Micro Motion Model 3711 Installation guide

Installation Manual

P/N 20002976, Rev. A

October 2005

Micro Motion

®

Model 3711

Gas Flow Computers

Installation Manual

Motion, Inc., Boulder, Colorado. MVD and MVD Direct Connect are trademarks of Micro Motion., Inc., Boulder, Colorado. Micro

Motion is a registered trade name of Micro Motion, Inc., Boulder, Colorado. The Emerson logo is a trademark of Emerson Electric

Co. All other trademarks are property of their respective owners.

Installation Manual i

Contents

Chapter 1 Before You Begin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.3 Model 3711 system components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.4 Model 3711 installation procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.5 Documentation resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.6 Micro Motion customer service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Chapter 2 Installing the Model 3711 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.2 Installation architectures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.3 Determining an appropriate location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.3.1 General guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.3.2 Power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.3.3 Maximum cable lengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.4 Mounting the Model 3711 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.5 Mounting the I.S. barrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.6 Mounting the core processor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.7 Grounding the Model 3711 system components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.7.1 Grounding guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.7.2 Grounding methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.8 Wiring the power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Chapter 3 Wiring the Model 3711 to the Sensor . . . . . . . . . . . . . . . . . . . . . . 13

3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3.2 Cable types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.3 Wiring for remote transmitter installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3.4 Wiring for remote core processor with remote transmitter installations. . . . . . . . . . . 17

Chapter 4 Communications Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4.2 Communications options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4.3 Wiring the Local Operator Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4.3.1 Wiring the preinstalled LOI cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4.3.2 Wiring a user-supplied null-modem LOI cable . . . . . . . . . . . . . . . . . . . . . 25

4.3.3 Using a standard serial cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.4 Wiring RS-232 remote communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.5 Wiring a dial-up modem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

ii Micro Motion

®

Model 3711 Gas Flow Computers

Contents

Chapter 5 I/O Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5.2 I/O terminals, types,and switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

5.3 I/O wiring guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5.4 Analog input wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5.5 Analog output wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

5.6 Discrete input wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

5.7 Discrete output wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.8 Pulse input wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.9 RTD input wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Appendix A Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

A.1 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

A.2 Wiring diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

A.3 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Appendix B Termination Boards and Board Access. . . . . . . . . . . . . . . . . . . . . . 49

B.1 About this appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

B.2 Termination boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

B.3 Accessing the termination boards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Appendix C Cable Glands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

C.1 About this appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

C.2 Shielding requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

C.3 Cable gland types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

C.4 Cable gland installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

C.4.1 Model 3711 cable gland installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

C.4.2 NEMA enclosure cable gland installation . . . . . . . . . . . . . . . . . . . . . . . . 55

Appendix D Return Policy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

D.1 New and unused equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

D.2 Used equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Installation Manual 1

Installation Communications WiringSensor WiringBefore You Begin

Chapter 1

Before You Begin

1.1 Overview

This chapter provides an orientation to the Micro Motion

®

Model 3711 Gas Flow Computer, the

Model 3711 installation manual, and the installation process.

1.2 Safety

Safety messages are provided throughout this manual to protect personnel and equipment. Read each

safety message carefully before proceeding to the next step.

1.3 Model 3711 system components

The Model 3711 system includes the following components:

• Model 3711 Gas Flow Computer

• Micro Motion sensor

• Micro Motion core processor (may be mounted on sensor)

•MVD

™

Direct Connect

™

I.S. barrier

1.4 Model 3711 installation procedures

This manual contains installation and wiring information for the Model 3711 Gas Flow Computer, the

I.S. barrier, and the remote core processor (if required by your installation). For installation

information for your sensor, see the sensor documentation.

WARNING

Improper installation in a hazardous area can cause an explosion.

For information about hazardous applications, refer to Micro Motion approvals

documentation, shipped with the transmitter or available from the Micro Motion web

site.

CAUTION

Improper installation could cause measurement error or flowmeter failure.

Follow all instructions to ensure transmitter will operate correctly.

2 Micro Motion

®

Model 3711 Gas Flow Computers

Before You Begin

To install the Model 3711, the following procedures are required:

• Install the Model 3711 unit – see Chapter 2

• Install the I.S. barrier – see Chapter 2

• Install the remote core processor (if applicable) – see Chapter 2

• Wire the Model 3711 to the sensor – see Chapter 3

• Wire communications – see Chapter 4

• Wire the Model 3711 I/O and RTD terminals (if applicable) – see Chapter 5

1.5 Documentation resources

Table 1-1 lists documentation resources for other required information.

