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Detailed Steps
STEP 1: SENSORS
STEP 2: TRANSMITTERS
STEP 3: CONTROL SYSTEMS
STEP 4: FLEXIRACKS
STEP 5: POWER SUPPLIES
STEP 6: PROTECTIVE
ENCLOSURES
STEP 7: ACCESSORIES
STEP 8: SPARE PARTS
STEP 9: CALIBRATION
STEP 1: SENSORS
A. Select
sensors by gas to be detected. Sensors are
available for combustible hydrocarbons, hydrogen, hydrogen sulfide (both
electrochemical and
solid
state), carbon monoxide, mercaptan, nitrogen dioxide,
oxygen and sulfur dioxide.
Select one sensor for each point (location) to be monitored. The 365-xxx are the
replaceable element
CommonSensors. They are available either in Aluminum or in
Stainless Steel. Disposable sensors are available for some gases.
If a combustible hydrocarbon sensor is being selected and the environment is
especially problematic, consider selecting a poison resistant sensor.
B. If the atmosphere is dusty, select dust covers. If the
atmosphere is wet or windy,
select splash guards.
If the sensor is to be mounted in a duct with a flow rate higher than 0.07 CFM
(cubic feet per minute) 2 LPM (liters per minute) or if the temperature of the
air exceeds the operating temperature of the sensor, the reclamation adaptor
should be selected.
Ported adaptors should be selected for remotely applying gas
(for calibration) a sensor located in an inaccessible location.
One flame arrestor tool should be purchased if the flame arrestor on the sensor
is likely to get clogged with dust or particles and will need to be cleaned on
site or replaced.
Delphian does NOT recommend on site replacement of the sensor element in the
combustible sensor as the elements are extremely fragile and damage during
replacement will void the warranty. Delphian recommends that element replacement
be performed by Delphian personnel (labor will not be charged) for guaranteed
success.
STEP 2: TRANSMITTERS
A. Select a
transmitter (by gas), one for each sensor.
B. Each transmitter requires an explosion proof housing (conduit box).
The
SafeCAL requires a different housing.
Choose the housing appropriate for the approval required:
CSA,
FMRC. or
BASEEFA.
Transmitter housings ordered as spares will have no approval label. All housings
are rated for groups ABCD (FMRC); BCD (CSA). BASEEFA housings are Zone 1, Group
IIB.
C. If
one person
remote calibration
is required there is a choice:
i. Analog remote calibration module which requires the conduit box to be opened
during calibration. If this option is selected a remote calibration module for
each transmitter (a 1-5mA module for controller based systems, or a 4-20 mA
module for standalone systems) is needed plus a remote calibration meter per
system. The remote calibration module fits in the same housing.
ii. Digital remote calibration module:
SafeCAL®. This option is programmed at
the factory, uses a magnet for calibration and does not require opening the
conduit box. It has a digital readout of gas concentration at the sense point.
See back page for configuring a SafeCAL system.
D. Consider lightning arrestors to protect transmitters? Each arrestor
protects one transmitter and requires its own explosion proof housing.
E. Consider an RFI filter with electrochemical sensors to reduce noise
produced from EMI and RFI.
F. The transmitter may need to be separated from the sensor. (The
electrochemical sensors put out too low a current to be separated from their
transmitter but it is possible with the other sensors). If it does, select (from
sensor accessories) the
sensor extension kit
(this kit includes a
housing, terminal block and connectors for user supplied wiring to separate
transmitter and sensor for up to 100 ft) or sensor extension cord (this is wire
with gold plug-in connectors) in lengths up to 72 inches. If the sensor is more
than a few feet from the transmitter, also select the ported adaptor for easy
calibration.
STEP 3: CONTROL SYSTEMS
Decide on the kind of control system that you need. Delphian offers
controllers mounted in a
Flexirack, and a sophisticated computerized plant-wide
control system (The Sage) which offers digitized speech activated calibration,
soft wiring of relays and documentation of events. If the system that you are
specifying will have 32 points or more, consider the Sage. See the page 6 for
information on configuring the Sage.
To choose a
Delphian controller:
A. Select the controller (by gas to be sensed). Two controller types are
available:
(a) Digital Controller (accepts 1-5mA or 4-20 mA input) - this is a double unit,
one controller for each of two sensor points. Each controller takes two slots in
a Flexirack. A configuration form should be filled out for each sensor point or
gas type.
(b) Analog Controller (accepts 1-5mA input only) single unit, one controller,
takes up one slot in a Flexirack.
B. Decide if
Zone Alarm Modules (ZAMs) are needed.
i. The CAM provides a single relay contact transfer whenever any one alarm
occurs in a rack.
ii. The SAM functions like a CAM but each alarm can be sequentially
acknowledged.
iii. The VAM provides a single relay contact transfer when a specified minimum
number of individual alarms occur in a rack.
C. Are lightning arrestors required to protect the
controllers? (one per controller, not required for ZAMs) Each arrestor needs its
own explosion proof housing.
