SECTION 3 - SERVICING COMPONENTS

B. PS310/360-series ovens

1.Description of heating system

All PS310/360-series electric ovens use an on-off sys- tem for heater activation. When the oven demands heat, the temperature controller activates mercury contactors that in turn activate the heaters at 100% power. The contactors open when the temperature rises to 2 degrees above the set point, and close when the oven’s temperature falls 2 degrees Fahrenheit below the set point. Because of residual heat within the oven, however, the temperature swing after preheating is about 5 degrees Fahrenheit above and below the set point.

IMPORTANT: Because the PS310/360-series electric oven uses an on-off system for heater activation, the temperature controller MUST be set to the on-off operating mode. Refer to Temperature Controller on Page 30.

Each bank of heaters (3 total) uses one mercury contactor and three fuses. 30A fuses were used through 1/91. Heat inside the machinery compartment can de-rate these fuses, causing the fuse to blow pre- maturely. To correct this situation, 40A fuses were used 2/91 and later.

NOTE: All control wire used on this oven is AWM rated at 221°F/105°C. DO NOT replace with lower rated wire.

2. Part number reference

Part No. Description

27374-0001 Heating element, 208V

27374-0002 Heating element, 240V

27374-0003 Heating element, 380V

28041-0016 Mercury contactor, 3 pole, 30A

27170-0251 Contactor tube replacement kit

27170-0250 Coil replacement kit

28154-0002 Fuse, 30A, class M (early)

28150-0134 Fuse, 40A, class T (current)

27021-0016 Fuse block, 40A (used when upgrading from 30A to 40A fuse - qty. 3 reqd.)

3.Supply

Ovens have a 208V, 220-240V, 380V, 416V or 480VAC electrical supply. The control current of the oven oper- ates at 110V, single phase. If the oven was specified for a 3 wire system, it was supplied with an optional control transformer to step the 3 phase current down for the control circuit. If the oven was specified for a 4 wire system, the 4th (neutral) wire is utilized to split 2 of the 3 incoming 3 phase legs and obtain a separate 110V circuit.

Figure 80

Figure 81

Removing the element bank mounting bolts

Electrical leads disconnected

142

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Image 143
Middleby Marshall PS224 PS310, PS570, PS360, PS200, PS555, PS220 Electrical leads disconnected, 142, PS310/360-series ovens
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PS224 PS310, PS220, PS555, PS200, PS360 specifications

The Middleby Marshall PS555 is a standout commercial pizza oven renowned for its performance, efficiency, and advanced technologies. Designed with the modern pizzeria in mind, the PS555 delivers exceptional cooking results while maximizing energy efficiency and throughput.

One of the key features of the PS555 is its innovative cooking technology, which incorporates both convection and radiant heat. This unique combination ensures that pizzas are cooked evenly and quickly, achieving a perfectly crispy crust and evenly melted cheese every time. The oven’s high-speed air impingement system accelerates cooking times, allowing pizzerias to serve more customers in less time without compromising quality.

The PS555 is designed with a spacious cooking chamber that can accommodate multiple pizzas simultaneously. With its ability to fit pizzas up to 18 inches in diameter, the oven is ideal for establishments with high demand. Additionally, the adjustable conveyor speed allows operators to customize the cooking time based on their specific menu items, enhancing versatility and productivity.

Energy efficiency is a hallmark of the Middleby Marshall PS555. The oven utilizes advanced insulation materials to minimize heat loss, ensuring that it operates at optimal temperatures while consuming less energy. This efficiency not only reduces operating costs but also contributes to a more sustainable kitchen environment.

User-friendly controls make it simple for operators to manage the cooking process. The PS555 features digital controls with programmable settings, enabling quick adjustments to temperature and cooking time. This ensures consistent quality across different shifts and helps maintain product standards while simplifying staff training.

Durability is another defining characteristic of the PS555. Built with high-quality materials, the oven is designed for heavy use in busy commercial kitchens. Its stainless steel construction ensures resistance to wear and tear, making it a worthwhile investment for any pizzeria.

In summary, the Middleby Marshall PS555 pizza oven is a high-performance piece of equipment that combines advanced cooking technologies, efficiency, and durability. Its ability to deliver consistently excellent results while streamlining operations makes it an essential asset for any pizza business aiming to enhance its productivity and customer satisfaction.
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