Item No. 6c_supp 
Meeting Date: September 25, 2018 
Variable Frequency Drive Renewal
and Replacement Project 
C800801 
WP U0332 

1

What is a Variable Frequency Drive
(VFD) & what does it do 
A VFD is a type of motor controller that drives an
electric motor by varying the frequency and
voltage of its power supply. The primary purpose of
a VFD is precise SPEED CONTROL so that motor
speeds can be ramped up and ramped down thus
using less energy by running the electric motor
efficiently 
VFD Definition 
2

What does a VFD look like 


In this picture a Variable Frequency Drive powering a Main Terminal Air Handling Unit fan running at 350 Horsepower 
3

Where are these old VFDs 


VFDs are in multiple locations 
4

The problem 
American Society of Heating, Refrigeration
and Air-Conditioning Engineers (ASHRAE)
recommends a VFD life span of 10-12 years. 
131 VFDs have outlived their useful live and
are considered obsolete by ASHRAE
standards. 
This project was deferred in 2016 
5

Scope of work solution 
Replace the 47 oldest Variable Frequency
Drives with this project in order to avoid
failures. 
Salvage components from these 47 VFDs
and add those components to the Port's
spare parts inventory. 
Extends the useful life of the 87 remaining obsolete VFDs 
6

Project schedule 
Request Commission Authorization for
Construction 3rd QTR 2018 
Construction Starts 1st QTR 2019 
In-Use Date 3rd QTR 2019 (1st group of VFDs) 
Due to complexity the construction duration is
18 months 
Construction durations 
7

Project Budget 
Design:      $1,175,000 
Construction: $2,820,000 
Total Project: $3,995,000 

This request is for construction authorization and budget 
8