Transcript Installation Considerations - Schaedler Yesco Distribution

Course # W 51 HVAC Motor Control Solutions
Presenter: John Polites - Automation Engineer
Wednesday, May 3rd - 9:00 AM – 10:00 AM
State College Room
Topics of Discussion:
–
–
–
–
Motor Load & Starting Methods
Motor Control for HVAC Applications
Energy Savings with Variable Frequency Drives
Introduction to PF400 HVAC Drive
AC MOTOR LOADS
AC Motor Load Types
– Constant Torque
– Variable Torque
– Constant Horsepower
Constant Torque Motor Loads
Variable Torque Motor Loads
Variable Torque Application Types
• Typical of Centrifugal Pumps and Fans
• Pumps: Hot Water, Chilled Water, Condenser
Water, Distribution
• Fans: Supply, Return, Relief, Exhaust, Cooling
Tower Fans
• Torque and Horsepower Drops As Square of Speed
Reduction;
• Excellent Potential for Energy Savings with a VFD versus a
throttling Valves, Dampers or Inlet Vanes
HVAC Pump Types
Two Pump Types:
• Positive Displacement Pumps
• Move fluid chamber to cause fluid to flow
• Constant Torque Load Profile
• Centrifugal Pumps
• Move fluid by rotation of an impeller
• Variable Torque Load Profile
• Hydronic Pumps: Hot Water, Chilled Water,
Condenser Water & Distribution
Components of the Pump System
•
•
•
•
•
•
•
Pump
Motor
Coupling
Base Plate
Piping
Valves
Inlet Source
– Above Pump
– Below Pump
• Discharge Static Head
Pump Type and Applications
HVAC Systems
HVAC Systems
• The purpose of an HVAC (heating, ventilating, and air-conditioning)
system is to provide and maintain environmental conditions within an
area called the "conditioned space."
• The commercial system selected for a particular application should
endeavor to provide the optimum environment for employee comfort
and productivity, process function, and good indoor air quality with
energy efficiency and cost-savings
Types of HVAC Systems
•
Air Handling Systems
– Air Handling Units (AHU), Rooftop Units (RTU), Makeup Air Units
(MUA), Exhaust Fans (EF), Variable Air Volume Boxes (VAV),,fan
unit (FU)
•
Hydronic Systems
– Chilled Water (CHW) – [Chillers and Pumping Packages]
– Condenser Water (CW) – [Cooling Towers]
– Hot Water (HW) - [Boilers and Pumping Packages]
•
Building Automation System (BAS)
– HVAC Controls, Direct Digital Controls (DDC), Energy Management
System (EMS), Facility Management System (FMS)
Typical Commercial HVAC Systems
HVAC Motor Control
(Starters or VFDs)
Traditional Variable Air Volume (VAV) Air Handling Unit
Controllers measure Static Pressure and send speed signals to both VFD’s
Supply fan will be controlled by PF400
Return fan will be controlled by PF400
VAV boxes located in each
room distribute conditioned air
Chilled Water Pumping System
Variable Frequency drives Replace the wasteful Check valve system
These motors are controlled by a Variable Frequency Drive
Condenser Water Pump System
Valves replaced when drives are used
Motors controlled by VFD’s in new applications
Building Automation Systems (BAS)
BAS SERVER
BAS PRINTER
BAS OWS
BUILDING
LOCAL AREA
NETWORK
NC
ASC
APPLICATION SPECIFIC CONTROLLER
(HOT WATER SYSTEM)
ASC
APPLICATION SPECIFIC CONTROLLER
(CHILLED WATER SYSTEM)
ASC
APPLICATION SPECIFIC CONTROLLER
(AIR HANDLING UNITS)
ASC
APPLICATION SPECIFIC CONTROLLER
(ROOFTOP UNITS)
ASC
APPLICATION SPECIFIC CONTROLLER
(VARIABLE VOLUME BOXES)
NETWORK CONTROLLER
TYPICALLY MOUNTED
IN NETWORK CLOSET
ETHERNET
FIELD BUS
> Controllers Send Output Commands to VFDs and Motor Starters: Start/Stop Control & Speed Commands
> Run/Fault Commands Sends Status Commands for Starter Device to Controllers.
Basic BAS Systems Control Strategies
• A pressure sensor within an air duct or pipe measures the
system pressure
• As the pressure changes an analog signal is sent to the
BAS
• The BAS sends a start stop and speed command to variable
frequency drives (VFDs) or motor starters
• When valves and dampers close, the pressure rises in the
ducts or pipes, which reduces the speed
Building Automation System Graphic
• This is a typical view on a building automation computer
screen showing the status of various points in an air handling
system
Motor Starting Methods
Types of HVAC Motor Starting Methods
• Full Voltage Starting
• Reduced Voltage Starting
– Wye - Delta Starters
– Autotransformer
– Soft Starters
• Variable Frequency Drives
Full Voltage Starting
•
Full Voltage Starting Characteristics
– Contacts close immediately supplying full line
voltage to motor.
