Concoa 536 Series Owner's manual

Before Installing or Operating, Read and Comply with These Instructions
Certified ISO 9001
ADI 3198-D
536/537 Series
AutoSwitch
Systems
For Use with
LiquidCylinders and High Pressure Gases
in HighPurityApplications
INSTALLATION AND OPERATION INSTRUCTIONS
Controls Corporation of America
1501 Harpers Road Virginia Beach, VA 23454
Telephone [phone] or 757-422-8330 • Fax [phone]
www.concoa.com
February 2022
Revision D

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DESCRIPTION OF PRODUCT..
The 536/537 Series AutoSwitches are automatic switchover systems designed to provide a
continuous supply of high purity gas. These units may be configured with or without the connections
to connect to both high pressure and liquid cylinders. The primary bank (left side) of the AutoSwitch
system is configured for use with liquid cylinders, pressure up to 600 PSI(41 bar). The reserve bank
(right side) is configured for high pressure cylinders filled up to 3500 PSI (241 bar). The standard
AutoSwitch system will maintain a regulated line pressure within the values shown in the table
below:
MODEL
RANGE
536 2XXX
0-50 PSI (0-3.5 BAR)
537 2XXX
0-50 PSI (0-3.5 BAR)
536 3XXX
0-100 PSI (0-7 BAR)
537 3XXX
0-100 PSI (0-7 BAR)
The continuous working inlet pressure on the primary bank (liquid cylinder) must be above 140 PSI
for the system to operate properly. When the primary bank falls below this value, gas will be pulled
from the reserve side.
Models of these AutoSwitches are available with or without pressure switch gauges. Models with
pressure switch gauges can be configured for use in conjunction with an optional remote alarm.
They cannot be connected directly to AC line voltage. Models with pressure switch gauges include
a power indicator light and LED status lights to indicate the condition of the gas cylinders. A green
indicator light signifies a “Normal” condition, while a red light indicates an “Alarm” (gas cylinder
empty) condition. The pressure switch AutoSwitch systems also include a strain relief on the bottom
through which wiring can be connected to an internal circuit board and to a remote alarm such as
CONCOA’s Altos 2 *.
Figure 1
INTENDED USE OF PRODUCT
The brass 536 Series AutoSwitch systems are intended for use in high purity, non-corrosive gas
applications. The stainless steel 537 Series AutoSwitch systems are for use in ultra-high purity
applications. Please note the safety information shown in the later sections.
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USER RESPONSIBILITY
The User of this equipment should follow all installation and operation instructions when using this
equipment. It is recommended that the user review all safety precautions listed in the safety section
of this manual.
This equipment must be checked periodically. Improperly working equipment should not be used.
Broken,worn, distorted, contaminated, or missing components should be replaced immediately.
CUSTOMER ASSISTANCE
In the event of equipment failure, call the CONCOA Customer Assistance Line: 1-800-225-0473.
Please be prepared to provide the model number and serial number of the equipment involved in
addition to some details regarding its application. This would include inlet and outlet pressures, flow
rate, environmental conditions, and gas service.
SAFETY
Carefully read and comply with these instructions before installing or operating any high pressure
gas manifold. These manifolds are designed, manufactured, and tested to conform to industry
standards for safety for high pressure gas manifolds for a maximum inlet pressure of 3500 PSI (241
bar) on the reserve (right) side. The primary (left) side is rated up to 600 PSI (41 bar).
Always observe the following safety practices:
√Store cylinders with valve caps screwed on and cylinders chained to a supporting wall or column.
√Handle cylinders carefully and only with valve caps screwed on. The cap will prevent the cylinder valve
from breaking off at the top of the cylinder if the cylinder is accidentally dropped or falls over. The cap
also protects the cylinder valve from damage to screw threads, which could cause leaky connections.
√Always open valves slowly when high-pressure gases are being used. Open valves all the way.
√Always be sure that a cylinder contains the correct gas before connecting it to any manifold.
√Always leak-test any manifold or distribution pipeline before using.
√Always be sure that the gas in a pipeline is the correct gas for the intended use.
