Emerson Micro Motion 7835 User manual

Installation Manual
MMI-20020999, Rev AC
May 2018
Micro Motion® Compact Density Meter (CDM)
7835/7845 Liquid Density Meter Retrofit Installation

Safety and approval information
This Micro Motion product complies with all applicable European directives when properly installed in accordance with the
instructions in this manual. Refer to the EU declaration of conformity for directives that apply to this product. The EU declaration of
conformity, with all applicable European directives, and the complete ATEX Installation Drawings and Instructions are available on
the internet at www.emerson.com or through your local Micro Motion support center.
Information affixed to equipment that complies with the Pressure Equipment Directive, can be found on the internet at
www.emerson.com.
For hazardous installations in Europe, refer to standard EN 60079-14 if national standards do not apply.
Other information
Full product specifications can be found in the product data sheet. Troubleshooting information can be found in the configuration
manual. Product data sheets and manuals are available from the Micro Motion web site at www.emerson.com.
Return policy
Follow Micro Motion procedures when returning equipment. These procedures ensure legal compliance with government
transportation agencies and help provide a safe working environment for Micro Motion employees. Micro Motion will not accept
your returned equipment if you fail to follow Micro Motion procedures.
Return procedures and forms are available on our web support site at www.emerson.com, or by phoning the Micro Motion Customer
Service department.
Emerson Flow customer service
Email:
•Worldwide: [email protected]
•Asia-Pacific: [email protected]
Telephone:
North and South America Europe and Middle East Asia Pacific
United States 800-522-6277 U.K. 0870 240 1978 Australia 800 158 727
Canada [phone] The Netherlands [phone] New Zealand 099 128 804
Mexico [phone] France 0800 917 901 India 800 440 1468
Argentina [phone] Germany 0800 182 5347 Pakistan 888 550 2682
Brazil [phone] Italy 8008 77334 China [phone]
Central & Eastern [phone] Japan [phone]
Russia/CIS [phone] South Korea [phone]
Egypt 0800 000 0015 Singapore [phone]
Oman 800 70101 Thailand 001 800 441 6426
Qatar 431 0044 Malaysia 800 814 008
Kuwait 663 299 01
South Africa 800 991 390
Saudi Arabia 800 844 9564
UAE 800 0444 0684

Contents
Chapter 1 Planning ...........................................................................................................................1
1.1 Retrofit installation overview ..........................................................................................................1
1.2 Installation checklist .......................................................................................................................1
1.3 Best practices ................................................................................................................................. 2
1.4 Pressure drop in the meter ............................................................................................................. 3
1.5 Power requirements .......................................................................................................................5
1.6 Spacing requirements .................................................................................................................... 9
1.7 Perform a pre-installation meter check .........................................................................................11
Chapter 2 Removing a 7835/7845 meter ........................................................................................ 12
2.1 Disconnect the 7835/7845 meter wiring ......................................................................................12
2.2 Remove the meter from the pipeline ............................................................................................14
Chapter 3 Mounting .......................................................................................................................15
3.1 Mount the meter ..........................................................................................................................15
3.2 Rotate the electronics on the meter (optional) .............................................................................16
3.3 Rotate the display on the transmitter (optional) ...........................................................................17
Chapter 4 Wiring ........................................................................................................................... 19
4.1 Wiring to external devices (HART multidrop) ................................................................................19
4.2 Terminals and wiring requirements .............................................................................................. 19
4.3 Retrofit wiring: terminal-to-output conversions ........................................................................... 20
4.4 Explosion-proof/flameproof or non-hazardous output wiring .......................................................22
4.5 Intrinsically safe output wiring ......................................................................................................26
4.6 Processor wiring for remote-mount 2700 FOUNDATION™ fieldbus option ....................................34
4.7 Wiring to signal converters and/or flow computers ...................................................................... 39
Chapter 5 Grounding ......................................................................................................................42
Contents
Installation Manual i

