Trane TSC060-120 manual Selection Procedure - SI Units

Selection Procedure - SI Units

Cooling Capacity

Step 1

Calculate the building’s total and sensible cooling loads at design conditions. Use theTrane calculation methods or any other standard accepted method.

Factors used in unit selection:

A

Total Cooling Load: 16.7 kW

B

Sensible Cooling Load: 11.7 kW

C

Airflow: 3400 m3/h

D

Electrical Characteristics: 380-415/50/3

E

Summer Design Conditions: Entering

Evaporator Coil: 27 DB, 19 WB Outdoor

Ambient: 35

F

External Static Pressure: 110 Pa

Step 2

Table PD-1 shows that aTSC060AD has a gross cooling capacity of 17.8 kW and

14.4kW sensible capacity at 3400 m3/h and 35 DB outdoor ambient with 27 DB, 19 WB air entering the evaporator.

To Find Capacity at Intermediate Conditions Not in the Table

When the design conditions are between two numbers that are in the capacity table, interpolation is required to approximate the capacity. Note: Extrapolation outside of the table conditions is not recommended.

Step 3

In order to select the correct unit which meets the building’s requirements, the fan motor heat must be deducted from the gross cooling capacity.The amount of heat that the fan motor generates is dependent on the effort by the motor - cfm and static pressure.To determine the total unit static pressure:

External Static (duct system)

	110 Pa
Standard Filter 1 in.	37 Pa
from Table PD-21
Economizer	5 Pa
(100% Return Air)	from
Table PD-21
Electric Heater Size 7.5 kW	17 Pa
from Table PD-21
Total Static Pressure	169 Pa

Note: The Evaporator Fan Performance Table PD-6 has deducted the pressure drop for a 25 mm filter already in the unit (see note belowTable PD-6). Therefore, the actual total static pressure is 169-17 (fromTable PD-21) = 152 Pa.

With 3400 m3/h and 152 Pa

Table PD-6 shows .67 kW for this unit. Note below the table gives a formula to calculate Fan Motor Heat,

Fan Motor Heat (kw) =

1.144 x (Fan kW) + 0.132

= 1.144 x 0.67 + 0.132 = 0.90 kW

Now subtract the fan motor heat from the gross cooling capacity of the unit: Net Total Cooling Capacity

= 17.8 kW - 0.9 = 16.9 kW.

Net Sensible Cooling Capacity = 14.4 kW - 0.9 = 13.5 kW.

Step 4

If the performance will not meet the required load of the building’s total or sensible cooling load, try a selection at the next higher size unit.

Heating Capacity

Step 1

Calculate the building heating load using theTrane calculation form or other standard accepted method.

Step 2

Size the system heating capacity to match the calculated building heating load. The following are building heating requirements:

A

Total heating load of 5 kW

B

2000 cfm

C

380 volt/3 phase Power Supply

The electric heat accessory capacities are listed inTable PD-23. From the table, the smallest heater will deliver 7.5 kW at 380 V. Referring toTable ED-2, the electric heater selection is BAYHTRR412A.

Air Delivery Selection

External static pressure drop through the air distribution system has been calculated to be 110 Pa. FromTable PD- 21 static pressure drop through the economizer is 5 Pa and the 7.5 kW heater is 17 Pa (110 + 5 + 17). EnterTable PD-6 for a TSC060AD at 3400 m3/h and 132 Pa static pressure. The standard motor will give the desired airflow at a rated kW of 0.64.

Accessory Selection

Select accessories needed to accommodate the application.

10 RT-PRC016-EN