Spirax Sarco TVA Series, TVA DN100, TVA DN80, TVA DN50 Installation And Maintenance Instructions Manual

1920050/2

IM-P192- 02

TVA Flowmeter

for Saturated and Superheated Steam Service

Installation and Maintenance Instructions

1. Safety information

MI Issue 2

2. General product
information

3. Installation

4. Commissioning

5. Maintenance

6. Spare parts

7. Fault finding

8. Settings table

IM-P192-02 MI Issue 2 1

© Copyright 2016

Printed in GB

Certain computer programs contained in this product [or device] were developed
by Spirax-Sarco Limited ('the Work(s)').

Copyright © Spirax-Sarco Limited 2016

All rights reserved

Spirax-Sarco Limited grants the legal user of this product (or device) the right to
use the Work(s) solely within the scope of the legitimate operation of the product
(or device). No other right is granted under this licence. In particular and without
prejudice to the generality of the foregoing, the Work(s) may not be used, sold,
licensed, transferred, copied or reproduced in whole or in part or in any manner
or form other than as expressly granted here without the prior written consent of
Spirax-Sarco Limited.

1. Safety information

Safe operation of this unit can only be guaranteed if it is properly installed,
commissioned and maintained by a qualified person (see Section 1.11) in compliance
with the operating instructions. General installation and safety instructions for
pipeline and plant construction, as well as the proper use of tools and safety
equipment must also be complied with.

Manufacturer:-

Spirax Sarco Ltd
Charlton House
Charlton Kings
Cheltenham
Glos
GL53 8ER

The product is designed and constructed to withstand the forces encountered
during normal use.

Use of the product for any other purpose, or failure to install the product in

accordance with these Installation and Maintenance Instructions, could cause

damage to the product, will invalidate the marking, and may cause injury or

fatality to personnel.

IM-P192-02 MI Issue 22

EMC directive

The product complies with the Electromagnetic Compatibility Directive
2004 / 108 / EC. A technical file with a reference number of 'UK Supply TVA flowmeter'
supports the Spirax Sarco claim that the product complies with the requirements of
the Directive and the product can be used in Class A (heavy industrial) and Class B
(domest ic / commercial areas).

The following conditions should be avoided as they may create interference above
the heav y industrial limits if:

The product or its wiring is located near a radio transmitter.

-

Cellular telephones and mobile radios may cause interference if used within

-

approximately 1 metre (39") of the product or its wiring. The actual separation
distance necessary will vary according to the surroundings of the installation
and the power of the transmitter.

If this product is not used in the manner specified by this IMI, then the protection
provided may be impaired.

1.1 Intended use

Referring to the Installation and Maintenance Instructions, name-plate and Technical
Information Sheet, check that the product is suitable for the intended use / application.

The product listed complies with the requirements of the European Pressure

Equipm ent Direc tive 97 / 23 / EC, car ries the mark when so required.

The product falls within the following Pressure Equipment Directive categories:

Product

TVA flowmetering
system

i) The product has been specifically designed for use on saturated and superheated

steam only which is in Group 2 of the above mentioned Pressure Equipment
Directive.

ii) Check material suitability, pressure and temperature and their maximum and

minimum values. If the maximum operating limits of the product are lower than
those of the system in which it is being fitted, or if malfunction of the product
could result in a dangerous overpressure or overtemperature occurrence, ensure
a safety device is included in the system to prevent such over-limit situations.

iii) Determine the correct installation situation and direction of fluid flow.

iv) Spirax Sarco products are not intended to withstand external stresses that may

be induced by any system to which they are fitted. It is the responsibility of the
installer to consider these stresses and take adequate precautions to minimise
them.

v) Remove protection covers from all connections and protective film from all name-

plates, where appropriate, before installation on steam or other high temperature
applications.

IM-P192-02 MI Issue 2 3

DN50 to DN100 - 1 - -

Group 1

Gases

Group 2

Gases

Group 1

Liquids

Group 2

Liquids

1.2 Access

Ensure safe access and if necessary a safe working platform (suitably guarded)
before attempting to work on the product. Arrange suitable lifting gear if required.

1.3 Lighting

Ensure adequate lighting, particularly where detailed or intricate work is required.

1.4 Hazardous liquids or gases in the pipeline

Consider what is in the pipeline or what may have been in the pipeline at some
previous time. Consider: flammable materials, substances hazardous to health,
extremes of temperature.

1.5 Hazardous environment around the product

Consider: explosion risk areas, lack of oxygen (e.g. tanks, pits), dangerous gases,
extremes of temperature, hot surfaces, fire hazard (e.g. during welding), excessive
noise, moving machinery.

1.6 The system

Consider the effect on the complete system of the work proposed. Will any proposed
action (e.g. closing isolation valves, electrical isolation) put any other part of the
system or any personnel at risk?
Dangers might include isolation of vents or protective devices or the rendering
ineffective of controls or alarms. Ensure isolation valves are turned on and off in a
gradual way to avoid system shocks.

1.7 Pressure systems

Ensure that any pressure is isolated and safely vented to atmospheric pressure.
Consider double isolation (double block and bleed) and the locking or labelling of
closed valves. Do not assume that the system has depressurised even when the
pressure gauge indicates zero.

1.8 Temperature

Allow time for temperature to normalise after isolation to avoid the danger of burns
and consider whether protective clothing (including safety glasses) is required.

1.9 Tools and consumables

Before starting work ensure that you have suitable tools and / or consumables
available. Use only genuine Spirax Sarco replacement parts.

1.10 Protective clothing

Consider whether you and /or others in the vicinity require any protective clothing to
protect against the hazards of, for example, chemicals, high / low temperature,
radiation, noise, falling objects, and dangers to eyes and face.

IM-P192-02 MI Issue 24

1.11 Permits to work

All work must be carried out or be supervised by a suitably competent person.
Installation and operating personnel should be trained in the correct use of the product
according to the Installation and Maintenance Instructions.
Where a formal 'permit to work' system is in force it must be complied with. Where
there is no such system, it is recommended that a responsible person should know
what work is going on and, where necessary, arrange to have an assistant whose
primary responsibility is safety.
Post 'warning notices' if necessary.

1.12 Handling

Manual handling of large and /or heavy products may present a risk of injury. Lifting,
pushing, pulling, carrying or supporting a load by bodily force can cause injury
particularly to the back. You are advised to assess the risks taking into account the
task, the individual, the load and the working environment and use the appropriate
handling method depending on the circumstances of the work being done.

1.13 Residual hazards

In normal use the external surface of the product may be very hot. If used at the
maximum permitted operating conditions the surface temperature of some products
may reach temperatures of 250 °C (482 °F).
Many products are not self-draining. Take due care when dismantling or removing the
product from an installation (refer to 'Maintenance instructions').

1.14 Freezing

Provision must be made to protect products which are not self-draining against frost
damage in environments where they may be exposed to temperatures below freezing
point.

1.15 Disposal

Unless otherwise stated in the Installation and Maintenance Instructions, this product
is recyclable and no ecological hazard is anticipated with its disposal providing due
care is taken.

1.16 Returning products

Customers and stockists are reminded that under EC Health, Safety and Environment
Law, when returning products to Spirax Sarco they must provide information on
any hazards and the precautions to be taken due to contamination residues or
mechanical damage which may present a health, safety or environmental risk. This
information must be provided in writing including Health and Safety data sheets
relating to any substances identified as hazardous or potentially hazardous.

IM-P192-02 MI Issue 2 5

2. General product information

T h i s ma n ua l ex pl a in s how to i n s t a l l , co m m i s s i on an d ma in t ai n the S p ir a x Sarc o T V A  o w m e t e r

for use on saturated and superheated steam.

2.1 Product description

The Spirax Sarco T VA owmeter is designed to reduc e the cost of owmetering and is used
as an accurate means to measure steam owrates and record total ow.
For satur ated steam installati ons the T VA ow meter is a stand alone device and requires no
o t h er e qui p m en t, s u c h as d i f fe r e n t ial p res s u re t ra n s m it te r s , p res s u r e se n s o rs, e tc . to c al cu l a t e
mass owrates of saturated steam.
With superheated steam installations, the addition of the pressure sensing kit is required to
ena b le mas s owra t es to be me asu r ed whe r e the re l ati o n bet w e en pr e s sur e and tem p era t ure
has been lost (steam saturation curve).

