Head Pressure Control - The microprocessor con- trols the condenser fans in order to maintain the lowest con- densing temperature possible, thus the highest unit efficiency. Instead of using the conventional head pressure control meth- ods, the fans are controlled by the position of the EXV and suction superheat.

As the condensing temperature drops, the EXV opens to maintain the proper suction superheat. Once the EXV is fully open, if the condensing temperature continues to drop, the suction superheat begins to rise. Once the suction super- heat is greater than 40 F (22.2 C), a fan stage is removed after 2 minutes,

As the condensing temperature rises, the EXV closes to maintain the proper suction superheat. Once the EXV has closed to 39.5% open (300 steps open), a fan stage is added after 2 minutes.

During start-up, all the condenser fans are started when the condensing temperature reaches 95 F (35 C) to prevent excessive discharge pressure during pulldown. See Table 5 for condenser fan sequence of operation.

Table 5 - Condenser Fan Sequence

 

FAN ARRANGEMENT

 

FAN NUMBER(S)

FAN

CONTACTOR

 

CONTROLLED

BY

 

 

 

WI

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

FC-Al

 

Compressor

Al

30GN040-050

I

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

FC-Bi

 

Compressor

Bl

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

 

FC-A2

 

First Stage

 

 

 

 

 

 

 

 

 

 

Microprocessor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

 

FGB2

 

Second

Stage

 

 

 

 

 

 

 

 

 

I

MicrODrOceSSOr

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

30GN060,070

 

 

 

FC-Al

I

Compressor

Al

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Compressor

Bi

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

First Stage

 

 

 

 

 

 

 

 

 

 

 

 

Microprocessor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5 6

 

FGB2

 

Second

Stage

 

 

 

 

 

 

 

 

 

 

Microprocessor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

30GN080,090

 

 

 

FC-Al

 

Compressor

Al

 

 

 

 

 

 

 

 

 

 

 

 

Compressor

Bi

30GNl00,110

(and associated modular units)

1

 

 

FC-Al

Compressor

Al

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

 

FC - 81

Compressor

Bl

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

 

 

FC - A2

First Stage

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

 

 

F&B2

Microprocessor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5,

7, 6,

8

 

FC-AS, FGB3

Second

Stage

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Compressor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

.

-_----

 

 

 

 

 

 

 

3, 4, 5, 6, 7, a

 

FC-A2, FC-A3,

Third

Stage

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FGB2,

FC-B3

Microprocessor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

30GN130 170

(and associated modular units)

 

 

5 7

 

 

FC-Al

Compressor

Al

 

 

 

WWER

 

 

 

 

 

 

 

 

6, 8

 

 

FC-Bl

Compressor

Bl

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FC-A2, FC-A3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

30GN190,210

(and associated modular units)

5, 7

 

I

FC-Al

Compressor

Al

 

 

 

 

 

 

 

 

 

 

 

I

6. 8

 

I

FC-Bi

Comwessor

Bl

 

 

 

 

 

 

 

 

 

 

 

 

 

3, 9

 

 

FC-A2

Frist

Stage

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4, 10

 

 

FC-B2

Microprocessor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 , 3, 9, 11

 

FC-A2,

FGA3

Second

Stage

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2, 4, 10,

12

 

FGB2,

FC-B3

Microprocessor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

*Control

box.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

26

Page 26
Image 26
Carrier 040-420 specifications Condenser Fan Sequence, FAN Arrangement FAN Numbers Contactor Controlled

040-420 specifications

The Carrier 040-420 is a highly regarded commercial HVAC unit specifically designed for efficient heating and cooling in medium- to large-sized buildings. Known for its reliability and advanced technology, this system is ideal for a variety of applications ranging from offices to industrial spaces.

One of the main features of the Carrier 040-420 is its energy efficiency. The unit utilizes advanced compressors and a high-efficiency heat exchanger, which work together to minimize energy consumption while maximizing performance. This is crucial in today’s energy-conscious environment, as businesses strive to reduce operational costs and their carbon footprint. The unit also boasts a high SEER (Seasonal Energy Efficiency Ratio) rating, making it an attractive option for those looking to lower their utility bills.

Equipped with advanced inverter-driven technology, the Carrier 040-420 allows for precise control of indoor climate conditions. This means that the system can adjust its output according to the actual cooling or heating demand of the space, resulting in enhanced comfort and reduced energy waste. The inverter technology also contributes to quieter operation, allowing for a more pleasant indoor environment.

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The robust design of the Carrier 040-420 ensures longevity and durability, even in harsh environmental conditions. Its weatherproof casing protects the internal components, enhancing the unit's performance and reliability over time. Maintenance is simplified with accessible design features, allowing technicians to conduct service checks and repairs without extensive downtime.

Overall, the Carrier 040-420 stands out as a modern HVAC solution that combines energy efficiency, advanced technologies, and user-friendly features. Its commitment to performance and sustainability makes it an ideal choice for businesses looking to enhance comfort while being mindful of their energy consumption. With its blend of innovation and reliability, the Carrier 040-420 continues to be a preferred option in the commercial HVAC market.