Page 256 - FanPedia - By Twin City Fan and Blower

FAN-PEDIA

Published by TECHNICAL DESCRIPTIONS
Twin City Fan & Blower

©2017 TCF.COM

Arrangement 4 – Horizontal (Plenum Fans)
Direct drive Arrangement 4 mounts the fan wheel directly onto the motor shaft. This arrangement
provides a compact fan/motor unit which eliminates belt residue and requires less maintenance than
other arrangements. For these reasons, Arrangement 4 plenum fans are widely used in cleanroom,
pharmaceutical, and other critical applications. Fans can be selected with varying wheel widths to

provide desired performance at direct drive motor speeds. Performance changes in the field are
usually achieved by means of variable inlet vanes or VFD.

Arrangement 4V – Vertical (Plenum Fans)
Vertical Arrangement 4 is available for mounting with either vertical up airflow (inlet under the
motor) or vertical down airflow (inlet above the motor).

Arrangement 1P (Plug Fans)
A belt drive arrangement where the fan is mounted to grade and the motor is mounted separate from
the fan. Typically used on larger fans and/or larger HP motors where the customer’s wall may not be
sufficient by itself. Mounting to the foundation also makes it better for meeting lower vibration
requirements. Mounting panel is optional on arr. 1P.

Arrangement 4 (Plug Fans)
Direct drive arrangement where the wheel is mounted to the motor shaft. The design is more
compact and requires less maintenance due to not having fan shaft, bearings or belts. High airstream
temperatures may limit the use of this arrangement.

Arrangement 4P (Plug Fans)
Same as the arr. 4 fan except the fan is mounted to grade. Typically used where the customer’s wall
may not be sufficient by itself. Mounting to the foundation also makes it better for meeting lower
vibration requirements. Mounting panel is optional on arr. 4P.

129