2.2 Equipment delivery and handling

Factory shipment

Prior to shipment, the Spirax Sarco TVA owmeter is tested, calibrated and inspected to

ensure proper operation, including the wired communications.

Receipt of shipment

Each carton should be inspected at the time of delivery for possible external damage. Any
visible damage should be recorded immediately on the carrier’s copy of the delivery slip.

Each car ton should be unpacked carefully and its contents checked for damage.

I f i t is f oun d t h a t so me i te ms h a ve bee n d a m ag ed o r ar e m i s si n g , not i f y S p ir ax S ar co i mm ed i a t el y
and provide full details. In addition, damage must be reported to the carrier with a request

for their on-site inspection of the damaged item and its shipping carton.

Storage

If a o wme ter is to be stor ed pr ior to ins t al lat ion , the envi ron menta l sto r ag e cond iti ons shou ld
be at a temperature between 0 °C and 55 °C (32 °F and 131 °F), and between 10% and 90 %
relative humidity (non- condensing).

2.3 Sizes and pipe connections

DN50, DN80 and DN100

The TVA owmeter is of a wafer design, suitable for tting between the following anges:
EN 1092 PN16, PN25 and PN40

BS 10 Table H
ASME B 16.5 Class 150 and 300
Korean Standard KS 20.

IM-P192-02 MI Issue 26

* Sensor cable

* 'U' syphon assembly

* Pressure sensor

Earth
cable

¼"

NPSM

boss

Earth
cable

TVA owmeter body

F

l

o

w

Flowmeter stem

* Items required for superheat operation

Fig. 1 TVA flowmeter

IM-P192-02 MI Issue 2 7

Electronics housing

2.4 Pressure / temperature limits

Pressure psi g

Steam
saturation

curve

Temperature °C

Pressure bar g

The product should not be used in this region due to the limitations of the software.

Temperature °F

Maximum allowable

PMA

pressure @ 239 °C (462 °F)

TMA Maximum allowable temperature 239 °C (462 °F)

Minimum allowable temperature 0 °C (non-freezing) (32 °F non-freezing)

Maximum
operating

PMO

pressure for
saturated

steam service

Minimum operating pressure 0.6 bar g (8.7 psi g)

TMO Maximum operating temperature 239 °C (462 °F)

Minimum operating temperature 0 °C (non-freezing) (32 °F non-freezing)

Maximum electronics ambient temperature 55 °C (131 °F)

Maximum electronics humidity level 90% RH (non-condensing)

Maximum
differential

PMX

pressure

Cold hydraulic test pressure of: 52 bar g (754 psi g)

Horizontal

ow

Vertical

ow

The pressure drop across the TVA owmeter at the maximum
rated ow is nominally 750 m bar (300 inches wg) for the DN50,
and 500 m bar (200 inches wg) for the DN80 and DN100

Saturated steam 32 bar g (464 psi g) otherwise as

Superheated
steam

Saturated
steam

Saturated
steam only

23 bar g @ 239 °C (333 psi g @ 462 °F)

32 bar g @ 239 °C (464 psi g @ 462 °F)

7 bar g @ 170 °C (101 psi g @ 338 °F)

the specied ange rating

*

IM-P192-02 MI Issue 28

High pressure syphon tube assembly

Maximum design pressure 80 bar g (1 160 psi g)

Maximum design temperature 450 °C (842 °F)

Maximum working conditions 60 bar g @ 450 °C (870 bar g @ 842 °F)

Pressure sensing kit

Maximum operating temperature 125 °C (257 °F)

Minimum operating temperature 0 °C (non-freezing) (32 °F non-freezing)

Maximum operating pressure 50 bar g (725 psi g)

Maximum ambient temperature

(cable+connector)

Important note

*

CAUTION:
If the electronic housing is mounted at
an angle of more than 45° from the
vertically downward position the PMO
(maximum operating pressure) must
be limited to 7 bar g (101 psi g) and
saturated steam applications only.

70 °C (158 °F)

Limited to

7 bar g (101 psi g)

and

saturated steam

applications

only

The electronic housing must be
mounted vertically downward for all
superheated applications.

Fig. 2 Installation limiting conditions

IM-P192-02 MI Issue 2 9

For saturated steam

applications

over 7 bar g (101 psi g)

to 32 bar g (464 psi g) and all

superheated applications up to

23 bar g (333.5 psi g).

2.5 Technical data

IP rating IP65 with correct cable glands.

Power supply Loop powered nominal 24 Vdc

4-20 mA (proportional to mass ow)

Outputs

Communication port

Performance

System uncertainty to ISO 17025

(95% condence to 2 STD)

Pulsed output V

R

10 kW, Von 0.7 V

min

EIA 232C 15 m limit - See Section 4.12

RS485 for longer distances
(conversion from RS232)

±2% of reading over the range of 10%
to 100% of maximum rated ow

±0.2% FSD from 2% to 10% of
maximum rated ow

Turndown: up to 50:1

28 Vdc,

max

max

2.6 Electrical connections

Electrical connections M20 x 1.5

2.7 Materials

Unit Part Material

Flowmeter body Stainless steel S.316 1.4408 CF8M

Internals 431 S29 / S303 / S304 / S316

TVA

Pressure
sensing kit

High pressure
syphon tube
assembly

Spring Inconel X750 or equivalent

Flowmeter stem Stainless steel 300 series

Electronics housing Aluminium LM25

Cable Polyvinyl chloride (PVC)

Sensor housing AISI 304 Stainless steel 1.4301

Sensor AISI 630 Stainless steel 1.4542

'O' ring Nitrile Butadiene Rubber (NBR)

Adaptor AISI 431 Stainless steel 1.4057

Tub e

Body Carbon steel

Valve

Seat PEEK/ Polymain

Carbon steel BS 3602: Part.1 1987 CFS 360
(zinc plated / passivated).

IM-P192-02 MI Issue 210

2.8 Dimensions/weights (approximate) in mm and kg

Size A Flowmeter ODC D E F G X Weight

TVA Superheat

DN50 35 103 322 125 65 250 160 300 2.67 0.3 0.5

DN80 45 138 334 11 5 65 270 160 300 4.38 0.3 0.5

DN100 60 162 344 155 65 280 160 300 7. 2 8 0.3 0.5

Note: Dimension 'X' is a recommended minimum distance between the pressure tapping

and the flowmeter. However it can be installed at any distance provided the cable allows
(Standard cable length is 1 m).

X

kit

A

D

'U'

syphon

Any free hanging cable must be

Caution:

secured to prevent contact with the

Fig. 3

steam pipe.

F

G

C

E

IM-P192-02 MI Issue 2 11

3. Installation

Note: Before actioning any installation observe the 'Safety information' in Section 1.

To meet its specified accuracy and performance it is essential that the following installation
guidelines are followed carefully. For steam applications sound steam engineering practices
should be followed, including the use of separators. The installation must conform to all

relevant construction and electrical codes.

Limited to

7 bar g (101 psi g)

and

saturated steam

applications

only

CAUTION:
If the electronic housing is mounted
at an angle of more than 45° from the
vertically downward position the PMO
(maximum operating pressure) must
be limited to 7 bar g (101 psi g) and
saturated steam applications only.

The electronic housing must be
mounted vertically downward for all
superheated applications.

Fig. 4 Installation limiting conditions

For saturated steam

applications

over 7 bar g (101 psi g)

to 32 bar g (464 psi g) and all

superheated applications up to

23 bar g (333.5 psi g).

A by pa ss line wil l enabl e sa fe removal of the TVA o wm eter for ma in te nance or calib ra tion.
Closing valves V1 and V2 and opening va lve V3 wil l al low the TVA owmete r to be is ol ated

for re-zeroing (temperature to be <20 °C).

V3

Strainer

Steam

Separator

Tra p se t

Fig. 5 Typical installation

V1

TVA

owmeter with

Superheat kit

tted

V2

Spool

piece

IM-P192-02 MI Issue 212

3.1 Environmental conditions

The owmeter should be located in an environment that minimises the effects of heat,
vibration, shock and electrical interference. (Pressure / temperature limits are detailed in
Section 2.4).

CAUTION: Do not lag (insulate) the TVA flowmeter or mating flanges as this may result
in excessive temperatures in the electronics. Exceeding specified temperature limits
will invalidate the warranty, adversely effect the performance and may damagethe TVA
flowmeter, see Figure 6.

