42
®
Wiring
Attach the cable supplied with the scanner to a junction box. Splice the cable wires to a pair of wires
not smaller than #l8. Install the complete run in a separate conduit to the control.
Continuous con-
duit bonding between scanner and the control is mandatory!
Scanner may be located up to 100
feet from control. Do not pass scanner wiring through any junction box containing other wires. Do
not run other wires through scanner conduit. Asbestos insulated wire should be avoided.
Keeping the Scanner Cool
The Infrared Scanner (Temperature Limit 125° F) should never get too hot to grasp comfortably in
the hand. Keep the scanner cool by one or more of the following methods.
1.
Use 6” to 8” length of pipe between scanner and hot furnace front plate.
2.
Use insulating tube (Part No. 35-69) on the end of the iron pipe.
3.
Force air into sighting tube. Use Fireye Sealing Union (Part No. 60-801).
4.
Make sure sighting tube does not extend more than halfway into refractory wall.
IINSTALLATION - 69NDl FLAME ROD
The 69NDl flame rod proves a gas pilot flame and/or main gas flame. It is a spark plug type unit con-
sisting of
1
/
2
' “NPT mount, a KANTHAL flame rod, a glazed porcelain insulating rod holder and a
spark plug connector for making electrical connections. The 69ND1 is available in 12,” 18” or 24”
lengths.
The flame rod may be located to monitor only the gas pilot flame or both the gas pilot and main gas
flames. It is mounted on a
l
/
2
" “NPT” coupling.
The following instructions should be observed:
1.
Keep flame rod as short as possible.
2.
Keep flame rod at least
1
/
2
" from any refractory.
3.
Flame rod should enter the pilot flame from the side so as to safely prove an adequate pilot
flame under all draft conditions.
4.
If the flame is nonluminous (air and gas mixed before burning), the electrode tip should extend
at least
1
/
2
" into the flame, but not more than halfway through.
5.
If the flame is partly luminous, the electrode tip should extend only to the edge of the flame. It is
not necessary to maintain absolutely uninterrupted contact with the flame.
6.
It is preferable to angle the rod downward to minimize the effect of sagging and to prevent it
from coming in contact with any object.
7.
An adequate grounding surface for the flame must be provided. The grounding surface in actual
contact with the flame must be at least four times greater than the area of the portion of the flame
rod in contact with the flame. It is essential to adjust the flame rod and ground area ratio to pro-
vide a maximum signal reading.
WRONG POSITION
OF ROD
INADEQUATE FLAME
PILOT BURNER
CORRECT POSITION
OF PILOT FLAME
CORRECT
POSITION
OF ROD
