External Insulating Requirements - Trane Performance Climate Changer PSCA Installation, Operation And Maintenance Manual

Hide thumbs

Table Of Contents

Table of Contents

When a single transmitter is supplied in a multiple fan

system, one or more fans will be brought back to the

transmitter as a manifold and the airflow will represent the

total airflow for the system. As a result, the factor should

be adjusted as follows:

K = N * K-Factor from

Table 15

Where:

K = The final factor to be used for controller

programming.

N = The number of active

If a fan fails in a multiple fan system where only one

transmitter is being supplied, and if the remaining fans will

continue to be used, the factor should be reduced

accordingly. Additionally, if the inactive fan was included

in the manifold back to the transmitter, the tubes from the

inactive fan should be temporarily removed and replaced

with tubes from an active fan (or simply plugged).

When a transmitter is supplied for each fan, the factor does

not need to be adjusted. The resulting airflow will

represent single-fan airflow. At the controller level, the

individual airflows should be summed to get the total

airflow. If a field-provided K-factor is to be used (see

below), the measured airflow for the system should be

divided by the number of active fans to get a single-fan 

K-factor.

Field-obtained factors can provide maximum accuracy. To

obtain the factor in the field, measure the differential

pressure output from the transmitter while measuring the

airflow through the system. Once these two values have

been measured, simply solve for K using the following

equation:

K = ACFM/SQRT(DP)

Where:

K = Field-provided constant factor.

ACFM = Actual airflow (ft

/min.) being measured at the air density

being measured.

DP = Differential pressure (inches w.g.) being measured by the

transmitter.

CLCH-SVX013B-EN

fans in the system.