1.6 Micro Motion customer service

For customer service, call the support center nearest you:

• In the U.S.A., phone 1-800-522-MASS (1-800-522-6277)

• In Canada and Latin America, phone (303) 527-5200

• In Asia, phone (65) 6770-8155

• In the U.K., phone 0800 - 966 180 (toll-free)

• Outside the U.K., phone +31 (0) 318 495 670

Table 1-1 Flowmeter documentation resources

Topic Document

Sensor installation Sensor documentation shipped with sensor

9-wire cable preparation and wiring

(if core processor is mounted

remotely from sensor)

Micro Motion 9-Wire Flowmeter Cable Preparation Guide

Model 3711 configuration

Model 3711 startup and use

Model 3711 troubleshooting

Micro Motion Model 3711 Gas Flow Computers: Configuration and Use

Manual

Hazardous area installation See the approval documentation shipped with the Model 3711 or

available on the Micro Motion web site

Installation Manual 3

Installation Communications WiringSensor WiringBefore You Begin

Chapter 2

Installing the Model 3711

2.1 Overview

This chapter describes how to install the Model 3711. The following general steps are required:

• Determine your installation architecture (see Section 2.2)

• Determine the location of the transmitter and other flowmeter components (see Section 2.3)

• Mount the transmitter (see Section 2.4)

• Mount the I.S. barrier (see Section 2.5)

• Mount the core processor, if required (see Section 2.6)

• Ground the flowmeter components (see Section 2.7)

• Supply power to the flowmeter (see Section 2.8)

2.2 Installation architectures

Your flowmeter installation will match one of the architectures shown in Figures 2-1 and 2-2.

Mounting, sensor wiring, and grounding requirements depend on this architecture.

Figure 2-1 Installation architecture – Remote transmitter

CAUTION

When installing units in a hazardous area, make sure that all installation

components selected are labeled for use in such areas. Installation and

maintenance must be performed only when the area is known to be

non-hazardous. Installation in a hazardous area could result in personal

inujury or property damage.

Model 3711

Sensor

Core processor

4-wire cable

(Distance y )

I.S. barrier

RS-485 cable

(Distance x )

Power supply cable

(Distance x)

Hazardous area Safe area

4 Micro Motion

®

Model 3711 Gas Flow Computers

Installing the Model 3711

Figure 2-2 Installation architecture – Remote core processor with remote transmitter

2.3 Determining an appropriate location

To determine an appropriate location for the Model 3711, ensure that the location meets the

requirements described in Appendix A.

If the Model 3711 will be installed in a hazardous area:

• Verify that it has the appropriate approval. See Appendix A.

• The Model 3711 components must be installed according to the National Electrical Code

(NEC) Article 501, and any local code requirements, if applicable.

In addition, you must consider the power supply to the Model 3711, the distance between the

components of the Model 3711 system, ground conditions, climate, and site accessibility. General

guidelines for location selection are provided in the following section.

2.3.1 General guidelines

The following are general guidelines for locating the Model 3711:

• Local, state, and federal codes often place restrictions on monitoring locations and dictate site

requirements. Examples of these restrictions are fall distance from a meter run, distance from

pipe flanges, and hazardous area classifications.

• Locate the Model 3711 to minimize the length of signal and power wiring. See Sections 2.3.2

and 2.3.3 for more specific information.

• Provide adequate clearance for wiring and service.

• The LCD should be visible and accessible to the on-site operator.

• Locate the Model 3711 unit away from heavy traffic areas to reduce the risk of being damaged

by vehicles. However, provide adequate vehicle access to aid in monitoring and maintenance.

Core processor

Junction box

Model 3711

I.S. barrier

9-wire cable

(Distance z)

Power supply cable

(Distance x)

RS-485 cable

(Distance x )

Sensor

4-wire cable

(Distance y )

Hazardous area Safe area

Installation Manual 5

Installing the Model 3711

Installation Communications WiringSensor WiringBefore You Begin

2.3.2 Power requirements

In Model 3711 installations, power is supplied to the Model 3711. The Model 3711 supplies power to

the barrier, the barrier supplies power to the core processor, and the core processor supplies power to

the sensor.

When planning the power supply, note the following:

• Model 3711

- Requires DC power

- Accepts input voltages ranging from 12 to 28 VDC at the charge terminals

(PWR+/PWR–) on the Mass Flow Interface board. Because it supplies power to the

barrier, a minimum of 24 VDC is required.