√Always install a blind gland and nut or piping plug on any manifold inlet fitting if no cylinder is
connected to the fitting before opening any cylinder valve which is already connected to the manifold.
√Always close all cylinder valves before disconnecting cylinders from a manifold.
√Always remove all empty cylinders from a manifold before connecting full cylinders.
√Always test cylinders to be sure they are full before connecting to a manifold.
√NOTE: Use of PTFE lined pigtails for oxygen installations is not recommended unless they are equipped
with a Distance Volume Piece (DVP). Components in the manifold system can create a dead end
passage. The combination of a dead end passage coupled with a rapid pressurization may lead to
adiabatic compression of the contained oxygen and subsequent failure of the pigtail by ignition.
√All gas distribution piping systems must meet appropriate industrial standards for the intended service,
and they must be thoroughly cleaned before using.
√Keep all cylinders away from any source of high temperature (not over 120° F, 50° C) or possible fire
hazards. High-pressure gas contained in a closed cylinder becomes increasingly dangerous when
exposed to high temperature because pressure increases and the strength of the cylinder decreases.
√No smoking should be permitted near oxygen, nitrous oxide, flammable gases, flammable mixtures or
in areas where cylinders are stored.
√Where oxygen or nitrous oxide is used, the manifold and cylinders must be kept clean. No oil, grease, or
combustible substances should come in contact with oxygen or nitrous oxide storage or handling
equipment. Such materials in contact with oxygen or nitrous oxide are readily ignitable and, when
ignited, will burn intensely.
√Never lift gas cylinders with a magnetic lifting device.
√Never use an open flame when leak testing. -4-

Comply with all safety rules and precautions of the following:
1. American National Standards Institute standard Z49.1 or Safety inWelding and Cutting,
American Welding Society, 2501 NW Seventh Street, Miami, FL 33125.
2. N.F.P.A. Standard 51, Oxygen-Fuel Gas Systems for Welding and Cutting, N.F.P.A., 470 Atlantic
Avenue, Boston, MA 02210.
3. N.F.P.A. Standard 51B, Cutting and Welding Processes, (see Address in #2)
4. CONCOA Publication ADE 872, Safety Precautions in Welding and Cutting.
5. Local ordinances.
6. O.S.H.A.
7. C.G.A. Pamphlet C-4, American National Standard Method of Marking Portable Compressed
Gas Containers to Identify the Material Contained.*
8. C.G.A.PamphletG-4, Oxygen-Information on the properties, manufacture, transportation,
storage, handling, and use of oxygen.
9. C.G.A. Pamphlet G-4.1, Equipment Cleaned for Oxygen Service.
10. C.G.A. Pamphlet C-4.4, Industrial Practices for Gaseous Oxygen Transmission and Distribution
Piping Systems.
11. C.G.A. Pamphlet G-5, Hydrogen - Information on the properties, manufacture, transportation,
storage, handling, and use of hydrogen.
12. C.G.A. Pamphlet G-6, Carbon Dioxide - Information on the properties, manufacture,
transportation, storage, handling, and use of carbon dioxide.
13. C.G.A. Pamphlet G-6.1, Standard for Low Pressure Carbon Dioxide Systems at Consumer Sites.
INSTALLATION
The site chosen for the installation of the system shall be level, well ventilated, and at a safe
distance from sources of flames, sparks, and excessive heat. The system should not be placed in
an area that may subject it to damage from passing trucks, cranes, or other heavy machines. Any
oxygen system must not be installed under shafting, belting, or other places where oil can drip on it.
Refer to the manifold instructions for manifold installation.
a. Be sure to consider all factors when selecting materials.
b. Do not use oil or grease on fittings.
c. Be sure that all fittings are secure and leak tight. PTFE tape must be used on pipe threads.
See Figure 6.
d. Relief valve: The purpose of the relief valve is to protect the AutoSwitch system and its
components only (Figure2). If there is pressure sensitive equipment downstream of the
AutoSwitch system, it is recommended that an appropriately sized relief valve be installed in
the line to protect this equipment.
e. Purge devices: These devices can be purchased as accessories. Purge devices are used to
remove toxic, corrosive, or flammable gases from the customer’s system to a safe discharge
area. This is particularly helpful when an internal problem occurs such as regulator
malfunction.
