ABB ACH550 Product Bulletin

Product Bulletin

ABB drives for HVAC applications

ACH550, 1 to 550 Hp

Contents

ACH550 Product Overview .......................................................2

Standard Features ....................................................................2

Available Options ......................................................................3

Specications ...........................................................................4

Drive Features - Human Interface .............................................6

Drive Features - Terminal Block Interface ..................................10

Drive Features - Communications Suite ....................................11

Drive Features - Power .............................................................12

Drive Features – Protection .......................................................14

Application Control Diagrams ...................................................15

Air Handling Unit Application Functions ....................................16

Chilled Water Pump Application Functions ................................18

Cooling Tower Application Functions ........................................20

Parameter Group Functional Descriptions .................................22

Standard Product Options ........................................................31

E-Clipse Bypass Product Options .............................................33

ACH550 Drive Pack ..................................................................36

Dimensions: ACH550-UH UL Type 1 / NEMA 1 .......................37

Dimensions: ACH550-UH UL Type 12 / NEMA 12 ....................38

Dimensions: ACH550-Vx UL Type 1 / NEMA 1 .........................39

Dimensions: ACH550-BxR UL Type 1 / NEMA 1 .......................40

Dimensions: ACH550-BxR UL Type 12 / NEMA 12 ...................41

Dimensions: ACH550-BxR UL Type 3R/ NEMA 3R ...................42

Dimensions: ACH550-Cx UL Type 1 / NEMA 1 .........................43

Dimensions: ACH550-Cx UL Type 12 / NEMA .......................... 44

Dimensions: ACH550-Cx UL Type 3R / NEMA 3R ....................45

Dimensions: ACH550-PxR UL Type 1 / NEMA 1 .......................46

Dimensions: ACH550-PxR UL Type 12 / NEMA 12 ...................47

Dimensions: ACH550-PxR UL Type 3R / NEMA 3R ..................48

ACH550 Product Bulletin | 1

ACH550 Product Overview

The ACH550 is an variable frequency AC drive designed specifically for the HVAC market that achieves the ultimate in flexible
motor control performance. Offering two modes of motor control: Scalar (V/Hz) and Sensorless Vector, the ACH550 provides
accurate speed control for any standard squirrel cage motor.
With drives ranging from 1 to 550 HP, the ACH550 series features an ‘intuitively obvious’ multi-lingual, graphic display panel that
also provides an assistant to aid users in start-up. The control panel can be mounted on the cover of the drive, or remotely, and
can upload, store, and download parameters.
The ACH550 comes equipped with an extensive library of preprogrammed HVAC application macros that, at the touch of a
button, allow rapid configuration of inputs, outputs, and parameters for specific HVAC applications to maximize convenience and
minimize start-up time.

The ACH550 can be used for the simplest to the most demanding HVAC applications. Two internal option slots can be configured
with additional relay outputs as well as a host of different communication bus adapters.

The ACH550 has a 110% short term overload rating for one (1) minute out of ten (10) and is capable of >130% short-term
overload rating for 2 seconds out of each minute. This provides the torque you need to start high inertia fan(s).

Standard Features

UL, cUL labeled, CE marked, BTL listed (BACnet Testing Lab) &
UL Plenum Rated
EMI/RFI Filter (1st Environment, Restricted Distribution)
Seismic Certification in accordance to
IBC 2000 referencing ASCE 7-98 and ICC AC156
IBC 2003 referencing ASCE 7-02 and ICC AC156
IBC 2006 referencing ASCE 7-05 and ICC AC156
Start-Up Assistants
Maintenance Assistants
Diagnostic Assistants
Real Time Clock
Includes Day, Date and Time
Operator Panel Parameter Backup (read/write)
Full Graphic and Multilingual Display
for Operator Control, Parameter Set-Up and Operating
Data Display:
Output Frequency (Hz)
Speed (RPM)
Motor Current
Calculated % Motor Torque
Calculated Motor Power (kW)
DC Bus Voltage
Output Voltage
Heatsink Temperature
Elapsed Time Meter (resettable)
KWh (reset-able)
Input / Output Terminal Monitor
PID Actual Value (Feedback) & Error
Fault Text
Warning Text

2 | ACH550 Product Bulletin

Three (3) Scalable Process Variable Displays
User Definable Engineering Units
Two (2) Programmable Analog Inputs
Six (6) Programmable Digital Inputs
Two (2) Programmable Analog Outputs
Up to six (6) Programmable Relay Outputs (Three (3) Standard)
Adjustable Filters on Analog Inputs and Outputs
Mathematical Functions on Analog Reference Signals
All Control Inputs Isolated from Ground and Power
Four (4) Resident Serial Communication Protocols

Johnson Controls N2
Siemens Buildings Technologies FLN (P1)
Modbus RTU
BACnet (MS/TP)

Input Speed Signals

Current 0 (4) to 20 mA
Voltage 0 (2) to 10 VDC
Increase/Decrease Reference Contacts (Floating Point)
Serial Communications

Start/Stop

2 Wire (Dry Contact Closure)
3 Wire (Momentary Contact)
Application of Input Power
Application of Reference Signal (PID Sleep/Wake-Up)
Serial Communications

Start Functions

Ramp
Flying Start
Premagnetization (DC brake) on Start
Automatic Torque Boost
Automatic Torque Boost with Flying Start

Standard Features

Auto Restart (Reset) – Customer Selectable and
Adjustable

Stop Functions

Ramp or Coast to Stop
Emergency Stop
DC Braking / Hold at Stop
Flux Braking

Accel/Decel

Two (2) sets of Independently Adjustable Ramps

Linear or Adjustable ‘S’ Curve Accel/Decel Ramps
HVAC Specific Application Macros
Separate Safeties (2) and Run Permissive Inputs
Damper Control
Override Input (Fire Mode)
Timer Functions

