General:
The Low Water Cutoff (LTA-2) is a microprocessor based low water
cutoff for detecting the presence to water in a boiler. The LTA-2
uses advanced signal processing to identify when the probe signal
levels have decreased due to possible fouling. These advanced
technologies permit extended operation for probe impedance up
to 40K Ohms. The LTA-2 functions longer without requiring probe
cleaning, and it functions normally under non-ideal installation
conditions. The LTA-2 is designed for use with hot water boilers
and hot water heating boilers. (See each boiler manufacturers'
specifications for recommended minimum safe water levels.)
During a low water condition, the "Status" LED will illuminate RED.
Under normal conditions, it will illuminate GREEN. See "Status
LED States" table for details.
Instruction Sheet
LTA-2 - Low Water Cutoff
for Hot Water Boilers
102-350
SUPERSEDES: 5403576 - Rev C Dated October 6, 2008
#5403576-REV D
PLANT ID 001-3915
EFFECTIVE: January 6, 2009
Listings/Approvals:
• UL GUIDE (MBPR) for Limit Controls per UL Standard
353 Limit Controls
• UL GUIDE (MBPR7) Controls, Limit Certified for Canada
CSA Standard C22.2
• Fully meets installation requirements of CSD-1 for
automatic controls
Maximum Probe Ratings:
Hot water only - 250 psi (17.6 kg/cm
2
) at 250°F (121°C)
Probe Sensitivity:
20K Ohms. Extended operation to 40K Ohms.
Ambient Temperature:
32°F to 150°F (0°C to 66°C)
Enclosure Rating:
NEMA 1 for indoor use only
Input Power:
2.8 VA @ 120 VAC
2.8 VA @ 24 VAC supplied by a Class 2 power source
Reset:
Automatic reset when water level returns to safe level
Testing:
Integrated test switch for testing safety shutdown
US Patents 6,904,800, 7,243,540
and 7,317,993
Other Patents Pending
• Installation must be performed by qualified personnel and in accordance with all national and local codes and ordinances.
• Read all instructions carefully and understand them before starting installation. Save instructions for future use.
• Instruct user how to test and operate this cutoff device as described in these instructions.
• Risk of explosion. Not for use in hazardous locations. Serious injury or death could result.
• The LWCO device must be installed in series ahead of other limit and operating controls installed on the boiler. When installations are complete,
check for correct operation of ALL limit and operating controls.
• For use with hot water boilers and hot water heating boilers only. Use on steam boilers could cause improper operation resulting in property damage,
serious injury, and death.
• Shock Hazard. Disconnect power source before servicing. Serious injury or death could result.
• Hot or pressurized boiler systems can discharge steam and hot water. Cool boiler system to 80º F (27º C) and to 0 psi (0 bar) before servicing.
Failure to do so could result in serious burns.
Contact Ratings*
Voltage
Motor Switch Rating
Pilot Rating
Full Load
Locked Rotor
24 VAC
-
-
50 VA
120 VAC
7.5 A
43.2 A
125 VA
240 VAC
3.75 A
21.6 A
50 or 60 Hz
* 1A resistive at 120°F to 150°F (49°C to 66°C)
