I.R.I.S. P522 User Manual
FLAME MONITORING SYSTEM
MODEL P522 SIGNAL PROCESSOR
APPLICATION MANUAL
IRIS MODEL P522 APPLICATION MANUAL
Table of Contents
IRIS MODEL P522 ---------------------------------------4
WIRING AND INSTALLATION------------------------4
FIGURE 1 - P522 REAR MOTHERBOARD-------4
WIRING TO THE PLUG-IN TERMINALS ----------5
WIRING OF VIEWING HEAD-------------------------6
FIGURE 2 - WIRING OF VIEWING HEAD --------6
FIGURE 3 - WIRING AND ASSEMBLY -
VIEWING HEAD -------------------------------------- 7
OPTIONAL LTA ADAPTER----------------------------7
POWER SUPPLY ----------------------------------------8
FIGURE 4 - POWER SUPPLY TABLE -------------9
FACTORY STOCKED POWER SUPPLIES------- 9
REDUNDANT POWER SUPPLIES------------------ 9
SELF-CHECKING FUNCTION --------------------- 10
APPROVALS -------------------------------------------- 10
POWERING UP THE P522-------------------------- 10
SET POINTS -------------------------------------------- 11
FIGURE 5 - SET POINTS---------------------------- 11
CHANGING SET POINTS --------------------------- 11
FLAME FAILURE RESPONSE TIME (F.F.R.T.) 12
4-20mA REMOTE OUTPUT------------------------- 12
FIGURE 6 - REMOTE METER ANALOG OUTPUT 12
INSTALLATION OF VIEWING HEAD------------- 13
FIGURE 7 - VEWING HEAD CROSS-
REFERENCE TABLE--------------------------- 13
SIGHTING OF THE VIEWING HEAD------------- 13
MULTIBURNER REQUIREMENTS --------------- 14
FIGURE 8 - CUTOFF FREQUENCIES----------- 14
MULTIPLE VIEWING HEADS ---------------------- 14
DETERMINING SIGHT PIPE SIZE---------------- 15
SELECTING THE PIPE------------------------------- 15
MOUNTING HOLE------------------------------------- 15
MOUNTING OF SIGHT PIPE ----------------------- 15
INSTALLING THE VIEWING HEAD--------------- 15
PURGE AIR---------------------------------------------- 15
SETUP AND ADJUSTMENT PROCEDURES -- 16
SIGHTING ADJUSTMENT--------------------------- 16
INITIAL SETUP ----------------------------------------- 16
ADJUSTING SET POINTS -------------------------- 17
TROUBLESHOOTING GUIDE --------------------- 18
NOISE INTERFERENCE AND GROUNDING-- 18
S506 VIEWING HEAD -------------------------------- 19
S506 SELF-CHECKING VIEWING HEAD------- 20
S509 VIEWING HEAD -------------------------------- 20
S511 VIEWING HEAD -------------------------------- 21
S512 VIEWING HEAD -------------------------------- 21
ORIFICING----------------------------------------------- 23
FIGURE 9 - ORIFICING: SIGNAL-REDUCING
CHARACTERISTICS OF DISCS ---------------- 23
SIGNAL SOURCES ----------------------------------- 23
VIEWING HEAD - ANGLE OF VIEW------------- 24
FIGURE 10 - VIEWING HEAD: ANGLE OF VIEW
- DISTANCE AND DIAMETER ------------------- 25
APPLICATION OF IRIS VIEWING HEADS ----- 25
LOW NOx APPLICATIONS-------------------------- 26
APPLICATION OF P522 ----------------------------- 26
USING A PLC WITH IRIS FLAME MONITOR-- 26
FIGURE 11 - VIEWING HEAD APPLICATION
TABLES ------------------------------------------------ 27
FIGURE 11 - VIEWING HEAD APPLICATION
TABLES Cont’d--------------------------------------- 28
BASIC BURNER START CIRCUIT ---------------- 29
FIGURE 12 - BASIC BURNER START CIRCUIT 30
MODULE COMMUNICATIONS -------------------- 31
MODBUS COMMUNICATION ---------------------- 31
COMMUNICATING WITH MODICON PLC ----- 32
COMMUNICATION WITH HUMAN-INTERFACE
HOST COMPUTER --------------------------------- 32
RS-232 to RS-422 CONVERSION----------------- 32
SETTING ADDRESSES------------------------------ 32
TECHNICAL HELP------------------------------------- 33
FIGURE 13 - SPECIFICATIONS------------------- 34
FIGURE 14 - MODEL P522 FRONT PANEL --- 35
FIGURE 15 - MODEL P522 SIDE VIEW --------- 36