Contents
ii Micro Motion Compact Density Meter 7835/7845 Retrofit

1 Planning
Topics covered in this chapter:
•Retrofit installation overview
•Installation checklist
•Best practices
•Pressure drop in the meter
•Power requirements
•Spacing requirements
•Perform a pre-installation meter check
1.1 Retrofit installation overview
Following is an overview of the tasks required to install the Compact Density Meter (CDM)
as a replacement to the Micro Motion 7835/7845 liquid density meter. We recommend
that you review this information before beginning the retrofit installation.
Process Reference
Confirm you have all parts necessary and meet the basic installa-
tion requirements.
See Section 1.2
Consider the installation best practices for the removal and in-
stallation of your meter(s).
See Section 1.3
Confirm any additional wiring, external power supplies, and/or
resistance needed to wire to the CDM.
See Chapter 4
Remove the existing 7835/7845 liquid density meter. See Chapter 2
Mount the CDM retrofit meter. See Chapter 3
Wire the meter according to the recommended practices for
your process environment and required approvals.
See Chapter 4
Ground the meter. See Grounding
1.2 Installation checklist
□Make sure that the hazardous area specified on the approval tag is suitable for the
environment in which the meter will be installed.
□Verify that the local ambient and process temperatures are within the limits of the
meter.
□Verify the spacing requirements for the retrofit meter installation (see Section 1.6).
Planning
Installation Manual 1

□Verify the retrofit wiring requirements, which may vary depending on your existing
transmitter configuration:
-Confirm the CDM input/output wiring requirements (see Chapter 4).
Tip
Depending on your current configuration, you may need additional wiring or can reuse
wiring that had been connected to devices no longer needed.
-For intrinsically safe hazardous area installations, you must purchase new barriers
or isolators. You cannot reuse existing safety barriers or galvanic isolators for
connecting to the CDM.
Tip
Micro Motion provides safety barrier and galvanic isolator installation kits for wiring the
CDM in a hazardous environment. These kits provide the appropriate barriers or isolators
depending on the outputs available and approvals required. Contact
[email protected] for more information on ordering these kits.
□If your meter will be wired to a remote-mount 2700 FOUNDATION™ fieldbus
transmitter:
-Refer to the instructions in this manual for preparing the 4-wire cable and wiring
to the processor connections. See Section 4.6.
-Refer to the instructions in the transmitter installation manual for mounting and
wiring the 2700 FOUNDATION™ fieldbus transmitter.
-Consider the maximum cable length between the meter and transmitter. The
maximum recommended distance between the two devices is 1000 ft (300 m).
Micro Motion recommends using Micro Motion cable.
□Install the meter so that the flow direction arrow on the meter case matches the
actual forward flow of the process. (Flow direction is also software-selectable.)
□For optimal performance, thermally insulate the meter and the inlet and bypass-
loop pipeline to maintain stable temperatures.
Tip
Micro Motion offers a soft, weather-proof insulating jacket that is easily fitted to all CDM
versions.
1.3 Best practices
The following information can help you get the most from your meter.
•Handle the meter with care. Follow local practices for lifting or moving the meter.
•Perform a Known Density Verification (KDV) check of the meter prior to installing
the meter in your system.
•Install the meter in the preferred orientation in a vertical pipeline with liquids and
slurries flowing upward.
Planning
2Micro Motion Compact Density Meter 7835/7845 Retrofit

Important
If you do not install the meter in the preferred orientation, you may need to apply a field
offset to ensure optimal performance. Refer to your organizational standards for sampling
and reference measurement to determine what the offset may be.
•If you are installing the meter into an application configuration requiring differential
pressure, confirm the current configuration is suitable for the CDM.
•Do not apply a compression force greater than 200 lbs (90.7 kg) when installing the
meter.
•Thermally insulate the meter and the inlet and bypass-loop pipeline to maintain
stable temperatures.
•There are no pipe run requirements for Micro Motion meters. Straight runs of pipe
upstream or downstream are unnecessary.
•Keep the meter tubes full of process fluid.
•For halting flow through the meter with a single valve, install the valve downstream
from the meter.
•Minimize bending and torsional stress on the meter. Do not use the meter to align
misaligned piping.
•The meter does not require external supports. The flanges will support the meter in
any orientation.
•For bypass configurations using a pump, install the pump downstream of the meter
to avoid pump heat transfer.
•For bypass configurations, maintain a target flow through the meter to ensure
sample integrity and consistent temperature with the main line.
1.4 Pressure drop in the meter
The pressure drop in the meter depends on the process conditions. The following figures
illustrate the pressure drop for the meter at varying fluid density and viscosity. In addition,
these charts show how the meter compares to the Micro Motion 7835/7845 liquid density
meters.
Important
For the most accurate pressure drop calculations using your process variables, use the Micro Motion
product selector available at www.emerson.com.
Planning
Installation Manual 3

