Honeywell 700, 800 User Manual

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Honeywell Model 700/800 Signal

Contents

Application ....................................................................... 1

Features ........................................................................... 1

Specifications ................................................................... 2

Approvals ......................................................................... 3

Installation ........................................................................ 3

Operation ......................................................................... 10

Modbus Communication .................................................. 14

Troubleshooting ................................................................ 17

Maintenance .................................................................... 17

Safety Manual: 700 Signal Processor .............................. 33

Safety Manual: S70X & 80X Viewing Head ..................... 36

Processor and Viewing Head

USER MANUAL

• Model 700ACSP Universal 85-265 VAC powered, plus
24VDC backup.

• Model 700DCSP 22-26VDC powered, plus 24VDC
backup.

The two Model 700 signal processors are similar, with 12
push-buttons, a two-digit numeric display, and four LED status
indicators for operator interface. The only difference between
the two is that one accepts AC power and the other accepts
DC power. Both models also accept 24VDC backup power.
Most of the signal processor connections are made through
Phoenix plug-in connectors. Communication connections are
made through modular phone jacks located at the top of the
signal processors (Fig. 8).

Both signal processor models mount on a standard 35 mm
DIN rail. They snap into place and may be released from the
rail using a flat screwdriver.

APPLICATION

The Honeywell Model 700ACSP and Model 700DCSP signal
processors are single-channel, fail safe, flame monitoring
systems when used In conjunction with the S70X/S80X
viewing heads. They offer easy setup, excellent discrimination,
and high reliability.

FEATURES

Viewing heads are interchangeable between the two signal
processor models. Any viewing head in the two families will
work with any of the signal processors.

Two signal processor models are available:

There are two types of viewing heads—IR/flicker-sensitive and
UV-sensitive—with various features offered resulting in ten
different models. See Table 1 on page 2 for details.

The S702 and S706 viewing head housings are larger in
diameter than the S80X series, are made of aluminum, and
are secured with over-center latches to their mounting blocks
(Fig. 9). In contrast, the S802 and S806 viewing head
housings are smaller in diameter and are made of stainless
steel (Fig. 10). An 800 series viewing head is secured in its
mounting block by a friction twist-lock.

The IR/flicker sensitive viewing heads have a high-pass filter
that passes flicker frequencies above 33 Hz. Some models
have a built-in high pass filter that only passes frequencies
above 155 Hz. The high frequency filter models are identified
by adding “HF” to the model number. The UV models respond
to the level of UV radiation—not UV flicker—so there is no
filter option.

66-2069-02

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD

Table 1. Available viewing head models and associated features.

Pipe Fit Connection

0.5 in. NPTM with 50-ft

Model Connector

S702 X X X

S702HF X X X X

S702PF X X X

S702HFPF X X X X

S706 X X X

S706PF X X X

S802 X X X

S802HF X X X X

S806 X X X

1. All models include Electronic self-check.

2. Flicker Frequency filter settings available for IR sensor

models.

3. Gain Selection available through Signal Processor.

The viewing heads, the viewing head connector, and the cable
provided are watertight, and have NEMA 4X ratings when the
connector is properly tightened with pliers and the cable is
protected from UV exposure.

The availability of both UV-sensing and IR/flicker-sensing
viewing heads ensures that the flame monitoring systems can
provide good discrimination in most single and some multiple
burners firing a single fuel. UV sensing is appropriate for
monitoring natural gas, some mixed gases and light oil flames.
IR/ flicker sensing is appropriate for monitoring heavy oil and
coal flames.

(15.2 m) pigtail

UVTron
Sensor IR Sensor

UV Detector Spec

S706 & S706PF, S806: UVtron with spectral response 185nm

to 260nm and a peak response at 210nm

UV Optical

Angle of View: 5 degrees (1 inch per foot)

Cable & Connectors - S70X/S80X Viewing Heads

New installations - highest level of EMI shielding available:

ASY785 --> 50 foot C330S cable with pre-wired ASY786

connector.

ASY785-200 --> 200 foot C330S cable with pre-wired

ASY786 connector.

ASY786 --> Field wireable connector with shield.

Dimensions

Refer to Fig. 9 and Fig. 10.

High

Frequency

Filter 155Hz

Aluminum

Housing

Stainless Steel

Housing

Model 700ACSP & Model 700DCSP Signal

SPECIFICATIONS

Series 700 and 800 Viewing Heads

MODELS S702, S702PF, S702HF, S702HFPF, S706,
S706PF, AND MODELS S802, S802HF, AND S806

Electrical

24VDC Power is supplied by Signal Processor

Environmental

Viewing Head Sealing: NEMA TYPE 4X rated when the

molded connector ring is tightened with pliers and a UV
protection is provided for the cable by installing in conduit.

