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POWERXL DH1 SERIES ADJUSTABLE FREQUENCY DRIVES
MN040041EN—August 2019 www.eaton.com
Chapter 6 — PID Application
Chapter 6 — PID application
Introduction
The PID Application is designed for preloaded application
sets for use with HVAC specific terminology and functions
when using PID control loops internal to the drive. This is
typically used with pump or fan process systems to maintain
a desired set point level. With using the PID Controller
reference selection the drive is setup to receive a setpoint
level from any of the standard control location and then it
also gets a feedback from typically some analog sensor to
indicate actual process conditions, then from there it will
adjust the output of the drive or an analog output to meet
the setpoint level. The reaction of this adjustment on the
output is determined by a Gain variable and an integral time
for most setups and can include the Derivative time. It
also will allow the drive to go into a sleep mode to prevent
continue run time and wear on the system. In addition it
includes all the standard settings from the previous Basic
Application in addition to a 2nd Motor parameter set for
control of 2 different motors with the same drive. It provides
the ability for the user to define its Hand and Auto control
and reference signals with the standard Off condition as
well. In addition there is the ability to scale the analog input
and output signals to be read based off the desired motor
response. There are also 8 digital inputs, 3 relay outputs,
and 1 digital output that can be programmed to allow for
control schemes that require the drive to have certain
functions. It provides full customization on the motor control
sequence with the ability to be in frequency or speed control
mode, and tuning of the V/Hz curve can be selected. Drive/
Motor protections can be customized to defined actions for
added user control. Below is a list of other features that are
available in the PID Application.
PID Application includes functions:
•
Bypass Control
•
Fire Mode
•
Damper Control
•
Pre heat/cold weather mode
•
Hand/Off/Auto in individual button for easy change of
control mode.
•
Damper Control
•
Programmable Protections
•
Programmable digital/analog input/output function
•
Programmable start/stop signal logic
•
Voltage and Current limiters
•
Energy Savings Calculator
•
Two independent set of Acceleration/Deceleration ramps
•
Skip frequency
•
Start source (Local/Remote control function)
•
Reference source
•
Flying start
•
Volts per Hertz control programmable
•
Real time clock—RTC time display
•
RTC Timers and Interval control
•
Auto restart on fault to drive or bypass
•
Programmable switching frequency
•
Multi-Preset speeds
•
Fan control
I/O controls
•
Terminal To Function (TTF) Programming
The design behind the programming of the digital
inputs in the DH1 drive is to use “Terminal To Function”
programming, which is composed of multiple functions that
get assigned a digital input to that function. The parameters
in the drive are set up with specific functions and by
defining the digital input and slot in some cases, depending
on which options are available. For use of the drives control
board inputs, they will be referred to as DigIN:1 through
DigIN:8. When additional option cards are used, they will be
defined as DigIN:X:IOY:Z. The X indicates the slot that the
card is being installed in, which will be either A or B. The
IOY determines the type of card it is, which would be IO1
or IO5. The Z indicates which input is being used on that
available option card.
•
Function To Terminal (FTT) Programming
The design behind the programming of the relay
outputs and digital output in the DH1 drive is to use
“Function To Terminal” programming. It is composed of
a terminal, be it a relay output or a digital output, that
is assigned a parameter. Within that parameter, it has
different functions that can be set.
The parameters of the Standard Application are explained in
Appendix A of this manual, “Description of Parameters.”
The explanations are arranged according to the parameter
number. For the DI function, we use Terminal programming
method to function (TTF), where there is a fixed input
that gets programmed to a list of functions. This allows
for multiple inputs to be used for different functions.
Connecting a certain input with a certain parameter function
is done by give a parameter an appropriate value. The value
is formed by the location of the input, either being on the
standard control board or an external option board and the
slot it is located in.
