MCO-GS-20-S

Overview

The Garland MCO-GS-20-S is a full-size, standard-depth, double-deck gas convection oven in Garland’s Master Series. It has two separate oven cavities, each with its own controls, temperature setting and timer. The oven is specified for natural gas and has a total input of 120,000 BTU, or 60,000 BTU per cavity. The two decks provide separate cooking spaces in a single stacked unit.

Each cavity measures 29 inches wide, 24 inches high and 24 inches deep. The overall dimensions are 38 inches wide, 41 1/4 inches deep and 70 1/2 inches high. The manufacturer listing gives a weight of 1,030 pounds (467.2 kg).

Key Features

• Two full-size oven cavities: Each deck has six chrome-plated racks and 13 rack positions, for 12 racks total.
• Master 200 controls: Solid-state controls include a three-position off, cook and cooldown switch, rotary temperature control and an electromechanical timer with an audible buzzer.
• Adjustable convection: Each cavity has a 3/4-horsepower fan motor with high- and low-speed settings.
• Ignition and gas safety: Electronic spark ignition operates the automatic pilot system. A safety valve shuts off gas, and the manufacturer’s specification describes a 100% safety shutoff.
• Doors and viewing: The 60/40 dependent doors have a full-length positive closure, double-pane thermal windows and interior lighting. A single handle opens each set of dependent doors.
• Construction and cleaning details: The front, sides, top and legs are stainless steel. The cavities have porcelain-enameled surfaces and coved corners.
• Operator access: Supplied product feature information places the top rack 60 inches from the floor.

Specifications

• Manufacturer: Garland
• Model: MCO-GS-20-S
• Series: Master Series
• Equipment type: Gas convection oven
• Size and depth: Full size; standard depth
• Decks and cavities: Double deck; two individual oven compartments
• Fuel: Natural gas
• Total gas input: 120,000 BTU (35.2 kW equivalent), 60,000 BTU per cavity
• Temperature range: 150°F to 500°F (66°C to 260°C); the manufacturer specification also gives the upper limit as 250°C.
• Interior dimensions, each cavity: 29 inches W x 24 inches D x 24 inches H (736 x 610 x 610 mm)
• Overall dimensions: 38 inches W x 41 1/4 inches D x 70 1/2 inches H (965 x 1,048 x 1,791 mm)
• Weight: 1,030 lb; manufacturer listing gives 467.2 kg.
• Racks: Six per cavity; 12 total
• Rack guides: 13 positions per cavity
• Fan motors: Two 3/4 HP motors, one per cavity; two-speed control
• Electrical supply: 120 V, 60 Hz, single phase
• Electrical rating: 19.6 A total is listed in the product detail; the manual’s double-deck table lists 9.8 A per deck.
• Power connections: Two 6-foot cords with NEMA 5-15P plugs, one per deck
• Gas connection: One 1-inch NPT inlet for the double-deck unit
• Exterior material: Stainless steel front, sides, top and legs
• Interior finish: Porcelain enamel with coved corners
• Door arrangement: 60/40 dependent doors with double-pane thermal windows and full-length positive closure
• Controls and timer: Master 200 solid-state control with electromechanical timer and audible buzzer
• Ignition: Electronic spark ignition with automatic pilot system and safety shutoff
• Listings stated in the product specification: UL, CUL Classified and NSF Listed

Installation & Requirements

Clearances and access

The installation and operation manual gives minimum clearances for double-deck models adjacent to combustible and non-combustible walls: 1 inch on the left side, 2 inches on the control side and 3 inches at the rear. Near high-heat-producing equipment, the manual specifies 1 inch on the left side, 6 inches on the control side and 3 inches at the rear. It recommends 12 inches of control-side service clearance for double-deck models. Entry clearance is 47 inches when crated and 32 1/2 inches when uncrated. The manual advises against placing the oven near equipment that produces high heat and grease-laden air, such as char-broilers or fryers.

