I&M V_9957_AA
ASCO Redundant Control System
2oo2D Enclosure with Proximity Sensor Diagnostics
Operation & Maintenance Guide
ASCO Valves® E301722 - 10/2020 All Rights Reserved. I&M V_9957_AA
©
ASCO, L.P. 160 Park Avenue, Florham Park, New Jersey 07932 www.emerson.com Page 1 of 10
Operation & Maintenance Guide
Redundant Control System
Table of Contents
Table of Contents
PRODUCT DESCRIPTION � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 3
GENERAL SPECIFICATIONS � � � � � � � � � � � � � � � � � � � � � � � � � � � � �4
INSTALLATION � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 4
Section 1� - Normally Closed � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 6
1. General Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2. Testing and Maintenance: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Section 2� - Normally Open � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 7
1. General Operation and Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2. Testing and Maintenance: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Section 3� - Double Acting � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 9
1. General Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2. Testing and Maintenance: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Section 4� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 10
1. Functional Test Certication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2. Spare Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4. Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
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ASCO, L.P. 160 Park Avenue, Florham Park, New Jersey 07932 www.emerson.com
Documentation Conventions
This guide uses the following typographic conventions:
EXAMPLE
NOTE
Notes containing supplementary information.
This symbol precedes information about potential
equipment damage.
This symbol precedes information about potential
personnel hazards.
Description
User Experience Prerequisites
To eectively use the Pneumatic RCS, users should have some
experience with pneumatic systems.
Warnings!
READ THIS ENTIRE MANUAL AND ALL RELATED
PUBLICATIONS PERTAINING TO THE WORK TO BE
PERFORMED BEFORE INSTALLING, OPERATING OR
SERVICING THIS EQUIPMENT.
• Follow all appropriate safety codes and standards.
• Failure to follow instructions may result in personal injury
and/or property damage.
• Use extreme caution when working around power-input
cables. These cables may have potentially lethal or
dangerous voltages.
• Prior to energizing the equipment, have qualified personnel
verify all wiring and connections against vendor drawings.
PRODUCT DESCRIPTION
The RCS is a two-out-of-two (2oo2) or one-out-of-one hot standby
(1oo1 HS) voting, solenoid-operated valve system designed for use as
a component in safety instrumented systems. It functions as a redundant
pneumatic tripping device to control the pilot air signal to a process valve
actuator. The RCS uses 2oo2 or 1oo1 HS voting solenoids to enhance the
reliability of the circuit. The RCS consists of two electrically actuated
solenoid valves (SOV1, SOV2) and a pneumatically operated (Manually
Controlled) bypass valve, and three proximity sensors. The proximity
sensors provide solenoid state feedback and are used during on-line
testing of the RCS unit. The bypass valve allows for maintenance of the
solenoid valves without having to shut down the process valve. The use
of the Maintenance Bypass Valve is not required for functional testing
of the RCS unit. The type of operation (2oo2 NC, 2oo2 NO, 2oo2 DA,
1oo1HS NC, 1oo1HS NO) must be specified by the customer at the time
of order.
Under normal operating conditions:
The RCS allows for periodic testing of the solenoids by cycling one
solenoid valve and then the other either manually or automatically
therefore attaining the desired safety availability. This testing is
performed online without the need for bypassing of the safety action
and without interruption of the process.
For all constructions, three proximity sensors are included to provide
indication of each solenoid-operated valve and bypass valve position.
Normally Closed Construction: The RCS supplies air to the process
valve actuator through the “Process” port when energized.
Normally Open Construction: the RCS blocks the incoming
pneumatic signal and connects the “Process” port to the “Exhaust”
port when energized.
Double Acting Construction: the incoming pneumatic control
signal passes through the RCS to one side (C2) of the process valve
actuator while the other side (C1) of the process valve actuator is
vented through the RCS when energized. The 1oo1 HS mode cannot
be used with the double acting construction�
Incorrect wiring and/or connections can result in equipment
damage or serious system failure. If you have questions or
need more information on installing and operating ASCO
equipment, contact ASCO.
Avertissements!
LISEZ LE MANUEL COMPLET AINSI QUE LES
PUBLICATIONS RELATIVE AU TRAVAIL À EFFECTUER
AVANT D’INSTALLER, D’UTILISER OU DE MAINTENIR CET
ÉQUIPEMENT.
• Suivez toutes les procédures et normes relatives à la
sécurité appropriées.
• Le non-respect des instructions peut entrainer des blessures
corporelles et/ou des dommages matériels
• Travaillez avec une extrême précaution à proximité des câbles
de puissance. Ces câbles peuvent présenter potentiellement
des tensions mortelles ou dangereuses.
• Avant de mettre l’équipement sous tension, faites vérifier
le câblage et les connexions par du personnel qualifié par
rapport aux plans du fournisseur. Un câblage et/ou des
connexions erronée peuvent endommager l’équipement
et provoquer une grave défaillance du système. Si vous
aves des questions ou avez besoin de plus d’informations
sur l’installation et l’utilisation des équipements ASCO,
contactez ASCO.
When a trip occurs:
Normally Closed Construction: the RCS blocks the incoming
pneumatic signal and connects the “Process” port to the “Exhaust”
port. This vents the air signal from the process valve actuator and
allows the actuator return spring to move the process to its fail-safe
position.
