Farr camfil STR2 User manual

Integrated Dust Collector and Solenoid
Controller
Model STR2-6
and
Model STR2-6-A22
User’s Manual
Installation, Operation and
Maintenance
Certified ATEX Zone 2 and 22:
II 3D Ex mD IP65 A22 T 90 Deg C
II 3G Ex mb IP65 T5

CONTENTS
GENERAL DESCRIPTION...................................................................................................... 3
ATEX CERTIFICATE................................................................................................................4
GENERAL CHARACTERISTICS............................................................................................. 5
FUNCTIONAL CHARACTERISTICS...................................................................................... 5
OPERAION...…………………………………………………………………………………….6
ACCESSING CONTROLS AND REGULATORS ................................................................ 7
ELECTRICAL CONNECTIONS............................................................................................... 9
SPECIAL WARNINGS FOR ATEX NORMATIVE.............................................................. 10
Precautions to be taken to avoid that certain ignition sources become active:....................... 10
Installation .............................................................................................................................. 10
Maintenance............................................................................................................................ 11
Use.......................................................................................................................................... 11
.

GENERAL DESCRIPTION
This device is an economical dust collector control timer. It is available with 2, 4, or 6
solenoids that will activate the dust collector diaphragm valves. The solenoids connect
to the diaphragm valves with ¼” od poly tubing. This control is simple to operate and is
suitable for small dust collectors. The frequency and duration of the timing functions are
adjusted with potentiometers which are accessed by removing a clear Lexan cover.
Electrical connections consist of a power connection and a two wire connection to the
control. This controller will also operate in “on-demand” mode when connected to a
photohelic differential pressure switch. An input is provided to initiate a post shutdown
cleaning of five pulses per filter.
The models are available standard or Atex certified. Their descriptions are designated
as:
Standard Atex
STR2 STR2-A22
STR4 STR4-A22
STR6 STR6-A22

ATEX CERTIFICATE (if applicable)
This series of devices are certified according to the European normative ATEX
(94/9/EC).They have been designed and built to be used in environments considered
potentially explosive because of combustible gas or dust suspended in the air.The
degree of protection offered against the dangers of explosion is shown in the CE-ATEX
labeled on the instrument.
Naturally, due to the importance of safety, it is essential and mandatory by law,
that all the involved people (manufacturer of the instrument, designers and
builders of the plant, installation technician, end user, maintenance man, etc.) is
aware of the safety obligations and observes the mandated procedures.
It is necessary to carefully read this manual and to check that the characteristics
specified by the manufacturer are suitable to the environmental characteristics of
the plant where the instrument will be used. You need to read the instructions
related to the installation of the instrument to ensure its correct use during its
working life and to understand the correct procedures in case of failure and/or
maintenance. These instructions are reported in the specified chapter of this
manual.
Every Cyclic Timer supplied by Autel s.r.l. is equipped with a CE-ATEX certificate of
conformity, with this manual and a nameplate conforming to the 94/9/EC directive that
carries the ATEXmark.
The marking of this instrument is:
II 3D Ex mD IP65 A22 T 90°C
II 3G Ex mb IP65 T5
Simplifying, we can say that this mark means that this device has been designed to
operate in a potentially explosive atmosphere caused by combustible dusts (D=dust)
and gases (G=gas) which will only occur rarely, for short intervals of time during
operation (operation in zone 22 / zone 2) and that the device is designed to offer a
normal level of protection under normal working conditions (no breakdowns). The
method of anti-explosion protection is identified by the letters "mib" meaning that
encapsulation with resin and a control device is used to limit the maximum surface
temperature.
It is guaranteed that the maximum surface temperature in every point of the enclosure,
even in the presence of a breakdown, doesn't overcome 90°C.
This data is important for plant designer, technician and maintenance man to determine
the maximum thickness of the layer of combustible dust and gas that is tolerable to
leave on the surface of the equipment before proceeding to clean it up.
Also they must check that the 90°C temperature level is less than 2/3 of the minimum
ignition temperature of the combustible dust or gas present in the plant that could
determine a potentially explosive atmosphere.

