sensing level. The low water cut-off controls must
be operationally tested by manually lowering the
boiler water level (by opening the drain valve).
The boiler should cycle off when the water level
drops below the control point of the low water cut-
off. When the water level is restored, the boiler
should cycle back on. Depress the manual reset
button of devices which require manual reset in
order to restore the boiler to operation. Carefully
read the enclosed literature on the low water cut-
off controls, particularly installing, operating and
servicing.
2.4.8 COMBINATION LOW WATER CUT-OFF &
FEEDER
The low water cut-off/feeder supplied with some
boilers serves as a low water cut-off (see above)
and also causes make-up water to be added to
the boiler, should the water level drop below its
control
point. This type of control must be operationally
tested as described in Section 2.4.1 and also to
assure that the make-up water is introduced as
needed. Carefully read the enclosed literature on
the Low Water Cut-off controls, particularly
installing, operating and servicing.
2.4.9 OTHER CONTROLS
Additional controls, as required for the particular
installation, may also be provided. Refer to the
literature on these devices included in the Boiler
Manual. All such devices must be operationally
tested to assure reliable operation of the boiler
and system.
2.5 RECOMMENDED DRAFT AND COMBUSTION READINGS
ATMOSPHERIC GAS-FIRED BOILERS
BOILER SERIES
DRAFT AT BOILER
OUTLET
(i.w.c.)
CO
2
@ HIGH
FIRE
O
2
@
HIGH FIRE
CO
(ppm)
SMOKE
NO.
F
-0.01 TO -0.04
7.5 TO 8.5 %
5.0 TO 7.5 %
< 400
0
CL
-0.02 TO -0.04
7.5 TO 9.0 %
4.8 TO 7.5 %
< 400
0
K
-0.02 TO -0.06
8.0 TO 9.5 %
4.0 TO 6.7 %
< 400
0
FORCED DRAFT GAS FIRED BOILERS
BOILER SERIES
DRAFT AT
BOILER OUTLET
(i.w.c.)
CO
2
@
HIGH FIRE
O
2
@
HIGH FIRE
CO
(ppm)
SMOKE
NO.
D
-0.01 TO -0.04
7.5 TO 9.5 %
4.0 TO 7.5 %
< 400
0
HED
-0.01 TO -0.04
7.5 TO 9.5 %
4.0 TO 7.5 %
< 400
0
CL
0.0 TO -0.04
8.5 TO 10.0 %
3.2 TO 5.0 %
< 400
0
HECL
0.0 TO -0.06
8.5 TO 10.0 %
3.2 TO 5.0 %
< 400
0
RV & RW
+0.50 TO -0.10
9.0 TO 10.0 %
3.2 TO 5.0 %
< 400
0
AB
+0.25 TO -0.06
9.0 TO 10.0 %
3.2 TO 5.0 %
< 400
0
Summary of Contents for AB Series
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