GE DewPro MMY31 User manual

Trace Moisture Transmitter
DewPro®MMY31
Installation and Operation Manual
GE Infrastructure Sensing
GE General Eastern

DewPro MMY31 Installation and Operation Manual
GE General Eastern 2
Caution!
Safety
General Notes
Caution!
Before installation please read all instructions.
Safety
- The DewPro is designed to be mounted to pressurized systems. Take necessary
precautions when mounting or removing the DewPro.
GE General Eastern reserves the right to change or modify our product appearance and
specifications at any time and without notice. Therefore, information in this document is
subject to change without notice and does not represent a commitment on the part of GE
General Eastern.
No part of this manual may be reproduced or transmitted in any form or by any
means, electronic or mechanical, including photocopying and recording, for any
purpose without the express written permission of GE General Eastern.
DewPro is a Registered Trademark of GE General Eastern.
If you should have questions regarding the product described in this document, or need
further assistance, please contact your local GE General Eastern Sales Centre
Version: FGE/ 220304/MMY31

DewPro MMY31 Installation and Operation Manual
GE General Eastern 3
Contents
General Notes 2
1.0 General System Information 4
1.1 Unpacking and Inspection
1.2 Introduction
1.3 Theory of Operation
2.0 Installation Guidelines 6
2.1 Mounting the Probe
3.0 Wiring for Configurations with One 7
3.1 Wiring, General Guidelines
3.2 System Configuration, Various
3.3 Mounting in Normal Environments
3.4 Mounting in Environments with Severe Electrical Noise
3.5 Electrical Connection
3 6 General Wiring Instructions
4.0 Optional Display/User Interface 10
4.1 Installation
4.2 Description of the DewPro MMR 31 Programming Matrix
4.3 Special Functions of the Pushbuttons
4.4 Functions of the Matrix (Refer to Figure 20 or appendix 12
5.0 Troubleshooting 17
5.1 General Problems
6.0 Technical Specifications 18
7.0 Accessories 19
7.1 Available Accessories
8.0 Contact adresses 20
Appendix 21

DewPro MMY31 Installation and Operation Manual
GE General Eastern 4
1.0 General System Information
1. 1 Unpacking and Inspection
Upon receipt of the DewPro MMY 31, examine the shipping carton for broken or
open packing, distortion, or any other evidence of mishandling. If inspection
indicates damage to the unit or any of its components, notify the carrier (within 15
days of delivery) and request an inspection.
Unpacking
Move the carton to a clean work area and unpack. The carton you receive should
contain:
• DewPro MMY 31
• Installation and Operation Manual
Compare the model number (on the product label) with product structure (see
below) to ensure you have received everything you ordered.
MODEL: MMY31-R 6 A 2 B
9...32 VDC
10124
SERIAL NO:
SUPPLY:
RANGE:
P max: 500 PSIG
GENERAL EASTERN
The Humidity Experts
Fig. 1
Product Structure MMY31 Check Model
Number
Certification/Approvals:
RStandard (not certified)
YOther
Process Connection
13" diameter galvanized floor flange with 12,7 mm (1/2” MNPT)
compression fitting
31/2" M NPT compression fitting
6No mounting hardware
8G 1/2 compression fitting (Male thread), gasket, SS ferrule
9Other
Protective Cap:
AStandard with 100 micron sintered filter
BWithout 100 u filter
Enclosure Conduit:
11/2" FNPT with cable gland and plug
2PG 16 (Female) with cable gland and plug
Output Configuration/Dewpoint Range:
AOutput 4-20 mA -90 … +10 oC dewpoint, no display, fault
status 22 mA
BOutput 4-20 mA -90 … +10 oC dewpoint, no display, fault
status Hold
COutput 4-20 mA -90 … +10 oC dewpoint, no display,
fault status 3,6 mA
DOutput 0 … 100 ppm-v, 1 bar, no displ, error 22 mA
EOutput 0 … 100 ppm-v, 1 bar, no displ, error Hold
FOutput 0 … 100 ppm-v, 1 bar, no displ, error 3,6 mA
GWith integral display, user interface; free programmable
R 6 A 1 B