- The maximum power for DC voltage sources is 300 mWatts.

• I.S. barrier

- Requires 24 VDC ±20%

- Maximum power consumption of barrier plus core processor is approximately 3.5 W

- Requires minimum DC input of 19.2 V at the barrier terminals.

- At startup, requires a minimum of 0.2 A of short-term current per core processor. The

maximum steady state current is 0.15 A.

2.3.3 Maximum cable lengths

Maximum cable length between flowmeter components depends on the installation architecture and

the cable type. See Table 2-1.

Be sure to size the power supply cable to the barrier so that sufficient power is provided to the barrier.

For assistance, refer to Table 2-2 and use the equation below:

Table 2-1 Wire sizes and lengths

Span Cable type Wire size Max length

Model 3711 to barrier

(Distance x in Figures 2-1

and 2-2)

RS-485 22–18 AWG (0,35–0,8 mm

2

)

100 ft (30 meters)

Power

(1)

(1) Wire must be sized to provide a minimum of 19.2 V at the barrier. See the following discussion.

22–18 AWG (0,35–0,8 mm

2

)

100 ft (30 meters)

Barrier to core processor

(Distance y in Figures 2-1

and 2-2)

4-wire Not applicable 500 ft (150 meters)

Core processor to sensor

(Distance z in Figure 2-2

)

Micro Motion 9-wire Not applicable 60 feet (20 meters)

MinimumSupplyVoltage 19.2V CableResistance CableLength× 0.15A×()+=

6 Micro Motion

®

Model 3711 Gas Flow Computers

Installing the Model 3711

2.4 Mounting the Model 3711

A 2-inch pipe mount kit is shipped with the Model 3711 (see Figure 2-3). To mount the Model 3711

unit:

1. Remove the U-bolt from the mounting bracket.

2. Slide the U-bolt around the pipe or pole.

3. Reattach the U-bolt to the mounting bracket.

Figure 2-3 Model 3711 with mounting bracket and U-bolt

Table 2-2 Typical power cable resistances at 68 °F (20 °C)

Gauge Resistance

(1)

(1) These values include the resistance of both high and low conductors in a cable.

14 AWG 0.0050 Ω/foot

16 AWG 0.0080 Ω/foot

18 AWG 0.0128 Ω/foot

20 AWG 0.0204 Ω/foot

22 AWG 0.0328 Ω/foot

2,5 mm

2

0,0136 Ω/meter

1,5 mm

2

0,0228 Ω/meter

1 mm

2

0,0340 Ω/meter

0,75 mm

2

0,0460 Ω/meter

0,5 mm

2

0,0680 Ω/meter

Mounting bracket

U-bolt

Installation Manual 7

Installing the Model 3711

Installation Communications WiringSensor WiringBefore You Begin

2.5 Mounting the I.S. barrier

The I.S. barrier is shipped with a NEMA enclosure (see Figure 2-3) and a 2-inch pipe mount kit. To

mount the I.S. barrier and the NEMA enclosure:

1. Open the cover on the NEMA enclosure.

2. Snap the I.S. barrier onto the 35 mm DIN rail that is attached to the mounting plate inside the

NEMA enclosure. You may mount it in either direction, as convenient for your installation.

3. Referring to Figure 2-3, install the two end clamps that hold the I.S. barrier in place. To do

this:

a. Hook one end of the end clamp over the DIN rail.

b. Position the end clamp snugly against the barrier.

c. Tighten the screw until the end clamp is securely fastened to the DIN rail.

4. Close the cover and fasten the clamps.

5. Remove the U-bolts from the mounting bracket.

6. Slide the U-bolts around the pipe or pole.

7. Reattach the U-bolts to the mounting bracket.

Figure 2-4 NEMA enclosure components

Figure 2-5 Cutaway view of NEMA enclosure with DIN rail, I.S. barrier, and end clamps

U-bolts

Cover

3X Cover clamps

Mounting bracket

Conduit openings

2X End clamps

DIN rail

I.S. barrier

8 Micro Motion

®

Model 3711 Gas Flow Computers

Installing the Model 3711

2.6 Mounting the core processor

This step is required only for remote core processor with remote transmitter installations (see

Figure 2-2). If you do not have this installation architecture, go to Section 2.7.

Figure 2-6 shows the remote core processor and mounting bracket. Using the mounting bracket,

mount the core processor in a location compatible with the cable length requirements discussed in

Section 2.3.3. For core processor dimensions, refer to Figure A-2.

