Energy and Cost Savings with the
CENTERLINE 2500
2 | Energy and Cost Savings with the CENTERLINE 2500
Energy and Cost Savings with the
CENTERLINE 2500
Industry
Overview
The goals for any commercial and industrial processes are simple: minimize overall costs
and enhance efficiency. To achieve these goals in the field, processes must be
performed by efficient systems that waste less energy, which in turn translates into cost
savings. Motor Control Centers (MCCs) occupy a prominent role in dissipating energy
and thus reducing the amount of power loss is essential for economic savings. For
example, consider a 2500 A, 480 V MCC which draws 960 kW at 80% efficiency. At
$0.10/kWh the MCC will use about $96/h in energy. Furthermore, if the MCC runs 2
shifts per day (roughly 16 hours) for 280 days per year, the total cost of energy amounts
to $430,080. The total energy consumed by an MCC can be over 5 times the average
purchase price each year!
The CENTERLINE 2500 Motor Control Center outshines its competitors due to its proven
busbar design. With a larger busbar cross-sectional area, the CENTERLINE 2500
decreases resistance and power loss more efficiently than its leading competitors. The
reduction in power loss can lead to savings of up to 3% of the purchase price of the MCC
each year.
Larger busbar crosssectional area with
the CENTERLINE
2500
Decrease in
Resistance
Reduces
Power Loss
Results in cost
savings for you!
This paper focuses on comparing cost savings with Rockwell Automation’s CENTERLINE
2500 MCC in relation with leading competitors in the industry through analysis of
busbar cross-sectional area, resistance, power loss and cooling costs.
MCC
Busbars
Excessive power loss and heat dissipation due to high busbar resistance called for the
need to create busbars with larger cross-sectional area. Larger cross-sectional area
lowers resistance, decreases heat dissipation, reduces power loss and conclusively
results in cost savings for the user.
Hence, the questions for today’s users are:
• What are the advantages of having a CENTERLINE 2500 MCC with a
comparatively large busbar cross-sectional area vs. its competitors?
• How can the larger cross-sectional area help reduce costs?
The following sections cover these topics and highlight some issues that users must
consider for an efficient MCC system.
3 | White Paper title here
Key Issues To Consider When Evaluating Power Usage of an MCC
CrossSectional
Area
The CENTERLINE 2500 surpasses its competitors due to its unique busbar design. With a
relatively larger cross-sectional area, the CENTERLINE 2500 MCCs reduce busbar
resistance more efficiently than its competitors. For example, a 2500 A rated busbar of
the CENTERLINE 2500 MCC has an area of 2000 mm² which equivalent to a 3200 A rated
busbar of Siemen’s Sivacon S8. Table 1 shows that even at a lower ampacity, namely a
22% decrease in ampacity for this example, the CENTERLINE 2500 MCCs have a
relatively larger cross-sectional area which is a significant contributor in reducing
resistance.
Table 1 displays cross-sectional area data for Rockwell Automation and its competitors.
CENTERLINE 2500 (Rockwell)
Current (A) X-sect Area (mm²)
1250
600
2500
2000
4000
4000
MNS (ABB)
Current (A) X-sect Area (mm²)
1500
600
3000
2400
3400
2400
Sivacon S8 (Siemens)
Current (A) X-sect Area (mm²)
1560
600
3200
2000
4000
3000
Blokset (Schneider)
Current (A) X-sect Area (mm²)
1500
625
2550
1250
4100
3125
Table 1: Cross-sectional data for Rockwell Automation and competitors
The larger busbar cross-sectional area in the CENTERLINE 2500 also reduces the current
per area ratio. As shown in Graph 1, the CENTERLINE 2500 busbars proves to be the
lowest in current per area ratio as compared to its competitors.
4 | Energy and Cost Savings with the CENTERLINE 2500
Graph 1: Current per area ratio for Rockwell Automation and competitors
Resistance
A larger cross-sectional area reduces the amount of resistance within a busbar and
consequently reduces I²R losses. The CENTERLINE 2500 exhibits this quality since it has
the largest busbar cross-sectional area compared with leaders in the industry. Hence,
the lower resistance of the CENTERLINE 2500 busbar system in relation with its
competitors leads to a reduction in power loss.
Shown below in Table 2 is the resistance and voltage data for Rockwell Automation and
the leading competitors.