FIGURE 16 - S5XX VIEWING HEAD
DIMENSIONS ------------------------------------------- 36
FIGURE 17 - IR VIEWING HEAD LOCATION-- 37
FIGURE 18 - UV VIEWING HEAD LOCATION 37
FIGURE 19 - OPPOSED FIRED VIEWING
HEAD SIGHTING -------------------------------------- 38
FIGURE 20 - VIEWING HEAD MOUNTING ---- 38
INDEX ----------------------------------------------------- 39
Page 2
IRIS MODEL P522 APPLICATION MANUAL
Figure Index
FIGURE 1 - P522 REAR MOTHERBOARD--------------------------------------------------------------------4
FIGURE 2 - WIRING OF VIEWING HEAD ---------------------------------------------------------------------6
FIGURE 3 - WIRING AND ASSEMBLY - VIEWING HEAD ------------------------------------------------7
FIGURE 4 - POWER SUPPLY TABLE --------------------------------------------------------------------------9
FIGURE 5 - SET POINTS----------------------------------------------------------------------------------------- 11
FIGURE 6 - REMOTE METER ANALOG OUTPUT-------------------------------------------------------- 12
FIGURE 7 - VEWING HEAD CROSS-REFERENCE TABLE-------------------------------------------- 13
FIGURE 8 - CUTOFF FREQUENCIES------------------------------------------------------------------------ 14
FIGURE 9 - ORIFICING: SIGNAL-REDUCING CHARACTERISTICS OF DISCS ----------------- 23
FIGURE 10 - VIEWING HEAD: ANGLE OF VIEW - DISTANCE AND DIAMETER---------------- 25
FIGURE 11 - VIEWING HEAD APPLICATION TABLES-------------------------------------------------- 27
FIGURE 11 - VIEWING HEAD APPLICATION TABLES Cont’d ---------------------------------------- 28
FIGURE 12 - BASIC BURNER START CIRCUIT----------------------------------------------------------- 30
FIGURE 13 - SPECIFICATIONS-------------------------------------------------------------------------------- 34
FIGURE 14 - MODEL P522 FRONT PANEL ---------------------------------------------------------------- 35
FIGURE 15 - MODEL P522 SIDE VIEW ---------------------------------------------------------------------- 36
FIGURE 16 - S5XX VIEWING HEAD DIMENSIONS ------------------------------------------------------ 36
FIGURE 17 - IR VIEWING HEAD LOCATION--------------------------------------------------------------- 37
FIGURE 18 - UV VIEWING HEAD LOCATION ------------------------------------------------------------- 37
FIGURE 19 - OPPOSED FIRED VIEWING HEAD SIGHTING------------------------------------------ 38
FIGURE 20 - VIEWING HEAD MOUNTING ----------------------------------------------------------------- 38
Page 3
IRIS MODEL P522 APPLICATION MANUAL
IRIS MODEL P522
The P520 and P522 Signal Processors are used with
the IRIS Model 500 Viewing Heads. The P522
Signal Processor is a relay panel mount version of the P520 plug-in module, and replaces the
M502 motherboard and its two plug-in daughter
boards, the A513 and the D504.
GND +26V BAT
SC C
F1
.75 A
WIRING AND INSTALLATION
Before wiring or installing the P522, we recommend
that you read the companion colour brochure describing the functions and attributes of this series of signal processors.
SC OFF
SC ON
RF C
RF OFF
SC
RELAY
RF ON
RF ON
RF
RELAY
RF C
RF OFF
RS-422
+TX
-TX
+RX
0-20mA or
4-20mA
ANALOG
CURRENT
DRIVE
-RX
GND
RMT
METER
+26V
SIG
GND SIG
VH SEL
RELAY
CHAN
SELECT
++--+
CHAN
SEL
V.H.
SEL
SIG
SHUTTER
DRIVE
+V
SC
SIG
GND
V.H.A. V.H.B.
GND
SIG
GND
F2
.25A
SIG
SC
+V
GND
Page 4
FIGURE 1 - P522 REAR MOTHERBOARD
IRIS MODEL P522 APPLICATION MANUAL
WIRING TO THE PLUG-IN TERMINALS
Figure 1 illustrates the plug-in terminals on the rear mother
board and how they are connected internally. The flame
relay and self-checking relay contacts are situated together
in the upper right portion of the diagram.