Figure 2
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WALL MOUNTING
Follow Compressed Gas Association, OSHA and all applicable local codes. Manifolds should not be
placed in locations where the temperature will exceed 102°F (49°C) or fall below 0°F (-18°C).
Manifolds installed in open locations should be protected from weather conditions. During winter,
protect the manifold from ice and snow. In summer, shade the manifold and cylinders from
continuous exposure to direct sunlight. Always leave access to the manifold for cylinder
replacement.
1. Determine and mark the vertical center line for installation of the AutoSwitch console. (Figure 3).
2. Measure from the floor 72” in height at this center line. With the AutoSwitch mounting
bracket at this height, the manifold header will be approximately 66” from the floor. Using a
level, mark a horizontal line at this point extending approximately 10 inches to the left and
right of center.
3. Remove the mounting bracket from the rear of the AutoSwitch console by removing the
retaining nuts at the bottom of the mounting bracket (Figure 5). Place the upper edge of the
bracket cross-member on the horizontal line so that it is centered with the vertical line.
Holding the bracket with the slotted extensions away from the wall, mark the location of the
two mounting bolts (Figure 4).
4. Using appropriate hardware based on wall construction, anchor the mounting bracket to the
wall (Figure 4).
5. Place the AutoSwitch system so that the mounting bracket slots align with the shoulder nuts.
With the AutoSwitch box hanging on the shoulder nuts, align the retaining bolts so that they
protrude through the bracket. Replace the mounting nuts that were removed in step 3.
Figure 3 - Center-line Mark Figure 4 - Mounting Bracket
Figure 5 - Console and Mounting Bracket
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Mounting Screws
Retaining Nuts
Mounting Bracket
Shoulder Nuts
Console

INLET AND OUTLET CONNECTIONS
General:
Use an open-end wrench, not a pipe wrench, to install accessories to the AutoSwitch system.
ALWAYS hold the bulkhead fitting with a wrench when installing the accessories to the
AutoSwitch system. Do not allow the bulkhead fitting to turn; otherwise, connections inside
the box may be loosened. NPT connections require the use of PTFE tape on the threads to make
a gas tight seal (see Figure 6). CONCOA uses PTFE tape on all of its NPT connections. Follow
these rules when using PTFE tape.
a. Do not use oil or grease on fittings. This is especially important for oxidizing gas service.
b. PTFE tape must be used on NPT threads to ensure a gas tight seal. Avoid impinging on the gas stream.
On stainless steel connections, PTFE tape also helps to prevent the connections from galling together
when tightening or loosening.
c. Before applying PTFE tape, inspect the NPT threads, and, if necessary, clean the fitting to remove any dirt
or thread sealant that remains on the threads.
d. Start the PTFE tape on the first thread leaving a slight section of the chamfer exposed as shown in Fig. 6.
Make sure the tape does not overlap the end of the fitting.
e. As tape is wound in the direction of the thread spiral, pull tightly on the end of the tape so that the tape
conforms to the thread.
f. Apply at least 2 but no more than 3 layers of tape to the threads, and cut off excess tape.
g. Press the end firmly into the threads.
Figure 6 - Pictorial View of Tape Seal
Installing the inlet connection:
Warning: The left bank of the AutoSwitch system has a maximum working pressure of
600 PSI (41 bar). Do not install high pressure cylinders to the left bank of the
AutoSwitch system.
When using a Maniflex system:
The ½ male NPT end of the manifold connector will need to be installed in the inlet port of the
AutoSwitch. The other end of the manifold connector will be connected to the starter block of the
528 series Maniflex system. Please follow the instructions provided with the Maniflex system when
connecting and operating the manifold system .