Do not

insulate the anges of the TVA owmeter

Flow

Fig. 6 Pipeline insulation

Other considerations

Be sure to allow sufcient clearance for:

-

Installation of conduit / wiring.

Removal of the electronics enclosure cover.

-

Viewing of the display. Note electronics housing and display can be rotated.

-

Do not allow the earth cable to touch the steam pipe or damage to the sheath will occur.

-

Tie up any loose (excess) cable.

Warning: Do not install the flowmeter outdoors where it can be subjected to adverse
weather conditions like driving rain or where it can freeze.

IM-P192-02 MI Issue 2 13

3.2 Mechanical installation

Warning: Do not alter the adjustment nut at the back of the TVA flowmeter shaft, as
this will affect the flowmeters calibration.

Orientation

The TVA owmeter can be installed in any orientation when used on saturated steam
applications and when the pressure is below 7 bar g (101 psi g), see Figures 7, 8 and 9.
When the pressure is above 7 bar g (101 psi g) or used on a superheated steam application
the T VA owmeter must be installed in a hor izontal pipe, with the electronics housing below
the body, see Figure 9.
Note: The TVA owmeter operates with ow in one direction only. It is not intended for use
with bi-directional ow. The TVA owmeter is clearly marked with a direction of ow arrow.

Fig. 7
Vertical flow limited
to 7 bar g (101 psi g)
and saturated steam
applications only

Caution: If the electronic housing is
mounted at an angle of 45° (or more) from
the vertically downward position the PMO
(maximum operating pressure) must be
limited to 7 bar g (101 psi g) and saturated
steam applications only.

The electronic housing must be mounted
vertically downward for all superheated
applications.

Flow

Flow

Flow

Horizontal flow limited to 7 bar g (101 psi g)

and saturated steam applications only

Fig. 8

IM-P192-02 MI Issue 214

Note: The 'U' syphon and pressure sensor
must be used for superheated steam
applications.

Rotating the electronics enclosure

The electronics housing can be rotated 270° to

enable sufcient clearance for installation. To

rotate the electronic s housing, loosen the 6 mm
grub scr ew located on the re ar of the electro nics

housing (see Figure 10). The electronics housing
can now be rotated to the required position.

When the el ectronics h ousing has been loc ated
into the co rrect positi on retighten the gr ub screw

to a torque of 1.3 N m (11.5 lbf in).

Flow

Fig. 9

Horizontal flow up to

32 bar g (464 psi g)

for saturated steam applications

and

23 bar g

(333.5 psi g)

for superheated steam applications

Warning: Do not loosen / remove the stem
from the main body of the unit.

Warning: Do not loosen /
remove the stem from the
main body of the unit.

6 mm grub screw

Earth

Fig. 10

IM-P192-02 MI Issue 2 15

cable

Rotating the electronics front panel

To rotate the electronics front panel loosen the four retaining screws and rotate the front

panel to the orientation, required.

Note: Take care not to damage or strain any of the wiring.

Retaining screws Retaining screws

A B C D

For applications with

st ea m ab ov e 7 ba r g

and all superheated
applications.

Note:

Fitting the TVA
in this orientation

when the RS485

board is fitted
ensures that the
display can be read
easily.

For vertical flow applications. For saturated steam

applications below
7 bar g.

Upstrea m / downstream p ipework

Th e T VA ow me te r shoul d be inst al le d in pi pe wo rk ma nu fa ctured to BS 16 0 0, ASME B 36.10
Schedule 40 or EN 10216-2 / EN 10216-5 equivalent, which corresponds to the following
pipeline internal diameters:

For dif ferent pipe standards / schedules,
if th e ow meter is bei ng op erate d at th e

extreme of its published maximum
range, and maximum accuracy is

required, downstream spool pieces
manufactured from pipe to the above

standard should be used.
It is impor tant that the internal upstream and downstream diameters of pipe are smooth.

Ideally seamless pipes should be used and there should be no intrusive weld beads on the
int ernal diameter. It is recommende d that slip -on a nges be used to avoid any intr usive weld

beads on the internal diameter of the pipe.
Note: See Figures 11 to 14 for other considerations which need to be noted before
determining the correct installation location.

Nominal diameter Nominal internal diameter

50 mm 52 mm

80 mm 77 mm

100 mm 102 mm

IM-P192-02 MI Issue 216

The TVA flowmeter normally

onl y req uir es a mini mum of 6

pipe diameters upstream and
3 downstre am of clear straig ht
pipe. These dimensions
assume a measurement

from a single 90° bend (see
Figure 11).

6D Minimum
6D Minimum

3D Minimum
3D Minimum

Flow

Fig. 11

If any of the following congurations are present upstream of the TVA owmeter:

Two right angled bends in two planes.

-

Pressure reducing valve.

-

Partly open valve.

-

Then it is recommended that the minimum upstream clear pipework is doub led to 12 diameters

(See Figure 12).

12D Minimum

3D Minimum

Note: The 'U' syphon
and pressure sensor
must be used for
superheated steam
applications.

Note: The 'U' syphon and

Flow

Fig. 12

IM-P192-02 MI Issue 2 17

pressure sensor must be used for
superheated steam applications.

Avoid installing the TVA owmeter downstream of an actuated valve as rapid cycling of
the valve could give rise to inaccurate results or damage the flowmeter. See Figure 13. In
configurations where there is more than one rapid acting pressure reducing valve close
coupled, the TVA owmeter should be installed with a minimum of 25 upstream and 3
downstream pipe diameters away from the valves.
Safety valves should also be as far away as possible from the flowmeter - at least 25D.

25D

Minimum

3D

Minimum

Flow

Fig. 13

Note: The 'U' syphon and

pressure sensor must be
used for superheated steam
applications.

IM-P192-02 MI Issue 218

To install the TVA owmeter pipeline unit into existing pipework and for aiding possible
flowmeter removal, a spool piece can be fabricated locally to the dimensions given below
(see Figure 14).

Size DN50 DN80 DN100

Flow

Fig. 14

Dimension A

180 mm 240 mm 300 mm

7.1 in 9.5 in 11. 8 i n

A

Spool piece

Note: The 'U' syphon and

pressure sensor must be
used for superheated steam
applications.

IM-P192-02 MI Issue 2 19

Location in pipework

Bolt ring gaskets having the same internal diameter of the pipework are recommended.
This will prevent possible inaccuracies being created by the gasket protruding into the pipe.

It is import ant that the TVA ow meter is located centrally in the pipework as any eccentricity
may ca use in ac cur at e re adings. The TVA owmeter has int eg ral cen te ring webs, wh ic h loc ate
on the internal diameter of the pipework (see Figure 15).

Integral centering webs

Integral centering webs

Earth cable

Fig. 15 Integral centering webs

Note: The 'U' syphon and

pressure sensor must
be used for superheated
steam applications.

Fig. 16 Gaskets fitted correctly

IM-P192-02 MI Issue 220

Fig. 17 Gaskets fitted incorrectly

Fig. 18 Gaskets and pipe offline, fitting incorrectly

IM-P192-02 MI Issue 2 21

3.3 Fitting the pressure sensor for superheated steam applications

To operate the TVA flowmeter on superheated steam the pressure sensor must be installed

upstream of the actual flowmeter. This is to give full density compensation and allow the

amount of superheat to be calculated.

A ¼" NPS M boss wi ll be re qu ired on the pip e fo r th e conne ct ion of the 'U ' sy ph on and pres su re

sensor. It should be sited as close to the upstream flange as practicably possible (see Figure

19, and take into account dimension 'X' in Section 2.8).

Note: The TVA must only be used for superheated steam application, when the pipe is in a
horizontal plane.

* Sensor cable

* 'U' syphon assembly

* Pressure sensor

Earth
cable

¼"

NPSM

boss

Earth
cable

TVA owmeter body

F

l

o

w

Flowmeter stem

* Items required for superheat operation

Fig. 19 TVA flowmeter

Electronics housing

IM-P192-02 MI Issue 222

3.4 Electrical installation

The TVA owmeter is a loop powered device. Thi s Sec tion describes loop wiring and shows
typical conductor terminations (The EIA 232C (RS 232) wiring is discussed in Section 4.11,
page 41). It also considers the effect of connecting additional equipment (e.g. recorder, loop
powered display) to the loop, plus the pressure sensor connection.

Wiring the TVA flowmeter

The wiring terminals can be accessed by removing the end cap of the enclosure. A typical

loop wiring diagram is shown in Figure 20.