Gas supply

Electrical supply

The manual calls for a 15-amp service for each oven. The unit has a cord and NEMA 5-15P plug for 115 V use, and each deck has its own cord. The receptacle must be properly grounded in accordance with applicable local requirements and the Canadian Electrical Code, CSA C22.2, where applicable. The manual says not to cut or remove the grounding prong. Garland recommends a separate 15-amp circuit for each 120 V unit.

Ventilation and air supply

The manual states that proper ventilation is important and identifies two methods for venting: a canopy hood or direct venting. It also warns that the gas burners and pilots need sufficient air. Do not obstruct airflow at the front of the oven or block the flue at the rear top during operation. Commercial cooking equipment requires an adequate ventilation system; the manual references NFPA 96 for vapor removal from cooking equipment in North America.

Operation

The Master 200 controls provide an off, cook or cooldown selection, a rotary temperature control, a timer and high- or low-speed fan selection. Set the temperature within the specified 150°F–500°F range. The timer signals the end of its cycle with an audible buzzer. The cavities are separate compartments, so each deck has its own controls and cooking space. Interior lighting and double-pane door windows let operators view food during cooking.

On a call for heat, the electronic ignition system first attempts to light the pilot. When the pilot flame is detected, the control opens the main gas valve so the pilot can ignite the burner. If the pilot is not established during the ignition trial, the service manual describes a safety lockout that requires a reset before another start attempt. In the event of a power failure, the service manual says not to attempt to operate the oven.

The operating manual recommends a one-hour break-in at 375°F (191°C) when the oven is new. After it cools, wipe the interior, including the racks, with a clean damp cloth before normal cooking.

Cleaning & Maintenance

Disconnect the line cord from the power supply before cleaning or servicing. The operating manual recommends establishing a regular exterior-cleaning schedule and wiping spills immediately. After the new-oven break-in period, allow the oven to cool before wiping its interior and racks with a clean damp cloth.

If aluminum foil is routinely used to wrap food or cooking vessels, the manual specifies periodic attention to the fan area: switch the oven off, remove the racks and rack guides, remove and clean the air baffle, and check the blower wheel and baffle for foil or food deposits. Clean deposits from the blower-wheel fins, taking care because their edges may be sharp, then reinstall the baffle, rack guides and racks. The manual describes the motor as having self-lubricating sealed ball bearings. It also notes that the motor cools itself through air entering at the rear of the motor case, so that area needs the clearance specified for installation.

Troubleshooting

Cooking results

• Cakes dark on the sides but underdone in the centre: Lower the oven temperature.
• Cake edges too brown: Reduce the number of pans or lower the oven temperature.
• Cakes have a light outer colour: Raise the temperature.
• Cake settles slightly in the centre: Bake longer or raise the oven temperature slightly. Avoid opening the doors too often or leaving them open for long periods.
• Cake ripples: The manual identifies overloaded pans or batter that is too thin as possible causes.
• Cakes are too coarse: Lower the oven temperature.
• Pies have uneven colour: Reduce the number of pies per rack or eliminate bake pans.
• Cupcakes crack on top: Lower the oven temperature.
• Meat is browned but underdone in the centre: Lower the temperature and roast longer.
• Meat is well done and browned: Reduce cooking time and limit moisture.
• Meat develops a hard crust: Reduce the temperature or place a pan of water in the oven.
• Rolls have uneven colour: Reduce the number or size of pans.

Pilot and ignition symptoms

The service manual’s pilot-flame troubleshooting information identifies a small blue flame as a possible sign of a clogged orifice filter, clogged pilot filter, low gas supply pressure or a pilot adjusted at minimum. A lazy yellow flame may indicate insufficient air, including a dirty air opening or lint screen where fitted. The ignition description says a failed pilot-lighting trial can put the control into lockout; the manual’s reset instructions call for turning the thermostat or controller below room temperature or to off, or switching system power off. Gas, ignition and control service should follow the manufacturer’s service instructions.

Applications

With two full-size cavities, separate deck controls and 12 racks across 13-position guides, the MCO-GS-20-S can suit foodservice operations that need to bake or roast different products in parallel. The manual’s cooking guidance addresses cakes, pies, cupcakes, meats and rolls. The two-speed fans and independent compartments give kitchen teams options for managing cooking across the upper and lower decks.