Normally Open Construction: the RCS supplies air to the process
valve actuator through the “Process” port. This allows the actuator to
move the process to its fail-safe position.
Double Acting Construction: (C2) of the process valve actuator is
vented through the RCS while the pneumatic control signal is applied
to (C1) of the process valve actuator. This causes the process valve
actuator to move from its normal operating position to its fail-safe
position.
HARDWARE
For proper operation, a pneumatic pressure of 0-150 PSI must be supplied
to the RCS [process connection] while a pressure of 40-150 PSI must
be supplied to the [pilot connection]. It is housed in a 20” x 16” x 8”
enclosure. The primary components include:
• Hard anodized aluminum manifold body
• Two low power solenoid-operated ISO-3 valves
• A key-actuated bypass valve. (Lever Optional)
• Three proximity sensors/switches
• An electrical terminal block for wiring termination (ATEX
rated Ex e IIC)
• Associated wiring.
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©
ASCO, L.P. 160 Park Avenue, Florham Park, New Jersey 07932 www.emerson.com
ASSEMBLY: 542349
ENCLOSURE NEMA 4, 4X
SIZE: 20" x 16" x 8"
MANUALLY ACTUATED
BYPASS SWITCH
MOUNTING BRACKET TOP (2)
PNEUMATIC MANIFOLD
SOLENOID OPERATED
PILOT VALVE 1
(SOV 1)
SOLENOID OPERATED
PILOT VALVE 2
(SOV 2)
BYPASS VALVE
(B/P)
MOUNTING BRACKETS BOTTOM (2)
PNEUMATIC CONNECTIONS
BREATHER DRAIN
EXTERNAL GROUNDING/
EARTHING CONNECTION
PROXIMITY SENSOR SWITCH (3)
INTERNAL GROUNDING/
EARTHING CONNECTION
FIELD WIRING TERMINAL BLOCK
INTERNAL GROUNDING/
EARTHING LOCATIONS
(STUD NOT VISIBLE)
EXTERNAL GROUNDING/
EARTHING LOCATION
GENERAL SPECIFICATIONS
Solenoid Operator:
12, 24, 48 or 120 Volt DC Low Power, Class
F coil-1.4 watts.
120/60-110/50 or 230/50-240/50 AC 10.1
Watts, Class H Coil.
Pneumatic Valve:
ISO-3; 5/2 air-spring valve; solenoid operated/
Requires external pilot air supply.
Bypass Valve:
ISO-3; 5/2 air-spring valve; manually
operated/Requires external pilot air supply.
Manifold:
3 - station ISO base; unique pneumatic circuit
design.
Proximity Sensor/Switch:
3 each
Switch Type:
SPDT switches, hermetically sealed, Stainless
Steel
Switch Contact Rating:
Silver Contacts
Resistive Load
4 amps @ 120 VAC
2 amps @ 240 VAC
3 amps @ 24 VDC
1.25 amps @ 12 VDC
INSTALLATION
This section provides the information needed to install the RCS.
Unpacking:
Upon receipt of the RCS, unpack it carefully and visually check for
damage. The packing list shows the complete model number and describes
the features of the unit.
1. If the unit is damaged, immediately contact ASCO.
2. If everything is in order, proceed to the instructions in the
following sections.
Mounting Location Considerations:
The RCS is designed to be field mounted near the process valve to be
actuated. The following factors should be considered when selecting a
mounting location:
Figure 1. RCS 2oo2D With Enclosure Components, Approx. Weight 28.1 kg (62 lbs)
Pneumatic Connections:
Pilot:
1/8” NPTF
Pilot Pressure:
40-150 psi
Inlet & Process:
1/2” NPTF
Exhaust Port:
1/2” NPTF
Inlet Pressure Range:
0 psi to 150 psi
Air Quality:
Instrument air per ANSI/ISA 7.0.01-1996
Particle size ≤ 40 microns.
Materials:
Enclosure:
Stainless Steel (304 SS, 316SS) or Fiberglass
Size:
20”x 16”x 8”
Weight:
Approximately 28.1 kg(62 lbs)
Mounting Panel
Painted Steel
Manifold:
Anodized aluminum.
• Accessibility: Allow ample space for door operation, and for wiring
and tubing runs.
• Temperature: Consider the amount of heat generated by equipment
in the mounting area. The RCS is intended for operation in ambient
temperatures from - 40 °C to 60 °C (-20 °C to 60 °C with local
manual reset option).
• Environment: Ensure that RCS unit is compatible with respect to
water ingress and corrosion resistance.
WARNING:
any component while circuit is live unless the area is known
Valves:
Body – Die-cast Aluminum alloy, SealingNitrile (NBR) and Polyurethane (PUR), Spool
- Stainless Steel.
Solenoid Coil:
Epoxy encapsulated.
Proximity Sensors/Switches:
316 Stainless Steel
Environmental:
Ambient temperature range:
Consult panel nameplate to verify.
• -40 °F to 140 °F (-40 °C to 60 °C)
• With local manual reset option = -4 °F
to 140 °F (-20 °C to 60 °C)
Approvals:
Exida
Certied SIL 3 capable (Standard Normally
Open and Normally Closed constructions,
see SIL certicate for special constructions).
Explosion Hazard! Do not remove or replace
to be non-hazardous.