GENERAL CHARACTERISTICS
Enclosure
IP65 – Totally protected from dust ingress and protected from
low pressure water jets.
Black Polyamide / glass sphere composite
Power Supply
90 – 240 Vac 50 /60 Hz
24 Vac 50/60 Hz or Vdc +/- 10% (optional
Power
25 W
Working Temperature
14 to 122 F (-10 to + 50C)
Electrical
Connections
Din 43652 – IP65 Connectors
Power in – black 3 pin
Pressure Switch and Shut Down Cycle – Grey 4 pin
Dimensions
Length 12.2” ( 310 mm)
Width 2.6” ( 65 mm)
Height 5.1” (130 mm)
Fuses
24 Vdc/ac 2A delayed thermal fuse
90 – 240 Vac 0.5A delayed thermal fuse
Functional Characteristics
Off Time
15 to 210 seconds in 15 second increments
4 seconds for special purposes
1 second for test purposes – see dip switch settings
On Time
80 to 650 milliseconds
Input for shut down
cleaning
Close contact to initiate shut down cleaning cycle of five pulses.
DIN contacts 1 and 2
Input Pressure
Input from differential pressure gauge to clean on demand.
Close for clean on demand. Open for continuous cleaning.
DIN contacts 3 and 4

Operation
The STR2-6 timer sequentially activates internal solenoid valves based on the on and
off timer settings. These valves are connected to the primary diaphragm valves on the
filter with ¼” od tubing.
The controller has two 43650 DIN connectors. One connector is for power and ground
and the other is for differential pressure control and initiating the shut down cycle. The
power connector has three prongs for line, neutral and ground. The other connector
has four prongs. Prong 1 and 2 initiate the shutdown cleaning cycle when closed.
Prongs 3 and 4 connect to a pressure switch.
On demand cleaning is controlled with a differential pressure switch such as a Dwyer
photohelic gauge. When contacts 3 and 4 are closed the controller stops pulsing.
Opening the contact will initiate cleaning based on the timer settings. Cleaning
continues until the low pressure set point is reached on the pressure gauge and the
contacts are closed.
The shutdown cleaning cycle is activated by closing contacts 1 and 2. When closed the
controller will fire all solenoids 5 times and then go dormant. This contact is normally
tied to the fan start up. The contact must open on start up or the controller will not start.
The shutdown cleaning cycle can be activated or deactivated through the setting of dip
switch SW#1:
SW#1=ON The shutdown cleaning is deactivated
SW#1=OFF The shutdown cleaning is activated
The shutdown cleaning cycle overrides the on demand cleaning input. The following
chart illustrates the control states for these functions.
SW#1 Shutdown Cleaning input On Demand Cleaning Input Status
On ---- Open Cleaning initiated
---- Closed Cleaning stopped
Off
Closed Open Shutdown cycle starts
Closed Closed
Open Open Cleaning initiated
Open Closed Cleaning Stopped
When the cleaning cycle is interrupted and then resumed the controller starts at the next
sequential output. This occurs even if power is lost.

WARNING:
The DIN inputs for on demand cleaning and/or the shut down cycle are not used the Din
cover must be installed and the wire inlet must be sealed with a 6 – 8 mm cap
(supplied) to maintain the electrical and ATEX ratings.
Lock out power before working on electrical connections to this device.
ACCESSING CONTROLS
To be able to modify the pause and work time, or to enable all or only some of the
installed valves, it is necessary to open the transparent plastic window located on the
cover of the device.This operation exposes the internal circuit to the potentially
explosive atmosphere therefore it is mandatory to follow the following precautions:
•Disconnect the power supply voltage.
•Unscrew the four screws and remove the window. Be careful not to lose the
screws, gasket or the plastic window.
•Adjust settings per the following instructions.
•When finished clean the contacting surface of the gasket and close the
transparent window, being careful to properly position the gasket, and firmly
tighten the four screws.
CONTROLS: DIP-SWITCHES, ROTATING COMMUTATOR AND TRIMMER
The STR Controller is provided with multiple solenoid valves which can vary from 2 to 6.
Dip switches SW#2 and SW#3 control how many valves are used as shown in the
following table. SW#1: Off = Shut down cycle enabled
On = Shut down cycle disabled
SW#2: See Table 1
SW#3: See Table 1
SW#4: ON = Test – off time = 1 sec
Off = Normal – off time per commutator settings
SW#2 SW#3 12345623456345634534
ON ON
OFF ON
ON OFF
OFF OFF
Solenoids Enabled
Table 1: Solenoid control DIP switch settings.