Ambient Temperature: -40°F to 185°F (-40°C to 85°C)

IR Detector Spec

S702, S702PF, S702HF, S702HFPF, S802, S802HF:

Germanium photodiode with spectral response 950nm to
1710nm (1/2 intensity points) and peak spectral response
at 1400nm

High Pass Filter Pickup: 33 Hz standard, 155 Hz high

frequency option (-HF)

IR Optical

Angle of View: 1 degree (1.45 in. dia. at 6 ft. or 3.7 cm dia. at

1.8 m)

Processer

Electrical: Model 700ACSP

Primary Input Power: 85-265VAC, 50-60 HZ, 0.07A Max.

fused (with either V.H. connected)

Battery Backup Voltage: 22VDC to 26VDC, 0.2A DC Max.

fused (with either V.H. connected)

Electrical: Model 700DCSP

Primary Input Power: 22VDC to 26VDC, 250 mA Max. fused

(with either V.H. connected)

Battery Backup Voltage: 22VDC to 26VDC, 0.5A DC Max.,

fused (with either V.H. connected)

Outputs

Flame Relay: 2 form C contacts
Self-Checking Relay: 1 form C contact
Relay Contact Ratings: 5A at 125 VAC, 277 VAC, & 30 VDC;

1/8 HP 125 & 250 VAC

Analog Flame Signal: Isolated 0 to 20 mA or 4 to 20 mA

output for remote meters or DCS, 360 ohms maximum
resistance

Environmental

Ambient Temperature: 32°F to 140°F (0°C to 60°C)

Dimensions

Refer to Fig. 11 and Fig. 12.

66-2069—02 2

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD

WARNING

APPROVALS

S70X/S80X Viewing Heads (Connector series and Pipe fit
series [PF])

CSA for CLASS I, DIV 2, GROUPS A, B, C, D & T4A
FM 7610/NEMA 4X and CLASS 1, DIV 2, GROUPS A, B, C, D

& T4A*
SIL 3 “Fit for Use”
IECEx CSA 10.0003 Ex nA IIC T4 Gc

-40<Ta<85ºC, -40<TA<185ºF

*IP67/NEMA 4/4X rating applies when connector ring is

properly tightened and cable is UV shielded

700ACSP and 700DCSP Signal Processors

CSA (C, US)
FM

INSTALLATION

When Installing These Products...

1. Read these instructions carefully. Failure to follow them

could damage the products or cause a hazardous
condition.

2. Check the ratings given in the instructions and one the
products to make sure the products are suitable for your
application.

3. Installer must be a trained, experienced, flame
safeguard control technician.

4. After installation is complete, check out product
operation as provided in these instructions.

Signal Processor Mounting

The 700ACSP and 700DCSP signal processors mount on a
standard 35mm DIN rail. They snap into place and may be
released from the rail using a flat screwdriver.

Grounding and Shielding

NOTE: Installer must be a trained, experienced flame

safeguard service technician and should be
familiar with the equipment operation and
limitations and be aware of any applicable local
codes and regulations.

1. Connect a safety ground to the viewing head housing (if

applicable). A ground screw is provided on the exterior
of the viewing head housing for this purpose.

The viewing head housing is grounded through
cable/signal processor, so you must ensure that
AC/DC potentials at ground of signal processor
and viewing head are the same, or damage to the
cable or signal processor can result.

2. The viewing head and all associated cable/conduit must

be at least 12 inches (31 cm) from any source of high
energy or voltage (for example, igniter equipment).

3. Install a ground wire from the ignition transformer case
to the igniter assembly.

4. Ensure all igniter wires and cables show no signs of
wear. Replace any igniter cables or wires that are frayed
or cracked.

5. The viewing head must be electrically isolated from the
burner front.
a. Electrical isolation can be accomplished by

installing an Ultem nipple (R-518-13) or an Ultem
locking coupler adapter (R-518-PT13 or R-518­PT13L) in conjunction with a locking coupler (R-518­CL13-HTG) between the viewing head flange and
the burner mount.

b. The purge air line should also be isolated from the

viewing head. This can be accomplished by
installing any insulating material, for example a
rubber hose, in between the purge air line and the
viewing head.

Signal Processor Power Connections

The Model 700ACSP power and relay connections are shown
in Fig. 1. The AC power supply to the 700ACSP Signal
Processor passes through a 2A fuse and an inrush current
limiter.

The Model 700DCSP power and relay connections are shown
in Fig. 2. The maximum current requirement for each
700DCSP is 250mA.

In the Model 700 signal processors the flame relay (RF A/B
ON, OFF, COM) has two sets of FORM C (SPDT) contacts
and the self-check relay (SC ON, OFF, COM) has one set (Fig.
1 and Fig. 2). The self-check relay is energized whenever the
signal processor is powered and is operating normally,
whether the flame relay is energized or not. Internally, the
flame relay is wired in series with the self-check relay (not
shown), which prevents the flame relay from energizing if the
self-check relay is not energized.

Unique fail-safe circuitry for the self-check and flame relays
ensure that in the event of any critical component failure
occurrence, system response will be to de-energize the self­check relay, which in turn de-energizes the flame relay.

Some of the internal power wiring of the Model 700ACSP and
Model 700DCSP signal processors is shown in Fig. 1 and
Fig. 2. Rectifier diodes separate the battery backup input from
the main power bus until the battery voltage exceeds the
internal DC voltage plus a diode voltage drop. Resettable
fuses (shown as resistors with slashes) and conventional
fuses prevent internal failures from loading the power sources.
With the Model 700DCSP, if a backup battery is to be used
with a main power supply, the two power sources would be
wired as shown in Fig. 2. If no backup battery is to be
installed, the main power supply can be connected at +26V
PWR and GND as shown in Fig. 2 or it can be connected to
the +24V BATT input and GND. It is preferable to use the
battery connections because it takes advantage of the
resettable fuse at the battery input; resettable fuses recover
automatically from a fault within a few seconds after power is
removed. At the +26V PWR input and its associated GND,
conventional1A fuses are used because they are able to
protect against 240VAC being applied by accident (this could
happen if a Model 700DCSP is installed in a cabinet wired for
a Model 700ACSP).