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ASCO, L.P. 160 Park Avenue, Florham Park, New Jersey 07932 www.emerson.com
AVERTISSEMENT:
Risque d’explosion! Ne pas retirer ou
remplacer les composants lorsque le circuit est sous tension
sauf en atmosphère non explosible.
ASCO components are intended to be used only within the technical
characteristics as specified on the nameplate. Changes to the equipment
are only allowed after consulting the manufacturer or its representative.
The surface temperature classification depends on the voltage, wattage
and ambient temperature which are stated on the nameplate. Depending
on the ambient/operation temperature heat resistant cabling capable for the
temperature as indicated on the nameplate must be used.
Mounting:
The RCS is designed to be mounted using the four mounting brackets
provided as shown in the figure below. It is recommended that four 3/8” or
10 mm diameter bolts be used.
254 mm
process
1/2” NPT
inlet (supply)
1/2” NPT
Normally Closed
exhaust
1/2” NPT
pilot (supply)
1/8” NPT
541 mm
406 mm
241 mm
Figure 2. Mounting Dimensions
Field Connections:
Pneumatic Connections (Figure 3A)
WARNING:
Explosion Hazard! Do not remove or
replace any component while circuit is live unless the area
is known to be non-hazardous.
AVERTISSEMENT:
Risque d’explosion! Ne pas retirer
ou remplacer les composants lorsque le circuit est sous
tension sauf en atmosphère non explosible.
The RCS should be mounted as closely to the process valve as possible.
In order to insure proper operation of the process valve, tubing runs
should be as straight and short as possible. Recommended piping for
the inlet and outlet pneumatic connections to the RCS is ½” stainless
steel tubing. Recommended piping for pilot supply is 1/8” stainless steel
tubing.
Wiring Guidelines
The following general guidelines apply to all wiring discussed in this
document.
WARNING:
Circuit power must be removed from the
device prior to disconnecting the wiring on either the eld
or internal side of the terminal strip.
AVERTISSEMENT:
L’alimentation électrique du circuit
doit être coupée avant de déconnecter le câblage ou le
bornier interne de l’équipement.
• Wiring shall be according to the National Electrical Code (ANSI-
NFPA 70), Zone 1 ATEX requirements or other applicable codes.
inlet (supply)
1/2” NPT
process
1/2” NPT
exhaust
1/2” NPT
pilot (supply)
1/8” NPT
Normally Open
inlet (supply)
1/2” NPT
C2 process
1/2” NPT
exhaust
1/2” NPT
C1 process
1/2” NPT
pilot (supply)
1/8” NPT
Double Acting
Figure 3A. Pneumatic Connections
• Wire size: stranded 16 and 18 AWG.
• The terminal clamps are designed for one wire only; DO NOT
attempt to terminate multiple wires into one terminal.
• Use care when running signal wiring near to or crossing conduit
or wiring that supplies power to motors, solenoids, lighting,
horns, bells, etc.
• AC power wiring should be run in a separate conduit from DC
power. All power wiring to and from the RCS should be in
grounded conduit.
• The RCS should be connected to a high quality instrument grade
ground with #14 AWG or heavier wire. A grounding stud is
provided both inside and outside the enclosure.
Electrical Connection (Customer Responsibility):
General (Figure 3B)
1. In all cases follow local and national electrical codes and conrm
compliance with Zone 1 ATEX requirements.
2. Placement of the conduit connection is up to the customer, in
compliance with Zone 1, ATEX requirements, based on location
Page 5 of 10 I&M_V_9957_AA
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INTERNAL GROUNDING/
EARTHING LOCATIONS
(STUD NOT VISIBLE)
EXTERNAL GROUNDING/
EARTHING LOCATION
codes as well as ATEX Zone 1 requirements. Green earthing terminal
blocks are provided for easy installation of conductor up to 4 mm sq.
Only insert one conductor per terminal block. Grounding studs are
provided inside and outside of the enclosure for additional grounding/
earthing requirements. (see Figure 3C)
RCS-R Base Unit
1. Connect the power source to the designated terminals (SOV1,
SOV2) as per wiring diagram provided with the RCS unit. Wiring
diagrams are available on the Internet at: www�ascovalve�com/
rcscongurator
2. Wire the three proximity sensors switches (PS1, PS2 & PS3) as per
wiring diagram.
3. Wire optional accessories.
Section 1� - Normally Closed
1� General Operation
The RCS is a two-out-of-two (2oo2) or one-out-of-one hot standby
(1oo1 HS) voting, solenoid-operated valve system designed for use as a
component in safety instrumented systems. It functions as a redundant
pneumatic tripping device to control the pilot air signal to a process
valve actuator. Both solenoids must be de-energized (De-Energize-ToTrip Version) prior to moving the process to its fail-safe position. Three
proximity sensors are included to provide indication of each solenoidoperated valve and bypass valve position.
The RCS allows for periodic testing of the solenoids by cycling one
solenoid valve and then the other either manually (when ordered with
a local initiation of SOV test option) or automatically by the system
DCS, therefore maintaining the desired safety availability. This testing
is performed online without the need for bypassing of the safety action
and without interruption of the system process.
