill will appear as a zero offset. If mounting in
this manner this effect may be taken out by re-setting zero in final
mounting orientation.
5.3 Installing Pressure Port Manifold
(1) Mounting 25.4mm Manifold (1⁄4˝ NPT female ports)
Manifold is secured using the (4) socket head bolts (M4x40) and
appropriate allen wrench which is supplied. Check for dust and
dirt on the O-ring and seal area, clean if necessary, before in-
stalling to ensure proper connection. The direction of the manifold
is not important, determine best position by ability to operate the
equalizing valve.The equalizing valve is used to open both ports
to the line pressure at time of installation. Once installed and the
system has been pressurized the valve needs to be closed to iso-
late the low and high pressure sides of the device.
Tighten the equalizing valve with a torque of 0.75 ft-lbs±15%.
When loosening the valve do not back off by more than three
turns from the closed position.
(2) Panel Mounting
Similar to (1) above except that the GC52 is put between the man-
ifold and the bracket and then the (4) socket head bolts (M4x40)
are installed.
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(2) 1/4˝ NPTF
1.4 (35)
.55 (14)
.83 (21)
1.8 (45.4)
1.0 (25.4) Hex .83 (21)
.33 (8.5)
Equalizing
valve
• 1.0 in. (25.4mm) mounting manifold
6. PIPING
Note: High (H) and Low (L) pressure
sides of the device are marked on the
yellow label affixed to the housing of
the unit.
Install the high pressure side of the ap-
plied differential pressure in the pres-
sure inlet of the high pressure side (H)
and the low pressure side in the pres-
sure inlet of the low pressure side (L).
(Refer to the outline drawing of section 14.)
After the piping is completed check for leaks.
(1) Piping of 1.0 in (25.4mm) Manifold (1⁄4˝ NPT female ports)
Use caution when installing to keep metal chips and other debris from
entering pressure transmitter. In addition, when sealing tape is used,
do not apply to last two threads at the end of the fitting
Low pressure
inlet (L)
Panel mounting
bracket
High pressure
inlet (H)
Equalizing
valve
M4 x
40
-rings
Lower connection diagram
Connection: Lower side.
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Terminal Strip
Cable
Requirements
SMKDSP1.5/2-5.08 Phoenix Contact
• Two core shielded cable
• Cable outer diameter: 0.35˝ to 0.47˝ 9-12mm
(Required for correct installation with Cable
Gland option)
• Wire Gauge: 14-22 AWG (multi-strand or solid)
Note:
• When transporting and / or mounting do not apply excessive shock
or use device as a step.
• The piping should be of proper length so as not to apply load to the
connection point on the transmitter.
• At the time of mounting or when bleeding air from the device be sure
to open the equalizing valve with a flathead screwdriver so that ex-
cessive pressure (more than the allowable maximum differential pres-
sure) is not applied to the differential pressure sensor. Maximum torque
to apply to equalizer valve is 0.75 ft-lbs ±5%.
7. WIRING
7.1 Cable/Wire Specifications
Use appropriate cable described below which is suitable for power
supply requirements and ground to housing.
7.2. Wiring Instructions
• To reduce potential for noise do not run pressure transmitter cable /
wires alongside (same conduit as) high voltage (line power) lines.
For optimum results use dedicated conduit for GC52 cable / wires.
• If using the Cable Gland termination option must use cable within
previously noted diameters to maintain environmental ratings.
• When connecting shield / drain wire, only connect one end which
should be at the receiver ground.
• Wiring stripping instructions, remove cable jacket 2-3˝ and strip wires
±0.25˝. Shield / drain wire should not be exposed at the pressure
transmitter termination.
• Remove cover and carefully remove the display to access the termi-
nal strip, take care not to mishandle the display and associated elec-
tronics.
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• Turn display over to
expose terminal strip,
make positive and
negative connections,
insert wire depth is
equal to recommended
strip length (0.25˝).