•
Advantages:
– Lowest starter cost
– Simple starter designs
• Easy to maintain and troubleshoot
•
Disadvantages:
– Inrush Current
• 6-10 times rated running current
• Issue when peak demand charges are
enforced by utilities
– Initial Torque
• Mechanically hard on system
• Reduced life of belts, gears
L1
L2
L3
Disconnect
Fuses
Contactor
Overload
Relay
T1
T2
T3
IEC & NEMA Motor Starters
NEMA Rated
Emphasis on:
Serviceability
Contacts
Replaceable
Flexible Overload Selection
IEC Rated
Emphasis on:
Replacement
Contacts only replaceable on
large sizes only
Conserve panel space
Class 10 Overload Protection
Solid State Soft Starters
Use SCR’s to ramp voltage supplied to
motor over a user defined time period
Advantages:
• Reduces inrush current
• Reduces starting torque
• Reduces mechanical stress
on motor & loads
Soft Starter Speed Torque Curve
Reducing the Voltage
Reduces the Current
LRT
100%
Reduction In Torque!!
(.5)2 = .25 or 25%
0
Percentage of Full Speed
100%
Commercial OEM Products
Manual Starters
• Range Overview
– 1HP, 115, 230, 277 VAC
– 0.75 HP, 115/230 VDC
– 1 or 2 Pole
– Thermal Overload
• Ideal for small Fan and
Pump Applications
Adjustable Speed Drives
Variable Frequency Drives Basics
Solid State AC Variable Frequency = Variable Speed
AC Input
Fixed
Frequency
Converter
AC
Output
Variable
Frequency
Inverter
DC
Bus
Benefits
• Solid state technology
• Wide control options
• Small size power units
• Good efficiency
• Lower cost, smaller motors
• Retrofit existing motors
• Bypass capability
AC
Motor
460
Max
Frequency
Volts
230
30
60
Hertz
Voltage
Hertz
Motor RPM
0
0
0
115
15
438
230
30
875
345
45
1313
460
60
1750
Base
Voltage
Base
Frequency
V/Hz
460
60
7.67
230
60
3.83
208
60
3.47
Why Should I consider using a Variable Frequency Drive (VFD)?
• To improve process control though speed
and torque control
• To improve system efficiencies
• To extend life of equipment by reducing
mechanical stress
• To Achieve Energy Savings on Fan and Pump
Applications
• To meet the ASHRAE Energy Standards 90.1 -2001
– Variable flow control on fan & pump systems
Allen Bradley PF400 HVAC Drive
•
•
•
Integral RS485 Communications
Supports DSI Accessories
Integral LCD Keypad
•
•
Application Specific Features for
Fans and Pumps
Rated for Variable Torque Loads
Optimized for Commercial Fan and Pump Applications
Stand-Alone
Packaged
PF400 Ratings
• Ratings
– 200-240V, 2.2-37 kW (3-50 Hp)
– 380-480V, 2.2-100 kW (3-150 Hp)
• 110% Overload for 60 seconds
• Enclosure
– IP20 / UL Open
• 3-10 HP (240V AC) & 3-20 HP (480V AC)
– IP30 / NEMA 1 / UL Type 1
• 3-10 HP (240V AC) & 3-20 HP (480V AC)
(with optional kit)
• 15-50 HP (240V AC) & 25-150 HP (480V
AC)
• Environment
– IP20 rated for 50° C
– IP30 rated for 45° C
Allen Bradley PF400 HVAC Drives
Standard VFD
Main Input
Disconnect
3 Contactor Full
Feature Bypass with
Disconnect
3 Contactor Basic
Bypass with
Disconnect
Variable Frequency Drive Control Capabilities
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Analog Output
Configurable Keypad with local – remote
Dip Switches
start/stop and speed controls
Compatible with Building Automation
Analog Input
Dip Switches
System Inputs/Outputs (Start/Stop,
Speed and Feedback)
24V DC
Standard BAS Communications:
Source/Sink
– RS485, Modbus RTU, Johnson
Controls N2 & Siemens P1
Future Communications:
– Lonworks & Bacnet
Process PI
Inertia Ride Through
Power Loss
Flying Start
S Curve, Accel & Decel profiles
V/Hz Control
Motor Overload protection
Communication interfaces to Building
Automation Systems
Analog & Digital inputs & outputs
Manual Bypass Capabilities
RS485
Relay Outputs
Analog and
Purge Start Input and Frequency
Ports
Discrete
Fire/Freeze Stat Interlock Inputs
Wiring
Motor Characteristics with Different Starting Methods
% Motor Starting Current
Starting
Method
% Voltage
at Motor
Terminals
Full Voltage
% Line Current
% Motor Starting
Torque
Lock
Rotor
Current
Full Load
Current
Lock Rotor
Current
Full Load
Current
Lock Rotor
Current
Full Load
Current
100
100
600
100
600
100
100
80 % tap
80
80
480
64
480
64
115
65 % tap
65
65
390
42
390
42
76
50 % tap
50
50
300
25
300
25
45
Part Winding
100
65
390
65
390
45
81
Star - Delta
100
33
198
33
198
33
60
Solid State
0-100
0-100
0-600
0-100
0-600
0-100
0-180
Variable
Frequency
Drive
0-100
0-100
0-200
0-100
0-200
0-100
0-180
Autotrans.