Under normal operating conditions, the RCS supplies pilot air to the
process valve actuator through the “process” port. When a trip occurs,
the RCS blocks the incoming pneumatic signal and connects the
“process” port to the “exhaust” port. This vents the air signal from the
process valve actuator and allows the actuator return spring to move the
process valve actuator to its fail-safe position.
Proximity sensors report solenoid valve positions as shown in
Table 1�
RUN MODE: De-Energized to Trip
• If either or both solenoid valves SOV1 and SOV2 are
in the energized position, INLET pressure is directed to
the PROCESS port.
• If both solenoid valves SOV1 and SOV2 are in the de-energized
position, INLET pressure is blocked and pressure from the
PROCESS port is vented to the EXHAUST port.
• Reference Table 1 for the various states of solenoid energization,
and the resulting status of the PROCESS/Outlet port and PS
proximity sensor contact state.
BYPASS MODE: De-Energized to Trip
Manually Actuated Maintenance Bypass valve operation:
The manually actuated bypass switch has two positions. NORMAL
for system run and MAINTENANCE BYPASS for the maintenance
of the solenoid valves. To change positions simply rotate the key to
mm
mm
mm
470
mm
25
483
25
25
mm
25
mm
178 mm
left side
127
mm
left side
Enclosure openings are
permitted in shaded
areas. Multiple openings
must have a minimum
of 102 mm. spacing.
Maximum number of
enclosure openings is 4
per side.
Stainless Steel
Enclosures
Entry of external
conductors and cable
must be thru properly
installed and suitable
ameproof cable entry
devices and conform to
local and national wiring
codes and zone 1 ATEX
requirements.
Composite
Enclosures
178 mm
rightside
127
mm
rightside
165
mm
165
mm
25
mm
483
mm
25
mm
470
mm
Figure 3B. Enclosure Openings
and ease of installation. The upper or lower left side of the box will
give the shortest run to the wire terminal.
3. Cable/conduit connections can be added in location as shown on
Figure 3B. Entry of external conductors and cables must be through
properly installed and suitable certified flameproof cable entry
devices and in accordance with ATEX Zone 1 increased safety
requirements. Assemble and install cable glands per manufacturer’s
instructions. Connect cable ground connections to the grounding/
earthing terminal blocks or grounding / earth studs provided
internally and externally.
4. It is recommended that standard industry practices are followed
to prevent condensation from entering the enclosure and, in some
cases of Class I, Div 2 or ATEX Zone 1 conditions, to prevent
hazardous gasses and vapours from migrating through the conduit
to the control room or open ignition source.
Grounding and Earthing. (Figure 3C)
Internal and external grounding studs are provided on the RCS product.
Ground/earth the product in accordance with local and national electric
desired position, indicated on the switch. (A lever option is available
in the place of the key)
• The manually operated bypass switch is used to isolate and
depressurize the solenoid valves during maintenance. The
maintenance bypass valve position is indicated by proximity sensor
No. 3 contacts (PS3).
• In bypass mode, the RCS INLET port is directly connected
to the PROCESS port. The solenoid valves are vented to
the EXHAUST port.
• In the bypass mode, the Normally Open contacts of PS1 and
PS2 are closed and PS3 is open, indicating that no pressure is on
solenoid valves.
• Reference Table 1 for the various states of SOV solenoid
valve energization, and the resulting status of PS proximity
sensor contact state.
2� Testing and Maintenance:
Testing:
Solenoid-operated valve testing
The solenoid-operated valves and their associated proximity sensors
Figure 3C. Grounding Connections
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can be tested online without interruption to the process. This testing is
Table 1 - RCS States, Normally Closed, De-Energize to Trip
State SOV1 SOV2 Bypass Valve
1 Energized Energized Normal Operation Open Open Closed Air Supply
2 De-Energized De-Energized Normal Operation Closed Closed Closed Vented
3 De-Energized Energized Normal Operation Closed Open Closed Air Supply
4 Energized De-Energized Normal Operation Open Closed Closed Air Supply
5 * * Maintenance Bypass Closed Closed Open Air Supply
* - SOV valves are vented to exhaust when in Maintenance Bypass mode.
implemented by cycling each solenoid-operated valve and comparing the
associated proximity sensor contact reading to the test table 1.
2. Verify that all 3 proximity sensor contacts are indicating the RCS is
Partial Stroke testing
A partial stroke of the process valve can be performed online without
interruption to the process. This testing is implemented by performing
solenoid-operated valve testing, then moving the process valve toward the
safe state for a predetermined time. At the end of the predetermined time,
the process valve is returned to the normal position.
Testing can be automated using a programmable logic controller (PLC) or
a distributed control system (DCS).
CAUTION:
(De - Energize - To - Trip Version) De -
energizing two solenoid valves at the same time will initiate
the switch and place the key in the bottom of the enclosure
until maintenance has been completed.
maintenance du commutateur et placez là au bas du boitier
jusqu’à ce que la maintenance soit terminée.
replace any component while circuit is live unless area is
known to be non - hazardous.
a shutdown.
ATTENTION:
(version « De-Energize-To-Trip ») la
coupure électrique de deux électrovannes simultanément
déclenchera un arrêt.
1. At all times during testing, one out of the two solenoid-operated valves
must be in the energized position (De-Energize-To-Trip Version).