Sample pressure drop calculations (fluid viscosity equals 2 cP)Figure 1-1:
A. Pressure drop (bar)
B. Flow rate (m3/hr)
Note
•Density = 800 kg/m3
•Viscosity = 2 cP
Planning
4Micro Motion Compact Density Meter 7835/7845 Retrofit

Sample pressure drop calculations (fluid viscosity equals 10 cP)Figure 1-2:
A. Pressure drop (bar)
B. Flow rate (m3/hr)
Note
•Density = 800 kg/m3
•Viscosity = 10 cP
1.5 Power requirements
Following are the DC power requirements to operate the meter:
•Explosion-proof/flameproof meters:
-24 VDC, 0.65 W typical, 1.1 W maximum
-Minimum recommended voltage: 21.6 VDC with 1000 ft of 24 AWG (300 m of
0.20 mm2) power-supply cable
-At startup, power source must provide a minimum of 0.5 A of short-term current
at a minimum of 19.6 V at the power-input terminals.
•Intrinsically safe meters:
-24 VDC, 0.7 W typical with 250 Ω barrier, 0.96 W maximum with 250 Ω barrier
-Minimum recommended voltage: 22.8 VDC with 1000 ft of 22 AWG (300 m of
0.25 mm2) power-supply cable
Planning
Installation Manual 5

Power cable recommendations for explosion-proof/flameproof meters
Minimum wire gauge (AWG per feet )Figure 1-3:
300ft 600ft 900ft 1200ft 1500ft 1800ft 2100ft 2400ft 2700ft 3000ft
B
2 1 . 6V
24 V
14
15
16
17
18
19
20
21
22
23
24
25
26
A
91.44m 182.88m 274.32m 365.76m 457.2m 548.64m 640.08m 731.52m 822.96m 914.4m
A. AWG maximum
B. Distance of installation
Planning
6Micro Motion Compact Density Meter 7835/7845 Retrofit

Minimum wire area (mm2 per meter)Figure 1-4:
0 . 00 0
0.100
0.200
0.300
0.400
0.500
0.600
0.700
10 0m 20 0m 30 0m 40 0m 50 0m 60 0m 70 0m 80 0m 90 0m 100 0m
B
2 1 . 6V
24 V
A
328.084 ft 656.168ft 984.253ft 1312.34ft 1640.42ft 1968.5ft 2296.59ft 2624.67ft 2952.76ft 3280.84ft
A. Minimum wire area (mm2)
B. Distance of installation
Planning
Installation Manual 7

Power cable recommendations for intrinsically safe meters
Minimum wire gauge (AWG per feet)Figure 1-5:
3 0 0 6 0 0 9 0 0 12 0 0 1 50 0 18 0 0 21 0 0 24 0 0 27 0 0 3 00 0
22 . 8 V
24 V
14
15
16
17
18
19
20
21
2 2
23
24
25
26
A
B
A. AWG
B. Distance of installation
Planning
8Micro Motion Compact Density Meter 7835/7845 Retrofit

Minimum wire area (mm2 per meter)Figure 1-6:
A. Minimum wire area (mm2)
B. Distance of installation
1.6 Spacing requirements
When determining spacing requirements, be sure to consider the height requirements of
the CDM in relation to the existing 7835/7845 meter (see Figure 1-8).
Planning
Installation Manual 9

CDM retrofit meter dimensionsFigure 1-7:
A. Dim. A — face to face is up to 40.4 inches (1026 mm) ± 0.125 in (3 mm)
B. Nominal flow direction — the meter can be configured for normal (forward), reversed, or bi-
directional flow
C. 2x 1/2-14 NPT female electronic interface
Note
Drawing dimensions are in inches.
7835/7845 meter dimensions (height only)Figure 1-8:
12.6
(320)
Dimensions in inches
(mm)
Explosion Proof 7835
Intrinsically Safe 7835/7845
6.2
(158.6)
Planning
10 Micro Motion Compact Density Meter 7835/7845 Retrofit

