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.