2. IF, during the test process, the proximity sensors do not indicate
what is expected according to the test table 1, the second solenoidoperated valve must not be de-energized.
Maintenance:
WARNING:
Use wet or damp cloth when cleaning any non-metallic/
painted surfaces.
AVERTISSEMENT:
électrostatique. Utilisez un chion humide quand vous
nettoyez toutes les surfaces non métalliques ou peintes.
The Pneumatic RCS requires no routine maintenance except periodic
inspections for loose wires and fittings. The enclosure should be
opened occasionally and the components checked to make sure they
are tight, clean, and dry. The Breather/Drain shall be inspected for
obstruction and that it is free of debris during routine maintenance
cycles and during manual proof testing.
Potential Electrostatic Charging Hazard.
Risque potentiel de décharge
Manually-Actuated Bypass Valve
If it is necessary to replace a solenoid-operated valve or coil during
normal operation, the manually-operated bypass valve is used.
This valve is used to isolate and depressurize the solenoid valves, for
maintenance only.
When the switch is rotated to the bypass position, the RCS manifold
channels the inlet pressure directly to the process port. Pressure to the
solenoid valves is vented to “exhaust”. The NORMALLY OPEN contacts
of PS1 and PS2 are closed, and PS3 is open, which signals the PLC/DCS
that the RCS is in bypass and not in shut down.
Manual Bypass Valve Operation
(for maintenance only)
WARNING:
enclosure unless area is known to be non-hazardous.
AVERTISSEMENT:
le boitier dans une atmosphère explosible.
1. Turn the key clockwise from “Normal” to “Maintenance Bypass”.
The system pressure is now bypassed directly from “inlet” to
“process” so that the process valve position is maintained.
Explosion Hazard. Do not open the
Risque d’explosion. Ne pas ouvrir
ou remplacer les composants lorsque le circuit est sous
tension sauf en atmosphère non explosible.
3. Turn off power to the RCS; disconnect appropriate wires from
4. Remove device (coil, solenoid valve) and install the new device
5. Turn on power to the RCS. Verify that each device has power and is
6. Replace key in the Maintenance Bypass and rotate counter-
7. Have the control room run through the programmed test to be sure
Section 2� - Normally Open
1� General Operation and Testing
The RCS is a two-out-of-two (2oo2) or one-out-of-one hot standby
(1oo1 HS) voting, solenoid-operated valve system designed for use as
a component in safety instrumented systems. It functions as a redundant
pneumatic tripping device to control the air signal to a process valve
actuator. Both solenoids must be de-energized (De-Energize-To-Trip )
prior to moving the process to its fail-safe position.
Three proximity sensors are included to provide indication of each
solenoid-operated valve and bypass valve position. The RCS allows for
periodic testing of the solenoids by cycling one solenoid valve and then
the other either manually (when ordered with a local initiation of SOV
test option) or automatically (by the system DCS) therefore attaining the
desired safety availability. This testing is performed online without the
need for bypassing of the safety action and without interruption of the
system process.
Under normal operating conditions, the RCS blocks the pilot air supply
from the process valve and connects the “process” port to the “exhaust”
port. When a trip occurs, the RCS supplies pilot air to the process valve
actuator through the “process” port. This allows the actuator to move the
process valve actuator to its fail-safe position.
The Proximity Sensors report solenoid valve positions as shown
in Table 2�
RUN MODE: De-Energized to Trip
• If both solenoid valves SOVl and SOV2 are in the de-energized
• If either or both solenoid valves SOVl and SOV2 are in the
Normally Open Contact State
PS1 PS2 PS3
in Bypass. Refer to table 1.
WARNING:
AVERTISSEMENT:
WARNING:
AVERTISSEMENT:
terminal block.
following instructions supplied. If replacing a solenoid valve, apply
a small amount of anti-seize to the bolt threads and torque to 160175 in-lbs in a crisscross pattern. Reconnect wires to appropriate
terminal, (see wiring diagrams).
in the correct state. (See Table 1).
clockwise to the “Normal” position.
the system is operating properly.
position, INLET pressure is directed to the PROCESS port.
energized position, INLET pressure is blocked and pressure
from the PROCESS port is vented to the EXHAUST port.
Remove the maintenance bypass key from
Retirez la clé de dérivation de
Explosion Hazard. Do not remove or
Risque d’explosion. Ne pas retirer
Process/Outlet
Page 7 of 10 I&M_V_9957_AA
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ASCO, L.P. 160 Park Avenue, Florham Park, New Jersey 07932 www.emerson.com
• Reference Table 2 for the various states of solenoid
energization, and the resulting status of the PROCESS/Outlet port
and PS proximity sensor contact state.
BYPASS MODE: De-Energized to Trip
Manually Actuated Maintenance Bypass valve operation:
The manually actuated bypass switch has two positions. NORMAL
for system run and MAINTENANCE BYPASS for maintenance of
the solenoid valves. To change positions simply rotate the key to the
desired position, indicated on the switch. (A lever option is available in
place of the key)
• The manually operated bypass switch is used to isolate and
depressurize the solenoid valves during maintenance. The
maintenance bypass valve position is indicated by proximity
sensor No. 3 contacts (PS3).
• In bypass mode, the RCS INLET port is blocked and the
PROCESS port and solenoid valves are vented to the EXHAUST port.