Figure 2-6 Remote core processor components

2.7 Grounding the Model 3711 system components

The sensor and the Model 3711 unit must be grounded independently. If the core processor is

mounted separately from the sensor, it must be grounded independently.

Grounding wiring requirements for DC voltage sources equipment are governed by the National

Electrical Code (NEC). When the equipment uses DC voltage sources, the grounding system must

terminate at the service disconnect. All equipment grounding conductors must provide an

uninterrupted electrical path to the service disconnect.

• The National Electrical Code Article 250-83 (1993), paragraph c, defines the material and

installation requirements for grounding electrodes.

• The National Electrical Code Article 250-91 (1993), paragraph a, defines the material

requirements for grounding electrode conductors.

• The National Electrical Code Article 250-92 (1993), paragraph a, provides installation

requirements for grounding electrode conductors.

• The National Electrical Code Article 250-95 (1993) defines the size requirements for

equipment grounding conductors.

2.7.1 Grounding guidelines

Proper grounding of the Model 3711 unit helps to reduce the effects of electrical noise on the unit's

operation and protects against lightning. The Model 3711 provides lightning protection for built-in

field wiring inputs and outputs. Install a surge protection device at the service disconnect on DC

voltage source systems to protect against lightning and power surges for the installed equipment. If

you have the optional dial-up modem communications card, a telephone surge protector may be

appropriate.

All earth grounds must have an earth-to-ground rod or grid impedance of 25 ohms or less as measured

with a ground system tester. The grounding conductor should have a resistance of 1 ohm or less

between the Model 3711 enclosure ground and the earth ground rod or grid.

End-cap

Mounting bracket

Core processor lid

Core processor housing

Conduit opening

for 4-wire cable

Conduit opening

for 9-wire cable

Installation Manual 9

Installing the Model 3711

Installation Communications WiringSensor WiringBefore You Begin

2.7.2 Grounding methods

Sensor

For information on grounding the sensor, see the sensor documentation.

Core processor

If the core processor is mounted integrally with the sensor, no additional ground is required for the

core processor.

If your installation includes a remote core processor, ground the core processor according to

applicable local standards, using either the internal or external grounding screw. The internal

grounding screw is shown in Figure 2-7. To access the internal grounding screw, remove the core

processor lid from the core processor housing (see Figure 2-6).

Figure 2-7 Core processor internal grounding screws

Model 3711

Ground the Model 3711 according to applicable local standards. The Model 3711 has two grounding

screws on the base termination board (inside the termination board compartment) and one grounding

screw on the housing (see Figure 2-8). If required, refer to Appendix B for instructions on accessing

the Mass Flow Interface board.

Micro Motion recommends using a minimum of 14 AWG wire to ground the Model 3711.

Core processor housing internal grounding screw

• For connections to earth ground (if core processor cannot be grounded via sensor

piping and local codes require ground connections to be made internally)

• Do not connect shield drain wires to this terminal

10 Micro Motion

®

Model 3711 Gas Flow Computers

Installing the Model 3711

Note the following:

• On pipes with cathodic protection, the Model 3711 must be electrically isolated from the pipe.

In this case, the Model 3711 must be grounded with a ground rod or grid system.

• On pipes without cathodic protection, the pipe itself may provide an adequate earth ground.

Test with a ground system tester to make sure the pipe-to-earth impedance is less than 2 ohms.

- If the pipe provides an adequate ground, you may not need to install a separate ground rod

or grid system. All grounding should terminate at a single point.

- If the pipe-to-earth impedance is greater than 2 ohms, the Model 3711 installation should

be electrically isolated and a ground rod or grid grounding system installed.

Figure 2-8 Model 3711 grounding screws

2.8 Wiring the power supply

The PWR terminals on the Mass Flow Interface board are used for both the power wires from the

power supply and the power wires to the I.S. barrier (see Figure 2-9). Be sure to size the wire so that

both wires can be connected to the terminal. Use enough length of wire to allow some slack in the

connection.

CAUTION

Wiring the power supply without appropriate electrostatic discharge

precautions could cause damage to the Model 3711 circuits.

To avoid damage to the Model 3711 circuits, use appropriate electrostatic

discharge precautions such as wearing a grounded wrist strap.

