YOKOGAWA AV550G User Manual
User’s
Manual
Model AC4/AC8 Automatic Calibration Unit
For Use With AV550G
Oxygen Analyzer Averaging Converter
I. Introduction.................................................................................................3
II. Overview......................................................................................................3
2.1 Models AC4/AC8 Multi-Channel Automatic Calibration ...............................................................3
III. Installation ...................................................................................................3
3.1 Location ..........................................................................................................................................3
3.2 Mounting .........................................................................................................................................3
3.3 Gas Sources ...................................................................................................................................4
3.4 Piping ..............................................................................................................................................5
IV. Wiring ..........................................................................................................6
4.1 Wiring the AC4/AC8 to the AV550G Averaging Unit ......................................................................6
4.2 Pressure Switch, M1133AR, Set Point Procedure .........................................................................6
V. Initial Flow Rate Set-Up ............................................................................. 7
5.1 Checking for Leaks .........................................................................................................................7
5.2 Setting for Reference Air Flow........................................................................................................7
5.3 Balancing Pressure Drops in the Cal Lines ...................................................................................8
5.4 Calibration Check ...........................................................................................................................9
VI. Programming .............................................................................................. 9
VII. Set-Up Menus for Calibration from the AV550G Averaging Unit ........... 9
7.1 Modes .............................................................................................................................................9
7.1.2 Calibration Setup Mode .............................................................................................................10
7.1.3 Zero Gas Concentration ............................................................................................................10
7.1.4 Span Gas Concentration ...........................................................................................................10
VIII. Maintenance ............................................................................................. 12
IX. Trouble shooting ....................................................................................... 12
9.1 Typical Calibration Problems ........................................................................................................12
X. Spare Parts and Accessories ..................................................................13
10.1 Spare Parts .................................................................................................................................13
10.2 Accessories ...............................................................................................................................14
10.2.1 Zero Gas Regulator, M1132ZX ........................................................................................15
10.2.2 Pressure Regulator, M1132KD ........................................................................................15
10.2.3 Pressure Gauge, M1132CG ............................................................................................15
10.2.4 Zero Gas Pressure Switch, M1133AR .............................................................................16
10.2.5 Fuses, M1132HG .............................................................................................................16
Appendix A Wiring Diagram AC4 to AV550 to ZR22G ..................................17
Appendix B Wiring Diagram AC8 to AV550 to ZR22G ..................................19
IM 11M6D2-02E-A
2nd Edition
3
IMPORTANT
NOTE
AUTO CALIBRATION UNIT FOR AV 550G
AC44 Channel System
AC88 Channel System
ENCLOSURE
-4 NEMA 4
-5 NEMA 4X
PL UM BING
-C Copper tubing , brass fittings
-S Stainless steel tubing and fittin gs
REFE RENCE AIR FLOW METER
-R*U Refere nce air flow meter
OPTIONS
/SCT Stainless Steel Tag
NOTE
IMPORTANT
I. INTRODUCTION
This manual details the operating instruction for the Yokogawa Model AC4/AC8 Automatic Calibration Unit, and the
integration with the AV550G Zirconia Oxygen Averaging
Converter.
The maximum input pressure for the span and zero gases is 35
psig. Exceeding 35 psig may result in damage to the AC4/AC8.
II. OVERVIEW
The AC4/AC8 Automatic Calibration System is designed to
work with the AV550G Oxygen Averaging Converter, providing accurate, automatic or semi-automatic calibration of the
ZR22 Zirconia Oxide Detector. The AC4/AC8 is assembled
with plumbing, flow control hardware and internal solenoid
wiring necessary to calibrate up to four or eight probes
respectively. The end user need only provide plumbing to the
individual probes, calibration gases, and interconnection wiring between the calibration unit and the converter.
Initial setup of the auto cal unit is further simplified by the
use of manual overrides for all solenoids. The overrides,
coupled with the flow regulation for each probe, allow for
fast balancing of each calibration line. Each probe also has
its own flow meter and flow control for the reference air flow.
2.1 Models AC4/AC8 Multi-Channel Automatic
Calibration
UStandard Specifications
Operating Pressure: 20 psi
Maximum Pressure: 35 psi
Flow meter range: 0.15 to 1 LPM (separate flow meter
for cal gas and reference air)
Flow rate: Cal Gas – 0.6 LPM;
Reference Air – 0.8 LPM
Cal tubing: 1/4” copper (standard);
1/4: stainless steel (optional)
Gas connection: 1/4” FNPT
Voltage: 110 VAC, 50/60 Hz (standard)
Ambient temp.: 80°C (176°F) maximum
Weight: Approximately 40 lbs (18 kg)
Construction: Outdoor installation (Indirect sunlight)
Enclosure: NEMA 4 or NEMA 4X
Reference gas
Consumption: 0.8 LPM per probe
Cal Gas Consumption
(Zero & Span): 0.6 LPM per probe,
during calibration only
Instrument air is used for both span calibration gas and
reference air.