• In the bypass mode, the NORMALLY OPEN contacts of PSl and
PS2 are closed, and PS3 is open, indicating that no pressure is on the
solenoid valves.
• Reference Table 2 for the various states of solenoid
energization, and the resulting status of PS proximity sensor
contact state.
2� Testing and Maintenance:
Testing:
Solenoid-operated valve testing
The solenoid-operated valves and their associated proximity sensors/
switches can be tested online without interruption of the process. This
testing is implemented by cycling each solenoid-operated valve and
comparing the associated proximity sensor contact to the test table 2.
Partial Stroke testing
A partial stroke of the process valve can be performed online without
interruption of the process. This testing is implemented by performing
a solenoid-operated valve testing, then moving the process valve
toward the safe state for a predetermined time. At the end of the
predetermined time, the process valve is returned to the normal
position. Testing can be automated using a programmable logic
controller (PLC) or a distributed control system (DCS).
CAUTION:
energizing two solenoid valves at the same time will initiate
a shutdown.
ATTENTION:
coupure électrique de deux électrovannes simultanément
déclenchera un arrêt.
1. At all times during testing, one out of the two solenoid-operated valves
must be in the energized position (De-Energize-To-Trip Version).
2. IF, during the test process, the proximity sensors do not indicate
what is expected according to the test table 2, the a second solenoidoperated valve must not be de-energized.
Maintenance:
WARNING:
Use wet or damp cloth when cleaning any non-metallic/
painted surfaces.
AVERTISSEMENT:
électrostatique. Utilisez un chion humide quand vous
nettoyez toutes les surfaces non métalliques ou peintes.
(De - Energize - To - Trip Version) De -
(version « De-Energize-To-Trip ») la
Potential Electrostatic Charging Hazard.
Risque potentiel de décharge
The Pneumatic RCS requires no routine maintenance except periodic
inspections for loose wires and fittings. The enclosure should be
opened occasionally and the components checked to make sure they
are tight, clean, and dry. The Breather/Drain shall be inspected for
obstruction and that it is free of debris during routine maintenance
cycles and during manual proof testing.
Manually-Actuated Bypass Valve
If it is necessary to replace a solenoid-operated valve or coil during
normal operation, the manually operated bypass valve is used.
This valve is used to isolate and depressurize the solenoid valves for
maintenance only.
When the switch is rotated to the bypass position, the “inlet” air
to the RCS is blocked. The “process” port is connected to the
“exhaust”. Pressure to the solenoid valves is vented to “exhaust”. The
NORMALLY OPEN contacts of PS1 and PS2 are closed, and PS3 is
open which signals the PLC/DCS that the RCS is in bypass and not
in shut down.
Manual Bypass Valve Operation
(for maintenance only)
WARNING:
enclosure unless area is known to be non-hazardous.
AVERTISSEMENT:
le boitier dans une atmosphère explosible.
1. Turn the key clockwise from “Normal” to “Bypass”. The
system pressure is now blocked by the RCS, “process” is
connected to “exhaust”.
2. Verify that all 3 proximity sensors contacts are indicating the RCS is
in Bypass. Refer to Table 2.
WARNING:
the switch and place the key in the bottom of the enclosure
until maintenance has been completed.
AVERTISSEMENT:
maintenance du commutateur et placez là au bas du boitier
jusqu’à ce que la maintenance soit terminée.
WARNING:
any component while circuit is live unless area is known to
be non - hazardous.
AVERTISSEMENT:
ou remplacer les composants lorsque le circuit est sous
tension sauf en atmosphère non explosible.
3. Turn off power to the RCS; disconnect appropriate wires from
terminal block.
4. Remove device (coil, solenoid valve) and install the new device
following instructions supplied. If replacing a solenoid valve, apply
a small amount of anti-seize to the bolt threads and torque to 160175 in-lbs in a crisscross pattern. Reconnect wires to appropriate
terminal (see wiring diagrams provided with unit). Wiring
diagrams are available on the internet at: www�ascovalve�com/
rcsconfigurator.
5. Turn on power to the RCS. Verify that each device has power and is
in the correct state. (See Table 2).
6. Replace key in the Bypass and rotate counter-clockwise to the
“Normal” position.
7. Have the control room run through the programmed test to be sure
the system is operating properly.
Explosion Hazard. Do not open the
Risque d’explosion. Ne pas ouvrir
Remove the maintenance bypass key from
Retirez la clé de dérivation de
Explosion Hazard. Do not remove or replace
Risque d’explosion. Ne pas retirer
Table 2 - RCS States, Normally Open, De-Energize to Trip
State SOV1 SOV2 Bypass Valve
1 Energized Energized Normal Operation Open Open Closed Vented
2 De-Energized De-Energized Normal Operation Closed Closed Closed Air Supply
3 De-Energized Energized Normal Operation Closed Open Closed Vented
4 Energized De-Energized Normal Operation Open Closed Closed Vented
5 * * Maintenance Bypass Closed Closed Open Vented
* - SOV valves are vented to exhaust when in Maintenance Bypass mode.