If an M75 0 display unit is purchased from Spir ax Sarco for use with the TVA ow meter, the
M750 must be congured to the ow of the T VA owmeter @ 20 mA. If the T VA owmeter
4 - 20 mA output is rescaled (see Section 4.6.1), it is important that the 20 mA input valve

on the M750 is also rescaled.

Recommendations:

Ensure the provided EMC gland is used to connect the wiring to the electronics housing.

-

When using the RS232/485 port, PVC covered steel conduit should be used.

-

All cables that run through conduit should be screened. The screens must be earthed at

-

the far end of the installation and not at the owmeter.

If using the loop and switch pulse ports:

-

- Either combine both por t outputs to one screened four core cable which is terminated
with an EMC gland.

-or, use exible conduit as described above.

Notes:

The flowmeter must be earthed. The TVA is supplied with a 350 mm earthing lead
attached to a 4 mm threaded hole at the rear of the enclosure close to the 20 mm
conduit holes.

Remove the silica gel from the enclosure after commissioning.

When connecting the superheat kit to the TVA, the cable from the pressure sensor
must be threaded through the 20 mm conduit hole on the rear of the electronics housing.

Plug the connector on to the pin header (as indicted in Figure 20) making sure that the
blanking pin is aligned correctly with the missing pin on the plug.

Refit the end cap ensuring that no wires are crushed and tighten the cable gland
to 13 N m (9.58 lbf ft) to ensure an IP65 seal.

IM-P192-02 MI Issue 2 23

EIA 232 (RS 232)

Communication port

(RJ11 socket)

Superheat pressure sensor
pin header connection

M750 display unit

with 4-20 mA active

input (supplying

current loop)

1

2

N

-

3

L

4

+

5

Remote NPN input

(maximum 28 V)

Power

R

0 Volts

Pulse Loop

+ - +-

Or R  10 k W

Power

+

R

0 Volts

Remote PNP input

(maximum 28 V)

Fig. 20 TVA with EIA 232 (RS232) Communications and 4-20mA wiring diagram.

9 - 28 Vdc

-

Loop powered
4-20 mA
display unit or
chart recorder

230 V
50 Hz

Fuse 1A

IM-P192-02 MI Issue 224

Note: Do not reconnect loop
power supply to these terminals

when RS485 board fitted.

-

Power supply 24 Vdc (19 - 28v) 50 mA maximum

+

GND data

B - data

A + data

Fig. 21 TVA with EIA 485 (RS485) Communications wiring diagram

IM-P192-02 MI Issue 2 25



Power supply requirements

A no minal 24 Vdc is nee de d to power th e flo wm et er. However, th e T VA owme te r wi ll oper at e

correctly as long as the power supply is in the range shown in Figure 20. A single, stand-

al one, supply may be capab le of powerin g se ve ra l trans mi tters . It can be mou nt ed in a con trol
room or in the fie ld, but cannot be on the same loop. Follow the power supply manuacturer’s
recommendations with regard to mounting and environmental considerations.
The graph (Figure 22) shows the range of power supply voltages and loop resistances over
which the TVA owmeter is cap able of operati ng. The loop resistan ce inc lu des all the wiring.

TVA owmeter

operating range

V = 0.022R + 6
9 V  V  28 V

R (ohms)



Fig. 22



V (volts)





Cable length

Generally the maximum cable length between the TVA owmeter and the power supply is
300 m (984 ft).
However the actual cable length is governed by the number of network devices, the total

resistance of the network and the cable capacitance.
Suggested cable type: for both loop and pulse should be shielded twisted pairs, each core,

seven stranded wire with cross sectional area of 0.5 mm².
EMC cable glands suitable for M20 x 1.5 to EN 50262 / IP68 are recommended.
The cable gland / body torque setting is 13 N m (9.58 lbf ft).
The gland nut torque setting (with cable fitted) is 12 N m (8.85 lbf ft).

IM-P192-02 MI Issue 226

4. Commissioning

total

power

After all mechanical and electrical work
has been completed, the following
commissioning instructions should be
followed.

The TVA flowmeter should
be commissioned with the
flow through the unit
isolated.

Note: The TVA owmeter is

factory set to display data in
metric units. To commission
the TVA to diplay imperial
units see Section 4.4.2.

Mounting screws

Fig. 23 TVA flowmeter display unit

All commissioning is carried out through the display unit installed behind the front end
cap of the T VA flowmeter enclosure. The display unit consists of a small LCD display and
a 5 button key pad.

As all the co mmissio ni ng sett in gs are stor ed in a non -v ol at ile mem or y, it is poss ib le to con ne ct
a 9 V PP3 battery to the TVA owmeter's 4 - 20 mA loop power supply and commission the
unit uninstalled. However, if using a T VA for a superheat application (with pressure sensor),

the sensor must be connected before powering up the flowmeter. Otherwise the pressure

channel calibration will be affected. The TVA owmeter should still be zeroed in-line (see
Section 4.5.3) and its operation checked. An M750 display unit can be used to provide a
remote display function if required, utilising the linear output.

Rotating the display

The display can be rotated through 180° to enable ease of commissioning. To rotate the

display disconnect the power supply, remove the mounting screws on the display unit,
carefully remove the display unit and rotate. Carefully replace the display unit and replace
mounting screws. Do not force the display unit into position. Reconnect the power supply.
Note 1 - Electrostatic discharge (ESD) procedures should be followed while rotating the

display.
Note 2 - DO NOT remove the 10 way connector from the display.

LCD

display

5 button

keypad

4.1 Run mode

Normally, the TVA owmeter will operate in the run mode, displaying the total flow, flow,

power, pressure or temperature of the fluid passing through the pipeline.

After initial power up, the TVA owmeter will automatically enter the run mode and all

commissioning menus can be accessed from this mode. (See Section 4.2, Commissioning

mode, for details on how to commission). In the run mode the fluid data is displayed on
several screens which can be accessed by pressing the up or down keys.
The display shows a numeric value and an arrow

indicating the reading type, i.e. total flow, flow, power,
pressure or temperature. All units (except °C) are
implied with imperial or metric units being indicated

by another arrow. The value of total flow is shown in
two parts. The first five digits of the total flow will be
displayed and after 10 seconds the following five
digits will be displayed. To access the first five digits

of total flow again it will be necessary to scroll up or
down and return to the total flow display.

IM-P192-02 MI Issue 2 27

Arrow

temp

flow

imp

pres

Fig. 24

total

power

total

power

4.1.1 Run mode data sequence

Total High

kg or lb

Total Low

kg or lb

Flow

POWER

Pressure

Temp. °C

Power kW or kBtu/h.

Pressure bar g or psi g, depending if

metric or imperial units are selected.

Temperature °C or ° F.

The following chart indicates the run mode data display sequence.
Depending on the configuration, the flow units will be:

Units Steam

Metric kg, kg / h, kW, bar g, °C

Imperial lb, lb / h, kBtu / h, psi g, °F

The TVA owmeter is fac tory set to display steam data in metri c units and pressing the up or

down keys will scroll through the following data.

pres

pres

flow

flow

Total flow

temp

temp

total

imp

imp

flow

power

pres

total

flow

power

pres

Flow

Temperature

Fig. 25

Power

temp

total

total

temp

temp

imp

flow

flow

imp

imp

power

power

pres

pres

temp

total

temp

imp

flow

imp

power

pres

Pressure

IM-P192-02 MI Issue 228

4.1.2 Error display messages

Any errors that occur will be displayed in the run mode. The errors will alternate with the
normal run mode display and will be prioritised. The errors will be latched and can only be
cancelled by pressing the 'OK' button. Once the error message has been cancelled the display

will show the next (if any) error.

Any continuous error will reinstate itself 2 seconds after it has been cancelled, and will be
indicated by a flashing exclamation mark (!).
Certain errors will also cause the 4-20 mA alarm signal to be initiated.

The error messages are displayed over two screens and are:

= Power interrupted.

= No signal from sensor.

(This can also activate the 4-20 mA alarm).

= Signal from sensor constant.

(This can also activate the 4-20 mA alarm).

= Flow above the maximum.

= Line conditions have changed from

superheat to saturation (only when pressure

POWER

OUt

NO

SIGNL

SENSR

CONSt

HIGH

FLOW

SUb
SAt

sensor enabled).