Four (4) Daily Start/Stop Time Periods

Four (4) Weekly Start/Stop Time Periods

Four Timers for Collecting Time Periods and Overrides

Seven (7) Preset Speeds
Supervision Functions
Adjustable Current Limit
Electronic Reverse
Automatic Extended Power Loss Ride Through (Selectable)
Programmable Maximum Frequency to 500 Hz
PID Control

Two (2) Integral Independent Programmable PID

Setpoint Controllers (Process and External)

External Selection between Two (2) Sets of Process

PID Controller Parameters

PID Sleep/Wake-Up
Motor Control Features

Scalar (V/Hz) and Vector Modes of Motor Control

V/Hz Shapes

Linear

Squared

Energy Optimization

IR Compensation

Slip Compensation

Three (3) Critical Frequency Lockout Bands
Preprogrammed Protection Circuits

Overcurrent

Short Circuit

Ground Fault

Overvoltage

Undervoltage

Input Phase Loss

Output Device (IGBT) Overtemperature

Adjustable Current Limit Regulator

UL508C approved Electronic Motor Overload (I2T)
Programmable Fault Functions for Protection Include

Loss of Analog Input

Panel Loss

External Fault

Motor Thermal Protection

Stall

Underload

Motor Phase Loss

Ground Fault

5% Equivalent Impedance
5% Equivalent Impedance with Internal Reactor(s)
Patented Swinging Choke Design for Superior Harmonic
Mitigation in frame sizes (R1 to R6)
3% Equivalent Impedance for frame R8

Available Options

3 Relay Extension Module (OREL-01)
115/230 V Digital input Interface Card (OHDI-01)
Fieldbus Adapter Modules

LonWorks
Profibus
DeviceNet
Ethernet
ControlNet

BACnet IP to MS/TP router
DriveWindow Light Start-up, Operation, Programming and
Diagnostic Tool

ACH550 Product Bulletin | 3

Specifications

Input Connection

Input Voltage (U1) ..................................................................... 208/220/230/240 VAC 3-phase +/-10%

208/220/230/240 VAC 1-phase +/-10%
380/400/415/440/460/480 VAC 3-phase +/-10%
500/575/600 VAC 3-phase +/- 10%

Frequency: ................................................................................ 48 - 63 Hz

Line Limitations: ........................................................................ Max +/-3% of nominal phase to phase input voltage

Fundamental Power Factor (cosj): .............................................. 0.98 at nominal load

Connection: ............................................................................... U1, V1, W1 (U1, V1, 1-phase)

Output (Motor) Connection

Output Voltage: ......................................................................... 0 to U1, 3-phase symmetrical, U2 at the field weakening point

Output Frequency: ..................................................................... -500 to 500 Hz

Frequency Resolution: ............................................................... 0.01 Hz

Continuous Output Current:

Variable Torque: ................................................................. 1.0 * I2N (Nominal rated output current, Variable Torque)

Short Term Overload Capacity:

Variable Torque: ................................................................. 1.1 * I2N, (1 min/10 min)

Peak Overload Capacity:

Variable Torque: ................................................................. 1.35 * I2N, (2 sec/1 min)

Base Motor Frequency Range: .................................................. 10 to 500 Hz

Switching Frequency: ................................................................ 1, 4, 8 or 12 kHz

Acceleration Time: ..................................................................... 0.1 to 1800 s

Deceleration Time: ..................................................................... 0.1 to 1800 s

Efficiency: .................................................................................. 0.98 at nominal power level

Short Circuit Withstand Rating: .................................................. 100,000 AIC (UL)

Connection: ............................................................................... U2, V2, W2

Enclosure Style: ......................................................................... UL (NEMA) Type 1, Type 12, or Type 3R

Agency Approval Listing and Compliance: ................................. UL, cUL, CE, BTL (BACnet Testing Laboratory), IBC2000, 2003, 2006

Ambient Conditions, Operation

Air Temperature: ........................................................................ -15° to 40°C (5° to 104°F), above 40°C the maximum output current is de-rated 1% for

every additional 1°C (up to 50°C (122°F) maximum limit.

Relative Humidity: ...................................................................... 5 to 95%, no condensation allowed, maximum relative humidity is 60% in the presence of

corrosive gasses
Contamination Levels:

IEC: ................................................................................... 60721-3-1, 60721-3-2 and 60721-3-3

Chemical Gasses: .............................................................. 3C1 and 3C2

Solid Particles: ................................................................... 3S2

Installation Site Altitude: ............................................................. 0 to 1000 m (3300 ft) above sea level. At sites over 1000 m (3300 ft) above sea level, the

maximum power is de-rated 1% for every additional 100 m (330 ft). If the installation site is
higher than 2000 m (6600 ft) above sea level, please contact your local ABB distributor or
representative for further information

Vibration: ................................................................................... Max 3.0 mm (0.12 in) 2 to 9 Hz, Max 10 m/s2 (33 ft/s2) 9 to 200 Hz sinusoidal

Seismic Certified referencing IBC 2000, 2003 and 2006

Ambient Conditions, Storage (in Protective Shipping Package)

Air Temperature: ........................................................................ -40° to 70°C (-40° to 158°F)

Relative Humidity: ...................................................................... Less than 95%, no condensation allowed

Vibration: ................................................................................... In accordance with ISTA 1A and 1B specifications

Shock (IEC 60086-2-29): ........................................................... Max 100 m/s2 (330 ft/s2) 11 ms

