Honeywell 700 Benutzerhandbuch

66-2069—02

8

 

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.

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 self-

check pulse arrival at the viewing head. The pulse rate of the 

green LED flashes can be used for aiming the viewing head.

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:

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.

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.

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.

Use a flexible air supply line, to allow for repositioning of the 

viewing head and sight pipe until a final and permanent 

M35140