During troubleshooting, the defrost time can be reduced to 20 seconds by shorting out the SW1 test pegs on the module. The pegs are 13mm (12in.) long, 1mm (316in.) apart and are mounted on a white base. See Figure 8.

LOCKOUT CONTROL

Any one of four conditions will put the system into a lock-out condition during the heating or cooling mode:

1.The discharge line temperature reaches 124°C (255°F) (102°C [215°F] reset) or,

2.The discharge pressure reaches 2770 kPa (398 PSIG) (2158 kPa [310 PSIG] reset) or,

3.The suction line freezestat equals -3°C (26°F) (3°C [38°F] reset) or,

4.The low-pressure cut-out equals 49 kPa (7 PSIG) (153 kPa [22 PSIG] reset).

A lock-outl energizes the emergency heat light on the thermostat and the red LED light on the unit relay board. Turning the thermostat switch to “Off” then back to “On”, will reset the system.

NOTICE TO OWNER:

If a lockout occurs, check for the following problems before calling a serviceman:

1.Dirty filters.

2.Snow accumulation.

3.Leaf or debris blockage.

After eliminating the problem, attempt to restart the system as follows:

turn the system switch on the thermostat to its “OFF” position for 10 seconds.

turn it back to its original position.

If the unit doesn't start, call a serviceman.

NOTE: Models with an anti-recycle accessory will have a 5- minute delay before starting.

CHECKING SUPPLY AIRFLOW

The speed of the supply air blower will depend on the required airflow, the unit accessories and the static resistances of both the supply and the return air duct systems. With this information, the speed for the supply air blower can be

TABLE 10 - BELT-DRIVE SUPPLY AIR MOTOR PULLEY ADJUSTMENT

TURNS

BLOWER DRIVE RANGE (RPM)

OPEN*

060

5

850

4

916

3

982

2

1048

1

1114

0

1180

*Pulley can be adjusted in half-turn increments.

determined from the blower performance and static resistance data on Tables 4, 5 and 7.

Knowing the required blower RPM and the blower motor kW (HP), the speed setting for the supply air motor can be determined.

The setting (turns open) for the optional belt-drive supply air pulley can be determined from Table 10.

OPTIONAL BELT-DRIVE BLOWER

All units with belt-drive blowers have single speed motors. The variable pitch pulley on the blower motor can be adjusted to

035-12984-001-A-0204

FIG. 9 - BELT ADJUSTMENT

obtain the desired supply airflow. Refer to Table 6 for blower motor drive data. The tension on the belts should be adjusted as shown in Figure 9.

Start the supply air blower motor. Adjust the resistances in both the supply and the return air duct systems to balance the air distribution throughout the conditioned space. The job specifications may require that this balancing be done by someone other than the equipment installer.

To check the supply airflow after the initial balancing has been completed:

1641912

1743518

516 “ HOLES

DAMPER

 

 

ASSEMBLY

INDOOR

533

 

COIL

21"

FILTERS

 

 

 

DUCT FLANGES

FRONT OF UNIT

 

 

L.H. END VIEW

 

(Back of Unit)

(Filter Access End)

FIG. 10 - HOLE LOCATIONS (PRESS. DROP READING)

1.Drill two 8mm ( in.) holes in the side panels as shown in Figure 10.

2.Insert at least 203mm (8 in.) of 6mm ( in.) tubing into each of these holes for sufficient penetration into the air flow on both sides of the indoor coil.

NOTE: The tubes must be inserted and held in a position per- pendicular to the air flow so that velocity pressure does not affect the static pressure readings.

Unitary Products Group

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York B3CH 048 and 060 installation instructions Lockout Control, Checking Supply Airflow, Turns Blower Drive Range RPM Open

B3CH 048 and 060 specifications

The York B3CH 048 and 060 are part of the advanced line of commercial rooftop units by York, known for their reliability and energy efficiency. Specifically designed for medium to large commercial applications, these units are engineered to provide optimal performance while minimizing operational costs.

One of the key features of the York B3CH series is its adaptable cooling capacity. The B3CH 048 has a cooling capacity of 48,000 BTU/h, while the B3CH 060 offers a slightly higher capacity of 60,000 BTU/h. This flexibility allows businesses to select the unit that best meets their specific cooling requirements, ensuring comfort and efficiency in any environment.

Both models utilize a highly efficient scroll compressor, which is known for its durability and quiet operation. The scroll compressor design allows for superior performance in varying load conditions, contributing to better energy efficiency. In addition, the units feature a multi-speed motor design that adjusts airflow based on demand, further enhancing performance and reducing energy consumption.

York has incorporated advanced technologies into the B3CH series to ensure reliability and ease of maintenance. These units come equipped with a smart control system that enhances user interface through advanced diagnostics and monitoring capabilities. The control system enables users to program temperature settings efficiently and oversees system operation to prevent potential issues. The built-in diagnostic features help facilitate quicker troubleshooting, minimizing downtime.

The units are designed with a robust and weather-resistant cabinet, ensuring durability in various environmental conditions. The galvanized steel construction aids in corrosion resistance, leading to a longer lifespan for the units. Additionally, both models are equipped with high-efficiency air filters that not only improve indoor air quality but also extend the life of the system by minimizing dust accumulation.

Energy efficiency is a significant consideration in today's commercial environments, and the York B3CH series excels in this aspect. With competitive SEER and EER ratings, these units not only comply with but often exceed industry standards, resulting in lower energy bills and reduced carbon footprints.

In summary, the York B3CH 048 and 060 are cutting-edge rooftop units that combine performance, reliability, and energy efficiency. They are ideal for businesses seeking effective solutions for climate control while maintaining operational and energy costs at a minimum.