Ambient Conditions, Transportation (in Protective Shipping Package)

Air Temperature: ........................................................................ -40° to 70°C (-40° to 158°F)

Relative Humidity: ...................................................................... Less than 95%, no condensation allowed

Atmospheric Pressure: .............................................................. 60 to 106 kPa (8.7 to 15.4 PSI)

Vibration: ................................................................................... Max 3.5 mm (0.14 in) 2 to 9 Hz, Max 15 m/s2 (49 ft/s2) 9 to 200 Hz sinusoidal

Shock (IEC 60086-2-29): ........................................................... Max 100 m/s2 (330 ft/s2) 11 ms

Free Fall: .................................................................................... R1: 76 cm (30 in)

R2: 61 cm (24 in)
R3: 46 cm (18 in)
R4 31 cm (12 in)
R5 & 6: 25 cm (10 in)

Cooling Information

Cooling Method: ........................................................................ Integral fan(s)

Power Loss: .............................................................................. Approximately 3% of rated power

4 | ACH550 Product Bulletin

Specifications

Analog Inputs

Quantity ..................................................................................... Two (2) programmable

Voltage Reference: .................................................................... 0 (2) to 10 V, 250kOhm, single ended

Current Reference: .................................................................... 0 (4) to 20 mA, 100Ohm, single ended

Potentiometer: ........................................................................... 10 VDC, 10 mA (1K to 10KOhms)

Input Updating Time .................................................................. 8 ms

Terminal Block Size .................................................................... 2.3mm2 / 14AWG

Reference Power Supply

Reference Voltage ..................................................................... +10 VDC, 1% at 25°C (77°F)

Maximum Load ......................................................................... 10 mA

Applicable Potentiometer ........................................................... 1 kOhm to 10 kOhm

Terminal Block Size .................................................................... 2.3mm2 / 14AWG

Analog Outputs

Quantity ..................................................................................... Two (2) programmable current outputs

Signal Level ............................................................................... 0 (4) to 20 mA

Accuracy ................................................................................... +/- 1% full scale range at 25°C (77°F)

Maximum Load Impedance ....................................................... 500 Ohms

Output Updating Time ............................................................... 2 ms

Terminal Block Size .................................................................... 2.3mm2 / 14AWG

Digital Inputs

Quantity ..................................................................................... Six (6) programmable digital inputs

Isolation ..................................................................................... Isolated as one group

Signal Level ............................................................................... 24 VDC, (10V Logic 0)

Input Current ............................................................................. 15 mA at 24 VDC

Input Updating Time: ................................................................. 4 ms

Terminal Block Size .................................................................... 2.3mm2 / 14AWG

Internal Power Supply

Primary Use ............................................................................... Internal supply for digital inputs

Voltage: ..................................................................................... +24 VDC, max 250 mA

Maximum Current: ..................................................................... 250 mA

Protection: ................................................................................. Short circuit protected

Relay Outputs

Quantity ..................................................................................... Three (3) programmable relay (Form C) outputs

Switching Capacity: ................................................................... 8 A at 24 VDC or 250 VAC, 0.4 A at 120 VDC

Max Continuous Current: ........................................................... 2A RMS

Contact Material: ....................................................................... Silver Cadmium Oxide (AgCdO)

Isolation Test Voltage ................................................................. 4 kVAC, 1 minute

Output Updating Time ............................................................... 12 ms

Terminal Block Size .................................................................... 2.3mm2 / 14AWG

Protections

Single Phase ............................................................................. Protected (input & output)

Overcurrent Trip Limit: ................................................................ 3.5 x I2N instantaneous

Adjustable Current Regulation Limit: .......................................... 1.3 x I2N (RMS) max.

Overvoltage Trip Limit: ............................................................... 1.30 x UN

Undervoltage Trip Limit: ............................................................. 0.65 x UN

Overtemperature (Heatsink): ...................................................... +115°C (+239°F)

Auxiliary Voltage: ........................................................................ Short Circuit Protected

Ground Fault: ............................................................................ Protected

Short Circuit: ............................................................................. Protected

Microprocessor fault: ................................................................. Protected

Motor Stall Protection: ............................................................... Protected

Motor Overtemperature Protection (I2t): ..................................... Protected

Input Power Loss of Phase: ....................................................... Protected

Loss of Reference: ..................................................................... Protected

Short Circuit Current Rating: ...................................................... 100,000 RMS symmetrical Amperes

Input Line Impedance: ............................................................... 5% Equivalent Input Impedance with internal reactor(s)

Patented swinging choke design for superior harmonic mitigation in frame sizes
R1-R6

Printed Circuit Boards ................................................................ Conformal coated

Notes

U1 = Input Voltage PN = Power – Normal Duty (HP)
U2 = Output Voltage 2N = Nominal Motor Current Normal Duty
UN = Nominal Motor Voltage
fN = Nominal Motor Frequency

ACH550 Product Bulletin | 5

Drive Features - Human Interface

User Friendly Operator Control Panel

The ACH550 includes an operator control panel that is as easy to understand and use as a cell phone. The standard display
mode can be user-configured to show the operating status information that you want to see. The panel is mounted on the
front face of the drive and can be hand held or mounted remotely.

Designed specifically for HVAC applications, the operator panel includes HAND, OFF, AUTO and speed INCREASE and
DECREASE keys are provided for manual operation. Two multi-function Soft Keys are provided for navigating through the
menus and setting parameters. A HELP key pulls up a brief description of the displayed or highlighted item.

