Honeywell L482A User manual

L482A
Low Limit Controller
INSTALLATION INSTRUCTIONS
BEFORE INSTALLATION
No special tools are required to install the L482A Low Limit
Controller. Refer to the job drawings for specific wiring and
installation information.
INSTALLATION
When Installing this Product...
1. Read these instructions carefully. Failure to follow them
could damage the product or cause a hazardous
condition.
2. Check ratings given in instructions and on the product to
ensure the product is suitable for your application.
3. Installer must be a trained, experienced service
technician.
4. After installation is complete, check out product
operation as provided in these instructions.
Mounting
IMPORTANT
1. The controller operates from the lowest temperature
along the entire 20 feet of the sensing element.
2. Locate controller case and bellows where ambient
temperature is always warmer than the set point.
3. For settings above the scale range midpoint it can be
necessary to locate the controller case close to a
steam pipe or other warm surface and make sure the
element does not extend across a cold surface.
Controller
Surface mount the controller (Fig. 1) vertically on any Fig. 1. L482A Low Limit Controller dimensions in in. (mm).
convenient location (including the duct itself). Orient the case
with the bellows positioned on the bottom.
SETPOINT
ADJUSTMENT
SCREW
4 (101)
2-3/32
(53)
7/8 (22) HOLE
FOR 1/2 CONDUIT
WITH 1-3/32 (28)
KNOCKOUT RING
FOR 3/4 CONDUIT
1-7/8
(48)
5/16
(8)
3/16 (5)
DIAMETER
MOUNTING
HOLE
3-1/4 (83)
5/16 (8)
1 (25)
1-1/8 (29)
3/8 X 3/16
(10 X 5)
DIAMETER
ELONGATED
MOUNTING
HOLE
C606A
SETPOINT
SCALE
4-11/16
(119)
MOUNTING
HOLES (2)
10-32 UNF-2B
THREAD
PUSH
TO
RESET
20 FT BY 1/8 INCH
SENSING ELEMENT
® U.S. Registered Trademark
Copyright © 2004 Honeywell International Inc. 95-7432-1
All Rights Reserved 996-496 Rev. A

L482A LOW LIMIT CONTROLLER
Sensing Element
IMPORTANT
• The maximum allowable sensing element tempera-
ture is 250°F (121°C).
• Uncoil only the amount of element required for the
application.
• Bend element carefully and only as much as neces-
sary. Bends require a minimum radius of one inch
(25 mm).
• Bend only some distance from the controller.
• Pulling on the element damages it.
• For elements subject to vibration, provide protection
from any surface which the element contacts.
• Mount element horizontally as shown in Fig. 2 and 3.
1. Locate the sensing element where it can sense the
temperature of the air to be controlled.
NOTE: Locate the element away from hot or cold air
inlets.
2. Punch or drill a 1/4 in. hole in the duct and install
CCT1802 Grommet (Fig. 2) to protect the capillary.
3. Carefully insert the element through the grommet into
the duct. Use as much element as possible to provide
maximum protection.
4. Mount the element inside the duct or fasten to the coil if
freezing can occur.
a. Duct mounting: Use CCT2600 Clip (Fig. 2).
b. Coil fastening: Use perforated metal straps (Fig. 3).
Fig. 2. Element mounted to duct with CCT2600 Clips.
Fig. 3. Element mounted in duct with
perforated metal straps.
C789
GROMMET ELEMENT
CLIP
DETAIL
USE NO. 10
SHEET METAL
SCREWS
BEND HERE
IF
NECESSARY
C790
WIRE FASTENINGSELEMENT
PERFORATED METAL STRAPS
OPERATION
On a temperature drop to setpoint, LINE 1 to M1 contacts
close and LINE 2 to M2 contacts open. Reset to the normal
state is manual.
WIRING
WARNING
Electrical Shock Hazard.
Can cause severe injury, death or equipment
damage.
Disconnect power supply before beginning installation
to prevent electrical shock or equipment damage.
IMPORTANT
– All wiring must agree with applicable codes,
ordinances and regulations.
– When switching both ac line voltage and an
automation input (Fig. 4), the input wires must
run no more than three feet in the same conduit.
See Fig. 6.
For typical L482A wiring, see Fig. 4 and 5.
NOTES:
– Screw terminals are provided for wiring
connections.
– Maximum wire size is 12 AWG.
– Use 8-32 x 1/4-inch screws for replacement if
necessary. Longer screws can interfere with the
switch mechanism and damage the switch.
L1
(HOT)
L2
TO STATUS
OR ALARM
INPUT OF
AUTOMATION
SYSTEM
LINE 2 LINE 1
M2 M1
FAN RELAY
C791
Fig. 4. Typical wiring diagram with automation input.
95-7432–1 2
996-496 Rev. A

L482A LOW LIMIT CONTROLLER
L1
(HOT)
L2 FAN RELAY
LOCAL ALARM
C79
2
Fig. 5. Hookup providing freeze protection by shutting
down fan with line powered local alarm.
LINE 2 LINE 1
M2 M1
36 INCH
(914 MM)
MAXIMUM
CONDUIT
T
O
F
AN
R
ELAY
JUNCTION
BOX
LINE 2 LINE 1
M1M2
TO
AUTOMATIO
N
SYSTEM
C79
3
Fig. 6. Providing separate conduit for switched ac and
automation input wiring.
Adjustment
Turn the setpoint adjustment screw (Fig. 1) on the top of the
controller case to the value called for on the job drawings.
NOTES:
1. The setpoint adjustment is limited to 35-55°F
(2-13°C) by an internal physical stop.
2. The setpoint is factory set at 35°F. Setpoint is the
temperature at which LINE 1 to M1 contacts close
and LINE 2 to M2 contacts open on a temperature
fall. The controller differential is fixed at 5°F (3°C)
nominal and is additive to the setpoint.
3. The operating point drops for elevations above
sea level. To compensate, increase the setpoint
adjustment 1°F (0.6°C) above the required set-
point for each 1000 feet (305m) above sea level.
CHECKOUT
Because of the L482A limited setpoint range, operational
checkout can be difficult. Use one of the following methods to
verify proper controller operation:
1. If the ambient temperature is below 50°F (10°C):
a. Turn the setpoint adjustment through the ambient
temperature and note the switch action.
b. When the setpoint is increased to equal the ambient
temperature:
(1) LINE 1 to M1 contacts should close.
(2) LINE 2 to M2 contacts should open.
c. Decreasing the setpoint to 5°F (3°C) below the
ambient temperature should not affect the contact
positions.
d. Pushing the manual reset button should:
(1) Open contacts LINE 1 to M1
(2) Close contacts LINE 2 to M2.
2. If the ambient temperature is above 50°F (10°C):
a. Immerse at least one foot of the element in ice water
(or wrap same in ice).
b. As the element drops through the setpoint:
(1) LINE 1 to M1 contacts should close.
(2) LINE 2 to M2 contacts should open.
c. Remove the element from the ice water (or ice
wrapping).
d. As ambient temperature rises to 5°F (3°C) the set-
point, there should be no effect on contact positions.
e. Pushing the manual reset button should:
(1) Open contacts LINE 1 to M1.
(2) Close contacts LINE 2 to M2.
3 95-7432–1
996-496 Rev. A

Automation and Control Solutions
Honeywell International Inc. Honeywell Limited-Honeywell Limitée
1985 Douglas Drive North 35 Dynamic Drive
Golden Valley, MN 55422 Scarborough, Ontario
M1V 4Z9
996-496 Rev. A
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95-7432–1 B.B. Rev. 4-04
paper containing at least 10%
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