DewPro MMY31 Installation and Operation Manual
GE General Eastern 5
1.2 Introduction
Unit descrip-
tion
The DewPro MMY 31 is a loop powered dew point transmitter for the trace moisture
range. The transmitter includes an aluminum oxide planar sensor element, a stainless
steel probe, a weather proof enclosure, and microprocessor electronics. It is designed to
be installed “in-line”. Various mounting hardware such as flange and compression fittings,
are available for mounting into a process chamber, process pipe, etc. The DewPro
MMY31 measures dew point temperature in oC or oF.
Fig. 2
MODEL:
9...32 VDC
PSIG
SERIAL NO:
SUPPLY:
DEWPOINT RANGE:
P max:
MMR 31
116
86
279
85
25
168
12,7
Thread
G ½
Compression fitting
50,8 mm
(2,0”)
74,6 mm
(3,0”)
1.3 Theory of Operation
4 to 20 mA
Loop
The DewPro MMY 31 microprocessor controlled electronics operate with a voltage supply
of 12 to 32 V DC. At the nominal 24 V DC supply, the maximum loop resistance is 750
Ohm. The signal is represented by the 4 to 20 mA loop current and is directly proportional
to the dew point temperature range of -90 oC to +10 oC (-130 oF to +50 oF).
Planar Sensor
The heart of the MMY31 is the newest Planar sensor element. It incorporates a new,
superior aluminum oxide sensor that provides longer calibration stability, improved
corrosion resistance, and faster speed of response. The sensor, mounted on a ceramic
substrate, also has a reduced temperature coefficient.
Calibration Each DewPro is factory calibrated against precise NIST certified moisture references and
has an accuracy of +/- 2 oC dew point. Recalibration should be performed approximately
once a year, depending on application and the required accuracy. GE General Eastern
has multiple calibration facilities world wide providing trace ability to national and
international standards.

DewPro MMY31 Installation and Operation Manual
GE General Eastern 6
2.0 Installation Guidelines
2.1 Mounting the Probe
Preferably, mount the probe vertically such that the sensor tip points down. Mount
the probe in a G 1/2 thread connection or with a flange. Be certain that the tip of the
probe does not touch the inside wall of the pipe.
Adjust the ferrule (nylon or stainless steel*) for a probe insertion length of 1”
(minimum) and tighten the compression fitting as follows:
• Hand-tighten the nut. Then, using a wrench, tighten the nut one and one-
half turns.
• Now the fitting is tight and can withstand pressure to 17 bar (250 psi)
(provided a stainless steel ferrule is used)
MODEL:
9...32 VDC
PSIG
SERIAL NO:
SUPPLY:
DEWPOINT RANGE:
P max:
MMR 31
Minimum 25mm
GENERAL EASTERN
TheHumidity Experts
Fig. 3

DewPro MMY31 Installation and Operation Manual
GE General Eastern 7
3.0 Wiring
3.1 Wiring, General Guidelines
Caution! Caution!
The DewPro system contains electronic components that are susceptible
to damage by static electricity. Proper handling procedures must be
observed during the removal , installation, or other handling of internal boards.
3.2 System Configuration, Various
Fig. 4
GENERA L EASTE RN
TheHumidityExperts
8888
8888
-~
-~
Optional loop powered
display available from
General Eastern, such as Md102
Customers power supply
24 V DC ( 9...32 V DC )
Power supply
available from General Eastern
115/230 V
AC
115/230 V
AC
Power supply with display
and optional relay available
from General Eastern such as Md102
NOTE: The voltage across the +/- terminal of the DewPro should not fall below 9 V DC.
The maximum loop resistance is an important measure for selection of the supply voltage.
Each device connected to the loop causes a voltage drop. For instance, using a loop-
powered display with an input impedance of 50 Ohm will cause a voltage drop of 1 V DC
at 20 mA following Ohm's law. Connecting the loop to a PLC will cause a voltage drop
across its input.
When designing your loop, add up all voltage losses across the devices connected to the
loop and add 12 V. The sum will be the minimum supply voltage required from the power
supply. Calculate with a 20% safety factor.
If a display is used, configure it to the proper range: -90 oC to +10 oC (- 130 oF to + 50 oF)
for dewpoint corresponding to 4 to 20 mA.