Red/Green Status LED

Operating Status and
Direction

Values of Three User­selected Parameters

Soft Key Function

Time of Day

Soft Key

AUTO Key

OFF Key

Set Speed

User-configured
Units of Measurement

Soft Key Function

Soft Key

IINCREASE/DECREASE or
SCROLL UP/DOWN Keys

HELP Key

HAND Key

Backlit, Multilingual, Text/Graphics Display

The liquid crystal display (LCD) is backlit and provided with
a contrast adjustment for optimum legibility under a range of
viewing conditions.

Graphical Display
Parameter values can be displayed in bar graph
meter format.
Plain English
The ACH550 presents information in “plain” English
(no codes).
User-selected Languages
In addition to US English, ten other languages are
available including French, Spanish, German, Italian,
Swedish, Finnish, Danish, Portuguese, Dutch and
international English.

6 | ACH550 Product Bulletin

Standard Display Mode

When the operator panel is in the standard display mode as
shown above, the top line of the display always shows the
drive operating status, HAND, OFF or AUTO, the direction of
motor rotation and the speed command setting.
The center three lines show the values of three user-selected
parameters in large numbers with user-selected units of
measurement.

The bottom line shows the functions assigned to the Soft
Keys for that particular display. In the menus, the function
of the Soft Key on the left is generally EXIT or CANCEL.
Repeatedly pressing the EXIT or CANCEL key brings the
display back to the standard display mode.

The local time is displayed in the center of the bottom line of
the standard display (12 or 24 hour format).

Drive Features - Human Interface

Control Panel Mounting Options

An optional panel mounting kit (OPMP-01) allows the control
panel to be mounted remotely or hand held. See “Control Panel
Mounting Kit” on page 33.

The control panel can be connected to and disconnected
from the drive at any time. If the drive is running under HAND
keypad control, disconnecting the keypad will cause the drive
to stop and display a fault message. Alternatively, the drive
can be programmed to continue operation after the keypad
is disconnected and run at a preset speed or at the average
speed over the previous 10 seconds.

Control Panel Keypad Operating Modes

Start/Stop and Speed Reference commands can be given
from the control panel keypad, from external command signals
connected to the customer terminal strip or transmitted
through a serial communication interface.

• Hand – Off – Auto Control

When the HAND key is pressed, the drive starts and
the reference frequency can be modified by pressing
the UP/DOWN keys. The HAND (keypad) control mode
is indicated on the LCD display.
When the OFF key is pressed, the drive stops and the
OFF control mode is indicated on the LCD display.
When the AUTO key is pressed, the AUTO mode
is indicated on the LCD display. The drive can be
started and stopped using whichever remote start/
stop command has been configured, a contact
closure applied to the Start/Stop input or a serial
communication command. The drive speed is
controlled by the external speed reference input or by
the PID controller.

Help Key

The HELP key pulls up a brief description of various displayed
or highlighted items including the Main Menu items, parameter
groups and individual parameters. In addition, help messages
and warnings are displayed automatically when parameter
changes or set-up procedures are initiated. The HELP Key also
displays possible causes and corrective actions for drive faults

• Bumpless Transfer

If the HAND key is pressed while the drive is running
in the AUTO control mode, the drive continues to
run without changing speed, but ceases to respond
to external input or PID speed reference changes
(Bumpless transfer). The reference frequency can be
modified by pressing the UP/DOWN keys.
If the AUTO key is pressed while the drive is running
in the HAND control mode, the drive continues to run
and follows the acceleration or deceleration control
ramp to the speed set by the external input or PID
speed reference (Bumpless transfer).

• Keypad Control Lock

Keypad HAND – OFF – AUTO control can be locked
out or enabled only when permitted by a terminal block
or serial communications input.

Date and Time Clock

The operator panel contains a clock with a battery backup (10
year life). The clock provides the date and time for use in the
FAULT LOGGER and timer functions.

ACH550 Product Bulletin | 7

Drive Features - Human Interface

• User Friendly Menu Structure

The MAIN MENU contains just seven items:

• PARAMETERS

The parameter menu displays the parameter values
and allows them to be edited. The parameters are
organized by function into numbered groups. See
“Parameter Group Functional Descriptions” on page

22. The first two digits of the parameter number are
the group number. Parameters include items with
adjustable values, configuration alternative selections
and read-only displays of actual values of operating
data items.

• ASSISTANTS

The programming assistants provide help in
configuring the drive. See below.

• CHANGED PAR

The changed parameters menu displays only the
parameters that have been changed from the default
values as loaded at the factory or loaded by executing
an application macro.

• FAULT LOGGER

The FAULT LOGGER displays the most recent faults.
See “Fault Logger” on page 9.

• CLOCK SET

The clock setting menu provides a means for selecting
the display format and setting the date and time.

• PAR BACKUP

The parameter backup menu has commands for
uploading the parameter settings to the operator panel
and downloading all or subsets of stored parameters
to any ACH550 drive.

• I/O SETTINGS

The I/O settings menu displays the I/O configuration
settings and allows them to be edited.

Programming Assistants

The programming assistants, used in conjunction with the
HELP key, provide a guided, step-by-step method for setting
parameters.

• Spin the Motor

For use prior to commissioning or during
troubleshooting. Allows manual operation with minimal
control functionality using the control panel keypad.

• Commission Drive

Provides a step-by-step procedure for the drive
commissioning configuration.

• Application

Provides direct access for loading an Application
Macro. Loading an application macro configures
the I/O parameters for the typical control circuit
connections required for common applications. The
ACH550 User’s Manual contains the appropriate
control circuit connection diagram for each macro.
In addition to the I/O configurations, some macros
also set other parameters such as initial PID tuning
adjustments. Loading the HVAC DEFAULT macro
resets the drive to the factory default I.O configuration.

