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LIMIT SETTING
To set the cutout
point
for the high limit switch,
move the high limit indicator
(Fig. 9) to the desired set
point.
Follow
setting
instructions
furnished
by the
furnace manufacturer
whenever possible. The limit dif-
ferential
is fixed at 25 F [ 14 C]. The switch breaks
at the setting
and remakes
25 F [14 C] below the
set point.
The high limit
setting
is provided
with a stop
~IMPORTANT~
to limit the maximum temperature
settmg. Do not
force indicator above this point.
FAN SETTING (ADJUSTABLE
DIFFERENTIAL)
The fan differential
is adjustable
from 15 to 50 F
[ 8 to 28 C]
.
The fan switch makes at the set point and
breaks
15 to 50 F [8 to 28 C] below the fan-on
setting, depending
on the position of the fan adjustment
dial. To change the setting, move the fan-on indicator
(Fig. 9) to the desired temperature.
Set the fan dif-
ferential
adjustment
dial (Fig. 9) to the desired dif-
ferential.
For constant
fan operation
(L4017B
only),
set the MANUAL-AUTO
switch in the manual position.
0
KNOCKOUT
0
CAPILLARY
0
INDICATOR
INDICATOR
HIGH LIMIT
FAN SWITCH
0
4 TERMINAL
AN TERMINAL
0
STAND-OFF
0
FAN DIFF.
2601
FIG. 9-L4017B
WITH
COVER
REMOVED.
L4017A
IS
SIMILAR
BUT
DOES
NOT
INCLUDE
THE MANUAL
FAN SWITCH.
FAN SETTING (FIXED DIFFERENTIAL)
Set the fan indicator
to the desired fan-off tempera-
ture. The fan will come on 35 F [19 C] above that
setting.
-
CHECKOUT
1. Follow
the furnace
manufacturer's
instructions
for placing the furnace
in operation.
If a manual
re-
set Pilotstat
control
is used,
make
sure that
it is
holding in.
-
2. Set the thermostat
and limit control
to call for
heat. The main burner should light.
3. To check the high limit control,
disconnect
the
fan motor
and close all dampers.
Set thermostat
to
call for heat. Main burner should light. When plenum
temperature
reaches limit control
setting, main burner
should shut off. When checkout
is complete,
connect
fan motor and open all dampers.
4. Make sure that the fan operates when the furnace
temperature
rises to the setting and shuts off when tem-
perature
drops below set point and through the desired
differential.
On fixed differential
models, the fan should
operate
when furnace temperature
rises to setting plus
differential
and shut off when temperature
drops to
setting.
OVERHEATING
FURNACE
(LIMIT
SWITCH
FREQUENTLY
CUTS OUT)
1. Make sure fan is operating
by jumpering
across
the fan terminals.
If fan does not operate,
check the
wiring.
2. Make sure that fan setting is low enough so that
the hot air is circulated
from the furnace
before the
plenum temperature
nears the high limit setting.
3. If limit switch continues
to cut out, check for
obstruction
to airflow
through
furnace.
Inspect
for
clogged air filters
and improperly
adjusted
dampers.
HONEYWELL
MINNEAPOLIS,
MINN.
55408
INTERNATIONAL
Sales Offices
in all principal
cities of the world.
Manufacturing
in
Australia,
Canada,
Finland,
France,
Germany,
Japan,
Mexico, Netherlands,
Spain, Taiwan,
United
Kingdom,
U.S.A.
PRINTED
IN U.S.A.
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