GE Sensing AT868 Operating Manual

Sensing & Inspection Technologies

AquaTrans™ AT868

Panametrics Liquid Flow Ultrasonic Transmitter

Abridged Manual

Sensing & Inspection Technologies

AquaTrans™ AT8688

Panametrics Liquid Flow Ultrasonic Transmitter

Abridged Manual

914-218D September 2004

The AquaTrans AT868 is a GE Panametrics product. GE Panametrics has joined other GE high-technology businesses under a new name—GE Sensing & Inspection Technologies.

September 2004

Warranty Each instrument manufactured by GE Infrastructure Sensing, Inc. is

warranted to be free from defects in material and workmanship. Liability under this warranty is limited to restoring the instrument to normal operation or replacing the instrument, at the sole discretion of GE Infrastructure Sensing, Inc. Fuses and batteries are specifically excluded from any liability. This warranty is effective from the date of delivery to the original purchaser. If GE Infrastructure Sensing, Inc. determines that the equipment was defective, the warranty period is:

• one year for general electronic failures of the instrument

• one year for mechanical failures of the sensor

If GE Infrastructure Sensing, Inc. determines that the equipment was damaged by misuse, improper installation, the use of unauthorized replacement parts, or operating conditions outside the guidelines specified by GE Infrastructure Sensing, Inc., the repairs are not covered under this warranty.

The warranties set forth herein are exclusive and are in lieu of all other warranties whether statutory, express or implied (including warranties of merchantability and fitness for a particular purpose, and warranties arising from course of dealing or usage or trade).

iii

September 2004

Return Policy If a GE Infrastructure Sensing, Inc. instrument malfunctions within the

warranty period, the following procedure must be completed:

1. Notify GE Infrastructure Sensing, Inc., giving full details of the problem, and provide the model number and serial number of the instrument. If the nature of the problem indicates the need for factory service, GE Infrastructure Sensing, Inc. will issue a RETURN AUTHORIZATION number (RA), and shipping instructions for the return of the instrument to a service center will be provided.

2. If GE Infrastructure Sensing, Inc. instructs you to send your instrument to a service center, it must be shipped prepaid to the authorized repair station indicated in the shipping instructions.

3. Upon receipt, GE Infrastructure Sensing, Inc. will evaluate the instrument to determine the cause of the malfunction.

Then, one of the following courses of action will then be taken:

• If the damage is covered under the terms of the warranty, the

instrument will be repaired at no cost to the owner and returned.

• If GE Infrastructure Sensing, Inc. determines that the damage is not

covered under the terms of the warranty, or if the warranty has expired, an estimate for the cost of the repairs at standard rates will be provided. Upon receipt of the owner’s approval to proceed, the instrument will be repaired and returned.

September 2004

Table of Contents

Chapter 1: Installation

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Site Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Electronics Enclosure Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Flowcell Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Transducer Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Cable Lengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Transducer Cables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Installing a Flowcell. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

CE Mark Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

EMC Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

LVD Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Making Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Preliminary Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Wiring the Line Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Wiring Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Wiring Standard 0/4-20 mA Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

Wiring the Totalizer/Frequency Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-10

Wiring the Serial Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

Wiring an External Totalizer Reset Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14

Programming the AT868 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14

Chapter 2: Programming Site Data

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Activating a Channel [CHx-ACTIV Menu] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Accessing the ACTIV Submenu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Entering System Data [CHx-SYSTM Menu] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Accessing the CHx-SYSTM Submenu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Selecting the Volumetric Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Selecting the Totalizer Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Selecting Mass Flow Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Entering Transducer and Pipe Parameters [CHx-PIPE Menu] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Accessing the PIPE Submenu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Special Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Special Clamp-On Transducers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Pipe Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Pipe Outside Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

Path and Axial Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

Lining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Setting Up a Tracking Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Fluid Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Reynolds Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

KV Input Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

Number of Traverses and Transducer Spacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

Entering the Zero Cutoff Value [CHx-I/O Menu]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11

Activating Mass Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11

September 2004

Table of Contents (cont.)