The following programming assistants can be used to step
through and manually set the more common configuration
parameters without entering the PARAMETERS menu.

• References 1 & 2

Defines the speed reference source or the means of
selecting the speed reference. Sets the reference and
output frequency limits.

• Start/Stop Control

Defines the source and configuration of the Start/Stop
and Direction commands. Selects start/stop functions
such as ramp or coast stop and flying start. Sets
acceleration and deceleration times.

• Protections

Configures protective functions such as current limit,
external interlocks, fault trip functions and automatic
reset functions.

• Constant Speeds

Configures preset speed selection functions.

• PID Control

Enables and configures the process PID controller.

• Low Noise Set-up

Configures the drive to minimize acoustical noise
produced by the motor. Sets the switching frequency,
enables flux optimization and configures the critical
speed avoidance feature.

• Panel Display

Selects the process variables displayed on the
operator’s panel and configures the display.

• Timed Functions

Configures the daily and weekly event program timers.

• Outputs

Configures the relay outputs and sets their delay times.
Configures and adjusts the analog outputs.

Application Macros

The ACH550 offers a choice of fourteen (14) HVAC application
macros and has been designed to offer users the ability to
program common applications in a simple and flexible manner.
By using the application macros supplied as standard with all
ACH550 drives, building-wide standardization will be greatly
simplified.

8 | ACH550 Product Bulletin

Drive Features - Human Interface

• Configure I/O Terminals Automatically

Application macros allow for complete configuring
of the analog and digital I/O’s, and certain drive
parameters for specific applications.

• Edit Automatically Configured Settings

The function of automatically configured analog or
digital I/O or drive parameters may be customized,
providing added flexibility.

• User 1 / User 2 Macros for Customized Settings

Customized user settings can be saved as USER S1
and USER S2 macros, and reloaded or loaded into
other drives for quicker set-up in installations with
multiple drives or switch between two different settings
and drive operation profile on one drive

Maintenance Assistant

The maintenance assistant is a series of usage level
measurement functions and trigger points that can be used to
prompt users to perform periodic preventative maintenance
tasks. When usage reaches the set trigger point, a notice is
displayed on the operator’s panel.

• Maintenance Trigger Parameters

The maintenance trigger parameters include the
following operating data items and associated trigger
setpoints. See “Maintenance Triggers – Group 29” on
page 27.

- Cooling fan accumulated operating time

- Accumulated motor revolutions

- Accumulated hours of drive run time

- Accumulated megawatt hours of drive power
usage

• Supervision Functions

Supervision functions monitor up to three user-selected
operating data parameters and energize relay outputs
if the parameter values deviate beyond user-set limits.
These functions can be used to set up maintenance
prompts based on deviations from normal operating
conditions. See “Supervision – Group 32” on page 28.

- Air Filter Alarm
With a fan drive, high load current can indicate
restricted air flow due to a dirty air filter.

- Broken Belt Alarm or Proof of Flow
An unusually low load current can indicate a
broken fan drive belt or a dry pump.

• Diagnostic Assistance Message

If a fault message is displayed, pressing the HELP
key displays a diagnostic assistance message. The
message displays, in plain language, possible causes
of the problem and potential solutions. For example:

- Fault 2
DC OVERVOLT
Check: Overvoltage in the input power supply,
insuff decel time, undersized brake chopper.

• Fault Logger

The three most recent fault messages are displayed by
entering the FAULT LOGGER, a MAIN MENU item.

Detail Key

For the most recent fault message, pressing the
DETAIL Soft Key displays additional operating data
including:

- Operating speed and frequency

- Motor voltage, current and torque

- Status of the digital inputs

Diagnostic Message Key

From the Detail display, pressing the DIAG Soft Key
displays the diagnostic assistance message.
The FAULT LOGGER data is also available in
parameter group 04. See “Fault History – Group 04”
on page 22.

• Test Meter and Monitoring Functions

The capability to display an extensive range of
operating data means that the ACH550 control
panel is a powerful tool for use in commissioning
and troubleshooting. It can be used to monitor
performance and diagnose problems in the ACH550,
the motor or the driven equipment and process. See
“Operating Data – Group 01 and Information – Group
33” on page 22.

• Load Analyzer

Used for analyzing the customer’s process and sizing
the drive and motor the peak value is logged at a 2
ms level, and the distribution loggers are updated on
a 0.2 (200 ms) time level. Three different valves can be
logged.

Diagnostic Assistant

The ACH550 includes several valuable diagnostic tools to
assist in getting the drive back into operation quickly if a
protective shutdown occurs.

• Fault Messages

When the drive detects a severe error or hazardous
operating condition, the motor is stopped, the
red operator’s panel LED is illuminated and a fault
message is displayed on the operator’s panel.

ACH550 Product Bulletin | 9

Drive Features - Terminal Block Interface

Introduction

The ACH550 is equipped with a very flexible complement of
programmable inputs and outputs for connecting a wide variety
of field devices to the drive.

Programmable Analog and Digital Inputs and Outputs

The ACH550 includes 13 I/O terminals as standard and 3
additional relay outputs can be added (page 24). I/O functions
are assigned by the user by loading an application macro or by
setting individual parameters (Group 10 to 81 pages 22 to 31.).

• 2 Analog Inputs

Group 11 & 12 Speed Reference inputs.
Group 35 Motor Temp PT100 or PTC input.
Group 40, 41 & 42 Process or External PID set point
and feedback inputs.

• 2 Analog Outputs

Group 15 Analog Outputs
Group 35 Motor Temp PT100 or PTC regulated
current.