DewPro MMY31 Installation and Operation Manual
GE General Eastern 8
3.3 Mounting in Normal Environment
• A standard two-wire, stranded cable can be used to interconnect the
DewPro with the power source
Standard
G
E
N
E
R
A
L
E
AST
E
R
N
The H u m id i ty E
x
p
erts
Shielded Two
wire Cable
External Ground
Capped
off
Fig. 5
3.4 Mounting in Environments with Severe Electrical Noise
• In areas where EMI/RFI interference is likely, a shielded signal cable is to
be used for full protection. The DewPro MMY31 meets requirements of IEC
801-1 through 6 (EN 50081-1, 50082-2) when properly shielded cable is
used
EMI/RFI
Shielded Two
wire Cable
Fasten Shield Under
Cable Clamp for
Maximum RFI Protection
External Ground
Capped
off
G
E
N
E
R
A
L
E
A
S
T
E
R
N
TheH umidit
y
E
x
p
erts
Fig. 6
3.5 Electrical Connection
GENERALEASTERN
TheHumidityExperts
24 V DC Nominal (9-32 V)
+
-
Electrical Connec-
tion
Fig. 7

DewPro MMY31 Installation and Operation Manual
GE General Eastern 9
3.6 General Wiring Instructions
1. Unscrew the cap on top of the unit.
2. Loosen the gray cable gland located on the side of the unit.
3. Feed the cable through the conduit opening.
NOTE: Use a standard signal cable size.
4. Retighten the gray cable gland to meet IP 67 and to relieve the wire and protect the
electronics from dust and moisture.
5. Supply 9 to 32 V DC power to the terminals marked + and -.
NOTE: This is the voltage that appears across the DewPro terminals. It is not
necessarily the supply voltage due to voltage loss in wire length, displays,
indicators, etc.
6. If the enclosure is ordered with a ½” FNPT conduit conection, the cable gland can be
removed to connect the conduit.

DewPro MMY31 Installation and Operation Manual
GE General Eastern 10
4.0 Optional Display/User Interface
4.1 Installation
If the DewPro is equipped with an optional display / user interface follow the
procedure below to access the terminals prior to applying power. Please use Figure
18 below as a reference when removing any parts from the DewPro.
GENERALEASTERN
TheHumidityExperts
Fig. 18
1. Unscrew and remove the protective lid from the top of the DewPro, exposing
the display module below
2. Unplug the display from the lower terminal board.
3. Carefully grasp the display bracket and pull straight up.
4. Follow the procedure outlined in Section 3.0, pages 8-10.
5. To replace the display module, locate the six holes on the underside of the
display bracket. The MMY 31 uses the holes with the additional markings
next to them.
6. Align the display bracket with the standoffs and snap the display bracket
onto the three standoffs.
7. Carefully rotate the display module on the display bracket until properly
aligned for readability.
8. Reconnect the display to the lower terminal board observing the key on the
plug and socket.
NOTE: When the display module is installed it takes over control, superseding the
rotary switch functions illustrated under Section 5.4 on page 16. Only the calibration
buttons on the printed circuit board remain active.

