Protecting The Viewing Head Cable; Viewing Head Connector Led Indicators; Viewing Head Mounting And Sighting; Pressure - Honeywell 700 User Manual

CABLE
NOTE: IMPORTANT INSULATE SHIELD WITH SHRINK TUBING LEAVING 3/8" STICKING OUT.
Protecting the Viewing Head Cable (Connector Series)
It is usually desirable to mechanically protect the cable going
to the viewing head. For the connector model viewing heads,
flexible conduit and adapters can be used for this purpose.
See Fig. 4. The 700LTA (liquid tight viewing head cable
adapter) is a custom part available from Honeywell; it screws
into the right-angle connector in place of the standard hex
bushing. The 700LTA is used with a Thomas and Betts #5330
liquid tight fitting which is designed to give a watertight seal for
®
flexible Liquatite conduit, such as part number LT-516 by
Electri-Flex. The components have internal dimensions to
clear a 5/16 in. diameter cable. For each viewing head a
700LTA, a flexible conduit, and two T&B fittings will be needed.
Honeywell sells the 700LTA while the other parts can be
purchased commercially. The installer can fit the liquid tight
flexible conduit over the cable supplied with the viewing head
by first unscrewing the hex bushing from the connector and
removing it from the cable and then sliding the 700LTA, T&B
and flexible conduit assembly over the cable and screwing the
assembly into the right-angle connector. The flexible conduit is
terminated with the second T&B fitting which ends with a 3/8
in. NPT thread.
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.
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
HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD
3 CONDUCTORS PLUS 1 COAX
3 CONDUCTORS: 18 AWG
COLOR WHITE: 38 AWG BRAIDED SHIELD 90% COVERAGE
JACKET: TPE (TPAF) LIGHT BLUE
GROMMET
FLAT WASHER OR RETAINER
CABLE ENTRY NUT
CABLE PREPARATION
Fig. 5. C330 Cable Preparation.
STRIP 3/8" TYPICAL
1-19/64 (33)
TYPICAL
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 self-
check pulse arrival at the viewing head. The pulse rate of the
green LED flashes can be used for aiming the viewing head.

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 the
actual 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. The mounting blocks are made from a hard Delrin
rated for continuous service to 180°F (82°C). An alternative
mounting block made from Ultem
and S80X viewing heads, rated for continuous service up to
320°F (160°C). 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
9
SHIELD
M33282
®
1000 is available for S70X
66-2069—01