3 66-2069—02

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD

APPROVED

AC IN

GROUND

TO VIEWING
HEAD

24 V
BACKUP BATTERY
(OPTIONAL)

0-20 OR 4-20 MA

FOR INDICATOR OR

INSTRUMENTATION
360 OHMS MAX

+

-

+

-

CHASSIS,
EARTH, OR
SYSTEM GND

M34280

+

+26VDC

GND

.125 A

.4A

2

A

AC POWER

SUPPLY

-t°

Fig. 1. Model 700ACSP Signal Processor Wiring.

66-2069—02 4

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD

+

+26VDC

GND

.4A1A 1A

.125 A

LIM

M34282

APPROVED

24 V
BACKUP BATTERY
(OPTIONAL)

+

-

0-20 OR 4-20 MA

FOR INDICATOR OR

INSTRUMENTATION

360 OHMS MAX

+

-

CHASSIS,
EARTH, OR
SYSTEM GND

DC POWER SUPPLY

250 MA

+

-

+26

PWR

TO VIEWING
HEAD

Fig. 2. Model 700DCSP Signal Processor Wiring.

5 66-2069—02

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD

WHITE

BLACK

RED

GREEN

TERMINAL

VH SIG

VH SC

VH +V

VH GND

CONDUIT

ENCLOSURE

S702PF, S702HFPF OR S706PF

SHIELD

C330S YELLOW 4-CONDUCTOR
WITH DRAIN AND SHIELD

STANDARD "PIGTAIL" LENGTH = 10 FEET (3 METERS)

M34285B

Viewing Head Connector and Wiring

Viewing heads are wired to the appropriate terminals located
on bottom of the 700ACSP, 700DCSP, P531 or P532 signal
processors. The terminals are listed functionally in Table 2.

Table 2. Terminal Descriptions.

700ACSP or

700DCSP

Ter minal

P531 or

P532

Terminal

VH SIG VH3 SIG Flame Signal from Viewing Head

VH SC VH3 SC Shutter Drive Signal to Viewing

Head

VH +V VH3 +V +24VDC Power to Viewing Head

VH GND VH3 GND GND Signal Ground

Connectors and cables are shown in Fig. 3, Fig. 4, and Fig. 5.
Fig. 3 shows the viewing head cable with the 1/2 in. NPT pipe
fitting and pigtail for use in a conduit. The PF model comes
with 50 feet of Honeywell C330S cable. This cable is
recommended for all new installations. It has ITC and CIC
ratings for hazardous location. Figs. 4 and 5 describe the
C330S cable used with the right angle field-wireable
connector. Refer to “Accessories” on page 9 for part numbers.

The customer may also supply his own cable; a replacement
mating viewing head connector should be ordered. Refer to

Description

“Accessories” on page 9 for part numbers. The use of 22g, 4­conductor cable with shield and drain is recommended. The
shield should be foil and braid type surrounding all
conductors. The shield should be connected to GND at the
processor end. The cable diameter should not exceed 0.307"
in order for it to go through the hex bushing in the connector.
But note that wiring the cable to the connector is not easy
because of the limited space. Also, the LED indicator
assembly must be mounted inside the connector and,
preferably, soldered in place. Thus, it is recommended to
purchase a pre-wired cable and connector assembly from
Honeywell.

NOTE: FOR CLASS I, DIV 2 RATING, CABLING IN

HAZARDOUS LOCATIONS MUST COMPLY WITH
NEC ARTICLE 500 REQUIREMENTS AND
APPLICABLE GOVERNING CODES.

In the U.S., cables should have UL’s ITC rating; in Canada,
cables should have CSA’s CIC rating. The recommended
C330S cable has both ratings.

NOTE: To obtain a NEMA 4X seal between the connector

and the viewing head, tighten the metal
connector ring securely.

Fig. 3. Model 700 Viewing Head Cable With 1/2 in. NPT Fitting.

66-2069—02 6

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD

NOTE: IMPORTANT INSULATE DRAIN WITH SHRINK TUBING LEAVING 3/8" STICKING OUT.

M35139

STRIP 3/8 INCH TYPICAL

1-19/64 (33)
TYPICAL

VH SC

5-16 (8)
MAX

VIEWING HEAD
CONNECTOR
LOOKING AT PINS

VH SIG

C330S YELLOW, 4 COND
WITH FOIL/BRAID SHIELD
AND DRAIN (ITC & CIC)

Fig. 4. Model 700/800 Viewing Head Cable Connections.

Cable Preparation

NOTE: This section will typically be used for reference

only. The S70X/S80X connector parts are very
small and delicate and difficult to assemble. It is
advisable to purchase pre-made cables from
Honeywell.