The pulse off time is controlled by a rotating commutator per the
positions in table 2.
The rheostat trimmer is used to set the on time.
Min: 80 milliseconds
Max: 650 milliseconds
Adjust on time so that you hear a sharp pulse similar to a shotgun
blast. The pulse is to long if excessive air hisses out of the valve after
the initial blast.
Table II: Off time
adjustment
Position
Pause
(sec)
0
15
1
20
2
25
3
30
4
35
5
44
6
52
7
60
8
75
9
88
A
100
B
118
C
148
D
175
E
210
F
4

L
NPOWER
SUPPLY
Ground Terminal
Controls
and
Regulators
1-2 - Shut down cycle
3-4 - On demand cleaning
ELECTRICAL CONNECTIONS
The power supply DIN connector is black and contains three contacts for Line, Neutral,
and Ground. This DIN connector has 3 contacts to differentiate it from the control DIN
connector and avoid interchanging of the connectors. The controller contains a bridge
rectifier and will accept AC or DC voltage. The device is not polarized so DC voltage
positive and negative lines can be connected to either L or N terminals.
The control DIN connector is grey. It contains four terminals where 1 and 2 are used for
the shutdown sequence activation and 3 and 4 are used for on demand cleaning and
connect to a differential pressure switch.

WARNINGS:
•Always connect the device to ground
•Do not swap the DIN connectors. If a connector requires excessive force check
that they are not swapped.
•To maintain the IP65 protection level of the DIN connectors follow the following
recommendations:
oDisconnect and lock out power to the controller.
oAllow 10 seconds for the capacitors to discharge.
oThe DIN PG9 compression fitting is designed for 6 to 8 mm (1/4” to 5/16”)
cable.
oCable ends and outer insulator must be fully inserted into compression
fitting.
oCable wires should be securely fastened to screw terminals.
oMake sure the ground is connected correctly for this circuit extends to the
brass bodies of the solenoid valves.
oMake sure the DIN gasket is installed correctly.
oThe screw on the connectors cap should be the original or an exact
equivalent.
SPECIAL WARNINGS FOR ATEX NORMATIVE
For the use of this device in a zone where a potentially explosive atmosphere
could be created due to combustible dust.
Precautions to be taken to avoid the activation of certain ignition sources:
•The plant designer, the installer and the final user must verify that the maximum surface
temperature declared for this device (90°C) is less than 2/3 of the minimum ignition
temperature for the type of dust found in the plant which can cause a potentially
explosive atmosphere.
•It is necessary to take protective measures against lightning strikes in the plant where
this device is installed. It is necessary to protect the device against stray electrical
currents coming from lightning strikes near where this device is installed
•Any accessory (electrical or not electrical) applied by the user to this product, must
conform to the directive 94/9/EC and must have classification CE – Ex compatible.
Moreover any such accessory must be installed in compliance with the instructions given
by its manufacturer/supplier.
Installation
•During the mounting of this device, be careful not to damage any internal components of
whatever it is being mounted to.
•During the mounting of this device in a dangerous zone, it is necessary to prevent the
formation of sparks due to the rubbing of oxidizable substances like iron or steel.
•During the installation phase this equipment must be grounded by means of a electrical
connection. All of the external metallic components will then be grounded.
•The cables for the power-supply, for the output relay contacts and for the other
input/output connections must be installed by the user by means of suitable entry

•Press-cables that don’t compromise the IP protection level declared for the enclosure
must be used.
•For all the device models it is always advisable to install outside of the danger zone, with
zener barriers on the power-supply lines, in order to limit the maximum energy of
possible sparks.
Maintenance
•If this equipment is installed in a place where the formation of a combustible dust layer is
expected, it is necessary to institute a maintenance plan for the periodic cleaning of the
dust layer. The maximum permissible thickness of these layers is a function of the
maximum surface temperature declared for this equipment (90°C), the type of dust and
other environmental conditions.
Use
•If tubes of plastic material (e.g. RILSAN) are present in the equipment in order to
measure the pressure inside it, or in order to carry compressed air to a solenoid valve,
those tubes can be a source of static electricity; therefore rubbing of the tubes must be
avoided.
•The plant designer and the final user must check that no excessive adiabatic air
compression takes place in the inside of the ducts connected to this device, because it
could cause a dangerous temperature rise.
•Before opening the small transparent window in order to access the controls and
regulators (dip-switch and/or trimmer), it is necessary to disconnect the electric power
supply. The electric charge stored in the internal capacitors will exhaust after a short
time (<10s). If the equipment temperature is abnormally high, it is necessary to wait for it
to cool down, or to dismount it, take it apart and then open it in a zone not subject to
explosive atmosphere.