Entering Global System Data [GLOBL-SYSTM Menu]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Selecting the GLOBL-SYSTM Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Selecting the System Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Setting Up the External Totalizer Reset Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

Selecting Mass Flow Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

Setting Up the Outputs [GLOBL-I/O Menu] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

Accessing the Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

Setting Up the Analog Output Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

Accessing the Totalizer/Frequency Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15

Setting Up a Frequency Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

Setting Up a Totalizer Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

Configuring the Communications Port [GLOBL-COMM] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

Taking Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

Chapter 3: Displaying Data

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Adjusting LCD Contrast and Brightness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Setting Up the Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Accessing the Display Submenu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Configuring the Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Resetting the Totalizers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Resetting Totalizers Using the Internal Keypad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Resetting Totalizers Using an External Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Chapter 4: Calibration

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Calibrating and Testing the Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Testing Linearity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Calibrating the Totalizer/Frequency Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Calibrating the Frequency Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Calibrating the Totalizer Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Appendix A: Menu Maps

Appendix B: Measuring P and L Dimensions

Measuring P and L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

Chapter 1

Installation

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Site Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

CE Mark Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Making Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Programming the AT868 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14

September 2004

Introduction To ensure safe and reliable operation of the AT868, the system must

be installed and programmed in accordance with the guidelines established by GE. Those guidelines are explained in detail in this chapter.

!WARNING!

Be sure to follow all applicable local safety codes and

regulations for installing electrical equipment. Consult

company safety personnel or local safety authorities to

verify the safety of any procedure or practice.

!ATTENTION EUROPEAN CUSTOMERS!

To meet CE Mark requirements, all cables must be installed

as described later in this chapter.

Site Considerations Because the relative location of the flowcell and the electronics

enclosure is important, use the guidelines in this section to plan the AT868 installation.

Electronics Enclosure Location

The standard AT868 electronics enclosure is a powder-coated aluminum NEMA 4X, IP66 weatherproof enclosure (see Figure 1-4 on page 1-15). Typically, the enclosure is mounted as close as possible to the transducers. When choosing a site, make sure the location permits easy access to the electronics enclosure for programming, maintenance and service.

Note: For compliance with the European Union’s Low Voltage

Directive (73/23/EEC), this unit requires an external power disconnect device such as a switch or circuit breaker. The disconnect device must be marked as such, clearly visible, directly accessible, and located within 1.8 m (6 ft) of the unit.

Installation 1-1

September 2004

Flowcell Location A flowcell is the section of pipe where the transducers are mounted. It

can be created either by mounting the transducers on the existing pipeline or by mounting them on a spoolpiece. A spoolpiece is a separately manufactured pipe section, matched to the existing pipe, which contains ports for mounting the transducers. A spoolpiece allows the transducers to be aligned and calibrated before inserting the flowcell into the pipeline.

Ideally, install the flowcell in a section of pipe with unlimited access, such as a long section of pipe that is above ground. However, if the flowcell must be installed in an underground pipe, dig a pit around the pipe to facilitate installation.

Transducer Location For a given fluid and pipe, the accuracy of the AT868 depends

primarily on the location and alignment of the transducers. In addition to accessibility, when planning for transducer location, follow these guidelines:

• Locate the transducers so that there are at least 10 pipe diameters

of straight, undisturbed flow upstream and 5 pipe diameters of straight, undisturbed flow downstream from the measurement point. Undisturbed flow means avoiding sources of turbulence in the fluid such as valves, flanges, expansions, and elbows; avoiding swirl; and avoiding cavitation.

• Locate the transducers on a common axial plane along the pipe.

Install the transducers on the side of the pipe instead of the top or bottom, because the top of the pipe accumulates gases and the bottom of the pipe accumulates sediment. These conditions cause attenuation of the ultrasonic signal. There is no similar restriction with vertical pipes. However, vertical pipes with downward flow should be avoided to ensure a full pipe at the measurement point.

1-2 Installation

September 2004

Cable Lengths Locate the electronics enclosure as close as possible to the flowcell,

preferably directly on the flowcell. However, GE can supply transducer cables up to 1,000 ft (300 m) in length for remote location of the electronics enclosure. If longer cables are required, consult the factory for assistance.

Transducer Cables When installing the transducer cables, always observe established

standard practices for the installation of electrical cables. Do not route transducer cables alongside high amperage AC power lines or any other cables that could cause electrical interference. Also, protect the transducer cables and connections from the weather and corrosive atmospheres.

Note: If you are using your own cables to connect the transducers to

the electronics console, they must have electrical characteristics identical to the cables supplied by GE. For transducer frequencies up to 2 MHz, the cables in each pair must be the same length within ±4 in. (±10 cm). For transducer frequencies above 2 MHz, the cables in each pair must be the same length within ±0.5 in. (±1.25 cm).

