Honeywell C7915A Information page 9

1. All wiring must comply with applicable electrical codes,
ordinances, and regulations. Use NEC Class 1 wiring.
2. Keep the coaxial cables from the flame detector to the
flame safeguard control subbase as short as possible.
Capacitance increases with coaxial cable length, reduc-
ing the signal strength. The maximum permissible coax-
ial cable length is fifty feet.
coaxial cable length is the flame signal current/voltage
Refer to Table 6, Adjustments and Checkout, page 10.
3. The detector comes with 30, 48, or 96 in. (0.76, 1.22, or
2.44 m) coaxial cable inside a flexible metal cable. The
coaxial cable is terminated with two leads—one blue and
one white. The coaxial cable is rated for 194°F (90°C).
The cable protects and electrically shields the coaxial
cables.
4. If the coaxial cables are not long enough to reach the ter-
minal strip or wiring subbase, make the required splices
in a junction box (see IMPORTANT below).
5. If splicing is necessary, use moisture-resistant no. 14
wire suitable for at least 167°F (75°C) if the detector is
used with a flame safeguard
194°F (90°C) if used with a flame safeguard program-
ming control.
For splicing in high temperature installations
6.
well specification no. R1298020 or equivalent for the F
coaxial cable. (This wire is rated up to 400°F [204°C] for
continuous duty. It is tested for operation up to 600 volts
and breakdown up to 7500 volts.) For the other coaxial
cable, use moisture-resistant no. 14 wire selected for a
temperature rating above the maximum operating tem-
perature.
IMPORTANT:
1. Flame detector coaxial cables must be as short as
possible. The maximum coaxial cable length from the
flame detector to the flame safeguard control is 50 ft
(15.2 m).
2. Extensions to the flame detector coaxial cables must
be run alone in either rigid or flexible metal conduit.
When flame detector coaxial cables exit a conduit,
they must be as short as possible, twisted, and not be
included in bundles or channels that contain other
wires. Rigid metal conduit is preferred when flame
detector coaxial cables are extended but flexible
metal conduit may be used if it is supported to mini-
mize movement.
3. The flame detector flexible cable shield must be
grounded to the flame safeguard control subbase
either directly or through the metal cabinet/conduit
system that contains the flame safeguard control sub-
base and flame detector coaxial cables.
4. When flame detector coaxial cables are routed
through junction boxes, identify the junction boxes
with the pressure-sensitive labels provided with the
flame detector (form 96-610).
5. UNDERWRITERS LABORATORIES INC. REQUIRES
THAT THE JUNCTION BOX BE MARKED TO INDI-
CATE THAT NO OTHER WIRING CONNECTIONS
CAN BE ROUTED THROUGH IT. APPLY CAUTION
STICKER (FORM 96-610, FURNISHED) TO THE
JUNCTION BOX.
6. Maximize the separation between ignition transformer
high voltage wires and the flame sensor wires to avoid
ignition interference.
The ultimate limiting factor in
primary
control, or at least
, use Honey-
C7915A
ASSEMBLY
FLEXIBLE CABLE (MECHANICALLY
SUPPORT TO MINIMIZE MOVEMENT)
.
1 1 BLUE WIRE AND 1 WHITE WIRE FROM THE C7915, CONNECT TO
FLAME SAFEGUARD CONTROL'S SUBBASE, KEEP WIRES AS SHORT
AS POSSIBLE, AND TWIST THEM.
2
FLEXIBLE CABLE MUST BE RIN TO FLAME SAFEGUARD CONTROL'S
SUBBASE AND GROUNDED WHERE THE EXPOSED WIRES BEGIN.
Fig. 10. Typical wiring of C7915A Infrared Flame Detector to
nearby wiring subbase or terminal strip.
FLEXIBLE CABLE (MECHANICALLY
SUPPORT TO MINIMIZE
MOVEMENT)
CONDUIT
FITTING
1
2
JUNCTION BOX
1 1 BLUE WIRE AND 1 WHITE WIRE FROM THE C7915; CONNECT
INSIDE JUNCTION BOX; LEADWIRES FROM JUNCTION BOX NEED
TO BE POLARIZED.
2
APPLY CAUTION STICKER, FORM NO. 96-610 SUPPLIED WITH
C7915, TO THIS JUNCTION BOX. BOX MUST BE GROUNDED.
3
USE RIGID CONDUIT, OR SUPPORT FLEXIBLE CONDUIT TO
MINIMIZE MOVEMENT.
4
CONDUIT MUST BE RUN TO FLAME SAFEGUARD CONTROL'S
SUBBASE AND GROUNDED THERE. KEEP EXPOSED WIRES AS
SHORT AS POSSIBLE AND TWIST THEM.
Fig. 11. Typical wiring of C7915A Infrared Flame Detector to
distant wiring subbase or terminal strip.
9
C7915A INFRARED FLAME DETECTOR
WIRING SUBBASE
GROUNDING
OR TERMINAL STRIP
STRAP
BLUE
WHITE
2
C7915A
ASSEMBLY
BX CABLE, SHIELDED CABLE,
OR TWISTED PAIR; MUST BE
ALONE IN CONDUIT.
FLAME SAFEGUARD
CONTROLS SUBBASE
3
4
F
1
G
M23446A
F
G
M23447B
65-0292-06