Figure 7 - Manifold connector for the Maniflex system
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1/2” NPT M
1/2” NPT M

For Non-Manifold Use:
If purchased with diaphragm valves, the male ½ NPT ends of the diaphragm valve elbows are
installed into the inlet ports of the switchover system. Install the male ¼ NPT end of each pigtail into
the ¼ NPT ports of the diaphragm valves. The connection available at the other end of the pigtail
will depend on how the system was purchased. If the pigtail does not have a cylinder connection
installed, there will be a female ¼ NPT thread on the end of each pigtail. The female ¼ NPT pigtail
end will connect to the user’s system. If configured with a CGA connection or foreign inlet
connection, the connection will be specific to the particular cylinder of gas to be used. Some
connections do require the use of a gasket. Please note that the material of the gasket must also be
compatible with the type of gas being used. Be familiar with the type of connection being used, and
its proper procedures for installation.
Figure 8 - Pigtail
Connecting to a Cylinder:
Figure 9 - Diaphragm Valve with
1/2” NPT Street Elbow
1. Before removing the cylinder cap, move the cylinder of gas to the work site:
a. Secure cylinder to the floor, wall, or bench with appropriate chain, strap, or stand to
prevent toppling.
b. Remove the cylinder cap.
c. Be sure the cylinder valve is tightly closed (clockwise).
d. Remove the cylinder valve plug, if any.
e. Inspect the cylinder valve and threads for damage or contamination.
2. Secure the cylinder connection to the cylinder in the following manner:
a. Do not force. Tightening the nut onto the cylinder connection should be easy. If it is not,
the connection may be wrong for the type of gas being used.
b. Left-hand threads are used on some cylinder connections. A notch in the middle of the hex
nut typically indicates a left-hand thread.
c. Gaskets are used on some inlet connections. Be sure the gasket is in good shape. Do not
over-tighten to avoid squashing the gasket into the gas line. Keep extra gaskets on hand.
d. Never use oil or grease on regulator or cylinder fittings, as it may contaminate pure
gases or create a fire hazard.
Installing the Outlet Connection:
The AutoSwitch system has the outlet connection at the top of the box. The connection is a 1/4”
tube connection. Connect tubing to the AutoSwitch that is compatible with the application and is
capable of handling the pressure required.
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Pressurizing the System for the First Time (Non-Manifold Use):
Before system startup, it is recommended that all systems be pressure tested, leak tested, and
purged with an inert gas such as nitrogen. To accomplish this with connections other than CGA
580, it will be necessary to use an adapter. The recommended use of an adapter is for temporary
use only for system start up and checks. Adapters should never be used on a permanent basis.
1. Wear safety glasses and gloves.
2. Be sure that both ends of all pigtails are secured before pressurizing. Turn the line regulator
knob counterclockwise until the knob stops turning.
3. When first pressurizing, do not stand in front of or contact the switchover system. Slowly
open the cylinder valve. Observe the high pressure gauge for a rise in pressure up to full
cylinder pressure.
4. Keep the hand wheel or wrench on the open cylinder valve at all times to allow prompt
emergency shut- off.
5. Inspect all connections for leaks, and fix any leaks. A leak detection solution may be applied
to the connections (if compatible with the application) which indicates leaks by bubbling. To
further check for leaks or if the leak detection solution cannot be used, close the cylinder
valve for a period of time (recommended 24 hours), and observe the high pressure gauge
for a drop in pressure. If so indicated, recheck the CGA connection and all other high-
pressure port connections. Never attempt to fix a leak under pressure. If leaks are detected,
depressurize the system, and retighten the connection. Begin again at step 3.
WARNING: While CONCOA assembles the AutoSwitch system components to exacting leak-tight
standards, the customer should also inspect for any loosening of internal parts that may occur in
shipping or installation by completing the pressure decay test detailed above. If all external leaks
have been found and corrected and the system still indicates a leak, disassemble the front cover
from the AutoSwitch after removing the eight screws shown in Figure 10. Check for leaks on the
system’s fittings as described above.
6. Slowly turn the line regulator knob clockwise. This will increase the pressure of the line.
Adjust to the desired working pressure and again check for leaks using the methods
described above.