Installing a Flowcell A flowcell is the section of pipe where the transducers are mounted. It

Installation 1-3

September 2004

CE Mark Compliance For CE Mark compliance, the AT868 must meet both the EMC and

LVD directives.

IMPORTANT: CE Mark compliance is required for all units intended

for use in EEC countries.

EMC Compliance For EMC compliance, the electrical connections must be shielded and

grounded as in Tabl e 1-1 below. Also refer to Figure 1-1 on the next page an example of acceptable wiring. After all the necessary electrical connections have been made, seal any unused cable entry holes with standard conduit plugs or equivalent.

Note: If the instructions in this section are followed, the unit will

comply with the EMC Directive 89/336/EEC.

Table 1-1: Wiring Modifications

Termination

Connection Cable Type

Transducer RG62 a/u Add metallic cable clamp

Modification

from braid to chassis ground.

Armored RG62 a/u or conduit

Input/Output 22 AWG Shield

(e.g. Baystate #78-1197)

Armored conduit None - grounded via

Power 14 AWG, 3 conductor,

shielded (e.g. Belden #19364)

Armored Conduit None - grounded via

Shielding Wires enclosed in a properly-grounded metal

conduit do not require additional shielding.

Terminate RG62 a/u shield to chassis ground.

Terminate shield to chassis ground at the AT868.

cable gland. Terminate shield to

chassis ground at the AT868.

cable gland.

1-4 Installation

September 2004

LVD C omp li anc e For compliance with the European Union’s Low Voltage Directive

(73/23/EEC). the analyzer requires an external power disconnect device such as a switch or circuit breaker. The disconnect device must be marked as such, clearly visible, directly accessible, and located within 1.8 m (6 ft) of the unit.

Note: If the instructions in this section are followed, the unit will

comply with the Low Voltage Directive (73/23/EEC).

Figure 1-1: Properly Wired AT868

Installation 1-5

September 2004

Making Electrical Connections

This section contains instructions for making all the necessary electrical connections to the AT868 electronics console. Refer to Figure 1-5 on page 1-16 for a complete wiring diagram.

!ATTENTION EUROPEAN CUSTOMERS!

To meet CE Mark requirements, all cables must be installed

as described in the previous section

!WARNING!

Always disconnect the line power from the AT868 before

removing the front cover.

Preliminary Steps Before making any electrical connections, prepare the AT868 by

completing the following steps:

1. Disconnect any previously wired power line from the unit.

2. Remove the screws on the front cover.

3. Loosen the two screws and remove the plastic shroud that protects

the electrical connections.

Note: For compliance with the European Union’s Low Voltage

Directive (73/23/EEC), a transparent plastic shroud protects the electrical connections. The shroud must remain in place, except while wiring the unit. Reinstall the shroud after the wiring has been completed.

4. Install any required cable clamps in the appropriate conduit holes on the bottom of the enclosure.

5. Note the labels inside the enclosure to assist in wiring.

Proceed to the appropriate section of this chapter to make the required wiring connections.

1-6 Installation

September 2004

Wiring the Line Power The AT868 may be purchased for operation with power inputs of

85-265 VAC or 12-28 VDC. The label on the side of the electronics enclosure lists the required line voltage and power rating. The fuse rating is listed on label located under the fuse.

IMPORTANT: Be sure to connect the meter only to the specified line

voltage.

Note: For compliance with the European Union’s Low Voltage

Refer to Figure 1-5 on page 1-16 to locate the power input terminal block and connect the line power as follows:

!WARNING!

Improper connection of the line power leads or connecting

the meter to the incorrect line voltage may damage the

unit. It may also result in hazardous voltages at the

flowcell and associated piping as well as within the

electronics enclosure.

1. Prepare the line power leads by trimming the line and neutral AC

power leads (or the positive and negative DC power leads) to a length 0.5 in. (12 mm) shorter than the ground lead. This ensures that the ground lead is the last to detach if the power cable is forcibly disconnected from the meter.

2. Install a suitable cable clamp in the conduit hole where the line power wires will enter the enclosure. If possible, avoid using a conduit hole containing any other cables cables, to minimize any interference in the circuitry from the AC power line.