＋
−
Terminal box
Display (board)
Shield
Power source
＋−
Receiver
Transmission cable
CASE
DISPLAY
CAP
Inside sensor Line
LCD holder
Notch
Transmission cab
(Twist)
Sheath
Display
Wire terminals
Wire Turn with a screwdriver
LCD clips (4)
Display board
Power supply
terminal block
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• After completing connections locate retaining clips in the appropri-
ate notches and carefully place into the housing. Be sure that inter-
nal sensor transmission wire does not cross the power supply lines
just installed.
• If using the Cable Gland be sure to properly tighten sealing grommet
before applying any tension on the cable, the cable gland provides
strain relief and environmental sealing.
• Tighten GC52 cover to maintain environmental rating.
• Connect to power source and receiver and power on to confirm cor-
rect wiring (see Section 10 for more detail).
• Power Supply Requirements: Although the 4-20mA signal can travel
over long distances one of the most common problems is inadequate
power at the pressure transmitter due to the voltage drop across the
loop. Be sure to review table below to determine that 12-32V is get-
ting to the pressure transmitter.
1000
750
500
250
0
0322010
1020
30
Load Limitations 4-20mA Output Only
12 24
545
OPERATING
REGION
Loop Resistance (⍀)
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CH+ CH–
GC52
In H
2
O
M
▼▲
Differential pressure
unit monitor
Test Terminals
MODE key
DOWN key
UP key
Scaling - Arbitrary
unit monitor
Measured data
display
8.8.8.8.8.8.
햲
햷
햴
햳
햶
햵
DESIGNATION FUNCTION
➀Measured data
display
➁Differential
pressure unit
monitor
➂Scaling; arbitrary
unit monitor
➃MODE key
(M)
➄DOWN key
S
➅UP key
T
8. DISPLAY FUNCTIONS
Differential pressure, linear scaling value are displayed.
When this unit monitor is ON, the differential pressure (in
H2O) is indicated on the measured data display.
When this unit monitor is ON, the scaling value of an arbi-
trary unit (linear scaling), is indicated on the measured
data display.
This key is used to switch the setting mode and the meas-
urement mode and to change the setting item.
This key is used to change (decrease) and select the set
value .
This key is used to change (increase) and select the set
value and to shift from the measurement mode to the zero
adjustment mode.
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9. MODE CHANGES
•Measurement Mode (Section 11 for further detail) will be entered upon
power-on. Setting Mode (Section 13 for further detail) is entered by
pressing and holding the MODE button for more than 3 seconds. If there
is no button operation for 10 minutes in the setting mode, it will shift back
to the Measurement Mode automatically.
•To go from the Measurement Mode to the Zero Adjustment Mode (Sec-
tion 14 for further detail) press and hold the UP Tbutton for more than
3 seconds.
10. POWER-ON MESSAGE
After the power is turned on, the power-on message is displayed for 6
seconds as shown below and then the display is shifted to the measure-
ment mode (section 13). In addition, the analog output during power-on
message is at the zero point (4mA).
8.8.8.8.8.8.
80.0
g[52
Power ON
Power on message
Measurement mode
Setting mode Zero adjustment mode
(M) key for more than 3 seconds (▲▲) key for more than 3 seconds
(M) key for more than 3 seconds or if there
is no operation for 10 minutes
All lights
two seconds
Differential
pressure range
two seconds
Product
Finish
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11. MEASUREMENT MODE
The measurement mode includes differential pressure display mode, and
linear (scaling) display mode. For the setting items 햲to 쎻
27 , please refer to
the Setting Mode (section13.1).
11.1 Filter
Set the filter before setting pressure display mode or linear (scaling)
display mode.
The filter is based on the moving average of the pressure data to de-
crease display “bounce” and to smooth the analog output due to sys-
tem pressure fluctuations at the user’s discretion.
Five selections: (0, 2, 4, 8, and 16 seconds).
If “0” is selected the filter is not applied.
See page 24 for full menu.