Model and code
III. INSTALLATION
3.1 LOCATION
The following guidelines should be used when selecting a
location for the auto-calibration unit.
1. The unit must be easily accessible for maintenance and
inspections.
2. The unit must be near the ZR22 probes as practical. This
will minimize the length and amount of tubing required for
plumbing.
3. Ambient temperature will not exceed 80°C (176°F).
4. Humidity is moderate and no corrosive gases are present.
5. Minimal presence of vibration.
6. Availability of 120 VAC and clean, dry instrument air.
7. Adequate spacing for reference and zero gas plumbing.
8. Not positioned in direct sunlight.
If ambient atmosphere contains corrosive gases or high dust,
the use of air purging is recommended.
3.2 MOUNTING
The unit is designed for wall mounting by securing the four
standoffs with bolts. Allow for sufficient space to connect the
copper or stainless steel lines to both sides of the enclosure.
Input gases (zero calibration gas and instrument air) are
connected to the left side, while all probe connections (cal
lines and reference air) are on the right side, when facing the
unit. Refer to Figure 1 for mounting dimensions and required
clearances.
Care must be taken to mount the unit as level as possible to
ensure the accuracy of the flow rates. If the unit is not level, the
flow rates will not be accurate!
IM 11M6D2-02E-A
4
NOTE
IMPORTANT
Figure 3.1: AC4/AC8 Dimensional Drawing
3.3 GAS SOURCES
Zero Gas
Typically, 1% oxygen balanced in nitrogen is used, however,
an oxygen mixture between 0.5% and 8% is acceptable.
NEVER USE PURE NITROGEN FOR ZERO CALIBRATION GAS. A compressed gas cylinder containing the zero
gas is fitted with a dual stage regulator. Zero calibration gas
cylinders with regulators may be purchased from a local
compressed gas supplier. Follow the operation and safety instructions as supplied from your gas supplier. The maximum
pressure of the calibration unit is 35 psi.
The compressed gas cylinder must have the same CGA connection fitting as the dual stage regulator (see accessories).
Span Gas
Typically, a clean dry air source is recommended, such as
instrument air (20.6% oxygen). An in-line filter is recommended to remove any moisture or dirt prior to the calibration unit. A regulator must be attached to the instrument air
source in order to reduce the flow to an appropriate pressure
(35 psig max) prior to reaching the calibration unit.
Reference Air
The reference air is the same air as the span gas. Thus, the
reference air is also clean dry instrument air. Unlike span gas,
which is use only during calibration, reference air flows to
the back side of the zirconium cell and should be used at all
times.
When the instrument air has a nitrogen backup (used for air
failure), instrument air for the reference gas should not be used.
In this instance the probe must use either bottled air (20.6%
oxygen balanced in nitrogen) or natural convection for reference
air flow.
IM 11M6D2-02E-A
3.4 PIPING
PCDE?Q
A?J
E?Q
/-2ĥ
DCK?JCLNR
/-2ĥDCK?JCLNR
WMIME?U?
O2 CALIBRATION SYSTEM
LCK?2V
INSTRUMENT AIR
ZERO GAS
35 psig MAX
PROBE 1
PROBE 2
PROBE 3
PROBE 4
PROBE 5
PROBE 6
PROBE 7
PROBE 8
NOTE
IMPORTANT
5
Figure 3.2
Piping Gases to the Auto Cal Unit
Piping (or tubing) is required from the instrument air line and
zero gas cylinder to the calibration unit. Standard tubing is _”
O.D. (Outside Diameter) copper or stainless steel. Stainless
steel is preferred, as it is less likely to develop leaks. The
separate tubing for both the instrument air and zero gas are
connected to the two separate 1/4” FNPT brass or stainless
fittings on the LEFT side of the calibration unit.