RF C refers to the common terminal of the flame relay,
with ON being flame on, and OFF being flame off. You
will note that there are two sets of contacts used for the
flame relay.
SC C refers to the common terminal of the self-check-
ing relay. There is only one pair of contacts used
for the self-checking function. Here, the designation ON refers to the self-checking taking place in a
normal manner. OFF indicates a failure in the viewing head or processor resulting from:
- the hardware (i.e. the shutter mechanism in
the viewing head, or the output relay itself);
- electronic components anywhere, or
internal software in the P522; or
- the power to the unit is OFF – the most
likely condition.
The main power feeds in through the terminals situated on the upper left side (see GND, +26V and BAT).
Each designated terminal is a double terminal, or pair,
so that the wiring from the power supply can be “daisy
chained” from one P522 to the next without having to
twist wires together into one termination.
The pair designated BAT is for battery backup, if
used. Note the rectifier used internally to prevent
the 26 VDC main power supply from feeding into
the battery. The backup battery, if used, should be
24 volts, to ensure that the 26 VDC power feeding
the P522 will not feed back into the battery. In other
words, no current will flow from the battery as long
as voltage of the main power supply is above that of
the battery. The negative side of the battery goes to
the GND terminal on the left.
and is rated at .25 Amp. On newer units (those with
NO, CAL, and YES in red letters on the front panel)
these fuses are self-resetting types, and will recover
from an overload automatically after power is removed from the P522 for 10 seconds.
The viewing head terminals (bottom right) are iden-
tified as V.H. A. and V.H. B. If only one viewing
head is used, you must wire to the V.H. A. terminals. To the left of the viewing head terminals are
two terminals marked V.H. SEL (viewing head se-
lector relay). Energizing this connection with 19 to
38 VDC will cause the relay on this PC board to
switch to viewing head B. The nominal voltage of
this relay is 24V, but the 26 VDC power circuit can
be used to switch this relay, if desired.
Only the viewing head signal wire (SIG) and the sig-
nal ground wire (SIG GND) are switched with this
changeover relay; the 26 VDC and power ground
circuit is not disturbed. Make sure that the viewing
head signal wire and signal ground (braided shield
in the four-conductor cable) are both connected, because this ground connection is the only return path
for the signal and self-checking circuit. Also, the 26
VDC used to switch this relay must be connected
with the proper polarity, because the relay used is a
single-side stable type. (Relays that are polarized
magnetically offer increased contact force resulting
in higher current-carrying capability). The two terminals marked V.H. SEL go directly to the relay coil.
The pair of terminals designated CHAN SEL (to the
left of the V.H. SEL terminals) is used for selecting
channel A or channel B on the P522. Energizing
this pair of terminals causes the B channel to be selected. Polarity must be observed when wiring this
connection (the positive terminal is on the right).
This is an isolated input, so two wires are required.
Any DC voltage from 7.5 to 30 may be used. The
current required will depend upon the voltage, because this is a photocoupler interface circuit with a
3900 ohm resistor feeding the LED light source.
Figure 1 shows how these terminals are connected
inside the P522. Note the two fuses marked F1 and
F2. F1 is the main power fuse for the signal processor as well as the viewing head(s), and is rated at .75
Amp. Fuse F2 feeds only to the viewing head(s),
For example: a 26 VDC voltage will result
in a current flow of 25/3900 = .0064 Amp.
If flame is being detected and the channels are
switched, the flame relay will remain energized for
Page 5
IRIS MODEL P522 APPLICATION MANUAL
one cycle regardless of the new set points, allowing
channel changes “on the fly,” so to speak. If the
new flame OFF set point is equal to or greater than
the current signal count, then the flame relay will
de-energize on the subsequent cycle.
The pair of terminals designated RMT METER (to
the left of the CHAN SEL terminals) is for the remote
meter connection. This output is a current-driven signal that ranges from 0 to 20 mA for remote meters,
and can be switched to a range of 4 to 20 mA for DCS
(distributed control system) applications (refer to sec-
tion 4-20mA REMOTE OUTPUT). Connect the
terminal marked “positive” to the positive meter terminal. This current signal can be used with a volt
meter by feeding the signal to a resistor connected to
the ground. The voltage developed across the resistor will follow Ohm’s law V = IR.
For example: a 3-volt meter can be used
with a resistor of 3/.02 = 150 ohms, which
will result in a full-scale reading of 3 volts
for a 20mA output.