1.7 Perform a pre-installation meter check
Check the meter prior to installation to confirm that no damage occurred to the meter
during shipment.
Procedure
1. Remove the meter from the box.
CAUTION!
Handle the meter with care. Follow all corporate, local, and national safety regulations
for lifting and moving the meter.
2. Visually inspect the meter for any physical damage.
If you notice any physical damage to the meter, immediately contact Micro Motion
Customer Support at [email protected].
3. Position and secure the meter in a vertical position with the flow arrow pointing
upward.
4. Connect the power wiring, and power up the meter.
Remove the back transmitter housing cover to access the PWR terminals.
Power supply wiring terminalsFigure 1-9:
MTL7728P+
3
4
1
2
A
A. Barrier wiring is applicable to intrinsically safe installations only
5. Perform a Known Density Verification (KDV) check.
Use the Known Density Verification procedure to match the current meter
calibration with the factory calibration. If the meter passes the test, then it has not
drifted or changed during shipment.
For more information on performing a KDV check, see the configuration and use
manual that shipped with the product.
Planning
Installation Manual 11

2 Removing a 7835/7845 meter
Topics covered in this chapter:
•Disconnect the 7835/7845 meter wiring
•Remove the meter from the pipeline
2.1 Disconnect the 7835/7845 meter wiring
Prerequisites
•Be prepared to manually record the existing wiring connections to the 7835/7845
meter. You will use this information in re-wiring to the CDM.
•If you are using the 7835/7845 with Advanced electronics, be sure to record the
parameters and ranges for the analog (mA) outputs — for example, Analog 1 is line
density; 4-20 mA is 700-1000 kg/m3.
CAUTION!
Confirm the applicable codes of practice for disconnecting and removing a meter. Meter
installation and/or removal should be performed by suitably trained personnel only.
Procedure
1. Power down the 7835/7845 meter.
2. If the meter is in a hazardous area, wait five minutes before proceeding to the next
step.
3. Remove the thermal insulation from the meter and the surrounding pipework (if
applicable).
4. Remove the electronics housing cover to reveal the 7835/7845 wiring connections.
5. Manually record the existing wiring connections to the 7835/7845 meter.
If you reuse the existing wiring, you should be sure to identify which wires
connected to specific outputs and/or input devices in your existing configuration.
You will use this information to match the wire connections to the appropriate
input/output on the CDM.
The following figures identify the terminal locations for the Standard electronics
board (see Figure 2-1) and Advanced electronics board (see Figure 2-2).
Removing a 7835/7845 meter
12 Micro Motion Compact Density Meter 7835/7845 Retrofit

Standard electronics terminal locationsFigure 2-1:
Advanced electronics terminal locationsFigure 2-2:
6. Disconnect wiring from the meter.
Removing a 7835/7845 meter
Installation Manual 13

2.2 Remove the meter from the pipeline
Prerequisites
Before you loosen or remove any connection, depressurize and drain the meter in
accordance with the applicable codes of practice.
CAUTION!
You must take suitable precautions to ensure your safety if the equipment has come into
contact with aggressive substances. Meter removal should be performed by suitably trained
personnel only in accordance with applicable codes of practice.
Procedure
1. Disconnect the meter (break the seal).
2. Remove the meter.
CAUTION!
Handle the meter with care when lifting and removing it from the pipeline.
Micro Motion recommends that you use lifting straps fitted to the flanged ends to
account for the meter weight and its sensitivity to impact.
3. Dispose of the meter in accordance with your local practices (if applicable).
Removing a 7835/7845 meter
14 Micro Motion Compact Density Meter 7835/7845 Retrofit

3 Mounting
Topics covered in this chapter:
•Mount the meter
•Rotate the electronics on the meter (optional)
•Rotate the display on the transmitter (optional)
3.1 Mount the meter
Use your common practices to minimize torque and bending load on process connections.
Tip
To reduce the risk of condensation or excessive moisture, the transmitter conduit opening should
not point upward (if possible). The conduit opening of the transmitter can be rotated freely to
facilitate wiring.
CAUTION!
Do not lift the meter by the electronics. Lifting the meter by the electronics can damage the
device.
Mounting
Installation Manual 15

Mounting the sensorFigure 3-1:
Notes
•Do not use the meter to support the piping.
•The meter does not require external supports. The flanges will support the meter in any orientation.
•All pipework joints and couplings must be airtight to minimize the presence of gas bubbles in the
fluid.
3.2 Rotate the electronics on the meter (optional)
You can rotate the transmitter on the meter up to 90°.
1. Using a 4 mm hex key, loosen the cap screw that holds the transmitter in place.
Mounting
16 Micro Motion Compact Density Meter 7835/7845 Retrofit