CENTERLINE 2500 (RA)
Current
(A)
Resistance (mΩ)*
1250
0.224
2500
0.067
4000
0.034
MNS (ABB)
Current
(A)
Resistance (mΩ)*
1500
0.224
3000
0.056
3400
0.056
5 | White Paper title here
Sivacon S8 (Siemens)
Current
(A)
Resistance (mΩ)*
1560
0.224
3200
0.067
4000
0.045
Blokset (Schneider)
Current
(A)
Resistance (mΩ)*
1500
0.215
2550
0.108
4100
0.043
Table 2: Resistance and voltage data for Rockwell Automation and competitors.
*Data is based on 8 m long busbar
The CENTERLINE 2500 maintains the least amount of resistance as compared to other
competitors which is essential for reducing power loss and sustaining an efficient
system.
Graph 3: Resistance for Rockwell Automation and competitors
Heat
dissipation
and Power
In addition to cutting down resistance, the larger busbar cross-sectional area in the
CENTERLINE 2500 contributes to lowering the amount of power loss. Consider this
example: a 4000 A busbar with Siemens Sivacon S8 has a power loss of 716 W. At an
equivalent ampacity, the CENTERLINE 2500 dissipates only 538 W of power and thereby
decreases the power loss by 25%. Furthermore, a 3400 A busbar with ABB’s MNS low
voltage switchgear series dissipates roughly 647 W of power. Even when compared to a
busbar with lower ampacity, the CENTERLINE 2500 reduces the power loss by 16.8%!
The decrease in power loss is a strong indication of the efficiency of the CENTERLINE
2500.
6 | Energy and Cost Savings with the CENTERLINE 2500
The larger bus cross-sectional area of the CENTERLINE 2500 also results in lower heat
dissipation. Due to the reduction in current per area ratio, the CENTERLINE 2500
dissipates less heat than its competitors. Consequently, the amount of wasted energy is
reduced. This is the foundation for an efficient busbar system which produces less heat
while ultimately reducing the amount of power loss.
Table 3 displays current and power data for Rockwell Automation and its competitors.
CENTERLINE 2500 (RA)
Power Loss
Current (A)
(W)*
1250
1,050.00
2500
1,260.00
4000
1,612.80
MNS (ABB)
Power Loss
Current (A)
(W)*
1500
1,512.00
3000
1,512.00
3400
1,942.08
Sivacon S8 (Siemens)
Power Loss
Current (A)
(W)*
1560
1,635.38
3200
2,064.38
4000
2,150.40
Blokset (Schneider)
Power Loss
Current (A)
(W)*
1500
1,451.52
2550
2,097.45
4100
2,168.89
Table 3: Power loss data for Rockwell Automation and competitors.
*Data is based on 3 busbars
Table 4 displays the percent increase in power loss at various ampacities for the leading
competitors compared with the CENTERLINE 2500 based on busbar size. The
competitors lag in reducing power loss as efficiently as the CENTERLINE 2500.
Percent Increase
MN
Current (A)
S
Sivacon S8
1200
44%
56%
2500
20%
64%
3400
20%
33%
Blokset
38%
66%
34%
Table 4: Percent increase in power loss of competitors compared with the CENTERLINE 2500
As shown below in Graph 4, the CENTERLINE 2500 has the lowest power loss when
compared to leading competitors.
7 | White Paper title here
Graph 4: Power loss for Rockwell Automation and competitors
Cost Comparison
Financial
Savings
Financial savings and efficiency are important factors for operating and maintaining
Motor Control Centers. The data shown above confirms that the CENTERLINE 2500 MCC
is the most efficient system as it has the least amount of power loss compared with
other MCCs in its class. This reduction in power loss ultimately results in cost savings for
the consumer.
Consider a typical scenario where a 2500 A MCC is desired to run at 80% efficiency for
16 hours/day for 280 days. At $0.10/kWh, the cost of energy and power loss is as
follows in Table 5:
MCC
CENTERLINE
2500
Current
(A)
Power loss
(kW)
Cost per hour
($)
Annual cost
($)
%
Increase
2500
1.26
0.13
564.48
MNS
3000
1.51
0.15
677.38
20%
Sivacon S8
3200
2.06
0.21
924.84
64%
2550
2.10
0.21
939.66
66%
Blokset
Table 5: Annual cost of power loss with CENTERLINE 2500 and competitors
As shown, the increase in power loss leads to an increase in total annual cost for
operating the MCC. Over time, these costs amount to significant values which lead to a
decrease in productivity and excessive costs. For example, the total cost from power
loss would be 20% higher with ABB’s MNS, 64% higher with Siemen’s Sivacon S8 and
66% higher with Schneider’s Blokset for equivalent bus sizes. The total cost of power
loss with the CENTERLINE 2500 is considerably lower than the competitors, helping to
cut costs and increasing efficiency when compared to any of its major competitors.