Internal grounding

screws

External

grounding screw

Installation Manual 11

Installing the Model 3711

Installation Communications WiringSensor WiringBefore You Begin

To wire the power supply:

1. Follow good wiring practice. All wiring must conform to state, local, and NEC codes. Use

either conduit or cable glands to shield the wiring. See Appendix C for instructions on

installing cable glands at the Model 3711 and the NEMA enclosure.

2. Follow the instructions in Appendix B to access the Mass Flow Interface board.

3. Refer to Figure 2-9 to locate and identify the PWR terminals on the Mass Flow Interface

board.

4. To wire the power supply to the Model 3711:

a. Strip 1/4 inch (5 mm) of insulation from the end of the wire.

b. Insert the wire through the conduit opening.

c. Insert the stripped end into the clamp beneath the termination screw on the Mass Flow

Interface board. Expose a minimum of bare wire.

5. To wire the PWR terminals to the I.S. barrier:

a. Strip 1/4 inch (5 mm) of insulation from each end of the wire.

b. At the Model 3711, connect the wires to the PWR + and PWR – terminals. Be sure that

both the incoming and the outgoing power supply wires are making a good connection.

c. At the NEMA enclosure, open the cover (see Figure 2-3).

d. Pass the wires through the appropriate conduit opening on the NEMA enclosure.

e. Connect the wires to terminals 11 and 12 on the barrier (see Figure 2-10), matching

positive and negative (+ and –).

f. Close the cover and fasten the clamps.

Figure 2-9 Power supply terminals on the Mass Flow Interface board

Mass Flow Interface board

PWR –

PWR +

From power supply

To I.S. barrier

12 Micro Motion

®

Model 3711 Gas Flow Computers

Installing the Model 3711

Figure 2-10 I.S. barrier terminals for power supply

14 (RS-485 B)

13 (RS-485 A)

11 (VDC –)

12 (VDC +)

Non-I.S. terminals

for connection to Model 3711

Installation Manual 13

Installation Communications WiringSensor WiringBefore You Begin

Chapter 3

Wiring the Model 3711 to the Sensor

3.1 Overview

This chapter describes how to connect the Model 3711 to a Micro Motion sensor.

Wiring requirements between the sensor and Model 3711 depend on the installation configuration

(see Figures 2-1 and 2-2

):

• If you have a remote transmitter installation, review the information on 4-wire cable in

Section 3.2, then follow the instructions in Section 3.3.

• If you have a remote core processor with remote transmitter installation, review the

information on both 4-wire and 9-wire cable in Section 3.2, then follow the instructions in

Section 3.4.

In all cases, the 4-wire connection is made through an I.S. barrier.

CAUTION

When installing units in a hazardous area, make sure that all installation

components selected are labeled for use in such areas. Installation and

maintenance must be performed only when the area is known to be

non-hazardous. Installation in a hazardous area could result in personal

inujury or property damage.

CAUTION

Removing the termination board cover in hazardous environments could

result in personal injury or property damage.

To wire the Model 3711 to the sensor, you must remove the termination board

cover. To avoid personal injury or property damage while wiring the Model 3711 to

the sensor, do not perform these installation steps in a hazardous environment.

CAUTION

Wiring the Model 3711 to the sensor with power connected could result in

personal injury or property damage.

To avoid personal injury or property damage, remove power from the Model 3711

and the I.S. barrier before wiring the Model 3711 to the I.S. barrier, or wiring the I.S.

barrier to the sensor.

14 Micro Motion

®

Model 3711 Gas Flow Computers

Wiring the Model 3711 to the Sensor

3.2 Cable types

Micro Motion offers two types of 4-wire cable: shielded and armored. Both types contain shield drain

wires.

User-supplied 4-wire cable must meet the following requirements:

• Twisted pair construction

• The gauge requirements as described in Table 2-2

• The applicable hazardous area requirements, if the core processor is installed in a hazardous

area (see the approvals documents shipped with the transmitter or available on the Micro

Motion web site)

Micro Motion offers three types of 9-wire cable: jacketed, shielded, and armored. Refer to Micro

Motion’s 9-Wire Flowmeter Cable Preparation and Installation Guide for detailed descriptions of

these cable types and for assistance in selecting the appropriate cable for your installation.

CAUTION

Wiring the Model 3711 to the I.S. barrier without appropriate electrostatic

discharge precautions could cause damage to the Model 3711 circuits.

To avoid damage to the Model 3711 circuits, use appropriate electrostatic

discharge precautions such as wearing a grounded wrist strap.

CAUTION

Large electromagnetic fields can interfere with flowmeter communication

signals.