GREEN
LED

VH +V

VH GND

METAL
CONNECTOR
RING

2. Pull braided and foil shield back so that only drain wire

3. Insulate the drain wire with heat shrink.

4. Strip other wires as shown in Fig. 5.

ORANGE
LED

CONNECTOR REAR VIEW
WITH NUT LOOSENED
AND COVER REMOVED

WHITE

BLACK

RED

SHIELD

GREEN

TERMINAL

VH SIG

VH SC

VH +V

VH GND

M34286A

is at 2 inch length. Trim the foil and braid shields at the
cable jacket.

Honeywell C330S cable is recommended for use with the
S70X/S80X viewing heads and signal processors. C330S has
a UL ITC rating and can be used in the U.S. in hazardous
locations.

NOTE: Shield shrink tubing is required on shield drain

wire at the signal processor end.

Preparation of the C330S cable at the signal processor should
be done as follows:

1. Referring to Fig. 5, strip cable 2 inches back to expose
the braided shield.

Fig. 5. C330S Signal Processor End Cable Preparation.

Connection of the Honeywell type C330 cable to the viewing
head plug is shown in Fig. 6. Cable preparation should be
done as follows:

1. Prepare C330S wire at plug end similarly to Fig. 5, but
shorten the drain/shield to approximately 1/4 inch only
at the plug end (see Fig. 6).

2. Assemble the field-wireable plug as shown in Fig. 6.
Ensure that:
a. Wires are in proper locations per Fig. 4.
b. Shield is pressed against connector housing.
c. Connector back plate gasket is in place before

installation.

d. After assembly, check that connector is tight and

well secured.

7 66-2069—02

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD

Fig. 6. ASSY786 Viewing Head Plug Assembly with C330S.

M35140

Protecting the Viewing Head Cable (Connector Series)

Note that when the wiring needs to meet Class I, Division 2
requirements for use in hazardous locations and when conduit
is used, the conduit must be sealed where the cable passes
from the hazardous location to the non-hazardous location in
order to keep potentially hazardous gases from being
conducted into the non-hazardous area.

Viewing Head Connector LED Indicators

The viewing head connector has orange and green LEDs
which can be viewed from the rear of the connector when the
connector cover is removed.

The green LED displays the pulses out of the viewing head
and the orange LED shows that the self-checking signal from
the signal processor is reaching the viewing head. If power is
on at the signal processor, the orange LED should flash at one
pulse per second, even if the viewing head is not plugged in.
This is helpful in troubleshooting.

With no flame signal present, the green LED will flash one
pulse per second in step with the self-checking signal. The
viewing head is sending back an ID pulse; this is part of the
self-checking system. When a flame is present, the green
LED will flash at a rate proportional to the flame signal, except
when the pulses are interrupted once per second for the self­check pulse arrival at the viewing head. The pulse rate of the
green LED flashes can be used for aiming the viewing head.

NOTE: The LED indicators are provided for alignment

and troubleshooting only. Reinstall cover with
gasket correctly in place at all times, and ensure
that connector coupling is tightened securely.
This gasket and cover must be installed properly
to maintain NEMA rating.

Viewing Head Mounting and Sighting

Mounting is 1/2-in. NPT (F) for all viewing head models with a
1/4-in. NPT (F) purge air connection. Before beginning
installation, determine the best location for mounting the
viewing head based upon the following factors:

Viewing Head Mounting Block

The S70X viewing heads are held firmly in place in their
mounting blocks by two galvanized steel latches. The S80X
viewing head is secured in its mounting block by a friction
twist-lock. Refer to the ACCESSORIES section for part
numbers.

Pressure

The S70X viewing head lens will withstand 50 psi (3.4 bar)
while the S80X lens will withstand 90 psi (6.2 bar), provided
the compression ring on the purge air adapter is tightened
properly. If the lens assembly is exposed to greater pressures
through the sight pipe, then an isolation unit must be used.
Honeywell isolation units with purge air entrance are available
as accessories; ISO-UNIT, ISO-UNITSS, ISO-UNITHPGT.
Each has a quartz window, two 1-in. NPTF connections and a
1/2-in. NPTF purge port.

Temperature

The case temperature of the viewing head housing must not
exceed 185°F (85°C) while the standard Delrin mounting
block must not exceed 180°F (82°C) continuous service. Care
should be taken to ensure the case housing and mounting
block temperatures do not exceed these values.

Purge air will help reduce conducted heat through the sight
pipe and flange. A heat insulating Ultem replacement viewing
head mounting block is available for both the S70X/S80X
models (part numbers 700UA and 800UA) with a continuous
service rating of 320°F (160°C) as well a 1/2-in. NPTM Ultem
nipple (part number R-518-13) or an Ultem locking coupler
adapter (R-518-PT13 or R-518-PT13L) to reduce the
conducted heat, but direct radiation can cause the housing
case temperature to exceed limits. If the ambient heat (direct
radiation) is excessive, then an air cooling canister with vortex
cooler should be considered or alternately a fiber optic
extension. The extension uses a fiber optic cable assembly
between the sight pipe and the viewing head, allowing the
viewing head to be placed further away from the heat source.
Refer to the Fiber Optic Manual 69-2683 or contact your
distributor or the factory for assistance with fiber optic
selection and pricing.

