AM15T

Overview

The Hobart AM15T is a tall, door-type commercial warewasher in Hobart’s AM Select dishwasher series. Hobart’s manual identifies the AM15T as model ML-130039. It is operated by loading a rack, closing the door and selecting a timed wash cycle; each wash cycle is followed by an automatic rinse. The manual describes a 1-minute cycle for normal serving ware and 2-, 4- or 6-minute cycles for more heavily soiled items.

AM15T configurations differ. Seller listings describe an AM15T-1 low-temperature model without a booster and an AM15T-4 hot-water and chemical-sanitizing model. Hobart’s manual also provides separate incoming-water requirements for hot-water and chemical sanitizing, and identifies gas heat as an option at extra cost. Confirm the exact model suffix and options on the unit’s data plate before planning utility connections.

Key Features

• Four timed cycles: 1, 2, 4 and 6 minutes, selected with the CYCLE button.
• Automatic rinse: The rinse follows the wash portion of the cycle; the display shows wash and rinse status and the corresponding water temperature.
• Door-activated operation: After the machine is filled and a cycle is selected, closing the door starts the cycle automatically.
• Multiple sanitizing configurations: Hobart’s manual specifies hot-water and chemical-sanitizing operating modes, with different incoming-water requirements.
• Commercial dishroom format: The tall door-type arrangement accepts a dish rack that slides into the machine between the tables.

Specifications

• Product: Hobart AM15T door-type warewasher; Hobart model number ML-130039.
• Material: Stainless steel, according to the AM15T-4 seller listing.
• Dimensions: 27 inches wide × 28.5 inches deep × 77.5 inches high, as listed for the AM15T-1; another listing gives the height as 77-1/2 inches.
• Weight: 388 lb, as listed for the AM15T-4. Confirm the weight for the specific configuration being purchased.
• Electrical details: A seller lists the AM15T-1 at 208–240 V, 60 Hz, three phase, 2 HP. Electrical details can vary by configuration; use the machine’s data plate for the unit being installed.
• Wash tank capacity: 14 gal, per the AM15T-1 seller listing.
• Cycles: Four timed cycles: 1, 2, 4 and 6 minutes.
• Racks per hour: 58–65, per the AM15T-1 seller listing.
• Water usage: 0.74 gal per rack, per the AM15T-1 seller listing.
• Water connection: 3/4-inch inlet, per the AM15T-1 seller listing. Hobart’s manual specifies a 3/4-inch line strainer connection for models without an electric booster.
• Listed water-temperature range: 14–180°F, per the AM15T-1 seller listing. This is not a substitute for Hobart’s configuration-specific incoming-water requirements below.
• Gas heat, when specified: Hobart’s manual lists 25,000 BTU/hr for natural gas and propane.

Installation & Requirements

Water supply

For AM15 and AM15T models, Hobart specifies flowing water pressure of 20 ± 5 psig at the dishwasher. If flowing pressure exceeds 25 psig, adjust the supplied pressure-reducing valve. The manual says the pressure is monitored while the solenoid valve is open and water is flowing, and that the pressure regulator must have a relief bypass. Without an electric booster, the supply connects to the 3/4-inch line strainer at the top rear of the machine and requires a minimum 1/2-inch supply line. A manual shutoff valve and pipe union are customer supplied.

Incoming-water temperature depends on the sanitizing mode and booster configuration. For hot-water sanitizing without a built-in booster, Hobart lists a 180°F minimum, 194°F maximum and 180°F recommended supply temperature. For chemical sanitizing, with or without a built-in booster, the manual lists 120°F minimum and 140°F recommended; it gives no maximum in that row. For hot-water sanitizing with a built-in booster, the listed minimum is 110°F and the recommended temperature is 140°F; no maximum is stated in that row. Follow the requirements for the exact machine configuration.

Electrical connection

The AM15T-1 seller listing specifies 208–240 V, 60 Hz, three phase and 2 HP. Hobart’s manual states that voltage adjustment applies to AM15 dishwashers rated 200–240 V, 50/60 Hz, three phase, and that the adjustment must be done only by a qualified electrician. The manual also calls for a customer-supplied fused disconnect switch or circuit breaker in the electrical service line or lines, sized to meet local electrical code requirements. Verify the data plate and applicable wiring information for the specific unit.

Gas heat, when specified

Hobart lists gas tank heat as an option. The manual specifies 25,000 BTU/hr for either natural gas or propane. Flowing inlet pressure specifications are 3.5–7.0 inches water column for natural gas and 9.0–11.0 inches water column for propane; manifold pressures are 3.2 inches water column for natural gas and 8.2 inches water column for propane. Static inlet line pressure must not exceed 14 inches water column. The manual calls for a 1/2-inch NPT gas inlet under the machine, a sediment trap supplied by others, and a leak test with soapy water rather than an open flame. Gas installation and conversion instructions require qualified service personnel and compliance with applicable codes.