Improper installation of cable or conduit can cause measurement error or flowmeter

failure. To reduce the risk of measurement error or flowmeter failure, keep cable or

conduit away from devices such as transformers, motors, and power lines which

produce large electromagnetic fields.

Installation Manual 15

Wiring the Model 3711 to the Sensor

Installation Communications WiringSensor WiringBefore You Begin

3.3 Wiring for remote transmitter installations

To connect the cable, refer to Figure 2-1 and follow the steps below.

1. To connect the core processor to the I.S. barrier:

a. You must shield the wiring.

• For unshielded cable, use continuous metallic conduit that provides 360° termination

shielding for the enclosed wiring.

• For shielded or armored cable, you may use cable glands. Two different cable glands

are required: a standard threaded cable gland at the core processor, and a standard

cable gland with a sealing washer, lock washer, and lock nut at the I.S. barrier. Both

cable glands are available from Micro Motion. Instructions on assembling and

installing the standard cable gland are provided in the sensor documentation.

Instructions on assembling and installing the cable gland at the I.S. barrier are

provided in Appendix C.

b. Prepare a 4-wire cable as described in the sensor documentation.

c. Identify the wires in the 4-wire cable. If you are using 4-wire cable supplied by Micro

Motion, use the blue cable. This cable consists of one pair of 18 AWG (0,75 mm

2

) wires

(red and black), which should be used for the VDC connection, and one pair of 22 AWG

(0,35 mm

2

) wires (green and white), which should be used for the RS-485 connection.

d. Connect the cable to the core processor as described in the sensor documentation.

e. At the I.S. barrier:

• Open the cover of the NEMA enclosure.

• Pass the wires through the appropriate conduit opening.

• Connect the wires from the core processor to the I.S. terminals at the barrier, matching

by function. See Table 3-1 and Figure 3-1. If you are using Micro Motion 4-wire

cable, you can identify the wires by color.

• Close the cover and fasten the clamps.

Table 3-1 Terminal functions at core processor, barrier, and Model 3711

Function

Wire color (Micro

Motion 4-wire cable)

Core processor

terminals

Barrier terminals

Model 3711

MVD terminalsI.S. Non-I.S.

RS-485 A White 3 43 13 A

RS-485 B Green 4 44 14 B

VDC + Red 1 42 12 + (not used)

VDC – Black 2 41 11 – (not used)

16 Micro Motion

®

Model 3711 Gas Flow Computers

Wiring the Model 3711 to the Sensor

Figure 3-1 Barrier terminals

2. To connect the I.S. barrier to the Model 3711:

Note: Micro Motion ships the Model 3711 with 10 feet (3 m) of gray jacketed (non-I.S.) cable for use

between the I.S. barrier and the Model 3711. Micro Motion recommends that this cable be used.

a. You must shield the wiring.

• For unshielded cable, use continuous metallic conduit that provides 360° termination

shielding for the enclosed wiring.

• For shielded or armored cable, you may use cable glands. Two different cable glands

are required: and a standard cable gland with a sealing washer, lock washer, and lock

nut at the I.S. barrier, and a standard threaded cable gland at the Model 3711. Both

cable glands are available from Micro Motion. Instructions on assembling and

installing both types of cable gland are provided in Appendix C.

b. At the I.S. barrier:

• Remove one inch of outer jacket from the end of the cable. Strip individual wires and

remove the drain wires.

• Open the cover of the NEMA enclosure.

• Pass the wires through the appropriate conduit opening.

• Connect the wires to the non-I.S. terminals at the barrier (terminals 13 and 14). See

Figure 3-1.

• Close the cover and fasten the clamps.

c. At the Model 3711:

• Follow the instructions in Appendix B to access the Mass Flow Interface board.

• Refer to Figure 3-2 to identify the terminals for the RS-485 connection to the sensor.

These terminals are in the MVD group on the Mass Flow Interface board, and are

labeled

A and B.

• Remove two inches of outer jacket from the end of the cable. Strip individual wires.

Do not remove the drain wires.

• Pass the wires through the appropriate conduit opening.

44 (RS-485 B)

43 (RS-485 A)

41 (VDC –)

42 (VDC +)

14 (RS-485 B)

13 (RS-485 A)

11 (VDC –)

12 (VDC +)

I.S. terminals

for connection to core processor

Non-I.S. terminals

for connection to Model 3711

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Micro Motion Model 3711 Installation guide

Micro Motion Model 3711 Installation guide

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