Purge Air

Use a flexible air supply line, to allow for repositioning of the
viewing head and sight pipe until a final and permanent

66-2069—02 8

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD

position has been decided. A continuous flow of air must be
maintained in order to reduce the conducted heat and to keep
the sight pipe and viewing head lens free of dirt and debris. Air
required is about 5 SCFM (0.13 Nm3 /min) delivered at 1 in.
(25mm) above the maximum pressure as measured at the “Y”
or “T” section of the purge air connection for each viewing
head. The air supply must be clean, free of oils and water, and
preferably cool. In order to electrically isolate the viewing
head, the purge air line should be installed using an insulating
material, such as a rubber hose, in between the purge air line
and the viewing head.

Vibration

Do not install the viewing head where it could be subject to
high vibration. Provide an anti-vibration mount if excessive
vibrations are present.

Clearance

Make sure there will be sufficient room to remove the viewing
head housing for servicing.

Viewing Head Mounting

Honeywell offers a range of swivel mounts, both pipe thread or
flange mounting for use with sight pipes or direct wind box
mounting. See “Accessories” on page 9 or the Honeywell
website for further details.

Viewing Head Sighting

The sighting of the viewing head should be parallel to the
center line of the burner in the direction of the flame. If used,
the sight pipe should be mounted as close to the center line
as possible so as to sight along the flame rather than across
the flame. Doing so will ensure continuous flame detection
under changing load conditions. See Fig. 15, 16 and 17.

Utilizing a sighting or the sight pipe aimed at the root of the
flame (where the turbulent combustion air mixes with the
flame) is a good starting point for optimizing the sighting.
Where practical, using a swivel mount to “zero-in” on the
highest signal will assure maximum performance. The
optimum scanner location is parallel to the burner center line.
The use of a swivel mount allows for line of sight adjustment,
where practical to use.

Examples of viewing head installation with and without a
swivel mount are shown in Fig. 13 and Fig. 14. If using a sight
pipe, its diameter should be large enough to allow a
reasonable field of view, and to allow for adjustment of the
swivel mount angle.

In some instances, it may be beneficial to use two sets of
setpoints for Flame On, Flame Off and gain. The two-channel
capability (primary and alternate viewing head settings) is
ONLY possible when using the P531 or P532 signal
processors; it is not possible when using the 700ACSP or
700DCSP signal processors. The switch-over from Channel A
to Channel B can be implemented from the burner control
system. Refer to the P531/P532 user manual, 66-2068, for
further information regarding switch-over and the use of
Channels A and B with independent settings.

ACCESSORIES

Orifice disks (kit M-702-6) - Used to reduce the signal

brightness in cases where the signal brightness is too strong.
Located immediately in front of the lens, it will reduce the
amount of signal to the sensor. Bag assembly contains orifice
disks and retaining rings. Orifice disks come with 3/8, 1/4,
3/16 and 1/8 inch diameter holes. Contact the factory for
guidance in using orifice disks.

Insulating nipple (R-518-13) - 1/2-in. NPTM Ultem heat and
electrical insulating nipple typically used in conjunction with a
swivel mount and union.

VH insulating mounting block (700UA, 800UA) - 1/2 in.
NPTF Ultem heat and electrical insulating mounting block,
used in place of the supplied Delrin mounting block. 1/4 in.
NPTF purge air connection. Typically used in conjunction with
a swivel mount. Rated for continuous service up to 320°F
(160°C).

Swivel mounts, small (700-1, 700-2, 700-3) - All have 1/2 in.
NPTM viewing head connections on one end with varying
process connections including 1 in. NPTF, 1/2 in. NPTF and
1/2 in. flanged.

Swivel mounts, large (M-701-1, M-701-2, M-701-2-FLG, M­701-2-SS, M-701-3, M-701-3P, M-701-4) - All have 1 in NPTF

viewing head connections, one end with varying process
connections including 2 in. pipe slip on, 2 in. NPTF, 2 in.
flanged, 2 in. NPTF in stainless steel construction, 4.5 in.
flanged with 3 bolts, 3 in. NPTF and 2-bolt flanged.
Appropriate fittings must be used to adapt the 1/2 in. NPTF
viewing head process connections.

Insulating locking coupler adapters (R-518-PT13, R-518­PT13L) - 1/2 in. NPTM Ultem adapters insulate the viewing

head electrically and thermally and are used with the R-518­CL13-HTG locking couplers. The R-518-PT13L has a quartz
lens.

Locking coupler (R-518-CL13-HTG) - Used with the R-518­PT13 and R-518-PT13L insulating locking coupler adapters.
Process connection end is 1/2 in. NPTF.

Connector - ASY786 --> Replacement field wireable
connector.

Cable and Connectors - S70X/S80X Viewing Heads
ASY785 --> 50 foot C330S cable with pre-wired ASY786
connector.
ASY785-200 --> 200 foot C330S cable with pre-wired ASY786
connector.

Cable (C330S) - 4-conductor with drain, foil/braided shield.
Sold per foot.

Isolation Units (ISO-UNIT, ISO-UNITSS, ISO-UNITHPGT) -
All have 1 in. NPTF connections with 1/2 in. NPTF purge ports
and quartz window. Painted aluminum or stainless steel
construction. The HPGT version has a 1/2 in. thick quartz
window for higher pressures. Appropriate fittings must be
used to adapt the 1/2 in. NPTF viewing head process
connections.