The four terminals called +TX, -TX, +RX, and -RX
(to the left of RMT METER terminals) are used for
the serial communication link. The serial communication is achieved by using ASCII character code
transmission at 4800 or 9600 baud through the RS232 com ports on the host computer. The P522 uses
RS-422 data transmission which is over two, twisted
pairs that are differentially transmitted and received,
allowing long wire runs to be used through noisy
environments. An RS-232 to RS-422 converter must
be used to communicate with the P522, and the connections are made to the terminals marked +TX, TX, +RX and -RX. The transmitting, twisted pair
goes to the TX terminals, and the receiving, twisted
pair goes to the RX terminals.
Note: the terms “transmit” and “receive” used here
with respect to the P522 will be reversed with respect to the RS-232 connection on the host computer.
Refer to later sections in this manual for a detailed
description of the software and how it is to be used
with the P522.
WIRING OF VIEWING HEAD
Wiring of the viewing head is made to the terminals
on the lower right side of the P522. These terminals
are described as follows:
TERM DESCRIPTION
+V 24 VDC power to viewing head
GND Power Ground
SC Self-check/shutter drive signal to
viewing head
SIG Flame signal from viewing head
SIG GND Signal ground
Figure 2 shows a four-conductor cable to the viewing head. Note that the flame signal wire going to
terminal SIG is shielded, and the shield is terminated
at both ends of the cable SIG GND.
WIRING SIDE VIEW - COVER REMOVED
CONNECT SHIELD
TO TER M 3
USE SHRINK TUBING
Page 6
WHITE
SHIELD
FIGURE 2 - WIRING OF VIEWING HEAD
RED
GREEN
BLACK
+V
GND
SC
SIG
GND
SIG
P522
+24VDC
GND
SHUTTER
DRIVE
GND
SIGNAL
CABLE ENTRY NUT
CABLE
IRIS MODEL P522 APPLICATION MANUAL
IRIS CABLE
3 CONDUCTORS PLUS 1 COAX
3CONDUCTORS: 16 AW G 19 STRAND INSULATED WITH
CROSSED-LINKED-POLYETHYLENE .017 THK
COLORS: BLACK-RED-GREEN
1 COAX: 16 AW G 19 STRAND INSULATED WITH
CROSSED-LINKED-POLYETHYLENE .017 THK
COLOR WH ITE
36 AW G B RAIDED SHIELD 90% COVERAGE
WITH .012 THK JACKET COLOR BLACK
CABLED: POLYPROPYLENE FILLERS FOR ROUNDNESS
JACKET: CROSSE D-LINKED-POLYETHYLENE
GROMMET
FLAT WASHE R
CABLE
PREPA RATION
STRIP 3/8“ TYPICAL
(TYP)
1 3/4“
SHIELD *
CABLE CLAMP
FINAL ASSEMBLY
Optional LTA Adapter
INSULATE SHIELD WITH SHRINK
TUBING LEAVING 3/8“ STICKING OUT
CONNECTOR WITH
REAR COVER REMOVED
CONNECTOR JACKSCREW
* CABLE IS SHOWN WITH SHIELD
ALREADY REMOVED FROM W HITE WIRE
FIGURE 3 - WIRING AND ASSEMBLY - VIEWING HEAD
Page 7
IRIS MODEL P522 APPLICATION MANUAL
A source impedance resistor is required when using
the P522 module with a S550 viewing head. This
resistor should be 330 ohm (factory installed) for
viewing head cable runs up to 500 feet, and it should
be 150 ohm for cable runs 500 feet to 1000 feet.
The resistor should be installed across the SC and SIG
GND terminals. A 1/4 watt resistor is suitable.
Originally, specifications of the IRIS Model 500 instructed that a five-conductor cable be used, with
one wire shielded. However, the standard is now a
four-conductor cable, with one wire shielded. In
this case, the shield is used as the signal ground wire
that goes to terminal SIG GND on the P522 and to
pin 3 on the viewing head plug. The shield should
be a braided type for this application –do not use a
foil type shield– so that a solid signal ground is maintained. This signal ground shield is also the selfchecking circuit return path. Refer to Figures 2 and
3 for wiring details.
Connections of the IRIS cable to the viewing head
plug should be performed as follows:
5. Slide nut (with threads toward the cable
end), the washer and the grommet onto
the cable approximately six inches.
6. Slip the cable through the bottom opening of the connector, making sure that the
cable’s outer jacket is secure under the
cable clamp, and tighten the two screws
on the cable clamp.
7. Reassemble the grommet, flat washer and
cable entry nut, and tighten.
8. Before wiring to connector, strip each
wire 3/8 inch, as shown in assembly diagram, Figure 3.
