Honeywell L7124U Installation Instructions Manual

APPLICATION
The L7124U Universal Oil Electronic Aquastat®
Controller provides electronic temperature sensing in a
UL limit-rated control with a single sensing probe. The
L7124U controls circulator, oil burner and boiler
temperature. The L7124U replaces the L8124A, L8124C
and L8148A Controllers.
General
The L7124U Universal Oil Electronic Aquastat®
Controller is a primary safety limit-rated device designed
for use with oil fired boilers with line voltage burners and
circulators. The boilers do not include wiring or control
compartments as part of the design, but are provided
with an integral, replaceable, immersion well that is the
mounting hardware for the L7124U. Wiring to the other
controls is done through flexible metal conduit. A
separate electromechanical high-limit is not required in a
system that uses this control.
A manually-adjusted potentiometer is used to set the
High Limit. The overall range of the High Limit dial is from
130°F to 240°F (54°C to 116°C). The High Limit is
calibrated for accuracy at 212°F (100°C). Some models
have limited ranges on the high limit setpoint; this limited
range is listed on the device label, but the potentiometer
travels the full mechanical distance.
Some models also have a Low Limit and Low Limit
Differential adjustment. The range of the Low Limit dial is
from 110°F to 220°F (43°C to 104°C). Rotating the Low
Limit potentiometer fully counterclockwise disables
the low limit function and turns on the Low Limit
Disabled LED.
The L7124U is designed for use with 24 Vac electronic
and electromechanical thermostats and has screw-type
terminals for easy field connection.
® U.S. Registered Trademark
Copyright © 2001 Honeywell • All Rights Reserved
Electronic Aquastat® Controller
L7124U Universal Oil
INSTALLATION INSTRUCTIONS
SPECIFICATIONS
Electrical Ratings:
Voltage: 120 Vac, 60 Hz.
Power: 10 VA maximum at 120 Vac plus external loads.
Thermostat current: 100 mA nominal at 24 Vac.
Burner Relay:
7.4A at 120 Vac Full Load Amperage (FLA);
44.4A inrush Locked Rotor Amperage (LRA);
Plus Ignition Load: 360 VA.
Circulator Relay:
7.4A at 120 Vac FLA; 44.4A inrush LRA.
Zone Controller (ZC): 7.4A at 120 Vac FLA;
44.4A inrush LRA.
Differential Ratings:
High Limit Differential: 15°F subtractive.
Low Limit Differential: Adjustable 10°F to 25°F
subtractive from Low Limit setpoint.
Environmental Ratings:
Temperature: -30°F to +150°F (-34°C to +66°C).
Humidity: 0 to 95% relative humidity,
noncondensing.
Approvals:
Underwriters Laboratories Inc. Component Recognized:
Pending approval.
Canadian Underwriters Laboratories Inc. Component
Recognized: Pending approval.
Accessories
Accessories (Ordered Separately):
120650 Heat Conductive Compound
124904 Well Adapter
32002190-001 Relay
32004955-001 Sensor
4074GYZ Fuse, 1A (10-pack package)
Table 1. Wells for L7124U Controller.
Part Spud Size
Number
123869A 1/2 NPT
123870A 3/4 NPT
Insertion
(in.) (in.)
3
3
Insulation
(in.)
1-1/2
1-1/2
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