IM-P192-02 MI Issue 2 29

4.2 Commissioning mode

The commissioning mode is used to zero the flowmeter, re-range, enable the pressure sensor

(for superheat applications), set and test the outputs and change the pass code.

All data entr y is performed via a menu and sub menu configuration with the key pad but tons
used for navigation, i.e. to go deeper into the menu the right hand key is pressed, to scroll

up and down the menu the up and down keys are pressed and to exit from a sub-menu the

le ft key is pre ss ed. Any dat a is entered us in g the OK bu tton. The previous ly ent er ed sele ct ion
will flash. Af ter a period of five minutes without any keys being pressed the TVA owmeter

will automatically default to the run mode.

For a full commissioning f low chart see Section 4.3.

To enter the commissioning mode press and hold down the 'OK' key for 3 seconds. The

display then shows:

Followed by:

The leading digit will flash indicating that this is the position of the cursor.

The default factory set pass code is 7452. (This can be changed from within the commissioning

mode). The pass code can be entered by using the up and down keys to increment the flashing
value and the left and right keys to move the cursor. Pressing 'OK' will enter the pass code.

If an incorrect pass code is used the display will automatically return to the run mode.

After the correct pass code is entered the display shows:

ENtER

PASS

7452

bASIC

dAtA

IM-P192-02 MI Issue 230

To exit from the commissioning mode at any stage, continually pressing the left key will return
to the run mode.

Pressing the up and down buttons scrolls through the various first level menus.

Pressing the right arrow button enters a particular sub-menu.

ENtER

PASS

8888

bASIC

dAtA

MEtER

OUt

PUts

PRES

SENSR

tESt

ALARM

SWVER

SEt

PASS

IM-P192-02 MI Issue 2 31

4.3 TVA flowmeter commissioning flow chart

Software

version number

(test

display)

Power on sequence; turn

on all segments, then

show the software version

no.

VER x.x

Normal run mode

display sequence

Total
high

Total

low

ENtER

PASS

kg or lb

(kWh or kBtu)

Default = 8888

but user settable.

8888

Conguration

sub-menus

bASIC

dAtA

Flow

Power

Pressure

Temp. °C

Error Messages

These alternate with the normal run mode display.
They will be prioritised and will be latched when
they occur.
Pressing the 'OK' button will cancel the displayed

alarm and allow the next one to be viewed.

A continuous alarm will re-occur on the display
2 seconds after it has been cancelled.

Power

from

sensor

sensor

Flow

above

POWER

OUt

NO

SIGNL

SENSR
CONST

HIGH

FLOW

SUb

SAt

The 4- 20 mA
alarm can also

be activated

The 4- 20 mA
alarm can also

be activated

Shows when

ow exceeds

maximum

Line temperature
drops below
steam saturation
temperature

interrupted

No signal

Signal from

constant

maximum

Temp below

saturation

kg /h or lb / h

kW or kBtu /h

bARG or PSIG, depending if metric or

imperial units are selected.

°C or °F

HIGH

LOW

OFF

ON

OFF

ON

OFF

xxxx

O/P

ALARM

POWER
ALARM

CONSt

ALARM

SEt

PASS

SWVERxxxx

ALARM

MEtER

OUt

PUtS

PRES

SENSR

dELAyXX

yES

NO

SAt

ALARM

tESt

IM-P192-02 MI Issue 232

dRy

xxx%

CLEAR tOtAL

ZERO MEtER

4- 20 mA

PULSE

COMMS bAUD

yES

NO

dIR

S/N

SORCE

NUM /

PULSE

PULSE
WIDTH

xxxxx

UNItS

tOtAL

AtMOS

PRES

tOtAL

ENRGy

xxxxx

in kg or lbs,

MJ or kBtu.

xxxmS

Must not
exceed 4 pulses
per second.

1200

MASS

ENERGy

xxx.xx

HORIZ dOWN

SORCE

SEt4 mA

SEt20 mA

CHECK

4 mA

CHECK

20 mA

MEt

IMP

UP

FLOW

POWER

xxxxx

in kg /h or lb /h,

kW or kBtu /h.

xxxxx

OP = 4 mA

Connect a DVM
and use the up
and down keys to
set 4 or 20 mA.

OP = 20 mA

yES

NO

tyPE

0CAL

25CAL

SH MARGN

PRES

ALARM

ASCII

MOdbuS

Press OK to select

XXXXX

XXXXX

yESNOLIMIt

ON

OFF

9600

Add

XXX

ALARM

dELAy XXX

OFF

ON

XXX

dISP

4-20 mA

OUt

PULSE

OUt

CANCL

Display

test

xxx.xxmA

ON

OFF

IM-P192-02 MI Issue 2 33

4.4 bASIC DAtA Sub menu

bASIC

dAtA

dRy

UNItS

tOtAL

AtMOS

PRES

xxx%

xxx.xx

MASS

ENERGy

MEt

IMP

4.4.1 dRy

Pressing the right key will display the dryness fraction. This is the dryness fraction of the
saturated steam being measured. This can then be edited to suit the application. Press the
'OK' button to confirm the selection.
After the dryness fraction is entered the display will automatically step to the next sub menu
and show 'UNItS'

4.4.2 UNItS

The units displayed and transmitted can be selected between metric (MEt), and
imperial (IMP).

A summary of the units is detailed in the Table below.

Units Steam

Metric kg, kg / h, kW, bar g, °C

Imperial lb, lb / h, kBtu / h, psi g, °F

Select either 'MEt' or 'IMP' and press the 'OK' button to confirm.

4.4.3 CLEAR tOtAL

This function is used to clear the total by pressing and holding the 'OK' key for 3 seconds.

Note: The total is backed-up every 8 minutes in the TVA flowmeter's non-volatile memor y.
If power is lost the TVA owmeter could lose up to 8 minutes worth of totalised steam.

4.4.4 AtMOS PRES

This value compensates the flowrates for atmospheric pressure. It should be used if a high
degree of accuracy is required or when the T VA owmeter is installed high above sea level.

Note: Values up to two decimal places can be entered.
If metric units are selected pressure units are bar absolute, for imperial units psi absolute.

IM-P192-02 MI Issue 234

4.5 MEtER Sub-menu

MEtER

This sub-menu contains information about
the flowmeter and is used to zero the
flowmeter and clear the total.

dIR

S/N

ZErO MEtER

CLEAR tOtAL

xxxxx

HORIZ

DOWN

UP

4.5.1 dIR

dIR is the orientation that the TVA owmeter is installed in. The TVA owmeter can be installed
with horizontal flow up to a pressure of 32 bar g (464 psi g). For installations that require
vertical flow either up or down the maximum pressure must not exceed 7 bar g (101 psi g).
By selecting down or up the effect of gravity on the cone is taken into account.

Note: Upon entering the dIR sub-menu, HORIZ is always shown rst. The actual direction
selected is the one which is ashing.

4.5.2 S/N

This is the factory set serial number of the TVA owmeter and is displayed by pressing the

ri ght key.

4.5.3 ZErO MEtER

Th is functi on is used to ze ro the TVA owm et er manually to co mp ensate for any elec tronic dr if t .
The procedure for zeroing the flowmeter is as follows:

- Isolate the pipeline where the flowmeter is installed and ensure that there is no flow. The
line temperatures should be above 5 ° C (41 °F) and below 30 °C (86 °F).

- Press and hold the 'OK' button for three seconds.

On completion the display will step back to S/N.
If 'ZErO ErrOr' is displayed, check to ensure that the line is isolated with no flow.
If 'tEMP ErrOr' is displayed the line temperature is below 5 °C (41 °F). Allow the temperature
to move above 5 °C (41 °F) and re-zero. Note: The flowmeter should ideally be zeroed

annually after 12 months service.

4.5.4 CLEAR tOtAL

This function is used to clear the total by pressing and holding the OK key for 3 seconds.

Note: The total is backed-up every 8 minutes in the TVA owmeter's non-volatile memory.
If power is lost the TVA owmeter could lose up to 8 minutes worth of totalised steam.

IM-P192-02 MI Issue 2 35

4.6 OutPutS Sub-menu

This sub-menu allows both the 4-20 mA and pulsed
outputs of the flowmeter to be configured.

4.6.1 4-20 mA Output sub-menu

OUt

PUtS

4-20mA

PULSE

OUt

PUtS

The 4-20 mA sub-menu allows
re-ranging and re-calibrating of
the 4-20 mA output.