9. Proceed to wire the connector. Refer to
Figure 2 for terminal locations.
– Connect the viewing head signal wire
WHT (the shielded wire) to terminal
No. 1 by inserting it into the opening,
then tightening the retaining screw.
After removing the plug from its packaging, take the
cable entry nut out of its housing. Remove rubber
grommet and flat sealing washer. With a pair of longnosed pliers, remove the center ring only of the rubber grommet.
1. Strip two inches of the cable’s outer cover
from the cable, removing any cellophane
wrap or filler material, and strip the insulation from the shielded wire (if insulated over shield) a full two inches, to
expose shield.
2. Slide the shield back until a bulge develops close to where the wire exits the
cable’s outer covering.
3. Carefully spread a few strands of the shield
at the bulge –making sure not to break any
strands– to create an opening, and slip wire
out of shield through opening.
4. Carefully return shield to original shape
and length by pulling gently, then cover
with plastic shrink tubing to prevent shorts.
– Connect the shutter drive signal wire
BLK to terminal No. 2.
– Connect the signal ground shield from
the WHT wire to terminal No. 3 with
shrink tubing.
– Connect the 24 VDC power wire RED
to terminal No. 4.
– Connect the power ground wire GRN
to terminal No. 5.
– Assemble the back of the plug and insert
jackscrew through the plug assembly.
The cable wiring at the other end going to the signal
processor is easier. The cable should be prepared in
a similar way to the plug end – particularly the shield
from the WHT wire. Make sure the shield doesn’t
touch the other terminals.
POWER SUPPLY
Careful consideration should be given to the power
supply used for the P522. 26 VDC is used to back
bias the “steering” rectifier, as shown in Figure 1, to
Page 8
IRIS MODEL P522 APPLICATION MANUAL
prevent the power from feeding into the 24 VDC
supply. Each P522 module draws approximately 150
mA, and each viewing head draws about 100 mA of
power (26 VDC). Actually, the S506 and S511 viewing heads use less current, but it is a good idea to
figure 100 mA for each viewing head used. Also,
the amount of current drawn by the P522 will depend upon other factors that can affect the peak current, such as whether or not there is flame being detected, the remote meter output is connected, and serial communication is occurring.
The viewing head is powered through the P522 via a
0.25 A self-resetting fuse. In other words, the 26
VDC power feeds into the P522 (through a 0.75 A
self-resetting fuse) and feeds back out through a 250
mA fuse to the viewing head, resulting in a current
drain of about 0.25 A for each P522 (with one viewing head). This small amount of current means that
one power supply could support a number of P522
modules. The self-resetting fuses change to high resistance when their current ratings are exceeded, but
recover to their normal low resistance when power
is removed.
with one viewing head each. And the 100-watt power
supply will support up to fifteen P522 modules with
one viewing head per each 100 watt. These “switching type” power supplies are efficient and very compact. To obtain the size and weight of the power
supplies, contact IRIS Systems Inc.
Each power supply can be either rail mounted or
panel mounted, and it is up to each end user to determine their installation preferences and requirements.
We recommend that not more than four P522 signal processors be supported by one 26 VDC power supply. For
instance, four P522 processors with one viewing head
each equals a total of 26 watts – a relatively small
power supply, particularly if an efficient, switching
type is used.
Other possible combinations can be used; for instance, the battery backup terminal could be used
for redundancy. However, care must be taken with
these redundant schemes to make sure that failure of
the primary power supply won’t affect the backup
power supply, as well.
REDUNDANT POWER SUPPLIES
STTAWNIYTICAPACYLPPUSREWOP225PLEDOMSIRI
YTQW5.7W51W03W05W001
1
2
3
4
5
6
7
8
9
01
XXXX
XXX
XXX
XX
X
X
X
X
X
X
FIGURE 4 - POWER SUPPLY TABLE
FACTORY STOCKED POWER SUPPLIES
Power supplies are readily available from the factory for the P522 modules. The 30-watt power supply will support up to six or seven P522 modules
with one viewing head each. The 50-watt power
supply will power up to six or seven P522 modules
It may be more economical to use larger-capacity
power supplies for applications using 12 or more
P522 signal processors.
For example: the 100-watt power supply
available from the factory can handle
twelve P522 modules, each with one viewing head. Should the power supply fail, a
redundant scheme utilizing two power
supplies with “steering” rectifiers to prevent current from flowing into a failed
power supply output would prevent the 12
flame monitors from being de-energized.