Note: Industry standards note that an increase in temperature of as little as 10º C cuts
8 | Energy and Cost Savings with the CENTERLINE 2500
electrical component life in half.
Assumptions
for cooling (if
applicable)
Motor Control Centers placed in enclosures generally require a cooling system to
control the heat generated from the power loss. Therefore, utilizing installed airconditioning units generate additional costs. For example: an air-conditioning unit runs
at 20% efficiency and costs $0.10/kWh to control heat dissipation within an enclosure.
For the 2500 A MCC used in the previous example, the air-conditioning energy loss
would cost the following:
MCC
CENTERLINE
2500
MNS
Sivacon S8
Blokset
Current
(A)
AC energy loss
(kW)
2500
3000
3200
2550
6.30
7.55
10.30
10.50
Cost per
hour ($)
0.63
0.76
1.03
1.05
Annual Cost
($)
%
Increase
2822.40
3382.40
4614.40
4704.00
20%
63%
67%
Table 6: Annual cooling costs with CENTERLINE 2500 and competitors
The annual cost of running a cooling system can be significantly reduced by the
CENTERLINE 2500, saving thousands of dollars over time. In this example the MCC
analyzed has a purchase price of $80,000. Thus, the resulting savings are 2 to 3 percent
of the MCC purchase price per year.
Raw Data and Additional Busbar Information
Rockwell
Automation
The following is cross-sectional area data for Rockwell Automation’s CENTERLINE 2500.
Rating
800A
1250A
1600A
2000A
2500A
3200A
4000A
Quantity /Size
(1) – 3mm x 100mm
(1) – 6mm x 100mm
(2) – 6mm x 100mm
(1) – 6mm x 100mm
(1) – 10mm x 100mm
(2) – 10mm x 100mm
(3) – 10mm x 100mm
with 10mm spacers
(4) – 10mm x 100mm
with 10mm spacers
9 | White Paper title here
Shown below are busbar connections of the CENTERLINE 2500.
800 A – 1250
A
ABB
1600 A – 2500
A
3200 A
The following is cross-sectional area data for ABB MNS.
Rating
1500
2100
3000
3400
Quantity /Size
(2) - 10mm x
30mm
(2) - 10mm x
60mm
(4) - 10mm x
60mm
(4) - 10mm x
60mm
Shown below is a cross-section of ABB MNS’s horizontal and vertical busbar system.
Siemens
The following is cross-sectional area data for Siemens’ Sivacon S8.
Rating
1560
2180
3200
4000
Quantity /Size
(1) - 10mm x 60mm
(1) - 10mm x 100mm
(2) - 10mm x 100mm
(3) - 10mm x 100mm
(3) - 10mm x 100mm (set of
7400
2)
10 | Energy and Cost Savings with the CENTERLINE 2500
Shown below is a typical layout of horizontal busbar systems of the Sivacon S8.
Schneider
The following is cross-sectional area data for Schneider’s Blokset.
Rating Quantity /Size
Single Busbars
1500 (1) - 5mm x 125 mm
2550 (2) - 5mm x 125 mm
3250 (3) - 5mm x 125 mm
3800 (4) - 5mm x 125 mm
4100 (5) - 5mm x 125 mm
Double Busbars
6000 (4) - 5mm x 100 mm (set of 2)
6600 (5) - 5mm x 100 mm (set of 2)
Shown below is the layout of horizontal busbar systems of the Blokset.
11 | White Paper title here
Summary
Findings/
Conclusion
Compared with competitors, the busbars of CENTERLINE 2500 MCC have a larger crosssectional area which allows a reduction in resistance. As resistance lessens, power
losses decreases along with it. As a result, the CENTERLINE 2500 not only offers a more
efficient system but also provides cost savings, in terms of power losses and cooling
costs, for the end user compared with leading competitors such as ABB, Siemens and
Schneider.
Larger busbar
cross-sectional
area with the
CENTERLINE 2500
Decrease in
Resistance
Lowers
Power Loss
Results in cost
savings for
you!
12 | Energy and Cost Savings with the CENTERLINE 2500
Resources
Please contact the following companies for more information.
Rockwell Automation
Mike Host
CENTERLINE 2500 Product Marketing Manager
nd
1201 S. 2 Street
Milwaukee, WI 53204
414-382-3441
http://ab.rockwellautomation.com/Motor-Control/Motor-Control-Centers/IEC-CENTERLINE-2500
Publication 2500-WP001A-EN-P – January 2012
Copyright ©2012 Rockwell Automation, Inc. All Rights Reserved. Printed