Normally Open Contact State
PS1 PS2 PS3
Process/Outlet
Page 8 of 10 I&M_V_9957_AA
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ASCO, L.P. 160 Park Avenue, Florham Park, New Jersey 07932 www.emerson.com
Section 3� - Double Acting
NOTE: One-out-of-one hot standby (1oo1HS) mode cannot be used
with the Double Acting RCS- L�
1� General Operation
The RCS is a two-out-of-two (2oo2) or one-out-of-one hot standby
(1oo1 HS) voting, solenoid-operated valve system designed for use
as a component in safety instrumented systems. Double acting RCS
units are only available in 2oo2. It functions as a redundant pneumatic
tripping device to control the air signal to a process valve actuator.
Both solenoids must be de-energized (De-Energize-To-Trip) prior to
moving the process to its fail-safe position.
Three proximity sensors are included to provide indication of each
solenoid-operated valve and bypass valve position. The RCS allows
for periodic testing of the solenoids by cycling one solenoid valve and
then the other either manually (when ordered with a local initiation
of SOV test option) or automatically (by the system DCS) therefore
attaining the desired safety availability. This testing is performed
online without the need for bypassing of the safety action and without
interruption of the system process.
Under normal operating conditions, the incoming pilot air supply for
the process valve actuator passes through the RCS to one side (C2)
of the process valve actuator while the other side (C1) of the process
valve actuator is vented through the RCS.
When a trip occurs, (C2) of the process valve actuator is vented
through the RCS while the pneumatic control signal is applied to (C1)
of the process valve actuator. This forces the process valve actuator
to move from its normal operating position to its fail-safe position.
The Proximity Sensors report solenoid valve positions as follows:
RUN MODE: De-Energized to Trip
• If both solenoid valves SOVl and SOV2 are in the energized
position, INLET pressure is directed to the C2 PROCESS port, and
C1 PROCESS port is vented to the EXHAUST port.
• If both solenoid valves SOVl and SOV2 are in the de-energized
position, INLET pressure is directed to the C1 PROCESS port, and
C2 PROCESS port is vented to the EXHAUST port.
• Reference Table 3 for the various states of solenoid energization, and
the resulting status of the PROCESS/Outlet port and PS proximity
sensor contact state.
BYPASS MODE: De-Energized to Trip
Manually Actuated Maintenance Bypass valve operation:
The manually actuated bypass switch has two positions. NORMAL
for system run and MAINTENANCE BYPASS for maintenance of
the solenoid valves. To change positions simply rotate the key to the
desired position, indicated on the switch. (A lever option is available in
place of the key)
• The manually operated bypass switch is used to isolate and
depressurize the solenoid valves during maintenance. The
maintenance bypass valve position is indicated by proximity
sensor No. 3 contacts (PS3).
• In bypass mode, the RCS INLET port is directed to C2 PROCESS
port and C1 PROCESS port and solenoid valves are vented to
the EXHAUST port.
• In the bypass mode, the normally open contacts of PSl and PS2
are closed, and PS3 is open, indicating that no pressure is on the
solenoid valves.
• Reference Table 3 for the various states of solenoid
energization, and the resulting status of PS proximity sensor
contact state.
2� Testing and Maintenance:
Testing:
Solenoid-operated valve testing
The solenoid-operated valves and their associated proximity sensors
can be tested online without interruption to the process. This testing is
implemented by cycling each solenoid-operated valve and comparing
the associated proximity sensor contact to the test table 3.
Partial Stroke testing
A partial stroke of the process valve can be performed online without
interruption to the process. This testing is implemented by performing
a solenoid-operated valve testing, then moving the process valve
toward the safe state for a predetermined time. At the end of the
predetermined time, the process valve is returned to the normal
position. Testing can be automated using a programmable logic
controller (PLC) or a distributed control system (DCS).
CAUTION:
energizing two solenoid valves at the same time will initiate
a shutdown.
ATTENTION:
coupure électrique de deux électrovannes simultanément
déclenchera un arrêt.
1. At all times during testing, one out of the two solenoid-operated valves
must be in the energized position (De-Energize-To-Trip Version).
2. IF, during the test process, the pressure switches do not indicate what
is expected according to the test table 3, the second solenoid-operated
valve must not be de-energized (DE-Energize-To-Trip Version).
(De - Energize - To - Trip Version) De -
(version « De-Energize-To-Trip ») la
Maintenance
WARNING:
Use wet or damp cloth when cleaning any non-metallic/
painted surfaces.
AVERTISSEMENT:
électrostatique. Utilisez un chion humide quand vous
nettoyez toutes les surfaces non métalliques ou peintes.
The Pneumatic RCS requires no routine maintenance except periodic
inspections for loose wires and fittings. The enclosure should be opened
occasionally and the components checked to make sure they are tight,
clean, and dry. The Breather/Drain shall be inspected for obstruction
and that it is free of debris during routine maintenance cycles and during
manual proof testing.
Manually-Actuated Bypass Valve
If it is necessary to replace a solenoid valve or coil during normal
operation, the manually operated bypass is used. The valve is used to
isolate and depressurize the solenoid valves for maintenance only.
When the maintenance bypass valve is in its maintenance bypass position,
the RCS “inlet” port is directly connected to the “process” port (C2), and
“process” port C1 is connected to the “exhaust” port. In the Maintenance
Bypass mode the NORMALLY OPEN contacts of pressure sensor PS1
and PS2 are closed, and PS3 is open.
Manual Bypass Valve Operation
(for maintenance only)
WARNING:
enclosure unless area is known to be non-hazardous.