3. Strip 1/4-in. of insulation from the end of each of the three line power leads.

4. Route the cable through the conduit hole and connect the line power leads to the power terminal block as shown in Figure 1-5 on page 1-16.

Installation 1-7

September 2004

Wiring the Line Power

5. Leaving a bit of slack, secure the power line with the cable clamp.

(cont.)

Caution!

Do not apply power to the AT868 until after the

transducers have been properly wired.

6. Do one of the following:

• Proceed to another section to continue wiring the AT868.

• Reinstall the plastic shroud, replace the front cover on the

enclosure and tighten the screws.

Wiring Transducers !WARNING!

Before connecting the transducers, discharge any static

buildup by shorting the center conductor of the transducer

cables to the metal shield on the cable connector.

Note: For transducer frequencies below 2 MHz, the cable lengths

must be within ±4 in. (±10 cm) of each other. If the transducer frequency exceeds 2 MHz, the cable lengths must be within ±0.5 in. (±1.25 cm) of each other.

1. Locate the CH1 transducer cables and connect them to the two CH1 transducers. Route the free ends of the cables through the selected conduit hole in the electronics enclosure.

2. If an optional lightening protector is being installed, connect it between the meter and the transducers.

3. Refer to the wiring diagram in Figure 1-5 on page 1-16 and connect the transducer cables to the terminal block labeled DN and

UP for Channel 1. Then, secure the cable clamp.

Note: The RED cable leads are the SIG(+) leads and the BLACK

cable leads are the RTN(-) leads.

Note: The AT868 can use two channels or paths to make more

accurate flow measurements by averaging, subtracting or adding the the two readings.

1-8 Installation

September 2004

Wiring Transducers (cont.) 4. For a 2-Channel AT868, repeat steps 1-3 to connect the CH2

transducers to the DN and UP terminal block for Channel 2.

Wiring Standard 0/4-20 mA Analog Outputs

Note: It is not

connected.

5. Do one of the following:

required that both channels of a 2-Channel unit be

• Proceed to another section to continue wiring the AT868.

• Reinstall the plastic shroud, replace the front cover on the

enclosure and tighten the screws.

IMPORTANT: Each channel must be activated before it can begin

taking measurements. See Chapter 2, Programming

Site Data, for instructions.

The AT868 has one isolated 0/4-20 mA analog output per channel (designated as Output A and Output C). These outputs can be configured independently. Typically, Output A is used for Channel 1 and Output C is used for Channel 2. However, either analog output can be configured for use with either channel.

Connections to the analog outputs may be made with standard twisted-pair wiring, but the current loop impedance for these circuits must not exceed 600 ohms. To wire the analog outputs, complete the following steps:

1. Refer to Figure 1-5 on page 1-16 for the locations of the

appropriate terminal blocks and wire the analog outputs as shown. Then, secure the cable clamp.

IMPORTANT: Outputs 1 and 2 in the wiring diagram correspond to

Outputs A and C in the AT868 software.

2. Do one of the following:

• Proceed to another section to continue wiring the AT868.

• Reinstall the plastic shroud, replace the front cover on the

enclosure and tighten the screws.

IMPORTANT: Prior to use, the analog outputs must be calibrated as

described in Chapter 4, Calibration.

Installation 1-9

September 2004

Wiring the Totalizer/Frequency Output

The AT868 also provides a second output for each channel (designated as Output B and Output D) that can be configured as a totalizer or frequency output using the Instrument Data Manager (IDM) software. These outputs can be configured independently. Typically, Output B is used for Channel 1 and Output D is used for Channel 2. However, either output can be configured for use with either channel.

Figure 1-2 below shows a wiring diagram for a typical totalizer or frequency output circuit.

Model AT868 Pulse/Frequency Counter

+5V

200

OUT

RTN

Figure 1-2: Totalizer/Frequency Output Wiring

Common

!WARNING!

NEVER CONNECT EXTERNAL POWER TO THE

PULSE/FREQUENCY OUTPUT TERMINALS.

To wire the totalizer/frequency outputs, complete the following steps:

1. Refer to Figure 1-5 on page 1-16 for the location of the terminal blocks and wire the totalizer/frequency outputs as shown. Then, secure the cable clamp.

Note: Outputs 1 and 2 in the wiring diagram correspond to Outputs

B and D in the AT868 software.