Air cooling canister (700ACC, 800ACC) - Has an air inlet
port on side. Used with vortex coolers. S80X models can be
used with the 700ACC if the 800ACC-RING adapter is used.

9 66-2069—02

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD

Vortex coolers (M3204, M3208, M3210, M4025) - Used with
air cooling canister. Contact your distributor or the factory for
selection assistance.

Cable restraints (800CR, 700CRLT) - Liquid tight S80X and
S70X cable restraint versions. The 800CR includes the
700CRLT and the 800ACC-RING adapter.

S80X adapter ring (800ACC-RING) - Adapter ring to fit S80X
viewing heads to 700ACC cooling jacket and 700CRLT liquid
tight cable restraint.

Right angle adapter (700RAA) - S70X/S80X viewing head
right angle adapter. 1/2 in. NPTF to 1/2 in. NPTM connections.

Mounting blocks (700DA, 700DA-1, 800DA) - Delrin
replacement adapter/mounting blocks for S70X and S80X
viewing heads. All have 1/4 in. NPTF purge air connections.
Rated for continuous service up to 180F (82C). The 700DA
and 800DA have 1/2 in. NPTF process connections while the
700DA-1 has a 1 in. NPTF process connection. For more 1 in.
NPT accessories that can be used with the 700DA-1, refer to
the S55XB/BE manual, 66-2064.

USB to RS422/RS485 Converter (COMMOD) - Protocol
converter for use with external communication with a remote
computer.

Fiber Optic System Compatibility - The S70X and S80X
viewing heads are compatible with the Honeywell FASA fiber
optic extension products. The S700FOAD and S800FOAD
adapters are applicable, depending on the application.
Contact your distributor or the factory for assistance with fiber
optic selection and pricing.

OPERATION

IR Detector

The S702 and S802 viewing head models use a Germanium
photodiode, which responds to IR radiation/flicker in the flame.
Flame flicker is caused by the combustion, or forced air
injected in to the flame. Combustion air can be mixed with the
fuel (pulverized coal) or can be introduced separately. In either
case, forced air is introduced in such a way as to aid the
combustion process. This air is usually made turbulent by
causing it to swirl with spin vanes located in the burner throat.
Flame flicker is created when turbulent air mixes with the
flame. It is composed of random frequencies and the amount
of high frequency flicker is dependent on the fuel and the
burner.

The S702, S702PF and S802 viewing head models respond
to flicker frequencies above 33Hz while the S702HF,
S702HFPF and S802HF viewing heads respond to flicker
frequencies above 155Hz. All flicker frequencies below the
filters are ignored, so it is important to sight the viewing head
on the highly turbulent portion of the flame that contains the
higher frequencies. The location of the higher frequencies can
be predicted by examining the burner with regard to where the
turbulent air enters the flame. The optimum scanner location
is parallel to the burner center line (Fig. 15). The use of a
swivel mount is encouraged to allow for line of sight.

Filter Selection for IR Viewing Head

If a good count ratio between BNR-ON and BNR-OFF cannot
be obtained when using an IR viewing head—particularly
when monitoring oil flames—an IR viewing head with the High
Frequency (HF) filter option is recommended. The standard IR
viewing head responds to flicker frequencies above 33 Hz;
with the HF option, the IR viewing head responds to flicker
frequencies above155 Hz.

UV Detector

The S706, S706PF and S806 viewing head models use the
UVTron tube, with a spectral response of 185-260nm and
peak response of 210nm to ultraviolet radiation. The output of
the detector is a pulse stream of randomly spaced pulses
whose average rate is proportional to the UV radiation present
in the flame. The UV radiation is a direct result of the
combustion process as oxygen combines with hydrocarbons
in the fuel in the blue part of the flame. The yellow part of
flames, and the background radiation from hot refractory, do
not emit UV radiation.

The spectral range of the UV tube makes it ideal for
discriminating between flame and glowing refractory. As with
any UV radiation, it can be absorbed or masked by unburned
fuel, smoke, oil mist, dirt dust and other impurities in the fuel.
Care should be taken to select the proper viewing head for the
fuel used. Additionally, the contaminants that mask UV can be
diluted by providing a strong flow of air through the sight pipe
to clear a viewing path through the attenuating material. See
“Purge Air” on page 8.

It may also be desirable to sight the detector at an area
containing fewer masking agents such as near the burner
nozzle or near the entrance of the combustion air. Increasing
the viewing area of the detector by shortening the sight pipe or
by increasing the diameter of the sight pipe can also reduce
the attenuating effects of the masking agents.

In general, the UV viewing heads will work well on natural gas
and light oil flames. The sighting for both oil and gas flames
should be parallel to the axis of the burner and aimed at the
root of the flame, as with the IR detector. (See previous
section, “IR Detector.”) The highest UV intensity occurs near
the root of the flame (Fig. 16). In addition, the zone of higher
UV intensity does not overlap the same zones of adjacent or
opposing burner so that, with proper sighting, discrimination
can be achieved.

With low NOx gas burners, the UV radiation is usually much
less in intensity and spread out. Relatively high readings can
be obtained from all over the furnace when many burners are
in service. This is particularly true when flue gas recirculation
is used. There will however, be a relatively stronger signal
near the “root” of the flame and the more intense spot should
be located during the aiming or sighting process. This “root” or
intense spot may be further out than with the standard gas
burner so it is imperative that a swivel mount be used when
making sighting adjustments.