Potential Electrostatic Charging Hazard.
Risque potentiel de décharge
Explosion Hazard. Do not open the
Table 3 - RCS States Double Acting
State SOV1 SOV2 Bypass Valve
1 Energized Energized Normal Operation Open Open Closed Vented Air Supply
2 De-Energized De-Energized Normal Operation Closed Closed Closed Air Supply Vented
3 De-Energized Energized Normal Operation Closed Open Closed Air Supply Air Supply
4 Energized De-Energized Normal Operation Open Closed Closed Vented Vented
5 * * Maintenance Bypass Closed Closed Open Vented Air Supply
* - SOV valves are vented to exhaust when in Maintenance Bypass mode.
Normally Open Contact State
PS1 PS2 PS3
Process
Outlet C1
Process
Outlet C2
Page 9 of 10 I&M_V_9957_AA
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ASCO, L.P. 160 Park Avenue, Florham Park, New Jersey 07932 www.emerson.com
AVERTISSEMENT:
Risque d’explosion. Ne pas ouvrir
le boitier dans une atmosphère explosible.
1. Turn the key clockwise from “Normal” to “Maintenance Bypass”.
The system pressure is now bypassed directly from “inlet” to
“process” port (C2) so that the process valve position is maintained
(a lever option is available in place of the key).
2. Verify that all three proximity sensor contacts are indicating the
RCS is in bypass. Refer to Table 3.
WARNING:
Remove the maintenance bypass key from
the switch and place the key in the bottom of the enclosure
until maintenance has been completed.
AVERTISSEMENT:
Retirez la clé de dérivation de
maintenance du commutateur et placez là au bas du boitier
jusqu’à ce que la maintenance soit terminée.
WARNING:
Explosion Hazard. Do not remove or
replace any component while circuit is live unless area is
known to be non - hazardous.
AVERTISSEMENT:
Risque d’explosion. Ne pas retirer
ou remplacer les composants lorsque le circuit est sous
tension sauf en atmosphère non explosible.
3. Turn off power to the RCS; disconnect appropriate wires from
terminal block.
4. Remove device (coil, solenoid valve) and install the new device
following instructions supplied. If replacing a solenoid valve, apply
a small amount of anti-seize to the bolt threads and torque to 160175 in-lbs in a crisscross pattern. Reconnect wires to appropriate
terminal, (see wiring diagrams provided with the RCS unit).
5. Turn on power to the RCS. Verify that each device has power and is
in the correct state. (See Table 3).
6. Replace key in the Maintenance Bypass and rotate counter-
clockwise to the “Normal” position.
7. Have the control room run through the programmed test to be sure
the system is operating properly.
Packaging
While the package for RCS is designed to handle the weight of the
unit, there are always hazards in shipping. Upon receipt of product,
unpack and check the product against the packing slip. If there is
damage to the product, immediately contact the Authorized ASCO
sales representative.
4� Disclaimer
Because of the variety of uses for the ASCO Redundant Control
System (RCS), the user and those responsible for applying this
equipment must satisfy themselves as to the acceptability of the RCS
for each application.
The illustrations in this manual are solely intended to illustrate the
text of this manual. Because of the many variables and requirements
associated with this particular installation, ASCO cannot assume
responsibility or liability for actual use based upon the illustrative uses
and applications.
In no event will ASCO be responsible or liable for indirect or
consequential damages resulting from the use or application of this
equipment. ASCO disclaims any implied warranties of merchantability
or fitness for a particular purpose.
ASCO DISCLAIMS ANY IMPLIED WARRANTY OR
FITNESS FOR A PARTICULAR PURPOSE�
No patent or copyright liability is assumed by ASCO with respect to
use of information, circuits, equipment or software described in this
text.
Reproduction of the content of this manual, in whole or in part, without
written permission from ASCO is prohibited.
Section 4�
1. Functional Test Certication
Once assembled and inspected the RCS is cycled through a generic
program to validate two-out-of-two (2oo2) or one-out-of-one hot standby
(1oo1 HS); shut down function; solenoid valve status and pressure switch
indication and manual bypass function.
2� Spare Parts
WARNING:
from ASCO or an authorized distributor or the certications
may be invalidated or there may be a risk of explosion.
AVERTISSEMENT:
uniquement être approvisionnées auprès d’ASCO ou d’un
de ses distributeurs agréés, sinon les certicats pourraient
être invalidés et il pourrait y avoir un risque d’explosion.
APPLICATION VOLTAGE
De-Energize-To-Trip 12/DC 326424 238714-903-D
De-Energize-To-Trip 24/DC 325909 238714-902-D
De-Energize-To-Trip 48DC 326425 238714-912-D
De-Energize-To-Trip 120/DC 326426 238714-904-D
De-Energize-To-Trip 120/60–110/50 326427 238814-032-D
De-Energize-To-Trip 230/50–240/50 326428 238814-059-D
Bypass ALL 323493 None
Replacement parts are only to be obtained
Le pièces de rechange doivent
VALVES AND COILS
VALVE
includes proximity
sensor/switch
COIL
Page 10 of 10 I&M_V_9957_AA
©
ASCO, L.P. 160 Park Avenue, Florham Park, New Jersey 07932 www.emerson.com
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