LT1

Overview

The Hobart LT1 is a door-type, low-temperature dishwasher that sanitizes with chemicals. It is suited to commercial dishrooms handling recurring racks of plates, cups, glasses, bowls and small wares. The installation and operation manual specifies up to 40 racks per hour and 1.7 gallons of water per rack. It describes an automatic wash sequence following the initial manual fill: the machine washes a rack, drains wash water, and refills with fresh water for the rinse. Rinse water remains in the machine for the next wash cycle. Detergent, rinse aid and sanitizer are pumped into the wash tank at the appropriate point in each cycle.

The LT1 has a hood-type, three-door assembly. All three doors open together when the spring counter-balanced handle is raised. Its front panel is optional; the manual notes that the stainless steel front panel is available separately as an option.

Key Features

• Low-temperature chemical sanitizing: Uses detergent, rinse aid and sanitizer, with a minimum water temperature of 120°F and a recommended temperature of 140°F.
• Rack throughput: The LT1 manual states capacity of up to 40 racks per hour.
• Water use: The manual specifies 1.7 gallons per rack.
• Flexible dishroom layout: The front rack track and splash guard can be repositioned to convert the unit between straight-through and corner arrangements.
• Automatic cycle start: With power on, closing the doors starts the cycle.
• Operator controls: Controls include a power switch, detergent, sanitizer and rinse-aid priming switches, a drain/fill switch, a cycle light and a sump thermometer.
• Serviceable wash system: The manual describes removable strainers and wash arms that can be checked and cleaned.

Specifications

• Equipment type: Low-temperature chemical-sanitizing, door-type dishwasher.
• Model: LT1.
• Capacity: Up to 40 racks per hour, according to the LT1 manual.
• Water consumption: 1.7 gallons per rack, according to the LT1 manual.
• Rack size: 19-3/4 × 19-3/4 inches.
• Cycle timing listed in the manual: Wash 40 seconds; drain 10 seconds; flush 3 seconds; fill 9 seconds; rinse 20 seconds. The manual also says the cycle light goes out after 90 seconds to indicate cycle completion.
• Water temperature: 120°F minimum; 140°F recommended.
• Water pressure: 20–25 psig recommended; 15–25 psig required at the dishwasher.
• Water hardness: 4–6 grains per gallon recommended.
• Water connections: 3/4-inch supply connection; 2-inch NPT drain fitting.
• Electrical conduit opening: 1/2 inch. The manual requires electrical and grounding connections to comply with applicable national and local electrical codes.
• Motor: 3/4 HP, as shown in the LT1 manual installation drawing.
• Dimensions: 28-5/8 inches wide × 24-15/16 inches deep × 68-7/8 inches high, as listed in the supplied product specifications.
• Net weight: 239 lb.
• Configuration: Straight-through or corner installation.
• Front panel: Optional.

Installation & Requirements

The manual calls for a 3/4-inch water supply connection and a 2-inch NPT drain connection. A water hammer arrestor meeting ASSE-1010 should be provided in the water supply line ahead of its connection to the line strainer. The recommended supply-water temperature is 140°F, with 120°F as the minimum. Recommended flowing pressure is 20–25 psig, and the manual gives a required range of 15–25 psig at the dishwasher. If pressure exceeds 25 psig, the manual says a pressure-regulating valve with an internal thermal-expansion bypass must be supplied in the water line. Recommended water hardness is 4–6 grains per gallon; the manual warns that softer water promotes corrosion and harder water may increase lime scale.

Verify that the electrical service agrees with the machine data plate. The manual requires electrical and grounding connections to comply with applicable national and local electrical codes. Before working on the circuit, disconnect electrical power and place a tag at the disconnect switch indicating that work is in progress. The electrical conduit opening is 1/2 inch.

Operation

Turn on the power switch. To prime a chemical pump, press and hold its corresponding detergent, sanitizer or rinse-aid priming switch until the chemical reaches the end of its delivery tube. The drain/fill switch opens the fill valve while held on FILL and opens the drain valve while held on DRAIN. The cycle light indicates when a wash cycle is underway, and the thermometer indicates sump-water temperature.

Scrape and/or rinse food particles from wares before loading. Place items in a rack without stacking them, so water can reach all sides. Stand plates edgewise in a peg-type rack; place cups, glasses and bowls upside down in an open or compartment rack. Lay silverware and other small pieces loosely in an open-type rack. Do not allow foreign objects, especially metallic contaminants, into the machine. The manual cautions that the sodium hypochlorite sanitizer can attack pewter, aluminum and silver, so those items should not be washed in the LT1.

Slide the loaded rack into the machine and close the doors to start the cycle. The manual states that the cycle light goes out after 90 seconds; the doors can then be raised and the clean rack removed. If a cycle is interrupted, it resumes from the point of interruption when operation continues. The machine functions only when the power switch is on and the doors are closed. After a long pause between racks, check the thermometer. If the water is below 120°F, manually drain the machine and refill it with fresh water.

Cleaning & Maintenance

Drain and clean the dishwasher at the end of each working shift. To drain it, hold the drain/fill switch on DRAIN until the machine is empty, or open the doors and remove the drain tube; its drain stopper is attached to the bottom. When drained, replace the drain tube and stopper, close the doors, and hold the switch on FILL for approximately ten seconds.

For cleaning, drain the machine and turn the power off. Thoroughly clean and flush the interior, then drain any water that has accumulated. Wipe the exterior with a soft cloth or brush and mild cleanser, remove remaining soil, and rinse. Do not allow food soil to collect on the tank bottom. Remove the pump intake strainer, drain tube and stopper, and drain pan strainer and scrub them in a sink. Check that wash arms spin freely and that no nozzles are clogged. Reinstall all removed parts, including the drain pan strainer. Use only products formulated for stainless steel on warewasher surfaces; do not use steel wool.

Troubleshooting

The LT1 manual lists the following possible causes. If the problem continues after checking them, it may require service.

• No machine operation: Check whether the power switch is off, a fuse has blown or a circuit breaker has tripped. The manual also lists the DELIME/NORMAL switch being in DELIME while the machine is in the middle of a cycle.
• Continuous operation: The manual lists the DELIME/NORMAL switch being in DELIME or a timer problem. For a timer problem, it directs operators to contact a local Hobart Service Office.
• Dishes not clean: Possible causes listed include a clogged pump intake strainer; blocked wash-arm nozzles or bearings preventing the arms from turning; incorrectly assembled wash arms or loose knurled disks; inadequate fill from low supply pressure or improper cycle-timer adjustment; water below the recommended temperature; unsuitable water hardness; or excessive lime deposits in the wash/rinse system. Clean and inspect the parts as described in the manual.

Applications

The LT1’s rack-type, door-operated format supports commercial dishroom workflows where staff load and unload racks at the machine. The manual’s loading directions cover plates, cups, glasses, bowls, silverware and other small pieces. Its straight-through or corner arrangement can accommodate different dishroom table layouts, subject to the installation drawing and site requirements.