Temperature Reset Based on External Temperature - If de- sired, temperature reset can be based on an external tem- perature, such as space or outdoor-air temperature. This re- quires a thermistor (TlO, Part No. 30GB660002) located in the space or outdoor air and wired to terminals as follows (also see Field Wiring section on page 71):

4 in/4 out Module - 57-15 and J7-16.

At the field configuration step, select external tempera-

ture reset by entering q when CRTYP 0 appears. Then enter set points as described previously in Example 5. See Fig. 5.

Temperature Reset Based on 4-20 mA Signal- If desired,

temperature reset can be based on a 4-20 mA signal. For proper connections, refer to Field Wiring section on page 71 and Fig. 6.

At the field configuration step, select 4-20 mA reset by entering q when CRTYP 0 appears. Then enter set points as described previously in Example 5. See Fig. 7,

Demand Limit, 2-Stage Switch Control - This control has been designed to accept demand limit signals from a build- ing load shedding control. The demand limit function pro- vides for 2 capacity steps. The keypad is used to set the 2 demand limit set points, which range from 100 to 0% of capacity. Capacity steps are controlled by 2 field-supplied relay contacts connected to the designated chiller terminals. (See Field Wiring section on page 7 1 and Fig. 6.)

Example 6 - Changing Reset Type

To change type of reset, first log on as shown in Table 11. Also refer to Set Point Function section, page 39, for information on entering reset set points using reset feature.

KEYPAD

DISPLAY

 

COMMENTS

ENTRY

RESPONSE

 

 

 

 

 

 

Field

configuration

 

FLD CFG

subfunction of

 

 

 

service function

 

CSPTYP 0

Scroll

past single cooling

 

set point

 

 

 

 

CRTYP 0

No reset has been

 

selected

 

 

 

 

 

 

Return water temperature

 

CRTYP 1

reset is selected and

 

 

 

activated

 

 

 

Reset type is changed to

 

CRTYP 2

space or outdoor-air

 

temperature reset and

 

 

 

 

 

 

activated

 

 

 

Reset type is changed to

 

CRTYP 3

4-20 mA signal reset

 

 

 

and

activated

 

CRTYP 0

Reset is deactivated

 

 

 

 

 

10 -

Y- 18

8- 16 ?-

8

6

2-

I -

O-

RESET REFERENCE TEMPERATURE (OUTDOOR AIR 1OR SPACE TEMP

Fig. 5 - Cooling External Temperature Reset

4 1

Page 40 Page 42
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Image 41
Carrier 040-420 specifications Example 6 Changing Reset Type, Reset Reference Temperature Outdoor AIR 1OR Space Temp
Page 40 Page 42

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.

Another feature that sets the Carrier 040-420 apart is its smart controls. The unit can be integrated with Carrier’s Building Automation Systems, enabling remote monitoring and management. This allows facility managers to optimize energy use and immediately respond to any performance issues. Additionally, the unit is compatible with various control interfaces, making it easy for users to adjust settings or schedule operations according to the building's occupancy patterns.

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.
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