DewPro MMY31 Installation and Operation Manual
GE General Eastern 11
4.2 Description of the DewPro MMY31 Programming Matrix
In the DewPro mid-range moisture transmitter with display option, a matrix-style input is
used for programming the unit of measure, measuring range, error status of output, and
output adjustment. For users of other General Eastern equipment, this 'GEI matrix" format is
familiar. The following describes the features and usage of the various matrix location as
they apply to the MMY 31.
Fig. 19
-
VH
88
8888
----------
VH Position
Indicators
Bar Graph
Numeric
Display User Interface
Keys
The display of the DewPro MMY 31 continuously shows the current matrix location using
the vertical (V) and horizontal (H) coordinates to designate the row and column,
respectively. The bar graph represents the output current in an analogue fashion (refer to
Figure 19). See the Appendix for an enlarged overview of the matrix.
Fig. 20
MMY 31 H0 H1 H2 H3 H4 H5 H6 H7 H8 H9
Moisture Unit V0
Display
Moisture
Value
Select
Moisture Unit
see table
below
Loop 1 at Fault
0= -10%,
1=110%, 2=Hold
Loop 1 Raw
Reading
Loop Range V1 Dewpoint °C
4 mA
Dewpoint °C
20 mA
ppmv
mA
V2
Constant;
Loop
Hardware
Calibration
V3
Pressure
Constant for
ppmv comp.
(bar)
Loop 1 D/A
Calibration
Low
Loop 1 D/A
Calibration
High
V4
V5
V6
V7
Access Key V8 Input Locking
50 = Unlock
Misc. Setup V9 Display
Present Error
Display
Previous Error Unit ID Software
Version
Reset To
Defaults
50 = Reset
System Reset
50 = Reset
Movement through the matrix is accomplished by using the "V" and "H" buttons to move
to another row or column. For example, beginning at VH 00 and successively pressing
"V", leads the user to VH 10, VH 20, VH 30, VH 40, VH 50, VH 60, VH 70, VH 80, VH 90
and back to VH 00. At any location where a value may be changed by the user, the
desired value is programmed using the "+" and “-“ buttons.

DewPro MMY31 Installation and Operation Manual
GE General Eastern 12
4.3 Special Functions of the Push buttons
1. Reset to "Normal" Display: Pressing the 'V' and “H” buttons simultaneously
returns the user to VH 00 (normal display).
2. Display Only: Note that eight (6) matrix locations me for display only and may not
be changed by the user (refer to Figure 20 or Appendix). The 'display only' fields
are as follows:
• VH 00 = normal display (in dewpoint oC)
• VH 08 = indicates digitized moisture signal
• VH 90 = during a system alarm, displays the error code for the fault
encountered
• VH 91 = during normal operation, the previous error code is displayed for
reference
• VH 92 = displays the factory issued identification number
• VH 93 = displays the factory issued reference number designating the
device type and software version
3. Default Values
A default value is assigned to each programmable matrix field. The values are
present after a reset to factory programmed data has been executed (see VH 95).
4.4 Functions of the Matrix (Refer to Figure 16 or Appendix
This section describes the functions available to the user through the matrix. grouped by
common function areas. The function is accessed by positioning to the specified location
within the matrix
DISPLAY AND OUTPUT MODE
1. Dewpoint display
Location in Matrix Description of Function
VH 00 This is the normal display of the transmitter when in operation.
The dewpoint is shown in oC or oF, or ppm-v as selected
under VH 01.
2. Selecting the Device Unit
Location in Matrix Description of Function
VH 01 Selects units to be displayed. Changing from oC to oF does not
change the current loop. Changing from dewpoint to ppm-v
does change the current loop.
NOTE: When switching to ppm-v, the display may indicate an
error " 3" if the dewpoint reading is above -20 oC. (For
example, the DewPro is exposed to ambient air.)

DewPro MMY31 Installation and Operation Manual
GE General Eastern 13
3. Loop at Fault
Location in Matrix Description of Function
VH 07 If any fault malfunction occurs, the loop can be set to either "-
10%" (=3.6 mA), to "110%" (=22 mA) or "Hold" (stays at last
valid value).
4. Selecting the Analogue Output Offset (4 mA)
Location in Matrix Description of Function
VH 10 The dewpoint value corresponding to the analogue output
offset (4 mA) is entered here.
Caution! Ensure this is always at least 20 OC below the value
assigned to 20 mA.
Default: -90 oC
5. Selecting the Analogue Output Span (20 mA)
Location in Matrix Description of Function
VH 11 The dewpoint value corresponding to the analogue output span
(20 mA) is entered here.
Caution! Ensure this is always at least 20 oC above the value
assigned to 4 mA.
Default: + 10 oC
6. Setting the Span Value for the ppm-v Range
Location in Matrix Description of Function
VH 12 Selection of this field sets the span value for the ppm-v range.
NOTE: The offset is always 0 ppm-v. Do not exceed 1000
ppm-v
Default: 100

