Pneumatic or Electric? -How to decide which actuator to use
This webinar will be available afterwards at
www.designworldonline.com
Q&A at the end of the presentation
Hashtag for this webinar: #PvsE
Before We Start
Moderator
Paul J. Heney Design World
Presenter
Bob Kral Bimba Manufacturing
Pneumatic or Electric?
How to decide which actuator to use.
• Criteria to Consider
• Pneumatic o Performance
o Costs
o Best application scenario
• Electric o Performance
o Costs
o Best application scenario
• Case Study: Pneumatic Over Electric
• Case Study: Electric Over Pneumatic
• Freebie: Pneumatic versus Electric Cost Calculator
• Q&A
Agenda
Criteria to Consider
• Performance advantages and disadvantages
• Installation and maintenance costs
• Operating (power) costs
• Productivity gains o Reduced downtime
o Increased capacity
o Labor savings
Pneumatic or electric actuators?
Pneumatic Actuator Performance
Characteristics • High force and speed
• Force and speed are independent and easily adjusted
• Economical to oversize
• Small footprint
• Simple implementation
• Extend and retract only
• System requirements: o Compressor
o Air lines
o Fittings
o Filters
o Regulators
o Lubricators
…which limit where it can be deployed
Pneumatic or electric actuators?
Pneumatic Actuator Costs
• Component costs are low
• Operating costs dominated by compressor power consumption (~76%) o Efficiency is lower at idle
o Idling at no load wastes electric power consumption
o Oversized cylinders and compressors waste money
• Other operating and maintenance costs (~24%)
• Best scenario: o Large scale deployment
o Efficiently sized compressor
o No labor savings or production downtime savings are achievable
Pneumatic or electric actuators?
Electric Actuator Performance
Characteristics • Trade speed for thrust and thrust for speed
• Accurate sizing is critical o Over sizing is expensive
o Under sized actuators will not perform
o Force and speed limits are locked in by design
• Precise control and positioning
• Adapt machines to flexible processes
• “Portable” – install anywhere electric power is available
• More complex to implement
Pneumatic or electric actuators?
• High unit cost
• High replacement cost o Modular designs help minimize replacement costs
o Mechanical wear parts – 3 year life
o Electrical components – 5 to 10 year life
• Low power consumption
• Flexibility can yield cost savings o Eliminate costly downtime
o Eliminate time consuming change-overs
o Not automatic – needs to be designed in
• Best scenario o Smaller scale deployment
o Effects process improvements or cost savings through automation
Pneumatic or electric actuators?
Electric Actuator Costs
Cost of Electricity • Average retail price: 9.74 cents per kilowatt-hour (kWh)
o Residential: 11.3¢ per kWh
o Transportation: 10.7¢ per kWh
o Commercial: 10.4¢ per kWh
o Industrial: 6.8¢ per kWh
• Highest average price of electricity: o Hawaii (29.20¢ per kWh)
o Connecticut (16.95¢ per kWh)
o New York (16.74¢ per kWh)
• Lowest average price: o West Virginia (5.59¢ per kWh)
o Wyoming (5.68¢ per kWh)
o Idaho (5.70¢ per kWh)
Pneumatic or electric actuators?
Compressor Sizing Calculator
Inputs: o Average bore size
o Average stroke length
o Average time for stroke
o Number of cylinders
o % of cylinders that actuate simultaneously
Output: o CFM required
o Find compressor HP using the CFM number and the manufacturer’s specifications
Pneumatic or electric actuators?
Case Study
Pneumatics over Electrics • Pneumatic solution
o 200 HP compressor
• 2,000 hours per year at full load, 93% efficiency ($0.10/kWh)
• When not in use it is off
o 150 pneumatic actuators deployed
• Average unit cost: $50
• Life expectancy: 3 years
• Electric solution o 150 electric actuators deployed
• All-in-one design: includes driver and controller but not DC power supply
• Average unit cost: $1,200
• Life expectancy: 3 years
o Actuator draws 6A fully loaded at 48 VDC; fully loaded 30% of the time
o Actuator draws 3A at 48 VDC 70% of the time
o Power supplies draw 6A at 120 VAC fully loaded, producing 9A at 48 VDC
Pneumatic or electric actuators?
Case Study
Pneumatics over Electrics • Pneumatic solution
o Annual cost of compressed air: $42,237
o Replacement cost of actuators: $2,500 per year
o Total annual cost: $44,737
o Total annual cost per actuator: $298
• Electric solution o Annual cost at full load: $4,320
o Annual cost at idle: $5,040
o Annual operating cost: $9,360
o Replacement cost of actuators: $60,000 per year
o Total annual cost: $69,360
o Total annual cost per actuator: $462
Pneumatic or electric actuators?
Case Study
Pneumatics over Electrics
Pneumatic or electric actuators?
Pneumatic Costs Electric Costs
Electrics over Pneumatics • Pneumatic solution
o 100 HP compressor
• 2,000 hours per year at full load, 90% efficiency ($0.10/kWh)
• When not in use it is idling at 25% power and 85% efficiency
o 20 pneumatic actuators deployed
• Average unit cost: $50
• Life expectancy: 3 years
• Electric solution o 20 electric actuators deployed
• Modular: Motor/actuator and separate controllers
• Average unit cost: $900 for actuator and $1,200 for electronics
• Life expectancy: 3 years for actuators, 10 years for electronics
o Actuator draws 6A fully loaded at 48 VDC; fully loaded 30% of the time
o Actuator draws 3A at 48 VDC 70% of the time
o Power supplies draws 6A at 120 VAC fully loaded, producing 9A at 48 VDC
o Process improvement: Automates a line change
• Saves 2 hours every week for 2 employees at $30/hr each
• Saves 2 hours of lost production: 100 products/hr, $1 per product
Pneumatic or electric actuators?
Electrics over Pneumatics
• Pneumatic solution o Annual cost of compressed air: $21,882 full load
o Annual cost of compressed air: $19,351 at 25% power
o Replacement cost of actuators: $333 per year
o Total annual cost: $41,506
o Total annual cost per actuator: $2,075
• Electric solution o Annual cost at full load: $576
o Annual cost at idle: $672
o Annual operating cost: $1,248
o Replacement cost of electronics: $2,400 per year
o Replacement cost of actuators: $6,000 per year
o Total annual cost: $9,648
o Savings, changeover labor: $6,240
o Savings, lost production: $10,400
o Net results of deployment: $6,992 COST REDUCTION!
Pneumatic or electric actuators?
Case study
Electrics over Pneumatics
Pneumatic or electric actuators?
Pneumatic Costs Electric Costs
Bimba now features a Pneumatic versus Electric Actuator
cost evaluation spreadsheet, which is available for download
from bimba.com
This spreadsheet allows a person to estimate pneumatic and
electric costs, facilitating a comparison and selecting the
correct actuator depending upon the application
Cost Evaluation Calculator
Thank you for attending!
Bimba.com
800-44-Bimba
Questions?
Design World Paul Heney [email protected] Phone:440.234.4531 Twitter:@wtwh_fluidpower
Bimba Manufacturing Bob Kral [email protected] Phone: 708.235.2067
Thank You
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