Filter Setting ==> item 햲
11.2 Differential Pressure Display Mode (Re-scaling in “inH20” units)
This mode is used for display and analog output of the actual differ-
ential pressure.
(1) Analog output
The analog output can be adjusted as follows; the zero point
(4mA) and the span point (20mA) can each be adjusted from –10
to 110%F.S. (URL)*.
(2) Pressure display
The pressure display has a display span between the zero
point and the span point as determined by the adjustment of zero
and span (see previous paragraph) and can display the range of
–5 to 105%F.S.(URL). In addition, the decimal point position of
the pressure display is fixed for each pressure range.
Pressure Unit: in.H2O
See page 24 for full menu.
Output zero point and span point setting ==> Setting item 햴, 햵
*This means that although the zero point is typically set at 0%F.S. (in the case of bi-directional
ranges 0%Span) and the span point is set as 100%F.S., the zero point can be adjusted to the
point where zero (4mA) is 110%F.S. and the span point (20mA) can be adjusted to -10%F.S thus
reversing the output. In addition, through this adjustment zero and span can be adjusted accord-
ingly for elevated tank levels.
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䡵Display and analog output
Ex. Differential pressure of 8 inH2O
• Differential pressure display: 8.00(H2O)
• Analog output: 12(mA) in.H2O
8.00
Differential
Pressure Analog
Display Output
(inH2O) (mA)
Output span point 18.00 ==> 20
兰兰
8.00 ==> 12
Output zero points –2.000==> 4
Setting example 1 : Differential pressure display mode
The setting to use the differential pressure range 0 to 20in.H2O (“W.C.)
and to display the zero point and span point of the analog output as –2
in.H2O and 18 in.H2O respectively is as follows:
In the example the filter (moving average time) is set at 2 seconds, the
differential pressure display and the analog output are based on the
moving average equivalent to the differential pressure data per 100ms
for the past 2 seconds (20 times).
Select the filter of “2 seconds” ==> Setting item 햲
Select the “Differential pressure display mode” ==> Setting item 햳
Set output zero point as “–10.0%F.S.” ==> Setting item 햴
Set output span point as “90.0%F.S.” ==> Setting item 햵
11.3 Linear Display Mode (Re-scaling in arbitrary user defined units)
This mode is used for display / analog output of the scaling value
where the differential pressure is linearly converted to an arbitrary
physical quantity.
(1) Linear display
By setting the OFFSET to the minimum differential pressure P1
and the FULL SCALE to the maximum differential pressure P2,
the linear display indicates the value on the line between the two
points (the maximum display span). The actual linear display
span depends on the setting of the zero point and span point of
the analog output as shown in (2) of the next page. It can display
the range of –5 to 105%F.S. of the linear display span.
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Min. differential pressure P1and
max. differential pressure P2setting ==> Setting item 햷, 햸
OFFSET & FULL SCALE setting ==> Setting item 햹, 햺, 햻
Display
Display
Full Scale
Full Scale
(20mA)
(4mA)
Offset
(4mA)
Offset
(20mA)
Differential
Pressure
Differential
Pressure
P1
(Min.) P2
(Max.)
P1
(Min.)
P2
(Max.)
(2) Analog output
The zero point (4mA) and span point (20mA) of analog output can be
set in the range of –10 to 110%F.S. of the maximum display span (be-
tween OFFSET and FULL SCALE). The span between the zero point
and the span point in this analog output is the linear display span.
Analog output zero point
and span point setting Setting item 햽, 햾
As shown in the previous diagram, usually, the OFFSET is set as Out-
put zero point (4mA) and the FULL SCALE is set as Output span point
(20mA), but the OFFSET can be reversed to Output span point
(20mA) and the FULL SCALE can be reversed to Output zero point (4mA).