DewPro MMY31 Installation and Operation Manual
GE General Eastern 14
SPECIAL CALIBRATION
7. Adjusting the pressure constant
Location in Matrix Description of Function
VH 30 The process pressure constant is entered in bar (absolute), which
is used to calculate ppmv. The moisture unit ppmv is the ratio of
water vapor pressure to the total process pressure and is,
therefore, independent of the process pressure. The reason is
that when compressing a gas (process pressure) all partial
pressures increase by the same factor (Daiton's Law).
The gold/aluminum oxide sensor is selective to water vapour
pressure monitoring a higher vapor pressure when the total
pressure (process pressure) increases. The formula utilized by
the analyser refers to the total pressure of 1 bar. An elevated
pressure of the process has to be corrected by programming the
actual process pressure to the matrix field VH 30.
The system should be designed to maintain a constant pressure,
for instance, by using a pressure regulator in a bypass system.
Default: 1 bar (absolute)
8. Adjusting the Current Loop at 4 mA
Location in Matrix Description of Function
VH 38 By connecting a mA-meter in the loop, the correct current (4 mA)
can be adjusted by increasing or decreasing the displayed digits.
NOTE: If the matrix input is locked (VH89), the calibration values
are displayed but the current output is unaffected. To enable
adjustments, VH89 has to be unlocked by entering "50" into this
field.
9. Adjusting the Current Loop at 20 mA
Location in Matrix Description of Function
VH 39 Selection of this field assists during calibration generating a
nominal 20 mA signal, but the actual value must be 21,92 mA, an
over range to a dewpoint of 22 oC.
By connecting a ma-meter in the loop, the correct current (21.92
mA) can be adjusted by increasing or decreasing the displayed
digits.
NOTE: If the matrix input is locked (VH89), the calibration values
are displayed but the current output is unaffected. To enable
adjustments, VH89 has to be unlocked by entering "50" into this
field.

DewPro MMY31 Installation and Operation Manual
GE General Eastern 15
MODE OF OPERATION
10. Input locking
Location in Matrix Description of Function
VH 89 Any number other than "50" will lock the instrument settings
from inadvertent or unauthorized changes. (The instrument is
only unlocked at "50".)
11. Displaying the present Error Code
Location in Matrix Description of Function
VH 90 In the event of a system fault, this field displays the diagnostic
error code for the fault encountered.
Error Code
0
1
2
3
4
5
7
Description
No error
Dewpoint underrange. The current
output has fallen below the 4.00 mA
point.
Dewpoint overrange. The current
output has exceeded the 21.92 mA
level.
The instrument is no longer reading
between -90 and -20 'C dewpoint while
in ppm-v mode and has fallen off of the
internal vapor pressure table.
ppm-v overrange. The current output
has exceeded the 20 mA level. Re-
range the ppm-v upper scaling limit to
keep this error from occurring.
Sensor is shorted.
Sensor is open.
12. Displaying the previous Error Code
Location in Matrix Description of Function
VH 91 When a system fault condition is cleared, the value of the error
code is stored in this location. That is, during normal operation,
the most recent error code is displayed for reference.

DewPro MMY31 Installation and Operation Manual
GE General Eastern 16
13. Instrumentation Identification number
Location in Matrix Description of Function
VH 92 The instrumentation identification number should always read
“100”.
14. Identification Field
Location in Matrix Description of Function
VH 93 This field indicates the software version (ie. version 2.02 or
higher).
15. Set to Default Values
Location in Matrix Description of Function
VH 94 This field sets all factory defaults
NOTE: Anything that has been calibrated will not be reset.
16. Resetting the Device
Location in Matrix Description of Function
VH 94 The device is reset in this field.
Note: Reset the device only after field calibration using
the DewComp MCY 40 calibrator.