• 6 Digital Inputs

Group 10 & 21 Start/Stop/Direction control functions
Group 11 & 12 Speed Reference and Preset Speed
selection functions
Group 16, 17 & 30 System Control, Override, and

• External Fault functions

Group 20 Torque Limit functions
Group 22 Accel/Decel time select and reset functions
Group 35 Motor Temp thermistor input
Group 36 Timer functions
Group 40 & 42 PID functions
Group 81 Pump or Fan Alternation (PFA) functions
Group 99 USER1 and USER2 save and load

• 3 Standard and 3 Optional Relay Outputs

Group 14 Relay Outputs

The Drive Provides Unitary Control Functions

The drive’s control capabilities and I/O complement allow the
ACH550 to handle auxiliary device functions in addition to
controlling the motor.

Built-in Control Capabilities

• Two Independent PID Controllers

Setpoints sent via serial communications or set locally
Feedback hard-wired to drive I/O terminals

- Flow or Pressure Control Based on Motor
Speed
Air duct static pressure control

- Independent PID Control for an External
Device
Chilled water valve control
Cooling tower bypass valve control

• Direct-to-Drive Contact-Closure Inputs

Firestat/Freezestat safety contacts
Fireman’s override (smoke purge) command
Damper end-switch proof contact

• Direct-from-Drive Contact-Closure Outputs

Maintained contact to open isolation damper
Maintained contact to override VAV box

• Built-In Timers

Built-in timers - utilizing the real-time clock - allow
starting and stopping the drive or changing the speed
according to the time of day or night. Relay outputs
can be operated with timers to control any auxiliary
equipment on site.

• Monitor Hard-Wired Devices Over Serial Link

All hard-wired analog and digital I/O points can be
monitored over the serial link.

• Pass-Thru I/O

Serial communications can be used to send and
receive analog signals and digital commands
through the ACH550 I/O points that are used not for
control functions provided by the drive. The Building
Management System can use the drive’s I/O to control
auxiliary devices.

• Advantages of Offloading Unitary Control
Functions to the Drive

- Eliminating external control components
simplifies the system and provides a more
economical installation.

- Integrating the auxiliary control into the drive
provides closer functional coordination and
better compatibility.

Customer Terminal Block

The analog I/O and digital input circuit common potential of
the customer terminal block is optically isolated from power
circuits and resistively isolated from the chassis by a 1 Mega­Ohm resistor. Shielded cable screen connection terminals are
connected to the drive chassis.

• 24VDC Control Power Supply

An internal power supply is available for contact
closure digital inputs.

• External 24VDC Control Voltage Inputs

Digital inputs can be supplied by an external voltage
source of either polarity.

• Optional 115/230VAC Control Voltage Inputs

See “115/230v digital input Interface Module” on page

32.

• 10VDC Reference Power Supply

An internal power supply is provided for potentiometer
voltage inputs.

• Several Separate Circuit Common and Grounding
Terminals

Separate terminals are provided for shielded cable
screen connections, analog input signal common,
analog output signal common, and digital input signal
common.

10 | ACH550 Product Bulletin

Drive Features - Communications Suite

Introduction

Serial communications is a powerful mode of operator and
supervisory control interface that provides a number of benefits
compared to other types of interface. The ACH550 is equipped
with an (RS) EIA-485 serial communications port that supports
a full range of drive monitoring and control functions through
serial communications.

Fieldbus

A fieldbus is serial communications network that connects a
master control unit such as a Building Management System
with several or many slave devices such as AFDs.

• ABB Leadership in Fieldbus Technology

ABB is a leading drives supplier to the U.S. HVAC
market, and has connected hundreds of thousands
of drives to building automation systems. Using its
standard (RS) EIA-485 port and embedded protocols
or internally mounted fieldbus adapter modules the
ACH550 can be connected directly to any of the
fieldbus network configurations commonly used in the
US HVAC industry. ABB is the first drive manufacturer
to offer BACnet as an embedded protocol.

• Embedded Fieldbus Protocols

Using the drive’s standard (RS) EIA-485 port, the
ACH550 can communicate using any of the following
protocols:

- Modbus®

- Metasys® N2

- APOGEE® FLN

- BACnet® (BTL Listed)

• Fieldbus Adapter Modules

Internally mounted adapter modules are available for
communication using the following protocols:

- DeviceNet®

- LonWorks®

- Profibus-DP®

- ControlNet

- EtherNet

- BACnet IP to MS/TP

Benefits of Serial Communications

• Reduced I/O Connections

One serial I/O connection can provide the functions of
multiple conventional I/O connections. This provides
wiring cost savings and savings in the number of I/O
points required in the Building Management System.

• Enhanced Energy Management Strategies

Low cost data collection through serial
communications makes it feasible to use enhanced
energy management strategies that result in lower
operating costs.

DriveWindow® Light PC Software

ABB’s DriveWindow Light provides a user-friendly way to set
up and control a drive system easily and comfortably from a
PC. It is ideal for drive commissioning as well as maintenance
and service purposes, troubleshooting and training. Learning
and using DriveWindow is easy – the look and feel of the user
interface is just like that of any Windows® application. All
features are easily accessed by clicking an icon or through a
clearly structured menu tree. This makes drive programming
and system configuration management simpler than ever.

The following are the DriveWindow Light features that are
available for use with ACH550 drives.

• System Configuration

The starting point of DriveWindow, providing an
overview of the system. All drives connected to the
system are clearly indicated here, along with the type
and status of each drive.

• Drives Panel

Enables full control of a drive with the following
commands: Local/Remote, Start, Stop, Change
Direction, Reference Setting, Step Function and Fault
Reset.