HVAC Motor Control Price Comparison
Motor HP
VFD
Soft Starters
NEMA Combination
Starters
IEC Combination
Starters
5
$
900
$
1,100
$
780
$
620
10
$
1,000
$
1,200
$
813
$
697
20
$
1,600
$
1,600
$
1,195
$
902
40
$
2,700
$
2,400
$
1,959
$
1,466
50
$
3,400
$
2,800
$
1,975
$
1,513
Standard Features:
•480 VAC, 3-Phase
•NEMA 1 Enclosure
• Input Disconnect Switch
•Motor Thermal Overload Protection
ENERGY SAVINGS WITH VFDs
Centrifugal Pump Energy Savings
There are two methods used to accomplish the continuously varying flow:
• One method is throttling which changes the system curve by use of control or throttling valve.
• The other method is to vary the speed of the pump which modifies the pump curve.
• Building Automation System controls the pump starter or VFD and control valve based on HVAC
sequence of operation.
Centrifugal Pump Energy Savings
Typical Pump Curves
Pump Curves Controlled by a VFD
Energy Savings with VFD’s
Pump Curves Throttled with Control Valves
(GPM Proportional Brake HP-Torque)
Fan Energy Savings
Many air handling systems require operation at a wide
variety of points. There are several methods used to
modulate or vary the flow (or CFM) of a system to achieve
the optimum points. These include:
• Cycling – As done in home heating systems. This produces
erratic airflow and is unacceptable for commercial or
industrial uses.
• Outlet Dampers – Control louvers or dampers are installed
at the outlet of the fan. To control airflow, they are turned to
restrict the outlet, which reduces the airflow.
• Variable Inlet Vanes – by modifying the physical
characteristics of the air inlet, the fans operating curve is
modified which
changes the airflow.
Typical Fan Curves
• Variable Frequency Drives – By changing the actual fan
speed, the performance of the fan changes producing a
different airflow.
Building Automation System controls the fan starter, control dampers
and air system sensors based on HVAC sequence of operation.
Fan Energy Savings
Fan Curves with Outlet Dampers
Fan Curves with Variable Inlet Vanes
Fan Curves with VFD
Sample Fan Energy Savings Report
• Energy Savings Software
– (www.sydist.com)
• Energy Savings Report
– VFD Specs
– Energy Savings Calculations
– Energy Savings Summary
VFD Energy Savings Software Tools
Schaedler Yesco Distribution
HVAC Market
Schaedler Yesco Distribution - HVAC Market
Plan & Spec Market
– New Construction, Additions and Renovations
– Track projects online through Harrisburg Builders Exchange
– Mechanical plans/spec takeoffs for motor control that’s
furnished by the HVAC contractor
– Application coordination with mechanical equipment specs,
building automation system sequences of operations and
electrical power system plans
Retrofit Market
– Provided electrical energy solutions/products to Design/Build
and Energy Service Teams i.e.: Variable Frequency Drives
and Lighting Retrofit Solutions
– VFD Fan or Pump Energy Savings Reports www.sydist.com
– VFD Replacement Program
Motor Control Support
• Local Central PA Support with (5) Staffed Motor Control
Specialist
• Product Guide Specifications & Submittal Packages
• Certified VFD Startup
– VFD Checklist and Reports
• Onsite Training
• Available Spare Parts
• 24/7 Emergency Service
• Online Allen-Bradley Drives Technical Support
– www.ab.com/support/abdrives
Questions ?
Please Take a Few Minutes
to Fill Out Seminar
Evaluation Form
THANK YOU