Berner International B-24 User Manual
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(F) Fan Starter: Although not normally considered a
safety device, the fan starter is wired so that its 13-14
interlock powers the control system. Thus the main fan
must be energized before the gas system can be pow-
ered. This provides one more assurance, in addition to
the Airflow Switch, that the fan is operating before heat
comes on.
(G) Secondary Safety** and Bleed Valves (or “Block &
Vent Valves): A second main line gas valve is installed
downstream of the primary safety valve. A vent line with
an electrically operated normally-open valve takes off lat-
erally between the two main line valves. This vent line
must be piped to atmosphere outside the building, by the
customer on installation (See Suggestions for Regulator.
)
IX.
O P E R ATION
X.
M A I N T E N A N C E
(Note:
See wiring diagram for part number and manufacturer
of any control component. See manufacturer’s instruction
sheets for more information.)
(A) Fan Motor Bearings: Refer to green sheet on mainte-
nance of direct-connected fans. Most fan motors have a
1/8" NPT pipe at each bearing, which may be removed
for lubrication, in the event lube tubes were not factory-
installed.
(B) Burner: Side plates and their air holes should be
checked periodically, to be sure these parts are not fouled
or plugged.
(C) Burner Adjustment: (See Operation).
(D) Fireye: The UVM-IF utilizes solid state components.
The only required maintenance is on its external compo-
nents; i.e., the Flame Rod and the Ultra -Violet Scanner.
See “Maintenance” in manufacturer’s bulletin C-400.
(E) Scanner: Remove scanner occasionally, clean lens,
and be sure that mounting pipe nipple is clear of insects
and dirt.
(F) Spark Ignitor: Ignition takes place by means of a spark
jumping from the ignitor to the side plate of the burner.
The spark gap should be 1/8" to 3/16" (. 12" -. 19"), and
located downstream of an air mixing hole, so that there is
a gas-air mixture to be ignited. Check for carbon “bridge”
between electrode and burner which may short out spark
and prevent ignition.
XI.
T R O U B L E S H O O T I N G
First check for loose wiring connections.
Then check the following for specific symptom:
(A) Fan Won’t Start -
(1) Selector in “OFF” position.
(2) Check 3-phase line leads for power across all 3
phases, if one line is dead, check fuses or breaker in
main disconnect.
(3) Check fuse on control circuit transformer.
(4) Try “SUM” setting. If fan runs, but won’t run on “@”,
check 1T’HS outdoor thermostat (if used) for open R-B
contact; check limit switch on door for open-contact.
(A) Gas Adjustment: Heat output is adjusted by varying
the outlet pressure of the regulator (see Gas Pressure
Regulator). A pressure gage may be attached to the pip-
ing at a leak-test connection. Table 1 shows performance
at various inlet pressures.
(B) Pilot Adjustment: This heater is equipped with inter-
rupted pilot; i.e., after main burner ignites, pilot is cut off.
Scanner then senses main flame only. Pilot flame was
properly adjusted at the factory. Field adjustment is pos-
sible by removing the protective cap and using a screw-
driver with a small bit.
G A S
SUPPLY
P R E S S U R E
(in. w.g.)
MODEL B-22, 6500 CFM
5”
700
99
169
6”
765
109
179
7”
820
117
187
8”
7” MAX. RECOMMENDED
1000’S
BTU/HR
RISE
(º F)
FINAL T E M P.
(º F)*
G A S
SUPPLY
P R E S S U R E
(in. w.g.)
MODEL B-24, 7900 CFM
5”
790
92
162
6”
865
101
171
7”
930
109
179
8”
990
116
186
1000’S
BTU/HR
RISE
(º F)
FINAL T E M P.
(º F)*
* Based on 70º F. inlet temperature.