Another factor that needs to be considered when aiming the
viewing head is the load condition of the boiler. The flames
from a burner can be radically different at different loads. This
is one of the reasons for choosing an optimum sighting initially
that will minimize signal swing due to changing loads.

66-2069—02 10

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD

Self-Checking

The self-check circuitry guards against internal component
failure. There are several tasks that require intelligent
interaction between the viewing heads and the signal
processor. If all of these interactions do not occur properly, the
viewing head will not send pulses back to the signal processor
and the flame relay will open.

Adjustment of VH Sighting and Gain

NOTE: Adjustment to the viewing head parameters

cannot be made unless the viewing head is
connected and communicating with the signal
processor.

The viewing head should be properly sighted before the
setpoints are adjusted. Adjustment can be made easier by a
1/2 in. swivel joint, which Honeywell can supply if one is not
available (refer to “Accessories” on page 9).

While the burner is firing, vary the viewing angle while
observing the green LED on the connector at the rear of the
viewing head. Adjust the viewing angle for the maximum pulse
rate, then lock the swivel joint to preserve this mechanical
setting. If the green LED pulse rate is very high or very low,
see the two paragraphs below. The locked mechanical setting
should still be correct when Model 700 viewing heads are
interchanged, because inside each Model 700 viewing head
the optical axis is aligned with the mechanical axis within ±1/4
degree. Also, the reading shouldn’t change when a viewing
head is rotated in the mount.

For the above sighting adjustments to work properly, the
flashing rate of the green LED in the connector at the rear of
the viewing head must be reasonable. On the -PF (pipe fitting)
version, there are no LEDs. The installer must observe the
flame signal on the signal processor instead.

A count rate of 16 to 20 is recommended for proper operation.
If the displayed count is above 25, the pulses begin to blur
together, making changes in the pulse rate difficult to observe.

If the displayed count is less than 8 or 10, it will be difficult to
maximize the count by adjusting the viewing head aim, since
the pulses occur too infrequently. In such a case the gain
should be increased. If the gain is set to a maximum and the
count rate persists below 8 or 10, the system can still be made
to work reliably as long as the count rate drops significantly
when the flame is removed. However, the setup should be
reviewed for proper viewing head aim and sight path to ensure
it is optimized.

Orificing

Orifice disks have been used in applications with older viewing
heads that did not have adjustable gain in order to reduce the
extreme brightness of certain burner flames. The orifice disk
kit is part number M-702-6. Orifice disks come with 3/8, 1/4, 3/
16 and 1/8 inch diameter holes. Contact the factory for
guidance is using orifice disks. The disks are installed with
retaining rings in the flange at the edge of the 1/2 inch NPT
female pipe thread for the process connection. An internal
type retaining ring is first installed by positioning a ring in the
machined groove inside the flange opening from the housing
side. The orifice disk is then inserted. Use a second retaining

ring to hold it in place so that it is sandwiched tightly between
the two retaining rings.

If the displayed flame count is 25 or higher when the gain is
set to 1, an orificing disc inserted in the back end of the
mounting block can be used. Choose a disc that gives a
reading of 12 to 24 at a low fire firing rate. The discs have a
range of orifice sizes; each size step results in about a 2:1
change in the counts displayed.

Signal Processor User Interface

The 700ACSP and 700DCSP signal processors have a user
interface that includes four lights, a two-digit display and
twelve push buttons for operation and programming. Each
button has at least one specific purpose.

To enter a menu, press and hold the applicable button for 2
seconds. Adjustments to the applicable setpoint can be made
via the INCREASE or DECREASE arrow buttons. To store the
new setting, press the STORE button until “--” is shown,
indicating the value has been accepted.

If no activity occurs for a period of four seconds while the
menu value is displayed, it will revert back to the operating
display.

To exit a menu at any time without saving changes, simply
press the RESET/rE button.

The following describes the functions of the LED indicators,
display and push buttons:

Front Panel LED Indicators and Display

• ON SEQ/AUTO SET LED (green):

— Used in conjunction with the BNR-ON SEQ START/

END and BNR-OFF SEQ START/END buttons during
the automatic setup process

• OFF SEQ/FAULT LED (green):

— Used in conjunction with the BNR-ON SEQ START/

END and BNR-OFF SEQ START/END buttons during
the automatic setup process

— Indicates a fault condition

• Two digit display

— When in operating mode, the display indicates the

current flame signal, which ranges between 00 and 29

— Upon power up, indicates whether an IR or UV viewing

head is attached and the selected gain setting; such
as r7 (IR with gain of 7) or u5 (UV with gain of 5).

— Indicates various characters during the automatic

setup process as well as whether the panel is locked

• FLAME SIG LED (yellow):

— When a flame is present, LED flashes at a rate

proportional to flame signal, except when the pulses
are interrupted once per second for viewing head self­checks.

• FLAME ON LED (red):

— When the flame signal is above the selected value, the

LED will be illuminated and the flame relay will be
energized.

Push Button Functions

• RELAY ON SETPOINT button:

— Allows user to select flame on threshold value. When

the flame signal is above the selected value, the flame
relay will be energized. Used in conjunction with the

11 66-2069—02

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD

INCREASE, DECREASE and STORE buttons (range
of 00 to 29).