STEP 4: FLEXIRACKS
If you have chosen controllers, select the
Flexirack mounting.
A. Decide between rack/panel mount, panel mount, or enclosure/wall mount
Flexirack. The 19" rack mount is a 16 slot flexirack.The panel/rack mount
is available from 2 to 16 slots. The wall/enclosure mount is available in from 2
to 16 slots and is most often selected to be installed in a NEMA 4X or NEMA 7
enclosure.
B. Count the number of sensors and zone alarm modules. Add any blank spaces
required for future expansion in enclosure or Flexirack. These are the number of
slots required in the Flexirack, and represents the two numbers before the x in
the Flexirack part number. The x indicates the number of slots on the right end
of the Flexirack which are designated ZAM slots. At a minimum this number must
equal the number of ZAMs purchased with the system. (For example 364-197-082 is
an 8 channel panel mount Flexirack with 6 controller slots and 2 ZAM slots). Add
blank (black) front panels for each slot designated for future expansion.
STEP 5: POWER SUPPLIES
Select a power supply, based on the number of Flexirack slots. (Each
controller channel requires 0.4 amps for combustible catalytic sensors and solid
state hydrogen sulfide sensors, 0.1 amp for electrochemical sensors, 0.2 amps
for infrared sensors and each ZAM 0.2 amps.)
There are three types of Delphian power supplies. All are regulated.
i. Supplies which convert AC (switchable to 117 or 240) to the 24 VDC required by
the Delphian system. (The standard choice).
ii. Supplies which convert 12 VDC to 24 VDC.
iii. Supplies which not only convert AC to DC but incorporate a battery charging
system (trickle charger, circuit breakers, output meters) for a battery back-up.
These power supplies come standard in NEMA 12 enclosures so separate enclosures
need not be selected. Delphian will custom design a battery backup system for
your application. Batteries should only be in NEMA 12 vented enclosures.
However, the power supply/charger can be incorporated into any enclosure type.
If more than 220 Amp Hours are needed, select a second battery set.
If the user supplies power, we suggest regulated or full wave rectified with 1%
ripple, although the system can accept unregulated power.
STEP 6: PROTECTIVE ENCLOSURES (if required)
A. Select a protective enclosure for flexirack/controller
configuration. The Flexirack configurations are intended to be installed in a
control room environment. If this is not the case, a wide variety of enclosures
are available:
NEMA 12 to protect against dust, NEMA 4x against water and
corrosion, and NEMA 7 (Class I, Div 1, C&D) against explosive atmospheres.
Wall mount Flexiracks are used with the NEMA 4x and NEMA 7 enclosures (except
for the special 2 channel NEMA 7), Panel mount Flexiracks are used with NEMA 12
enclosures. All sizes in price sheet are HxWxD in inches. Enclosures are
intended to accommodate the number of controllers specified and the appropriate
power supply. A larger enclosure may need to be chosen to accommodate a
telephone dialer or annunciator panel in the same enclosure or a power
supply/battery back up system.
NOTE: Delphian will custom design an enclosure for your
application.
B. Select options and accessories for the enclosure chosen. For NEMA 4x and NEMA
12 the system accessories in step 7 may also be selected.
STEP 7: ACCESSORIES
Select accessory items for the system. Don’t forget owners manuals. One owner’s
manual will be provided with each system for each gas. Most owners need
several copies. The SafeCAL and Determinator have separate operations
manuals which cover these modules. Select tags and specify engraving if
required.
STEP 8: SPARE PARTS
Don’t forget to specify spare parts. These should include transmitters,
sensors, flame arrestors and flame arrestor sensor tools, remote calibration
modules and meters, calibration screwdrivers.
STEP 9: CALIBRATION
Your system will need to be calibrated regularly
A. Select a
calibration system for each gas to be monitored. Some gases
can be calibrated by a flow method;others are considered too dangerous to use
this method and a static system is provided for them.
Flow calibration kits (which supply gas by flowing it over the sensor)
are of two types. Type A includes everything (a sensor gas connector with
tubing, a pressure and flow regulator assembly and a calibration screwdriver),
except the gas cylinder, needed to calibrate a sensor and comes in a carrying
case which can hold one or two cylinders of calibration gas. Type B does not
include the carrying case. In each instance, A or B, the appropriate gas must be
ordered with the Kit. These gases are offered in 105 liter cylinders and provide
approximately 75 calibrations.
Zero calibration: If there is a background gas, a cylinder of zero air
and a calibration kit should be selected so that a true zero calibration can
occur. This is especially important for toxic gases such as hydrogen sulfide
where a large background can exist without the calibrator’s knowledge. The
infrared sensors require zero air for re-zeroing.
Static calibration systems come in one kit form, Type C, which includes a
calibration chamber, a gas calibration gauge and valve assembly and a
calibration screwdriver. You must select the gas to be used separately. These
gas cylinders are 36 liters and provide approximately 400 calibrations.
Copyright ©2023 Delphian Corporation, Northvale, N.J.,
U.S.A.
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