The positive output from each power supply is wired
to the anodes of the MBR 1545CT. This dual,
Schottky-type rectifier, rated for 15 Amps, will present
a low forward voltage drop for this application. Both
power supplies can be adjusted for 26V output, and a
low-voltage indicator light can be used on the output
of each power supply to monitor their outputs.
Larger power supplies can be used with this redundant wiring scheme if there are more than twelve P522
Page 9
IRIS MODEL P522 APPLICATION MANUAL
modules in a system. Care should be taken when wiring multiple P522s to ensure the selected bus wires
will carry the current. The plug-in terminals on the
P522 will accommodate a wire size up to 14AWG,
allowing for relatively high currents. Note that, if the
power wiring (26 VDC) is “daisy chained” by using
the terminal pairs provided, the pairs are “jumpered”
by copper traces on the mother board; so, if the plug
is pulled out, the jumpered connection is broken.
SELF-CHECKING FUNCTION
When energized, the self checking function indicates
that both the P522 and the viewing head are functioning properly. The software in the P522 activates
the self-checking relay only if there are less than 10
pulses coming in from the viewing head during each
dark period. To energize this relay, the software must
generate pulses –at a particular rate and with a specific duty cycle– to a self-checking circuit. If this
regular pattern is not maintained, or if any of the
circuitry fails, the relay will drop out. The blinking
LED on the front panel labelled SELF-CHECK O.K.
is evidence that voltage is applied to the coil of this
self-checking relay, because both are energized by
the same voltage. The difference is that the voltage
to the coil is applied steadily, while the voltage from
the relay to the LED is gated on and off by the software in conjunction with the pulses counted during
the dark period.
Note that, with regard to the viewing head, the self
checking function still works the same way as with
the M502, A513 and D504 signal processors. For
instance, a runaway UV tube will cause a “lockout
condition” (more than 10 pulses counted during the
dark period). (Refer to section EXPLANATION
OF 1-9, > 10 PULSES COUNTED DURING THE
DARK PERIOD, in the Model 500 Signal Proces-
sor Application Manual.)
A runaway UV tube or any component failure, in-
cluding the shutter, will cause a lockout condition that
will de-energize the flame relay. The LOCKOUT light
on the P522 will indicate this condition, requiring a
reset to return to normal flame monitoring mode. A
reset can be achieved only if the lockout condition
has been corrected, and can be performed from the
front panel (by pressing the RESET button), or remotely through the serial communication.
APPROVALS
The P522 and viewing heads have Factory Mutual (FM)
Approval for Combustion Safety; Canadian Standards
Association (CSA) Certification, and National Recognized Testing Laboratories (NRTL) Listing.
POWERING UP THE P522
Once the power is connected (26 VDC) to the plug-in
connector, the P522 will be operational. There is no
ON/OFF switch on the P522; the moment it is powered on, it will reset and start up. The self-checking
light will start blinking, and one of the channel LEDs
(A or B) will light (A will be ON if the channel select
input at the plug-in connector is de-energized). Make
sure the voltage is 24 to 26 VDC. The P522 will be
reset when the power is turned on; however, the power
must be a step function (i.e., the power must be applied abruptly) for this reset to work properly.
The P522 has been designed to deal with any foreseeable power failure or anomaly.
For example: if the power goes off while
you are in the process of storing a set
point (either from the front panel or from
the remote, host computer), the internal
power monitor circuit will signal the
P522 processor to complete the store
function before shutting down in an orderly manner. This prevents bogus numbers from being stored and protects existing data in the EEPROM (Electrically
Erasable Programmable Read Only
Memory) from corruption, and is facilitated by a special internal power supply
that holds a charge (like a battery) just
long enough to allow the processor to do
its job before going dead.
This internal circuit monitors the 26 VDC power
feeding the P522, and when the voltage drops to
about 19 volts, the processor shuts down, the program stops running, and the self-checking function
ceases (the self-checking relay de-energizes). The
Page 10
IRIS MODEL P522 APPLICATION MANUAL
blinking, SELF-CHECK O.K. light on the front panel
will go out, and the flame relay will de-energize.
Please note that the S509 and S512 viewing heads
will shut down at about 17.0 volts; these heads have
their own power-monitoring capability, and will shut
down on their own, independent of the signal processor.