Figure 10 –Cover Screws
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OPERATION
As the gas in the primary side (liquid cylinders) is depleted, there will not be a drop in gas pressure
on the left gauge until the cylinders are empty. When the inlet pressure drops to the pressure
setting of the reserve side regulator, flow will begin from the reserve cylinder. The inlet pressure on
the primary side will stabilize at 130-140 PSI. This is called a changeover. At this point, the gas
pressure on the reserve side will drop. This indicates that it is time to change the liquid cylinders on
the primary side. Before removing the cylinder, be sure to close the cylinder valve and any other
valves that connect the cylinder to the system. Remove the depleted cylinder(s) and replace with a
full cylinder(s). Note: While changing cylinders on one side, there will be no interruption in flow.
WARNING: After several changeover cycles, it is possible that the reserve cylinder may not have
sufficient reserve capacity. Periodically check the pressure of the reserve high pressure cylinders.
Maintain enough gas in the high pressure cylinders so that when a changeover occurs, the system
will not run out of gas before the liquid cylinders are replaced.
For Pressure Switch Gauge Models:
Adjusting the alarm set point does not affect the switchover point of the AutoSwitch. The alarm is
used to provide an audible and visual warning that a changeover is about to occur. If the nearly
depleted cylinders are changed when the alarm LEDs illuminate, the cylinders will not be as empty
as if the actual changeover had occurred. Slide the red tab seen on each inlet gauge to adjust the
alarm set points. The lowering of the alarm set point pressure may cause the alarm to not work
properly. When adjustments are made, check the function of the system. Pressurize the system and
shut off the inlet pressure to both sides. Allow the inlet pressure to decrease by allowing a small
flow (50 CFH). Observe both inlet gauges. When the left bank is low (below the set point on the
gauge), the red LED will illuminate. Make sure the left red LED illuminates before the pressure on
the opposite side starts to decrease. Allow the system inlet pressure to decrease further until the
right red LED illuminates. This should happen before both inlet pressures start falling together.
Figure 11
MAINTENANCE
Atregularintervals,thesystem shouldbecheckedforleaksandproperfunction(seetroubleshooting).
Any leaks in the system should be corrected immediately. The pigtail check valve should also be
checked for leaks when a depleted cylinder is removed. Note: the system inlet and pigtail should be
pressurized when checking for leaks. At no time should the preset regulator factory settings be
changed. -10-

TROUBLESHOOTING
Symptom
Cause
1. Gas leakage at the line regulator outlet when the
adjusting knob of the line regulator is completely
backed out.
2. With no flow through the system (downstream
valves closed and adjusting screw in) line
pressure steadily increases above set pressure.
3. Gas leakage from spring case (adjusting screw/
knob end of regulator).
4. Gas leakage from any joint.
5. Excessive drop in working pressure with
regulator flowing gas.
6. Gas leakage from relief valve.
7. Gas leakage from any gauge.
8. Gauge does not return to zero when not under
gas pressure.
9. Gauge does not consistently repeat the same
reading.
10. The system makes a noise or hums.
1. Regulator(s) have malfunctioned. Replace or
repair.
1. Inlet gauges not reading pressure.
1. Checkthatthevalvesonthecylindersareopened. If
usingamanifoldsystem,checkthatthevalveon the
manifold is opened.
1. Switchover system seems to be using gas from
the primary and reserve cylinders
simultaneously (pressure is decreasingonboth
inletgaugesatthesametime.)
1. Observe the inlet pressure. It may be necessary to
do this during times of the heaviest use. If the inlet
pressure is less than the values listed below,replace
the high pressure cylinders.
536 2XXX 140PSI (10 BAR)
536 3XXX 140PSI (10 BAR)
537 2XXX 140PSI (10 BAR)
537 3XXX 140PSI (10 BAR)
If the inlet pressure increases significantly when the
system in not in use, then the system is over-
withdrawing the liquid cylinders. Additional capacity
may be added to the system to prevent this.
1. Power light is not on.
1. Check that the remote alarm is powered on.
2. Check that the cable between the AutoSwitch and
the remote alarm is wired correctly.
3. For models with a circular connector on the
AutoSwitch, check that the cable connectors are
properly plugged in at both ends.
1. Status lights are not on.
1. Check that the remote alarm is powered on.
2. Check that the cable between the AutoSwitch and
the remote alarm is wired correctly.
3. For models with a circular connector on the
AutoSwitch, check that the cable connectors are
properly plugged in at both ends.