2. Do one of the following:

• Proceed to another section to continue wiring the AT868.

• Reinstall the plastic shroud, replace the front cover on the

enclosure and tighten the screws.

1-10 Installation

September 2004

Wiring the Serial Port The AT868 is equipped with a built-in serial communications port.

The standard port is an RS232 interface, but an optional RS485 interface is available upon request. Proceed to the appropriate section for wiring instructions.

Wiring an RS232 Interface Use the serial port to connect the AT868 to a printer, an ANSI

terminal or a personal computer. The RS232 interface is wired as Data Terminal Equipment (DTE), and the signals available at the COMMUNICATION terminal block are shown in Table 1-2 below.

To wire the RS232 output, complete the following steps:

1. Use the information in Tabl e 1-2 below to construct a suitable

cable for connecting the AT868 to the external device. If desired, an appropriate cable may be purchased from GE.

Table 1-2: RS232 Connection to DCE or DTE Device

COMMUNICATION

5WhiteDTR (Data

Colors for

GE Cable

(flying leads)*

Signal

Description

Terminal Ready)

DCE DB25 Pin #

20 4 20 4

DCE DB9

Pin #

DTE DB25 Pin #

DTE DB9

Pin #

4 Yellow CTS

(Clear to Send) 3 Green COM (Ground)7575 2 Red RX (Receive)2332 1 Black TX (Transmit)3223

*For standard GE cables 704-659, -660, -661 and -662.

Note: Signal names that imply direction (e.g., transmit and receive)

are named from the point of view of the DTE device (the GE meter is usually considered the DTE device). When the RS232 standard is strictly followed, these signals are labeled with the same name and pin # on the DCE device side. Unfortunately, the convention is not followed because the DTE and DCE side get confused. Therefore, connections that imply direction are changed to reflect their direction on the DCE side.

4758

Installation 1-11

September 2004

Wiring an RS232 Interface (cont.)

2. Route the flying leads end of the cable through the conduit hole and wire the leads to the COMMUNICATION terminal block as shown in Figure 1-5 on page 1-16. Connect the other end of the cable to the printer, ANSI terminal or personal computer. Then, secure the cable clamp.

3. Do one of the following:

• Proceed to another section to continue wiring the AT868.

• Reinstall the plastic shroud, replace the front cover on the

enclosure and tighten the screws.

Note: Consult the User’s Manual for the external device to configure

it for use with the AT868.

Wiring an RS485 Interface Use the optional RS485 serial port to network multiple AT868 flow

transmitters to a single computer terminal. Upon request, the standard RS232 port on the AT868 may be configured as a two-wire, half-duplex RS485 interface, through a device such as the INMAC Model 800052 RS232-RS422/RS485 converter.

Note: If the AT868 is configured at the factory for RS485 operation,

the INMAC converter is not necessary.

Proceed to the appropriate following section to wire the RS485 interface.

1-12 Installation

September 2004

Using an INMAC Converter To wire the RS485 serial port using an INMAC converter, refer to

Figure 1-5 on page 1-16 and complete the following steps:

1. Route one end of the cable through the conduit hole and wire the leads to the COMMUNICATION terminal block as shown in Figure 1-5 on page 1-16. Then, secure the cable clamp.

2. Connect the other end of the cable to the converter, as shown in Figure 1-3 below.

3. Do one of the following:

• Proceed to another section to continue wiring the AT868.

• Reinstall the plastic shroud, replace the front cover on the

enclosure and tighten the screws.

Model AT868

Using a Factory Serial Interface

N.C. 5

N.C. 4 1 TD OUT

N.C. 3 2

RX 2 3

TX 1

Figure 1-3: Typical RS485 Connections

Use the following steps to link the AT868 to the control system using a factory-installed RS485 serial interface:

1. Route the wires through the conduit hole and connect the TMT+ lead to Pin 2 (RX) on the COMMUNICATION terminal block (see Figure 1-5 on page 1-16).

2. Connect the TMT- lead to Pin 1 (TX) on the COMMUNICATION terminal block. Then, secure the cable clamp.

3. Connect the other end of the cable to the control system.

4. Do one of the following:

Converter

4 RD IN

• Proceed to another section to continue wiring the AT868.

• Reinstall the plastic shroud, replace the front cover on the

enclosure and tighten the screws.

Installation 1-13

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