When the power feeding the P522 exceeds 19 volts,
the processor starts the program again. The SELFCHECK O.K. light will start blinking, and the selfcheck relay will energize. If flame is present and a
S509 or S512 viewing head is being used, the flame
signal will not come back on until the power reaches
21.5 volts. This can cause a lockout condition if the
viewing head turns on during the dark period (defined
by the periodic self-check signal going to the viewing
head each second), requiring a manual reset of the
P522. There is a 20 per cent probability that a lockout will occur because of the duty cycle of the selfcheck function (200 mSEC on and 800 mSEC off).
The other viewing heads (the S506, S511) do not incorporate the power-monitoring shutdown function,
and will not cause a lockout condition.
To see what the current set points are, simply push the
desired button. For instance, to determine the current
FLAME ON set point, press the FLAME ON button. The
set point will be displayed on the readout for about four
seconds, then return to normal. The set points displayed
will be for the channel that is active, which is indicated by
a steady illumination of push-button A or B.
To see the other channel set points, first select the channel (A or B), then press the desired set point button.
For example: if channel A is already ON,
indicating it is functional, and B is
pressed, A will go out and B will proceed to blink slowly, indicating that further action is required. If A is already
ON and A is pressed, it will stay steady
ON and start to blink rapidly after a set
point button is pressed.
In all cases, A or B will rapidly blink after the set
point is selected. This action alerts the user that the
current display is no longer that of the flame signal,
and further action is required.
These design precautions ensure that there will never
be an unsafe situation created by abnormal line power
(115 VAC) conditions. The 26 VDC power is very
unlikely to come on gradually, but, if this did occur,
the P522 would not get a proper reset. So, there is
another function in the 87C52 processor (used in the
P522), implemented by circuitry and software, that
causes the P522 to appear dead (i.e., the front panel
will be dark) and to stay this way until the power is
recycled in an abrupt manner, initiating the reset.
SET POINTS
There are 10 set points stored in memory in the P522,
divided into two equal sets, A and B.
SET POINT DISPLAY NUMBER
FLAME ON 4 DIGIT NUMBER 0001-2999
FLAME OFF 4 DIGIT NUMBER 0000-2999
GAIN S ET 2 DIGIT NUMBER 00 - 99
F.F.R.T. 1 DIGIT NUMBER 1, 2 OR 3
TIME DELAY ON 1 DIGIT NUMBER 0, 1, 2 or 3
The fact that A or B is already on has nothing to do
with the process of viewing the current set points,
except that you do not have to select the channel if it
is already on. The steady illumination of A or B indicates which channel is functionally active, and is selected at the plug-in terminals marked CHAN SEL.
At any time, you can press the reset button causing
the P522 to go back to its normal operating condition. The reset button is also used for resetting the
lockout condition as explained in the section SELF-
CHECKING FUNCTION.
CHANGING SET POINTS
Changing any of the five set points is easy. Simply
bring up the desired set point and change it using the
UP or DOWN arrow buttons. When the desired number is displayed, press the STORE button. When
the set point is stored, four dashes are displayed
momentarily, indicating that the selected number was
stored into the EEPROM. Illogical settings cannot
be made; so, if four “E’s” are displayed when pushing STORE P.B., then an error was made when se-
FIGURE 5 - SET POINTS
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IRIS MODEL P522 APPLICATION MANUAL
lecting the set points. For instance, selecting a flame
out set point that is equal to or greater than the flame
on set point will result in this error indication.
As well, the set points can be selected remotely through
the serial communication port using a host computer –
explained in greater detail later in this manual.
FLAME FAILURE RESPONSE
TIME (F.F.R.T.)
The flame failure response time, or F.F.R.T., is defined as the time it takes for the flame relay to deenergize after the flame signal (from the viewing
head) drops out. This time delay is programmable
from both the front panel of the P522 and a remote,
host computer. Only three settings are possible: one,
two and three seconds.
The maximum time delay is limited to three seconds
in compliance with the FM (Factory Mutual) limit
of the F.F.R.T. to not more than four seconds.
The P522 decision-making process occurs on a periodic basis, and the decision to start a F.F.R.T. time
delay before de-energizing the flame relay is initiated every second in step with the sampling rate of
the flame signal. This means that the actual flame
out condition (i.e., drop-out of the flame signal from
the viewing head) will, in all probability, occur during the sampling period that causes the actual
F.F.R.T. to be greater than the set time.
For example: suppose the signal from
the viewing head drops out immedi-
ately after a sampling from the P522,
and the sampling perceives flame to
be present. If the F.F.R.T. set point is
set for three seconds, there will be an
actual time delay of nearly four seconds. In other words, the actual
F.F.R.T. will be the current set-point
time, plus an additional amount of
time not exceeding one second, depending upon when the flame signal
from the viewing head drops out.