DewPro MMY31 Installation and Operation Manual
GE General Eastern 17
5.0 Troubleshooting
5.1 General Problems
1. The loop current is outside the range of 4-20 mA, as shown on display or current
meter.
SOLUTION: The process dewpoint is out of range. If the dewpoint is above
+22 oC (+ 77 oF), the current will go to the fault current specified on the order or
in the matrix field VH 07. Apply dry air for a few minutes. If the dewpoint doesn't
decrease, consult factory.
SOLUTION: If the dewpoint is below -90 oC (-130oF), the current will go to the
fault current specified on the order or in the matrix field VH 07. Move the sensor
into a wetter environment for a few minutes. If the dewpoint doesn't increase.
the cause may be a defective sensor assembly or an electronics malfunction.
Consult factory.
2. There is no current.
SOLUTION: Check voltage and polarity across +/- terminals with a DC voltmeter
If the voltage is within 12-32 V DC, consult the factory.

DewPro MMY31 Installation and Operation Manual
GE General Eastern 18
6.0 Technical Specifications
Sensor element
Measuring range(s)
Recommended calibration cycle
Calibration accuracy
Repeatability
Maximum RH
Temperature coefficient
Operating and storage temperature
Max. operating pressure
Helium leak rate
Temperature coefficient
Signal output
Process connection
Probe Tube:
Sensor protection
Electronics
Power supply
Protection
Weight
: Gold/aluminum oxide, capacitance
principle
: -90°C to +20°C dew point temperature;
0 to 10 ppm-v, 0 to 100 ppm-v or
0 to 1000 ppm-v (adjustable with
integrated display)
: 6 to 24 months, depending on the
application and the required accuracy
: ±2°C dewpoint
: ±1°C dewpoint
: 50% at dew point > 0°C
: < 0,2°C/°C
: -40°C to +60°C
: 120 bar (1750 psig)
: <10 -6 mbar l/s
: Td /T < 0,2°C/°C
: 4 - 20 mA, 16 µA resolution
: 1/2“ (12,7 mm) x G 1/2“ (DIN ISO 228) or
1/2“ (12,7 mm) tube x 1/2“ MNPT
compression fittings
: Stainless steel 1.4571, 1/2“ (12,7)
diameter, insertion length 2“ (50 mm) to
3,5“ (90 mm)
: Sintered filter 100 micron
: Microprocessor-controlled
: 24 VDC nominal, 12 to30 VDC range
: NEMA 4X (IP 67)
: 1,5 kg (3.2 lb)

DewPro MMY31 Installation and Operation Manual
GE General Eastern 19
7.0 Accessories
7.1 Available Accessories
Accessory Description
Single power supply
Panel mount display, power supply, no relays
Panel mount display, power supply, two alarms
Panel mount display, power supply, two alarms. 4 to 20 repeating output
Consult GE General Eastern
Example Example
+
_
GENERAL EA
S
T
E
R
N
TheHumidityExperts
Optional loop powered
display available
from General Eastern
Optional loop-powered
display available from
General Eastern
Customer’s 24 V (9...32V DC)
or power supply available
from General Eastern
Fig. 22

DewPro MMY31 Installation and Operation Manual
GE General Eastern 20
8.0 Addresses
For More information, please contact one of the following GE General Eastern
offices:
USA
GE General Eastern Instruments
500 Research Drive
Wilmington, MA
Tel. [phone]
Fax. [phone]
Germany
GE General Eastern
Branch of GE Measurement & Sensing Technologies
Bergische Strasse 10
D – 42781 Haan
Tel. [phone]
Fax. [phone]
Netherlands
GE General Eastern
PO Box 49
NL - 1400 AA Bussum
Tel. [phone]
Fax. [phone]
United Kingdom
GE-TEC
General Eastern – Technical Centre
Unit 6, Block 3 Vestry Estate
Otford, Seven Oaks
Kent TN14 5EL
Tel. [phone]
Fax. [phone]
www.generaleastern.net