4-20 mA FLOW

SORCE

SEt4 mA

SEt20 mA

CHECK

4 mA

CHECK

20 mA

POWER

XXXX

XXXX

OP = 4mA

OP = 20 mA

4.6.2 SORCE

This changes the source data for the 4-20 mA between flow and power.

4.6.3 SEt4 mA

This sets the value for the flowrate or power, which is equivalent to 4 mA. The minimum
value that can be set as 4 mA is 0 and the maximum is the 20 mA equivalent value less one.

4.6.4 SEt20 mA

This sets the value for the flowrate or power, which is equivalent to 20 mA. The minimum
value that can be set as 20 mA is the 4 mA equivalent value plus one and the maximum is
the meters rated maximum at 32 bar g. The 20 mA value must always be a minimum of one
greater than the 4 mA value.

4.6.5 CHECK 4 mA

This allows the 4 mA value to be re-calibrated. A digital volt meter / multimeter should be

connected in series with the 4-20 mA output. Pressing the right arrow button will display OP

= 4 mA and the TVA owmeter will output a steady 4 mA. If the multimeter does not read 4

mA the up and down arrow buttons can be pressed to alter this current until 4 mA exactly is
indicated. Pressing the 'OK' button confirms the setting.

4.6.6 CHECK 20 mA

This allows the 20 mA value to be re-calibrated. A digital volt meter/multimeter should be

connected in series with the 4-20 mA output. Pressing the right arrow button will display OP

= 20 mA and the TVA owmeter will output a steady 20 mA. If the multimeter does not read

20 mA the up and down arrow buttons can be pressed to alter this current until 20 mA exactly
is indicated. Pressing the 'OK' button confirms the setting.

IM-P192-02 MI Issue 236

4.6.7 Pulse Output

This sub-menu allows the pulsed output to be configured.

PULSE

NO

4.6.8 PULSE

This selects whether the pulsed output is to be used or
disabled.

SORCEyES

NUM/

PULSE

PULSE
WIDTH

tOtAL

ENRGy

xxxxx

xxxmS

4.6.9 SORCE

This selects the source data for the pulsed output.

The source data can be either unit mass per pulse (tOtAL) or unit energy per pulse (ENRGy).

4.6.10 NUM / PULSE

This allows the total mass, or energy, which is equivalent to one pulse to be configured.
Units are dependent on the UNIt setting. Metric units will be kg for total or MJ for energy,

imperial units will be lb for total or kBtu for energy.

4.6.11 PULSE WIDTH

This allows the width of the pulse to be set. The width can be set in 0.01 second increments
from 0.02 seconds to a maximum of 0.2 seconds.

4.6 .12 C OMMS

This allows the connection to other communications protocols.

COMMS bAUD

1200

tyPE

ASCII

MOdbuS

Press OK to select

9600

Add

xxx

4.6.13 bAUD

This allows the communication speed to be set to either 1200 or 9 600. This must match the
rate set within the device it is communicating to.

4.6 .14 t y PE

This gives the choice to select either ASCII or Modbus protocols.

4.6 .15 A dd

If you have selected Modbus communications you must add an address. This is a three digit
number between 001 - 255. Again this must match the address that the device that you are

communcating to is set to.

IM-P192-02 MI Issue 2 37

4.7 PRES SENSR sub-menu

PRES

SENSR

yES

NO

0CAL

25CAL

SH MARGN

PRES

ALARM

XXXXX

XXXXX

ON

OFF

yESNOLIMIt

ALARM

dELAy XXX

XXX

OFF

ON

Selecting 'YES' at the PRES SENSR menu will enable the pressure sensor option.

4.7.1 0 C AL

When the pressure sensor has been enabled, the 0CAL menu will be displayed. Pressing the

right arrow key (>) will display the 0CAL bits values.

The calibration certificate supplied with every pressure sensor kit lists the 0CAL and
25CAL bits values that are required to be entered.

4.7. 2 25 C A L

Pr es sing th e do wn ar ro w key (v) will displ ay the 25CA L bi ts values. Th e calib ra ti on ce rti fic at e
supplied with every pressure sensor kit lists the 25CAL bits values that are required to be

entered into this menu.

When the bits values for the 25CAL have been entered press the OK but ton to confirm. This
will automatically display the SH MARGN menu.

4.7.3 SH MARGN

The SH MARG N menu enabl es the conf iguration of the super heat alarm, the superheat limit
(in degrees C) and delay before the alarm is triggered.

LIMIt Number of degrees of superheat have dropped before alarm is triggered.

ALARM Can be set to ON or OFF.

dELAy The alarm in seconds before the alarm is triggered.

4.7.4 PRES ALARM

In the event the alarm is triggered 'LOWS-HT' will be displayed. The PRES ALARM is
activated in the event that the pressure has exceeded 30 bar g. In this event 'OVER PRES'

will be displayed.

4.7. 5 WAIT

On exiting the 'PRES SENSR' menu the wait command will be displayed. At this point the

software is zeroing the pressure channel. This will return to normal after approximately
5 seconds.

IM-P192-02 MI Issue 238

4.8 tESt sub-menu

The tESt sub-menu allows access to the TVA owmeter's diagnostic tools. From here the

display, 4-20 mA and pulse outputs can be tested.

tESt dISP

4-20mA

OUt

PULSE

OUt

CANCL

xxx.xxmA

ON

OFF

4.8.1 dISP

This allows the display to be tested. Pressing the right button will cause all the segments on
the display to be turned on. Pressing the left button cancels the test and steps to the next
stage.

4.8.2 4-20 mA Out

Th is allows the 4-20 mA ou tput to be te st ed . By edit in g the va lu e and pre ss ing the 'OK' but ton

the output can be set to the selected output. This current will continue to be transmitted for

five minutes unless the cancel option is chosen.

4.8.3 PULSE OUt

This allows the pulsed output to be tested. By selecting 'ON' or 'OFF' the desired test state
of the pulsed output can be selected. Once the 'OK' button is pressed the pulsed output will

remain in the selected state for five minutes or until the cancel option is chosen.

4.8.4 CANCEL

This al lows th e 4-20 mA output and pulsed output test si gnal se lecte d above to be cancel led
before the five minutes duration has expired.

IM-P192-02 MI Issue 2 39

4.9 ALARM sub-menu

Th is sub- menu gi ve s ac ces s to sett in g the act io n that is req ui re d on th e 4-20 mA output whe n
an error is det ected by th e T VA owme te r el ect ro ni cs. It al so gives ac cess to the power al ar m

function.

dELAyXX

4.9.1 O / P AL ARM

If the self-diagnostic electronics determine that the sensor output has been

HIGH

LOW

constant for a period of time, or is not giving out a signal, it will set the 4-20 mA

output to 22 mA.

If the self-diagnostic electronics determine that the sensor output has been

constant for a period of time, or is not giving out a signal, it will set the 4-20 mA

output to 3.8 mA.

HIGH

LOW

OFF

ON

OFF

yES

NO

O/P

ALARM

POWER

ALARM

CONSt

ALARM

SAt

ALARM

ALARM

ON

OFF

OFF

This disables the 4-20 mA alarm function.

4.9.2 POWER ALARM

OFF

ON

This disables the power alarm function.

This enables the power alarm function.

IM-P192-02 MI Issue 240

4.9.3 CONSt ALARM

This allows the constant f low alarm to be turned off.
The constant alarm is switched to on by the default factory setting. It detects if the flow has
been constant for long periods when at pressure, which may indicate a stuck cone due to
debris. If the system that the T VA is fitted to, has long periods where there is zero flow, but

the line is kept at a constant pressure, it is advisable to turn the alarm off to avoid unwanted

alarm messages.

ON

OFF

dELAy

This enables the saturated steam alarm.

This disables the saturated steam alarm.

This enables the time duration before alarm is displayed.

4.9.4 SAt ALARM

yES

NO

dELAy

This allows the Sub Saturation Alarm to be enabled or disabled.
The Sub Saturation alarm is switched off by default. If set it will alarm if the steam temperature
drops 2 °C below saturation temperature.

4.10 S W VER

This allows the soft ware version to be viewed.

4.11 SEt PASS

This allows the default pass code to be changed

to a user defined value.

It is impor tant that if the default pass code is

ch anged tha t th e ne w va lu e is not ed and kep t safe.

The new pass code can be recorded on the Table

in Section 9, page 50.

Enables the Sub Saturation Alarm.

