Soft start UK guide to energy saving new

April 2010
Energy Saving in Automation & ControlEnergy Saving in Automation & Control
INTRODUCTION TO Softstart UK
Softstart UK is an Industrial Automation
supplier and system builder. Having a
warehouse with VFD’s to 75KW and Soft
Starters to 400KW available ex-stock.
We have a training facility in Great
Yarmouth with an extensive stock level of
automation products including PLC’s, HMI’s,
Power Supplies, AC Servo, and Power
Quality products..

April 2010
HOW MUCH HAS YOUR ENERGY COSTS
INCREASED IN THE LAST 12 MONTHS?
 All AC motors cost money £££ example:
(A 22kW fan running continuously 24hrs a day, 365 days a year costs on average £7,708)
 AC Motors are responsible for 70% of UK Industries energy bills.
 The Climate Change Levy applies an additional 15% surcharge to all heavy
and light industrial consumers.
 On average 70% of industrial fan, pump and consumer applications would benefit by
using a modern AC Variable Speed Drive both through process and energy saving benefits.
 Payback can be as little as 3-4 months on some fan and pump applications.

April 2010
INTRODUCTION TO VARIABLE SPEED DRIVES
 What is a VSD
 Where to use VSDs
 Example application for VSDs

April 2010
Poles 50Hz 60Hz
2 3000 3600
4 1500 1800
6 1000 1200
8 750 900
RPM =
120 x f (Hz)
Poles

April 2010
Pressure
Temperature
Variable Speed
Drive
Motor
Protection
Communications
The Intelligent Motor

April 2010
 Energy saving ability
 PID Control with sleep modes
 Built in 10K step PLC
 Multi-pump control
 Improved process control
 Near-DC performance without the maintenance
 Good power factor
 Built-in soft-start
 Built-in energy optimising
 Controllable via a BMS or PLC
The Benefits

April 2010
 Flow proportional to the speed
 Pressure proportional to the speed squared
 Power proportional to the speed cubed
Fan Affinity Laws

April 2010
Cube Law Characteristic
Speed (%)
InputPower(%)
100
0
80
60
40
20
0
10 20 30 40 50 60 70 80 90 100

April 2010
Power Consumption & Power Saved
Percent Flow
Power
50 100 150
Fixed speed
power input
0
Power saved
Power input
to drive
Power loss
in pump,
motor and
VSD
Useful power
to produce
system flow

April 2010
Flow Rate (%)
InputPower(%)
10
10 20 30 40 50 60 70 80 90 100
20
30
40
50
60
70
80
90
100
110
120
130
140
Damper
Inlet Guide Vanes
Disc Throttle
Ideal Fan Control
Variable Pitch
Axial Fan
PWM Inverter
Fan Power Requirements with different methods

April 2010
Look for: . . .
 Centrifugal Fans and Pumps
 Systems with a low static head
 Compressors
Saving Energy with VSD’s

April 2010
A VSD controls the speed of the motor to match the load imposed on it under varying process and
environmental conditions. As power consumption is proportional to the cube of the motor speed,
significant savings can be achieved. Although several industrial applications can benefit from inverter
control, the most significant savings can be made with centrifugal loads such as fans and pumps.
Typical Saving Calculations;
Motor running costs £ Cost of Electricity to run the motor for 1 year.
Motor power kW Power rating of motor.
Run Hours Number of hours run for 1 year assumed to be 1 x 365 x 24 = 8760 hrs.
Cost of electricity Assumed to be 4p/unit. One unit equals 1kWhr
Energy Saving factor Fans and Pumps operate on a cube law principle the energy saved reduces by
the cube of the speed reduction therefore a motor running at 50% speed will use
0.5 x 0.5 x 0.5 of the power ie: 0.125 or only consume 12.5% of the normal power.
Savings Savings are the difference between the normal running costs and the running
costs with an inverter.
Pay Back The number of months taken to pay for the cost of an inverter and installation.
VARIABLE SPEED / ENERGY SAVING

April 2010
Formula;
Motor Running Costs = Motor Power x Saving Factor x Hours Run x Electricity Costs
Savings = Normal Running Costs – Inverter driven running costs
Pay Back in months = (Cost of Inverter ÷ Savings per annum) x 12
Example;
45kW Centrifugal Pump running continuously. Calculate normal running costs and cost when driven
by an inverter at 90% for 8 hours a day and 50% for the remaining part of the day.
DOL Motor running costs = 45 x 1 x 8760 x 0.04 = £15768 per annum
Inverter running costs = (45 x 0.729 x 2920 x 0.04) + (45 x 0.125 x 5840 x 0.04) = £5156 per annum
Savings = £15768 - £5156 = £10612 per annum
Typical cost of 45kW Inverter = £2795
Pay Back = (£2795 ÷ £10612) x 12 = 3.16 months

April 2010
Some newer technology Inverters provide additional energy saving features which provide further savings.
The graph below shows detail of the automatic energy saving function available from the Hyundai N300E
Frequency Inverter. This function insures that the motor operates at minimum current in response to the
torque required by the load.

April 2010
www.eca.gov.uk

April 2010
INTRODUCTION TO SOFT STARTERS
 What is a Soft Starter
 Where to use Soft Starters
 Example application for Soft Starters

April 2010
AC Input Supply
Fixed Supply Frequency
UK = 50Hz
Single Phase 240V
Three Phase 415V
Soft Starter Thyristor Output
Varying Voltage
Motor Fixed Speed
Ramped Start
Ramped Stop

April 2010
Digital Control
Soft Starter
Motor
Protection
Communications
The Intelligent Motor

April 2010
The Benefits
Advantages:
 Solid state - no moving parts, less maintenance
 Reduced starting current & mechanical shock
 Smooth, step less acceleration & deceleration
 Closed current loop starting
 Easy adjustments for all applications
 Comprehensive motor protection package
 Special features: “Pump Control”, Soft stop, Slow speed with
electronic reversing.
Uninterrupted operation of unmanned installations such as
irrigators, flood pumps, remote pump stations is aided by the
LV-DS soft starter’s Auto-Reset function.

April 2010
The Benefits
Some advanced digital soft starters provide additional features such as;
Emergency Run ModeEmergency Run Mode
•In the case of fire, equipment such as ventilation fans in high rise
buildings can be required to run at all costs.
•Activation of the LV-DS’s Emergency Run mode initiates a start
and deactivates all protections, enabling the motor to run as long
as possible despite the deteriorating environment.

April 2010
Look for : . . .
 Centrifugal Fans and Pumps
 Compressors
 Generator Supply
 Low Capacity Supply
 Application requiring reduced mechanical shock
Where to use Soft Starters

Soft start UK guide to energy saving new

More Related Content

Similar to Soft start UK guide to energy saving new

Recently uploaded

Soft start UK guide to energy saving new