• Signals and Parameters Tool

Displays a list of all or selected signals and parameters,
along with their values, units, types and setting ranges.
Features include parameter upload and download,
changing parameter values, saving values to a file,
reading values from a file, comparing two parameter
sets, and finding a parameter.

• Monitor

A trending tool providing a graphic interface to actual
drive values. Up to six items from different drives can
be selected for monitoring simultaneously. Actions
such as setting triggering conditions, scaling the axis,
zooming and printing the graphs can be performed.

• Data Logger Tool

Used for controlling the drive data loggers, selecting
their variables and setting triggering conditions. It
allows high-precision analyses of rapid phenomena.
Data logger contents can be presented in a numeric or
graphic form.

• Event logger

Shows the application specific drive events, each with
a description and a time stamp.

• Fault Logger

Shows the last 10 faults and warnings, each with a
time stamp. The FAULT LOGGER also allows resetting
of an active fault.

ACH550 Product Bulletin | 11

Drive Features - Power

Introduction

The ABB ACH550 AC drive combines a sophisticated
microprocessor with an advanced IGBT power switching
technology to deliver a full featured drive in an extremely
compact design. The ACH550 is a highly efficient and
dependable (PWM) drive designed specifically for the HVAC
industry.

• Input Power – Tolerated Voltage Window

The ACH550 is available in three line voltage ratings
each with a 35% undervoltage to 30% overvoltage
window of tolerated voltage deviation.

Line Voltage

Range

208 - 240V 135V 312V
380 - 480V 247V 624V
500 - 600V 325V 780V

• Low Line Harmonics – Swinging Choke

Drives and other non-linear load equipment contribute
to harmonic currents in a power distribution system.
IEEE Standard 519-1992 explains the reasons for
limiting harmonics and recommends limits to be
applied in various situations.

• Swinging Choke

ACH 550 drives have a unique, built-in harmonic
limiting device, a swinging choke. The swinging choke
is an inductor that has an inductance value that is
inversely proportional to its operating current.

• Swinging Choke Advantages

- Limits harmonics as effectively as a 5% linear
choke but requires less space in the drive

- A built-in component, no extra equipment to
purchase, mount and wire

- High efficiency, minimal power loss

- Configured as a 3-phase input reactor or dual DC
bus choke for added impedance

- No need to oversize branch circuit wiring
The swinging choke assures that the drive’s
input current will never exceed the output current
supplied to the motor. The rated input current
marked on the drive’s nameplate is the same as
the rated output current. This means that there
is no need to oversize the branch circuit wiring,
disconnecting means and protection to comply
with the National Electrical Code.

- Contributes to electromagnetic compatibility and
transient voltage protection

Undervoltage

-35% Trip Point

Overvoltage

+30% Trip Point

• Electromagnetic Compatibility (EMC)

Electromagnetic compatibility (EMC) is the ability
of electrical/electronic equipment to operate in its
installation environment while neither causing nor
experiencing electromagnetic interference (EMI). EMI
is any interference with normal equipment operation
caused by abnormal energy entering the equipment
either by conduction though wiring connections or by
radiated wave reception. Radiated EMI is also called
radio frequency interference (RFI). Conducted EMI is
also called high frequency line noise.

The ACH550 is equipped with built-in EMI / RFI filters
to assure that the drive will not interfere with any
sensitive equipment.

EMC Standards

• IEC EN61800-3

The ACH550 includes standard filters that meet the
IEC 61800-3 EMI/RFI standards and emission limits
for Restricted Distribution and installation in the First
Environment.

• Federal Communications Commission Regulations,
Part 15, Requirements for Class A Digital Devices

As an item of industrial equipment or a component of
a commercial HVAC system, an adjustable frequency
drive is exempt from any FCC labeling or authorization
requirements.

• CE Marking

The ACH550 conforms to the European Union
Electromagnetic Compatibility directive and meets
the other requirements that allow it to carry the CE
marking.

Easily Serviceable Cooling Fans

The cooling fans in the ACH550 can easily be removed to clean
the heatsink and fans or to replace the fans. The fans can be
removed without removing the drive from the wall or removing
circuit boards. To maximize their operating life, the fans are
cycled on and off as required to maintain the drive at a safe
operating temperature.

Vector Drive – Vector or Scalar Control Mode

The ACH550 is a sensorless vector controlled drive with user­selectable vector and scalar control modes.

• Scalar Control – Optimum for HVAC Drives

The scalar control mode is normally used in HVAC
applications. It provides all the performance you want
with no motor profiling.

• Vector Control Advantages in the Scalar Control
Mode

The ACH550 vector control design enhances scalar
mode performance of the following features:

- High Performance Current Limit
The ACH550 current limit is fast, accurate and
reliable.

- Flying Start to Catch a Forward or Reverse

12 | ACH550 Product Bulletin

Drive Features - Power

Spinning Motor
The ACH550 starts smoothly and reliably with a
spinning motor connected. If the motor is spinning
in the forward direction, the drive simply picks
up the motor at its current speed and smoothly
accelerates or decelerates to the desired operating
speed. If the motor is spinning in the reverse
direction the drive decelerates the motor and re­accelerates in the forward direction.

- Flux Optimization
Flux Optimization provides the right motor
excitation for every set of operating conditions.
This results in reduced energy consumption plus
cooler and quieter motor operation.

- The Vector Mode is Available if Needed
For unusually demanding applications, the
sensorless vector mode of operation can be
engaged by making the appropriate parameter
selections.

Energy Savings

The ACH550 provides some unique energy savings features to
complement the inherent energy savings gained by using an
adjustable frequency drive to modulate flow.