Disables the Sub Saturation Alarm.

This sets the time duration before alarm is displayed. Can be zero.

SWVER

SEt

PASS

xxxx

xxxx

IM-P192-02 MI Issue 2 41

4.12 TVA communications

4.12.1 TVA UART set-up

The TVA flowmeter has an EIA 232C compatible communications link and supports two

protocols: a simple Line Feed [LF] terminated ASCII protocol and a subset of Modbus/RTU.

This enables users to easily interrogate the TVA flowmeter for steam data using either a dumb
terminal or a P.C. loaded with a simple terminal emulation program or a standard Modbus

Master / Client application. The connection length is limited to 15 metres and must be in the
same building / area as the TVA flowmeter.
The TVA’s communication set up should be as follows:

TVA ASCII set-up TVA Modbus set-up

Baud rate

Data bits

Stop bits

Parity

Echo

Response time:

The TVA will start responding within 500 msec. The actual time to fully receive a response

from the T VA is baud rate dependent, for example a Modbus poll of 12 registers @1200 baud

rate could take ((5 + 24) bytes x ~10 ms / byte) + 500 ms ≈ 800 ms to complete.
The polling frequency can be faster if the polling algorithm is set to poll immediately after
receiving a valid response to a poll.

4.12.2 Using the EIA 232C communications

It is assumed that:

The elec trical wiring f or the EIA 232C commu nications has been c arried out in ac cordance

-

with the EIA 232C standard. Please note the TVA EIA 232C connection requires a
c o nnector RJ11 li n k e d to a 9 wa y D-type ada p t o r. Fig ur e 2 5 i l l u s t r a tes the T VA owm et e r ' s
RJ11 socket from the front.

1200 or 9600

7

one

none

off

Baud rate 1200 or 9600

Data bits 8

Stop bits one

Parity none

Echo off

The table below lists the RJ11 socket's pin connections.
The signals are named from the PC (or data terminal) end.

RJ11 pin 9-way D-type Signal

1 Not used

2 4 DTR

3 5 GND

4 2 RX

5 3 TX

6 8 CTS

6 5 4 3 2 1

Pin numbers

Fig. 26 RJ11 socket

IM-P192-02 MI Issue 242

The commu n i c a t i ons prot o c o l ha s been set up on th e co m m u nicati n g de v i c e a s de s c r i b ed

-

earlier in this Section. The following is a Table of operating codes in ASCII characters:-

ASCII communications

Please note that all the following commands are case sensitive…

User transmits TVA responds (metric) TVA responds (imperial)

AB[LF] Pressure in bar g [LF] Pressure in psi g

AC[LF] Line Temperature in °C [LF] Line temperature in °F

AH[LF] Energy total in kWh [LF] Energy total in kBtu

AP[LF] Power in kW [LF] Power in kBtu / h

AR[LF] Flow rate in kg / h [LF] Flow rate in lb / h

AT[ LF] Total in kg [LF] Total in lb

4.12.3 Using RS485 Communications

The TVA is available with RS485 communications. This is achieved by converting the
communication from RS232 by an additional PCB. The PCB is fitted at the factor y when the
TVA is ordered with RS485 communications.

However, the RS485 communications board is available if ordered with a replacement

electronics front panel.

Note: RS232/4-20mA outputs are not available if the RS485 board is fitted.

The TVA is a RS485 slave device and must be powered by connecting 24VDC to terminals

4 and 5.
The data terminals are 1-3 and all must be connected for the communication to work correctly.

Terminal Signal

1 Data +

2 Data -

3 Data GND

4 Power +

5 Power -

4.13

After installation or maintenance ensure that the system is fully functioning.
Carry out tests on any alarms or protective devices.

IM-P192-02 MI Issue 2 43

4.14 Modbus communications

The TVA flowmeter has Modbus communications, in addition to the ASCII Modbus comms

that are avai la ble th rough the TVA RS232 port . An RS48 5 to RS2 32 converter is re quired, or
alternatively, an Ethernet to RS232 converter, both of which are widely available.

Modbus comms protocol

Format: Request frame

Address 1 by te

Function code 1 byte

Start address 2 bytes

Quantity of registers 2 bytes

Error check (CRC) 2 bytes

Tot al 8 bytes

Format: Response frame (normal)

Address 1 by te

Function code 1 byte

Byte count 1 byte

Register data 2 x Quantity of registers, MSB first, low register address first

Error check (CRC) 2 bytes

Tot al 5+ (2 x Quantity of registers) bytes

Format: Response frame (error)

Address 1 by te

Error code 1 byte (error code = function code plus 0x80)

Exception code 1 byte (01 or 02 see below)

Error check (CRC) 2 bytes

Tot al 5 bytes

Note: Only ‘Read holding registers’ (function code ‘03’) is currently supported

4.14.1 ModBus request frame structure example.

Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Byte 8

Device

address

The above frame will poll all Modbus registers from Total low 16-bits up to and including

Software Version.

Function

code

x

(3)

Register

start

address

(MSB)

(0)

Register

start

address

(LS B)

(0)

Register

quantity

(MSB)

(0)

Register
quantity

(LS B)

(12)

IM-P192-02 MI Issue 244

CRC

(LS B)

x

CRC

(MSB)

x

Register
number

40001 0 Total low 16 bits x1 Kg

40002 1 Total high 16 bits x1 Kg

40003 2 Flow x1 Kg/h

40004 3 Pressure x10 0 BarG

40005 4 Temperature x10 °C

40006 5

40007 6 Power x1 kW

40008 7

40009 8

40010 9 Alarm status - (bit-fields) Look table below

40011 10 SxS device ID - - T VA = 0

40012 11 Software version - -

40021 20 Total low 16 bits x1 Lbs

40022 21 Total high 16 bits x1 Lbs

40023 22 Flow x1 Lbs/h

40024 23 Pressure x100 PSIg

40025 24 Temperature x10 °F

40026 25

40027 26 Power x1 KBTU/h

40028 27

40029 28

Note Modbus protocol requires that Modbus addresses star t at offset 0, not 1. Register

addresses start from 1 in description but 0 in binar y. Most parameters are 16 bits and few

pa ra meters ar e 32 bits. Mo db us regi st er s are 16 bits, i.e. 1 dev ic e pa rameter nee ds 1x an d 2x
Modbus register(s) respectively. As a general note on Modbus, register types and reference
register number ranges are implemented as follows:

0x = Coil = 00001 - 09999

1x = Discrete input = 10001 - 19999

3x = Input register = 30001 - 39999

4x = Holding register = 40001 - 49999

Modbus
address

Parameter Received

Water equivalent

flowrate

Energy low
16 bits

Energy high
16 bits

Water equivalent

flowrate

Energy low
16 bits

Energy high
16 bits

data

scale

x10 L/hour

x1 kWh

x1 kWh

x10 Lbs/hour

x1 kBTU

x1 kBTU

Units Notes

M ultiply by the invers e 'Rece iv ed Dat a

*

Scale' to extract data in relevant units,
i.e. divide polled 'Temperature' by 10
to get the value in °C… Tip: use real
(float) type to retain 2-decimal-point

accuracy.

Total = (Total high x

65536) + Total low

Energy = (Energy high x

65536) + Energy low

200 is sw ver 2.00, 201
is sw ver 2.01 etc

Total = (Total high x

65536) + Total low

Energy = (Energy high x

65536) + Energy low

*

*

*

*

IM-P192-02 MI Issue 2 45

4.14.2 Alarm status register bit-fields:

Bit 1 Bit 0 State Alarm code

0 0 Superheat 0x0000

0 1 Not applicable Not applicable

1 0 Saturated 0x0002

1 1 Sub-saturated 0x0003

Bit Set (1) Cleared (0)

Bit 2 (0x0004)

Bit 3 (0x0008) Superheat margin active Superheat margin idle

Bit 4 (0x0010) Hi flow alarm is active Hi flow alarm is idle

Bit 5 (0x0020) Sensor constant alarm is active Sensor constant alarm is idle

Bit 6 (0x0040)

Bit 7 (0x0080)

Bit 8 (0x0100) Hi flow alarm has latched -

Bit 9 (0x0200) Sensor constant alarm has latched -

Bit 10 (0x0400)

Bit 11 (0x0800) Power failed alarm has latched nothing

Bit 12 (0x1000) Low superheat (Low S- HT) alarm -

Bit 13 (0x2000) Over pressure alarm (OVEr PRES) -

Bit 14 (0x4000) - -

Bit 15 (0x8000) - -

A maximum of 12 Modbus registers can be polled together at the same frame. It has to be

noted that only a poll with a valid start address and quantity that falls within the supported

register range will produce a normal frame response. If you ask for a frame with start address

outside this range or a frame that the start address + quantity falls outside this range, the

TVA will reply with an 'illegal data address' error message. If the function code is incorrect,
it will reply with an 'illegal function' error message.