• LOAD FACTORY DEFAULTS button:

— Used to restore all settings to the factory default

values

•

↑ INCREASE button:

— Used to increase parameter value when in

programming mode

• RATIO (%) RELAY OFF/RELAY ON button:

— Used along with the INCREASE, DECREASE and

STORE buttons to set the RELAY OFF setpoint at a
percentage of the RELAY ON setpoint. Adjustable
from 20% to 80%.

•STORE button:

— Stores new parameter values during programming
— After making changes “--” will be displayed indicating

•

the new values are accepted and stored

↓ DECREASE button:

— Used to decrease parameter value when in

programming mode

• BNR-ON SEQ START/END button:

— Used to initiate and proceed through the automatic

parameter setup sequence, which includes the RELAY
ON, RATIO (%) and GAIN settings (the FFRT, mA
output and communication address must be set
manually)

• BNR-OFF SEQ START/END button:

— Used during the automatic parameter setup sequence

• ACCEPT RATIO/SET GAIN button:

— Allows user to set the viewing head gain in conjunction

with the INCREASE, DECREASE and STORE buttons

— Used in conjunction with the BNR-ON SEQ START/

END and BNR-OFF SEQ START/END buttons during
the automatic setup process

• FFRT 1/2/3 SEC OPTION button:

— Used to set the FFRT timing along with the

INCREASE, DECREASE and STORE buttons

• 0-20MA 4-20MA OPTION button:

— Used in conjunction with the INCREASE, DECREASE

and STORE buttons to select the proportional mA
output for the flame signal

• RESET rE button:

— Resets a lockout condition
— Also used to exit a menu while programming
— Used to set the Modbus address along with the

INCREASE, DECREASE and STORE buttons

Manual Setup of Setpoints

The keypad of the signal processor is used to set the IR/UV
GAIN, RELAY ON, RATIO % (Relay Off), FFRT and mA output
option setpoints. The following section describes this process.
Also refer to Fig. 22, 23, 24, 25 and 26.

To change the gain, press and hold the SET GAIN button for
two seconds until the current value is displayed. Use the
INCREASE and DECREASE buttons to change the setting as
appropriate while the value is displayed. To store the new
setting, press the STORE button until “- -” is shown, indicating
the value has been accepted.

If no activity occurs for a period of four seconds while the
value is displayed, the display will return to the operation
mode without saving the new setpoint.

To exit the menu at any time without saving changes, simply
press the RESET/rE button.

The gain is live; changes are effective immediately, but if the
displayed gain value is not stored (by pressing STORE), and
no other buttons are pressed, the processor returns to the
previous setting after four seconds.

Relay On Setpoint

The two numeric digits on the Model 700 signal processor
normally display the incoming count during operation; that is,
the number of pulses that arrive between self-check pulses.
This count ranges from 00 to 29.

Refer to Fig. 22 for a flowchart of setting the Relay On
setpoint. Press and hold the RELAY ON SETPOINT key for
two seconds to access this setpoint. The RELAY ON SET
POINT value will be displayed. If no further keys are pressed,
this display will disappear in four seconds and the incoming
count will again be displayed. If the RESET key is pressed,
the display will return immediately to displaying the incoming
count.

While the RELAY ON SET POINT is displayed, you may
increase or decrease the setting by using the INCREASE and
DECREASE arrow keys. To store the new setting, press the
STORE button until “- -” is shown, indicating the value has
been accepted.

To exit the menu at any time without saving changes, simply
press the RESET/rE button or wait 4 seconds until the display
reverts to the incoming count value. To extend the display
time, press the RELAY ON SETPOINT button again; the
display will time out for four seconds after the key is released if
no other buttons are pressed.

The displayed value of the RELAY ON SET POINT is live; that
is, if the relay is off and the adjusted value falls below the
current flame signal count, the relay will turn on immediately
(FFRT settings are ignored). This immediate response can be
seen if the count is low and the RELAY ON SET POINT is set
above it; if the RELAY ON SET POINT is then adjusted down
to the count level, the FLAME ON relay will be energized.

Setting the Viewing Head Gain

The gain of the IR and UV viewing heads can be adjusted. In
addition to the information in this section, refer to Fig. 26. At
power-up, the 700 signal processors display codes to tell the
operator what type of viewing head and what gain is being
used. Default values are “r5” for the IR viewing head and “u5”
for the UV viewing head. The “r” or “u” denote IR or UV
viewing heads, respectively, while the numeric digit indicates
the current gain setting. The gain can be adjusted from 1 to 9
with a gain of 5 being the factory default gain.

66-2069—02 12

Ratio (%) Relay Off/Relay On Setpoint

For a flowchart of this setpoint process, refer to Fig. 23. The
key labeled RATIO (%) RELAY OFF/RELAY ON is used to set
the RELAY OFF SET POINT at a percentage of the RELAY
ON SET POINT. This percentage is adjustable from 20% to
80%. For example, if the RELAY ON SET POINT is set to 16
and the RATIO (%) is set to 50% (the factory default values)
the relay will energize if the displayed count goes to 16 or
higher and de-energize when the count drops to 08 or less for
one to three seconds, depending on the FFRT (Flame Failure
Response Time) setting. The adjustment of the RATIO setting