FD3-75

Overview

The Hobart FD3-75 is a commercial food waste disposer in Hobart’s FD3 family. The product listing identifies the basic unit with a 3/4 HP motor; the family specification sheet describes continuous-duty motors and heavy aluminum grind and discharge housings. During operation, cutter blocks and flywheel rotation force food waste against the stationary shredder ring. Flushing water assists grinding and carries the ground waste into the waste line.

The disposer is self-feeding, so operators do not need to force waste into the grinding mechanism. The manual states that the unit can be filled with waste while idle and will start and operate at full load. Controls and accessory groups are available for different installation arrangements.

Key Features

• Grinding assembly: A stationary shredder ring works with a Ni-Resist flywheel and hardened stainless steel cutter blocks. The flywheel has a center breaker blade, and the two cutter blocks can be replaced and indexed to present new cutting edges.
• Reversible grinding: The disposer can grind in either direction of flywheel rotation. With Control Groups 2, 3 or 4, the operator can control the direction to help free a jam and support the life and efficiency of the grinding elements.
• Motor protection: The motor has a manual-reset thermal overload protector. The motor is continuous-duty rated and has permanently lubricated ball bearings.
• Service access: Four bolts connect the motor unit to the grind chamber, allowing the motor unit to be removed.
• Mounting isolation: A vinyl isolating ring at the cone mounting reduces metal-to-metal contact, vibration and noise transmission.
• Optional fitment: Hobart lists accessory groups and components for different installation needs. Compatibility depends on the disposer housing and installation arrangement.

Specifications

• Manufacturer: Hobart.
• Model: FD3-75.
• Equipment type: Food waste disposer.
• Motor rating: 3/4 HP.
• Motor duty: Continuous duty.
• Motor protection: Manual-reset thermal overload protector.
• Electrical motor configurations listed for FD3-50 and FD3-75: 110–120/200–240 V, 50/60 Hz, single phase; or 200–240/380–415/460 V, 50/60 Hz, three phase. Confirm the disposer data plate and electrical service before installation.
• Grind and discharge housings: Heavy aluminum.
• Shredder ring: 1 3/4 inches high, with 4 machine-ground primary-action breaker bars and 42 secondary-action grinding teeth.
• Flywheel: 6 3/16 inches in diameter, made of Ni-Resist, with slots undercutting the shredder ring.
• Cutter blocks: Two hardened stainless steel blocks, fastened to the flywheel with nylock screws; replaceable and indexable for new cutting edges.
• Standard cone mounting: 7-inch inside-diameter throat opening, except when using accessory group E.
• Drain connection: Chrome-plated brass tail-piece for connection to a 1 1/2-inch standard drain trap.
• Approximate shipping weight: 60 lb, excluding accessory group and controls.
• Listing and standard: Listed by Underwriters Laboratories Inc. and meets A.S.S.E. Standard No. 1009. The specification sheet states that 50 Hz electrical specifications are not UL listed.
• Available accessory component specifications: The family sheet lists a cone water-swirl inlet at 1/2-inch N.P.T., a fixed-direction water inlet at 1/2-inch N.P.T., and a 5-gallon-per-minute flow control at 3/4-inch N.P.T. These are accessory components, not stated as included with the basic unit.

Installation & Requirements

Before installation, check the disposer for shipping damage and verify that the electrical service agrees with the specifications on its data plate. The manual calls for temporary support during installation to avoid excessive stress at a welded or soldered cone-to-table connection.

For regular-duty cone mounting, the manual describes clamp rings attached to the disposer flange. The disposer is lifted into position on the cone flange, the remaining clamp-ring halves are fitted, and the screws are tightened evenly after the unit is rotated to the desired position. The family specification sheet states that standard mounting is to a cone with a 7-inch inside-diameter throat opening, except when accessory group E is used. The manual also describes accessory group E as a sink adapter for a 3 1/2- to 4-inch sink opening; accessory fitment depends on the disposer configuration.

Water-supply components vary with the selected controls and installation. The manual refers to a pressure-reducing valve and, for Control Group 3, a pressure switch installed between the solenoid valve and pressure-reducing valve. If there is no pressure-reducing valve, it directs installation of the pressure switch between the solenoid and shut-off valve. Install a vacuum breaker according to local plumbing codes. If local codes prohibit a vacuum breaker, the manual describes using an air-gap water inlet, not supplied, while observing local codes.

The disposer must be connected to a dedicated, acceptable motor control switch with a marked OFF position that disconnects the appliance from all ungrounded supply conductors. The switch must be within sight of the disposer or sink opening. The manual calls for electrical and grounding connections to comply with applicable portions of the National Electrical Code and/or local electrical codes. Use the wiring diagram supplied with the machine that matches the disposer and electrical service. Flexible conduit is specified to permit movement of the unit for periodic servicing and maintenance. Disconnect power and tag the disconnect switch before working on the circuit.

Operation

Before starting, make sure the disposer is clear of foreign objects such as metal or wire clippings, screws or nails, and check that the flywheel turns freely. Never use a hand to check flywheel rotation or remove foreign material. The manual directs operators to use a stick or similar object to turn the flywheel; foreign matter can be removed with tongs or pliers.

Start the disposer before feeding food waste and make sure water is flowing. With typical optional controls, water flow and disposer starting occur simultaneously and automatically. Feed food waste into the unit without forcing it into the grinding mechanism. Do not put china, metal, rags, clam shells or similar material into the disposer, and do not put grease or oil into it, as these can clog the drain. After grinding, let the disposer run briefly to flush the unit and waste line; some optional controls manage this flushing automatically. Never reach inside the disposer while it is operating.

Cleaning & Maintenance

Keep the disposer clean and sanitary. After food waste has been processed, run the unit for a few minutes to flush its interior. The manual warns that waste left to accumulate through improper cleanup can cause offensive odors. For heavier cleaning, it describes using a stiff brush with strong soap and hot water. For light cleaning, grind ice and a lemon through the disposer. Do not use chemical solvents or drain-cleaning compounds through the unit.

No lubrication is required. If cutter-block edges become worn, the manual says they may be rotated by a qualified Hobart Service Technician. The disposer motor has a resettable thermal overload protector. If it trips, allow approximately five minutes for cooling, then press the manual reset button on the motor shell opposite the motor junction box; an arrow on the shell indicates the button location.

A small weep hole in the lower housing vents the dry side of the water seal. Water leaking from the weep hole indicates water-seal leakage and the seal should be replaced. Do not plug or grease the weep hole.

Troubleshooting

• The overload protector trips: Allow approximately five minutes for the motor to cool, then press the manual reset button on the motor shell opposite the junction box. Restart using the normal operating procedure. If the protector continues to trip, contact a Hobart Service Office.
• Water leaks from the lower-housing weep hole: The manual identifies this as an indication of water-seal leakage; the water seal should be replaced. Do not plug or grease the hole.
• The flywheel does not turn freely before use: Do not check or turn it by hand. Use a stick or similar object to turn the flywheel, and use tongs or pliers to remove foreign matter.
• Drain clogging or odor: The manual cautions against putting grease or oil into the disposer because it can clog the drain. Run water and allow the disposer to flush after grinding; accumulated food waste can cause offensive odors.

Applications

The FD3-75 is intended for food-waste grinding in commercial kitchen cleanup systems. The Hobart family literature describes FD3 disposers as suited to small- to medium-sized cleanup systems. Optional controls and accessory groups can be selected for the installation, with components available for cone or sink arrangements and water-inlet configurations. Confirm accessory and control compatibility with the disposer’s housing configuration and site requirements.