If a message is received with the wrong CRC, it will be ignored. The TVA response time is
not instant (look below) so wait for it to reply before asking for more data, other wise it will
ignore new requests.

Pressure alarm is active
(too high or too low)

No signal from sensor alarm is

active

Power failed (has been turned off

and on) alarm is active

No signal from sensor alarm is
latched

Pressure alarm is idle

No signal from sensor alarm is
idle

Power failed alarm is idle

-

IM-P192-02 MI Issue 246

Important note: T he TVA is a lo op powere d de vi ce. It requires the CTS and DTR ter minal s

to be wired and enab led to power the commu nicat ions interface. Failure to do so wil l prevent

the communications working.

4.14.3 Response time:

The TVA will start responding within 500 msec. The actual time to fully receive a response

from the T VA is baud rate dependent, for example a Modbus poll of 12 registers @1200 baud

rate could take ((5 + 24) bytes x ~10 ms / byte) + 500 ms ≈ 800 ms to complete.
The polling frequency can be faster if the polling algorithm is set to poll immediately af ter
receiving a valid response to a poll.

5. Maintenance

The T VA owmeter should be zeroed using the zero meter sub-menu at least once a year.
This will remove any electronic long term drift that may occur. Frequency of re-calibration
depends upon the service conditions experienced by the meter and the application.
Re-calibration frequency can be typically between 2 and 5 years.

5.1 Replacement of the TVA flowmeter display electronics

To replace the electronics:

Disconnect the power supply.

-

Remove the front housing.

-

Remove the mounting screws on the display unit and carefully remove the electronics.

-

Carefully unplug the ribbon cable.

-

Reconnect the ribbon cable to the new electronics and carefully replace.

-

Replace the mounting screws and reconnect the power supply.

-

Note: Electrostatic discharge (ESD) procedures should be followed while installing the new

electronics.

Do not force the electronics/display unit into position.

IM-P192-02 MI Issue 2 47

6. Spare parts

1. Spare electronics for the T VA owmeter are available from Spirax Sarco and consist of:

TVA owmeter replacement display and electronics with front housing. State if

-

RS485 board is fitted.

It is impor t an t th at the se rial numb er of the TVA owmeter is gi ve n at the ti me of ord er ing.
Example: 1 of f Spirax Sarc o display and el ectro nics panel for a DN100 T VA owm eter
having the following Serial number D_ ____ _ . This can be found on the product label

on the stem.

2. Superheated steam conversion kit. This comprises of a new electronics front panel,

co mplete wi th pressu re sen sor and syp ho n. Please not e: the ser ial num be r of the exis ti ng
TVA must be provided at the time of order placement.

IM-P192-02 MI Issue 248

7. Fault finding

Many faults which occur on commissioning are found to be due to incorrect wiring or setting up,
therefore it is recommended that a thorough check is carried out should there be a problem.

The TVA owmeter display has in-built diagnostic features and will indicate a number of
errors on the display and via the 4-20 mA output.

The errors will alternate with the normal run mode display and will be shown according to
priority. The errors will be latched and can only be cancelled by pressing the 'OK' button.

Once the error message has been cancelled the display will show the next (if any) error.

Any continuous error will re-instate itself 2 seconds after it has been cancelled, and will be
indicated by a flashing exclamation mark (!).

Symptom Possible cause Action

Display is blank dc voltage is not within

Display shows:
NO SIGNL

Display shows:
POWER Out

Display shows:
SENSR CONST

the range of 9-28 Vdc.

Supply connected with

reverse polarity.

Electronics faulty.

Insufficient supply

voltage.

Current loop resistance

is greater than Rmax.

Electronics faulty.

Power supply
interrupted.

Cone jammed.

Electronics Faulty.

Check power supply/current

connections. See Section 3.3.

Change polarity.

Refer to: Spirax-Sarco Limited

Check supply voltage is between 9 and

28 Vdc.

Check current loop resistance and
reduce if necessary.

Check current output electronics (refer

to Sections 4.6, 4.7 and 4.8).

Refer to: Spirax-Sarco Limited

Ensure power supply is secure and
cancel error using the OK key.

Totals transmitted may not be valid.

Remove unit from pipeline and check
cone movement.

Check current output electronics (refer

to Sections 4.6, 4.7 and 4.8).

Refer to: Spirax-Sarco Limited

Display shows:
HIGH FLOW

IM-P192-02 MI Issue 2 49

Meter undersized. Check sizing and replace

if necessary.

Symptom Possible cause Action

Constant 3.8 mA Error signal set to Low. Check display for errors

Constant 22 mA Error signal set to High. Check display for errors

Flow indicated
responds to
changes in actual
flow but value
indicated does
not correspond to
actual flowrate

Flowmeter not properly
centred in the pipeline.

Gaskets at the
flowmeter protrude into
the pipe bore.

Irregularities on the
surface of the pipe bore.

Signal falsified due to
bi-phase medium.

Insufficient upstream/

downstream pipe
lengths.

Flow direction reversed.

and rectify as above.

Check current output electronics (refer

to Sections 4.6, 4.7 and 4.8).

and rectify as above.

Check current output electronics

(refer to Sections 4.6, 4.7 and 4.8).

The axis of the flowmeter bore should
be aligned with that of the pipe.

See Section 3, Figures 16, 17 and 18
for proper installation of gaskets.

Pipe bore should be free of
irregularities.

Bi-phase media are not permitted.
Use a separator for wet steam droplets
from the steam.

See Section 3 for correct lengths of
upstream and downstream pipes.

Check flow direction arrow
on primary.

Pulse output is
incorrect

Pulse output incorrectly
set.

Pulse width incorrectly
set.

Pulse output is

overloaded.

Pulse output electronics
faulty.

Check programming of pulse output,
Section 4.6.7.

Check maximum pulse width of
counter electronics.

Check load ratings.

Test pulse output.
If faulty replace unit.

IM-P192-02 MI Issue 250

Symptom Possible cause Action

TVA produces
large amount of
noise (banging and
clattering)

Non zero flow
indicated when no
actual flow is in the
pipe.

RS232/Modbus
communications
not working

Additional fault finding for versions with RS485 conversion board fitted.

Symptom Possible cause Action

No power and no
diodes lit up.

Upstream/downstream

installation lengths
incorrect.

Unit not zeroed at
commissioning.

4 mA output not
calibrated.

4 mA retransmission set

to a value higher than

zero.

Interference.

CTR/DTS not
connected/powered.

No power to terminals
4 and 5

Power to terminals 4
and 5 wrong way round.

Re-install following the installation
guidelines (Section 3).

Zero unit.

Calibrate 4 mA output (Section 4.6.5).

Reset 4 mA.

Check earthing.

Connect CTR/DTS terminals

Check power supply.

Connect to terminals 4 and 5 correct
way round.

No communication,
Green diode lit
only.

No communication,
Green diode lit,
Yellow diode
flashing, blue
diode off.

IM-P192-02 MI Issue 2 51

No query received from

computer system.

A and B wires
connected wrong way
round.

Baud rate set wrong. Change baud rate.

ASCII / Modbus

selected wrong.

Check communication cable
connection.

Wrong configuration of computer

system (wrong port, etc.)

Connect A and B wires correct way
round.

Change ASCII to Modbus or Modbus to
ASCII.

8. Settings table

This Table shows all changeable options, and enables records to be made of any changes

made to the pass code or other settings. It provides a convenient reference should future
changes be required.

Sub-menu

Basic data

Outputs

Error High

Pass code 745 2

Changeable
settings

Dryness fraction 1.0

Units Metric

Nominal pressure

Atmospheric pressure 1.01 bar a

4-20 mA

Source data Flow

4 mA setting 0

20 mA setting

Pulse ON

Source data Tota l

Number of pulses 1 per kg

Pulse width 50 mS

Factory

settings

Flowmeter

maximum

@ 32 bar g

Customer

settings

Further

changes

IM-P192-02 MI Issue 252