4-20mA REMOTE OUTPUT
The standard remote meter output has a 0-20mA
range and is designed to drive remote meters, as explained earlier in this manual. You can convert this
output to a 4-20mA range, as follows:
Press the front panel push-buttons (indicated
in the table below) while holding down both
the ⇑ and ⇓ buttons. Press all in each row
together (i.e., three in the first row, two in
the second row, and three in the last row).
EMALF
NO
XXX
XXX
FIGURE 6 - REMOTE METER ANALOG
Doing this toggles the function back and forth between the 0-20mA and 4-20mA ranges.
The change will be verified by four dashes “----”
and “4-20” momentarily displayed. If the module is
programmed for the 4-20mA range, “4-20” will be
displayed; toggling back to the 0-20mA range will
again cause four dashes to appear on power-up of
the unit. Tha factory default setting are 4-20.
One thing to consider when feeding the 4-20mA signal to a remote computer or DCS, is that there is no
isolation between the P522 ground and the remote
system ground. If there is a ground potential difference between the two systems, then there could be
serious noise and performance problems. You will
not encounter this problem when using a remote
meter by itself, because it will not be tied into another electrical system (will not be sharing grounds).
The bargraph reading on the front panel will not be
affected by this change to 4-20mA output. It will remain the same as before (i.e., go to zero on no signal
EMALF
FFO
OUTPUT
TESNIAGTRFF
XX
NO
LEDEMIT
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IRIS MODEL P522 APPLICATION MANUAL
detected). The 4-20mA output will still perform the
same way on the high end (i.e., on a strong signal, it
will saturate at the same level, slightly above 22mA).
Specifications for the analog current output signal
are provided in SPECIFICATIONS Figure 13.
INSTALLATION OF VIEWING HEAD
Before beginning the actual installation, determine
the best location for mounting the viewing head based
upon the following factors:
VIEWING HEAD CROSS-REFERENCE
REBMUNDLOREBMUNWEN
605S605S
S2XRI905S
SGRI115S
SRI215S
The model S5xx series of viewing heads have in
place a sensor for sensing the internal temperature
of the head. To access the reading of the viewing
head temperature, press the “Reset” and the “Down”
arrow key at the same time. The temperature reading will be displayed in the four-digit readout. The
reading (indicated in °C) will disappear and the normal reading will continue after several seconds.
VIBRATION
Do not install the viewing head where it could be
subject to vibration. A vibrating viewing head
(flicker type) can simulate flame when viewing a
glowing background. Provide an antivibration mount
if excessive vibrations are present.
CLEARANCE
Make sure there will be sufficient room to remove
the housing for servicing (see Figure 16).
SIGHTING OF THE VIEWING HEAD
FIGURE 7 - VEWING HEAD CROSS-
REFERENCE TABLE
PRESSURE
The viewing head lens will withstand 5 psi. If the
lens assembly is exposed to greater than 5 psi through
sight pipe, then an isolation unit must be used. An
IRIS isolation unit with purge air entrance is available as an accessory.
TEMPERATURE
The viewing head will withstand an ambient temperature to 80°C (176°F). However, the case tem-
perature of the housing must not exceed 60°C
(140°F). Purge air will help reduce conducted heat
through sight pipe to flange (a plastic nipple will also
help), but direct radiation can cause housing case
temperature to exceed limits. If the ambient heat
(direct radiation) is excessive, then a fiber optic extension should be used (please refer to the IRIS
Model 500 Fiber Optic System manual). This system is composed of a viewing head, a fiber optic
assembly, and an amplifier module.
In general, the sighting of the viewing head should
be parallel to the center line of the burner in the direction of the burner flame. This applies to both the
UV type as well as the flicker type. Flicker type
detectors respond to the high frequency flicker of
the flame; so, in order to achieve maximum discrimination between burners, the near portion of the
primary combustion zone should be favoured –
meaning the sight pipe should be mounted as close
as possible to the burner center line. The sight pipe
should be aimed at the root of the flame, which radiates the most intense, high-frequency flicker energy.
Sighting along the flame rather than across it permits the detector to view a greater depth of the flame
root, obtaining better response (see Figure 17).
When sighting for a UV viewing head, you must aim
for the UV zone, which is usually at the very first
part of the flame root. UV radiation from most flames
is restricted to a narrow region: it starts very close
to the burner nozzle and does not extend out very far
from the burner nozzle. You may have to angle the
sighting inward toward the flame root, as shown in
Figure 18.
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