Piping Gases to ZR22 Probes
The tubing to the ZR22 probes is run from the RIGHT side of
the calibration unit to each of the ZR22 probes as shown in
Figure 2. Quarter inch (1/4”) tubing should be used between
the auto cal unit and the probes. It is important to note 1)
the reference air tubing is connected to the REF IN port
at the probe; 2) cal gas tubing is connected to the CAL
IN port on the probe. The REF IN and CAL GAS ports are
located on the bottom of the ZR22 probe junction box. The
check gas and reference air ports require a 1/4” FNPT fitting.
Flexible stainless steel hose is recommended for the connection
between the ZR22 and the tubing.
This will allow for probe movement due to thermal expansion of
the duct.
To prevent leakage, all compression fittings should be installed
per manufacturer’s recommendations. In addition to this, a
check valve is usually installed on the cal gas inlet of the ZR22
probe to protect the cal tubing from moisture contamination.
IM 11M6D2-02E-A
6
NOTE
WARNING
Pressure
Switch
Relay
Calibratio n
Status
Cal Gas
Pressure
OK ?
Relay Deenergized
and
CLOS ED
Pressure Switch
OPEN
Relay Energi zed and
OPEN
Pressure Switch
CLOS ED
CALIBRATE
YES
NO
STAR T
DO NOT
CALIBRATE
Pressure Switch Used as Input to Relay
Calibration
Using
Pressure Switch AND Relay
IV. WIRING
4.1 Wiring the AC4/AC8 to the AV550G Averaging unit
Please refer to appendix A for the system configuration
drawing.
Solenoid, Relay and Pressure Switch wiring connections
The AC4/AC8 uses 120VAC, 60 Hz for all solenoids. Although two internal 1 amp fuses are provided for the ±120
VAC terminal, an external 5 amp circuit breaker is recommended. Included with each fuse is an LED that is activated
when the fuse is blown. Recommended wiring is 14AWG,
run in conduit. If conduit is not used, wiring should have a
suitable jacket to meet environmental and regulatory codes.
The AC4 unit requires a maximum of 8 conductors, whereas
the AC8 requires 12 conductors.
A 120 VAC relay (included with NEMA 4 enclosure), shown at terminal K1, is required at the AV550G if a pressure switch is used.
This prevents noise caused by a low voltage pressure switch
signal from being run in the same cable as the 120 VAC solenoid
signal.
Figure 4.2: Calibration Using Pressure Switch and Relay Flow
Chart
The recommended pressure switch configuration is to the
high pressure side of the zero gas regulator. This is preferred
because it gives the earliest warning of a decrease in zero
gas pressure. The switch is threaded into the high pressure purge port of the dual stage regulator on the zero gas
cylinder.
4.2 Pressure Switch, M1133AR, Set Point Procedure
The relay is prewired as NORMALLY CLOSED (NC) to
contact input #1 at the control card (terminal 7 and 9) of the
AV550G.
Figure 4.1 AV550G Input Contact Screen
When the relay is deactivated, the unit will not calibrate. The
relay remains closed unless a 120 VAC source is connected to
energize it. Terminal 7 of the relay provides 120 VAC. Neutral
voltage is connected to terminal 2 of the relay from the AC4/AC8
calibration unit.
The relay switch is designed to OPEN when energized as
depicted in the flow diagram shown in Figure 4.2. A pressure
switch input completes the 120 VAC signal used to energize
the relay, which is wired at the calibration unit as Normally
Open (NO), where Open = Low or Zero tank pressure. The
AC4/AC8 unit is prewired with the jumper in place, so that
the relay will be energized and OPEN. However, if the pressure switch input is used, then remove the jumper between
the terminals labeled PS at the calibration unit’s terminal
strip, and attach the pressure switch. The pressure switch is
wired as normally open.
For the AC4/AC8 Autocal units, a gas pressure set point is
used to indicate that the calibration gas (zero gas) is low.
Pressure Switch M1133AR is a cylindrical style pressure
switch which uses a diaphragm or piston sensor to detect a
pressure change. The recommended set point is 200 psi on
the fall. At the predetermined set point, a SPST switch actuates, converting a pressure signal into an electrical signal.
M1132ZX Dual
Stage Regulator
M1133AR
Pressure Switch
Figure 4.3: Pressure Switch and Dual Stage Regulator
The following procedure is required to adjust the set point:
1. Thread the pressure switch into the high pressure gauge
port on the regulator.
2. With power disconnected, slide the cover on the switch
toward the electrical termination while twisting it to overcome friction.
3. Connect the power to the terminal or leads.
4. Insert a flat head screwdriver (1/8”) into the adjustment
slot and turn counterclockwise to increase the setting or
clockwise to decrease the setting.
IM 11M6D2-02E-A
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