COMPRESSOR START RELAY

This is a current type relay and contains a N.O. contact which is connected in series with the start winding of the compressor. The relay coil is electrically in series with the run winding. When power is applied, the compressor draws high current which sets up a magnetic field around the magnet coil which causes the relay to operate, closing the relay contact. As the compressor approaches operating speed, the current flowing through the coil decreases, permitting the relay contact to open, thereby opening the starting circuit.

POTENTIAL RELAYS

The potential relay is used as a compressor starting relay, The contact in the potential relay is N.C.. The magnet coil is connected across (parallel) the start winding and is affected by induced voltage, generated by the start winding. As the compressor comes up to design speed, the voltage across the relay coil increases and at running speed is sometimes as much as 2 1/2 times the supply voltage. This voltage sets up a magnetic field which causes the relay to operate. The starting relay is calibrated to remove the start capacitor (open the starting circuit) at approximately 85% of the motor design speed.

NOTE: BOTH TYPES OF RELAYS ARE DESIGNED TO OPERATE WITHIN VERY NARROW LIMITS OF VOLTAGE AND CURRENT DICTATED BY MOTOR DESIGN, THEREFORE, WHEN MAKING A REPLACEMENT OF A RELAY ALWAYS PROVIDE AN EXACT REPLACEMENT, RECOMMENDED BY THE COMPRESSOR MANUFACTURER.

CAPACITORS – GENERAL

An electrical capacitor is a device which stores up electrical energy. Capacitors are used with single phase motors to provide starting torque and improve running characteristics; by feeding this energy to the start winding in step with the run winding.

Any capacitor has three (3) essential parts, two (2) of which are usually foil plates separated and insulated by the third part called the dielectric.

Two general types of capacitors are used with electric motors. The electrolytic starting capacitor usually uses a very thin film of oxide on the metallic plate as the dielectric. The running capacitor usually is of the liquid filled type.

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Cornelius 750 (R404A), SERIES 1100 (R22), 2400 (R404A) service manual Compressor Start Relay
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2400 (R404A), SERIES 1100 (R22), 750 (R404A) specifications

Cornelius 750, 1100, and 2400 are part of a line of refrigeration systems designed to meet the diverse needs of various industries, including food service and beverage dispensing. Each model utilizes specific refrigerants—R404A for the 750 and 2400, and R22 for the 1100—highlighting their engineering innovations and operational efficiencies.

The Cornelius 750 (R404A) is engineered for optimal performance in demanding environments. It is noted for its compact design, making it ideal for applications where space is limited. With advanced thermal management technologies, it guarantees rapid cooling and maintains temperature integrity, which is crucial for preserving the quality of stored goods. The energy-efficient compressor employed in this model not only reduces operational costs but also minimizes its environmental footprint, adhering to modern sustainability standards.

Similarly, the Cornelius 1100 (R22) is a robust refrigeration unit best suited for larger scale operations. It features heavy-duty construction and advanced coil technology, which enhances its heat exchange efficiency. The R22 refrigerant used in this series is well known for its effectiveness in high-temperature environments, making it a preferred choice for various cooling applications. Despite the phase-out of R22, systems utilizing it remain widely in service, offering reliability and performance that many operators depend on.

The Cornelius 2400 (R404A) is designed for high-capacity applications, tailored to meet the demands of busy food service environments. One of its standout features is its ability to maintain consistent temperatures even under heavy load conditions. This model incorporates enhanced insulation and improved airflow mechanisms that contribute to reduced energy consumption. The use of R404A refrigerant allows for robust cooling performance while also being more environmentally conscious than older refrigerants.

All three models emphasize advanced features such as electronic controls, customizable settings, and diagnostic capabilities, allowing for easy monitoring and maintenance. These technological enhancements not only improve operational efficiency but also extend unit longevity, saving users time and money in the long run.

In summary, the Cornelius 750, 1100, and 2400 refrigeration series showcases a combination of reliability, efficiency, and performance attributes. Their unique refrigerants, advanced cooling technologies, and innovative design make them ideal choices for varied refrigeration needs in the commercial sector.
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