• Swinging Choke DC Bus Filter Design

The swinging choke helps provide the ACH550 with
a DC bus filter that saves energy both inside the drive
and in the power distribution system. See “Low Line
Harmonics – Swinging Choke” on page 12.

• Fan Modulation

The cooling fans in the ACH550 operate upon
application of power to provide indication of their
proper operation. The fans turn on given a run
command and remains on after a stop command is
give until drive temperature is to an acceptable level.

• Flux Optimization

The flux optimization feature monitors the load and
automatically adjusts the motor excitation to suit
the operating conditions. Whenever load conditions
permit, the magnetic flux in the motor is reduced
to save energy, and provide cooler and quieter
motor operation. The energy used by the motor is
automatically optimized in balance with the load
requirements.

ACH550 Product Bulletin | 13

Drive Features – Protection

Introduction

Drive protection features assure reliable operation and long­lasting equipment. The ACH550 has a very flexible and
extensive line-up of protection features.

Power Line Protection
Surge Withstand Capability

ACH550 drives include a coordinated AC transient voltage
protection system consisting of four Metal Oxide Varistors
(MOVs) rated 120 joules each (phase to phase & phase to
ground), a capacitor clamp, and 5% impedance swinging
chokes.

Short Circuit Current Rating

The UL 508A or 508C labeled short circuit current rating
of the ACH550 is 100,000 A when installed with any NEC
compliant branch circuit protection. Class T (Bussmann Type
JJS) fuses are recommended but not required. The ACH550
has electronic protection circuits and other design features that
eliminate the need for fast acting semiconductor input fuses.
The drive is fully protected from an output short circuit whether
it is present when the drive is started or occurs after the drive is
running.

Mis-wiring Protection

ACH550 units rated 75 Hp and smaller are protected from
input and output power mis-wiring. If one or more input power
conductors are connected to motor terminals, the drive will
sense the problem and display an OUTPUT WIRING fault
message.

Switching Frequency Foldback

Since reducing the drive’s switching frequency reduces the
heat generated by the IGBTs, the ACH550 has a switching
frequency control feature that can be set to reduce the drive’s
switching frequency if the heatsink temperature rises above
80-90°C. This would only engage when both the ambient and
load are at the maximum load. When the load and temperature
drops, the carrier frequency will revert back to the initial setting.

Integral Protection Circuits

The ACH550 was designed to protect the drive and motor from
the hazards of continuous service in the most demanding of
applications. Built-in protection circuits include the following:

• Overcurrent trip limit - 350% instantaneous

• Adjustable current regulator limit - 130%

• Overvoltage trip limit - 130%

• Undervoltage trip limit - 65%

• Over temperature protection (heatsink)

• Switching frequency foldback temperature
limiter

• Auxiliary voltage short circuit protection

• Output ground fault and mis-wiring protection

• Output short circuit protection

• Microprocessor fault protection

• Adjustable motor stall protection

• Adjustable motor overload protection (I2t) - UL
listed

• Motor PTC thermistor and Pt100 RTD inputs

• Loss of reference protection (programmable)

• Single phasing protection on input and output

• Underload protection (programmable)

• Keypad control panel loss protection

(programmable)

• Serial communication loss protection

• Two (2) programmable external fault interlock

inputs

• Adjustable output frequency and motor speed

limits

• Pass code parameter-change protection

• Keypad operator control lockout

• Extended power loss ride-thru by inertial energy
recovery

Automatic Reset

In order to minimize the nuisance shutdowns, the ACH550
can be set to automatically reset certain faults and attempt to
restart. See “Automatic Reset (Auto Restart) – Group 31” on
page 28.

Enclosure Offerings

Since the NEMA enclosure designations can be used without
third party certification, ABB has chosen to obtain UL listings
that include the enclosures to assure customers that the
ACH550 enclosures meet nationally recognized standards.

• UL Type 1 (NEMA 1)

Suitable for most mounting locations

• UL Type 12 (NEMA 12)

Increased protection from dirt and dust but still rated to
deliver continuous full output current at 40°C.

• UL Type 3R (NEMA 3R)

Increased protection against falling rain and is
undamaged with the formation of ice on the enclosure

• Enclosures are Plenum Rated by UL

Offers more flexibility in selecting a mounting location.
Note that plenum ratings are available only for UL listed
enclosures.

14 | ACH550 Product Bulletin

Versatile Protection

Many of the protection features are adjustable or programmable
to suit the requirements of individual applications. Refer to
the following parameter group descriptions for additional
information:

• “System Controls – Group 16” on page 24

• “Limits – Group 20” on page 25

• “Motor Control – Group 26” on page 26

• “Fault Functions – Group 30” on page 27

• “Automatic Reset (Auto Restart) – Group 31” on

page 28

• “Supervision – Group 32” on page 28

• “Motor Temperature Measurement – Group 35” on

page 28

Application Control Diagrams

HVAC System Overview
The HVAC System Diagram on the following page shows
the principal elements of an HVAC system including typical
adjustable frequency drive applications.

• Chiller

Speed control of the chiller compressor is a special
application undertaken only with close coordination
between the drive and chiller manufacturer.

• Cooling Tower

The cooling tower fan speed control is typically based
on the water temperature at the discharge point.
See “Air Handling Unit Application Functions” on page
16

HVAC System Overview Diagram

• Chilled Water Pump

The chilled water pump speed control is typically
based on the differential pressure across the cooling
coil that is located farthest from the chiller or the most
distant significant load.
See “Chilled Water Pump Application Functions” on
page 18.

• Air Handling Units (AHU)

The AHU fan speed control is typically based on the
pressure in the air duct.
See “Cooling Tower Application Functions” on page

20.

ACH550 Product Bulletin | 15