For gas-heated units, the manual says combustion and ventilation air must not be obstructed, materials must not be stored underneath the machine, and the flue at the rear must be at least 1 inch from combustible construction. It specifies service access of 20 inches at the front—or at the left side for a corner installation—and 15 inches at the right side, each extending to 27 inches above the finished floor. For straight-through installations, the same 15-inch right-side service access is specified. For a corner installation, the manual specifies 20 inches beneath the left-hand tabling and 15 inches at the right side, both to 27 inches above the floor; it also says to position the controls and display at the front corner for operator access.

Operation

1. Put the strainer screen and scrap basket in position in the wash tank.
2. Close the door and press ON. The display shows FILL while the machine fills.
3. When filling is complete, the display shows the wash-water temperature. Press CYCLE to select 1 minute for normal serving ware or 2, 4 or 6 minutes for more heavily soiled items.
4. Load a dish rack, open the door and slide the rack into the machine.
5. Close the door. The machine starts automatically. During washing, the display shows WASH and the wash-water temperature; during rinsing, it shows RINSE and the rinse-water temperature.
6. When the rinse is complete and the rinse indicator disappears, remove the rack of clean dishes.

Hobart advises pre-scraping ware to remove large food particles and debris, not stacking dishes or racks, and using commercial detergents and chemicals with the AM Select. Consult a chemical professional about deliming frequency.

Cleaning & Maintenance

Hobart says to clean the machine thoroughly at the end of each working shift or at least daily. Never use steel wool; use products formulated to be safe on stainless steel. The AM15T operation instructions give this cleaning sequence:

1. Press OFF and open the machine door.
2. Clear the dish tables into the dishwasher, then drain the machine by lifting the drain lever.
3. Remove the rack track, strainer screen and scrap basket. Wash and rinse them thoroughly.
4. Remove the overflow tube and wash and rinse it inside and out.
5. Clean and flush the dishwasher interior thoroughly, removing remaining food soil.
6. Check that the wash and rinse arms rotate freely and are clear of obstructions. If needed, remove the arms and clean out the obstructions.
7. Reassemble the machine: replace the overflow tube, strainer screen and scrap basket; reinstall any removed wash and rinse arms; and replace the rack track.
8. Wipe the exterior with a clean, wet dishcloth. Do not use steel wool, a scouring pad or abrasive material.

For end-of-day cleaning, leave the door open after cleaning to let the interior air out and dry. For deliming, Hobart directs operators to disable the detergent feeder according to the chemical manufacturer’s recommendation, then follow the manual’s delime procedure and the deliming-agent supplier’s instructions for the tank. The manual’s procedure uses the CYCLE and ON buttons to enter delime mode, calls for adding the agent to the tank, and says not to turn the unit off until the tank is empty. Deliming frequency should be confirmed with a chemical professional.

Troubleshooting

Hobart’s manual lists the following possible causes and checks. Disconnect electrical power before checking a pump intake, and contact Hobart Service where the manual directs.

• No machine operation: Check that the machine is on and check for a blown fuse or tripped circuit breaker. Check the tank water level.
• Dishes are not clean: Possible causes include a drain obstruction preventing proper drain closure, a worn or torn drain O-ring, an obstruction at the pump intake or reduced water pressure, incorrect water temperature, incorrect detergent dispensing, mineral deposits, clogged strainers, obstructed or non-rotating wash arms, a clogged detergent dispenser, excessive soil or improper rack loading. Clean the machine and arms as directed in the manual; the manual advises contacting service for water-temperature adjustment or repair.
• Leaking valve: Foreign material, including pipe compound or metal shavings, may prevent the valve from operating properly. The manual says to shut off the supply line before valve cleaning. If a solenoid valve is malfunctioning, contact Hobart Service.
• No wash-tank heat: Check for low water level, an overflow tube out of position, or an obstruction restricting the low-water float or its magnet. For gas-heated units, check whether the gas line is closed and whether a fuse is blown or a circuit breaker has tripped. Contact Hobart Service for a gas heat control board or gas pressure failure.
• No or slow fill: The manual identifies a standpipe obstruction, a closed hot-water supply valve or a dirty line strainer as possible causes. It instructs operators to turn off the hot-water supply before removing and cleaning the strainer screen.
• Rinse-temperature alarm on a booster-equipped machine: The manual says a low booster temperature can extend the wash cycle; if the final rinse temperature does not reach the specified value after repeated cycles, the machine displays error code EA and requires service by a qualified technician.
• ADD DETERGENT or error code Eb: The manual says this can occur when the detergent supply is empty after three consecutive cycles. Replenish and prime the detergent supply, then turn the machine off and back on.

Applications

The AM15T suits commercial dishroom workflows that process racks of serving ware through timed wash and rinse cycles. Its manual specifically distinguishes normal serving ware from more heavily soiled items, which can be assigned a longer cycle. The door-type format can be used in a straight-through or corner dish-table arrangement, subject to the installation requirements for the selected configuration.