䡵Setting example 2 : Linear display mode
A level gauge using a differential pressure range of 0 to 200 in.H2O,
the linear display setting to display the OFFSET for minimum 20
in.H2O as 0.0, the FULL SCALE for maximum differential pressure 120
in.H2O as 50.0, the unit as arbitrary unit (m), the zero point (4mA) ana-
log output as 0.0, and the span point (20mA) as 50.0 is as follows:
•The setting range for the minimum differential pressure P1and
the maximum differential pressure P2is 0 to 100%F.S. of the dif-
ferential pressure range, and the maximum differential pressure P2
is set from the value which is more than 25%F.S. of the differential
pressure range above the minimum differential pressure P1.
•The setting range for the OFFSET and FULL SCALE values is
–1999 to 1999, and the decimal point can be set arbitrarily. At this
time, the arbitrary unit monitor turns on
See page 24 for full menu.
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For display mode, select “Linear display mode” ==> Setting item 햳
Set min. differential pressure P1 as “20 in.H2O”==> Setting item 햷
Set max. differential pressure P2 as “120 in.H2O”==> Setting item 햸
Set decimal point position of linear display
as “one digit” ==> Setting item 햹
Set OFFSET of linear display as “0.0m” ==> Setting item 햺
Set FULL SCALE of linear display as “50.0m” ==> Setting item 햻
Set output zero point as “0.0%F.S.”
(0.0m) of max. display span* ==> Setting item 햽
Set output span point as “100.0%F.S.”
(50.0m) of max. display span* ==> Setting item 햾
*Maximum display span: OFFSET to FULL SCALE
䡵Linear display and analog output
Ex. Differential pressure 70 in.H2O
• Linear display: 25.0(m)
• Analog output: 12(mA)
m (1)
8.00
Differential Linear Analog
Pressure Display Output
(in.H2O) (m) (mA)
120 ==> 50.0 ==> 20 Span Point
兰兰 兰
70 ==> 25.0 ==> 12
20 ==> 0.0 ==> 4 Zero Point
(1) Put the arbitrary unit sticker.
See page 24 for full menu.
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11.4 Out of Range Display
(1) Range Over display
In the Measurement Mode, if the pressure is below –15% F.S.
(URL) “–FFF” will be displayed, and if it is more than 115%F.S.,
“FFF” will be displayed.
(2) Span Over display
When the user has adjusted the span of the device this case will
apply. The display range in each display mode is –5 to 105%F.S.
of the display span. When this range is exceeded, the value of
–5%F.S. or 105%F.S. will be held (depending upon whether unit
is below or above the span values) in a blinking state.
(3) Analog output
The analog output is linked with the display and is at 3.2mA when
the display span is at or exceeded –5%F.S. and at 20.8mA when
the display span is at or greater than 105%F.S.
䡵Out of Range Display
Differential pressure mode (Differential pressure range 0 to 20in.H2O)
Pressure display span 20in.H2O)
Span point: 20.0
Zero point: 0.0
• Overage display
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• Overage display
-0.050
-fff fff
1.050
–15%F. S. (–3.0 inH2O) more/less
– 5%F. S. (–1.0 inH2O) more/less
115%F. S. (23.0 inH2O) more/less
105%F. S. (21.0 inH2O) more/less
12. ZERO ADJUSTMENT MODE
In the measurement mode, the pressure connection (H, L) is open to the
atmosphere and Tkey is pressed for more than 3 seconds in order to shift
to zero adjustment mode (refer to section 11) for zero point adjustment of
the differential pressure sensor.
• If the zero point adjustment is correctly performed, the message "AdJ"
will be displayed for 2 seconds, and the display will return to the meas-
urement mode.
• If zero point correction is performed when the applied pressure is over
±10%F.S., the error message “E-0” will be displayed for 2 seconds, and
the display will return to the measurement mode without completing the
zero point adjustment.
CAUTION: Only perform the zero point correction when both the H
and L ports are open to the atmosphere. If done incorrectly the ac-
curacy of the device may be effected.
13. SETTING MODE
The setting modes include differential pressure display mode setting and
linear display mode setting. In addition, loop check (refer to section 13.4)
can be performed in each mode setting.
• Span over display
Adj e-0
– Normal Message – – Error Message –
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