-11-

TROUBLESHOOTING (Continued)
Symptom
Cause
1. Green status light(s) is lit when the pressure is
belowthesetpointon the gauges.
2. Redstatuslight(s)islitwhenthepressureisabove
theset pointonthegauges.
1. Cable to remote alarm wired incorrectly. Follow
instructions in remote alarm instruction manual
to correct problem.
1. With full tank pressure, red alarm light(s) is on.
1. Check that the set points on the gauges are
set properly.
SERVICE
A Unit that is not functioning properly should not be used and should be returned to CONCOA for
service. A Return Material Authorization (RMA) number must be issued for any product returned to
CONCOA for service. Please contact a Customer Service Representative at 1-800-225-0473 to
receive this number. You will be asked to provide:
1. Model Number
2. Gas Service
3. Inlet pressure and type of gas supply
4. Outlet pressure
5. Approximate gas usage
When shipping product back to CONCOA for repair the, following steps should be followed:
1. Package the product sufficiently to prevent damage. If possible return product in its original
packing.
2. Include RMA number on the outside of the carton.
3. Ship prepaid.
4. Include a written decription of the problem you encountered with the product inside the package.
5. Include a statement of the gas service the product was used in.
6. Purge all equipment before shipping to protect the transporter and service personnel.
Purging is especially important if the equipment has been in hazardous or corrosive gas
service.
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Warranty Information
This equipment is sold by CONTROLS CORPORATION OF AMERICA under the warranties set
forth in the following paragraphs. Such warranties are extended only with respect to the purchase of
this equipment directly from CONTROLS CORPORATION OF AMERICA or its Authorized
Distributors as new merchandise and are extended to the first Buyer thereof other than for the
purpose of resale.
For a period of one (1) year from the date of original delivery (90 days in corrosive service) to Buyer
or to Buyer’s order, this equipment is warrantied to be free from functional defects in materials and
workmanship and to conform to the description of this equipment contained in this manual and any
accompanying labels and/or inserts, provided that the same is properly operated under conditions
of normal use and that regular periodic maintenance and service is performed or replacements
made in accordance with the instructions provided. The foregoing warranties shall not apply if the
equipment has been repaired: other than by CONTROLS CORPORATION OF AMERICA or a
designated service facility or in accordance with written instructions provided by CONTROLS
CORPORATION OF AMERICA, or altered by anyone other than CONTROLS CORPORATION OF
AMERICA, or if the equipment has been subject to abuse, misuse, negligence or accident.
CONTROLS CORPORATION OF AMERICA’s sole and exclusive obligation and Buyer’s sole and
exclusive remedy under the above warranties is limited to repairing or replacing, free of charge, at
CONTROLS CORPORATION OF AMERICA’s option, the equipment or part, which is reported to its
Authorized Distributor from whom purchased, and which if so advised, is returned with a statement
of the observed deficiency, and proof of purchase of equipment or part not later than seven (7) days
after the expiration date of the applicable warranty, to the nearest designated service facility during
normal business hours, transportation charges prepaid, and which upon examination, is found not
to comply with the above warranties. Return trip transportation charges for the equipment or part
shall be paid by Buyer.
CONTROLS CORPORATION OF AMERICA SHALL NOT BE OTHERWISE LIABLE FOR ANY
DAMAGES INCLUDING BUT NOT LIMITED TO: INCIDENTAL DAMAGES,
CONSEQUENTIAL DAMAGES, OR SPECIAL DAMAGES, WHETHER SUCH DAMAGES
RESULT FROM NEGLIGENCE, BREACH OF WARRANTY OR OTHERWISE.
THERE ARE NO EXPRESS OR IMPLIED WARRANTIES WHICH EXTEND BEYOND THE
WARRANTIES HEREINABOVE SET FORTH. CONTROLS CORPORATION OF AMERICA
MAKES NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE WITH RESPECT TO THE EQUIPMENT OR PARTS THEREOF.
-15-

ADI 3198-D
Certified ISO 9001
Controls Corporation of America
1501 Harpers Road Virginia Beach, VA 23454
Telephone [phone] or 757-422-8330 • Fax [phone]
www.concoa.com