ENERGY SAVINGS THROUGH POWER CONDITIONING WITH
THE USES® SHUNT EFFICIENCY SYSTEM
Abstract
Efficient operation of the electrical system of any facility is essential to controlling
operational costs while maximizing the performance of motors and electronic equipment
and minimizing equipment downtime. Poor power factor and high levels of total
harmonic distortion in the current and voltage of an electrical circuit result in wasted
power as the result of motor and transformer inefficiencies, copper losses and heat.
Poor power quality also affects the reliability of electrical equipment, resulting in higher
maintenance and repair costs. Utility providers are increasingly charging penalties for
poor power quality which, together with steadily rising energy rates, result in higher
operating costs.
In 1992, a patent was issued to the USES Manufacturing Company of Quaker Hill, CT
(U.S. Patent #5,105,327) for a revolutionary new type of power conditioning system.
The USES® Shunt Efficiency System provides a new and innovative approach to
electrical circuit protection, power factor correction and the reduction of harmonic power
on the circuit. The USES® system improves overall power quality in three principal
ways, each accomplished through coupling of the three phases of power:
1. It provides effective spike and surge protection, including protection against
lightning strikes, ground faults and transients. It does this in a superior fashion to
conventional Transient Voltage Surge Suppression (TVSS) systems by shunting
the electrical disturbance to all three phases and absorbing the disturbance
through magnetic chokes.
2. It corrects Power Factor in a fundamentally different way than Power Factor
Correcting Capacitors by using transformers to generate current which is fed to
the opposite phases in a way which cancels out reactive power. The USES®
system does not create dangerous resonance, making it a much more
advantageous power factor correction system than capacitors.
3. It reduces the total harmonic content of the circuit by taking some power off the
circuit to generate an equal amount of new power through the transformers. The
power delivered by the USES® system is free of harmonics because the power is
delivered through band-pass filters which filter the power to 60 hertz.
As a result of these actions, each USES® 480 volt unit will reduce the demand for
electricity by between 13,140 and 26,280 kilowatt-hours (kWh) per year while reducing
reactive power by approximately 22 KVAR. Additionally, amperage is reduced and
voltage is increased on each phase. One USES® 480 volt unit is specified for each
30,000 kWh/month or for each 85 amps (see sizing chart below). Typical facility
installations require multiple units.
This unique, sole-source system combines the benefits of power factor correction with
harmonic filtering and superior surge and spike protection, all in one compact power
conditioning system. There is no other product on the market that corrects power
factor, filters harmonics or absorbs spikes and surges in a similar manner as this
system. Because of this, the USES® system results in the reduction of the demand and
consumption of real power on the circuit which goes beyond that which is possible with
power factor correcting capacitors alone.
USES® Power Factor Correction
With the USES® system, capacitive reactive power is not generated by capacitors but is
the product of transformer action inherent in the design of the USES® device. The
system couples the three phases of power supply using transformers coupled to 60Hz
band-pass filters. The transformers develop current in phase with one phase, and
deliver the current simultaneously to the second and third phases. The delivered
current assumes the properties of capacitive reactive power and cancels out an equal
amount of inductive reactive power. The amount of capacitive reactive power
generated by the USES® product is dependent on the circuit voltage and model
specified. Because the USES® system does not rely on the design of capacitors to
generate its capacitive reactive current, problems associated with resonance are
avoided.
USES® Current
generated in
phase with Phase
#1….
…is delivered
simultaneously
to Phase #2….
2
…and to Phase
#3, thus
canceling out
Reactive Power.
USES® Harmonic Filtering
By coupling the transformers with 60Hz band-pass filters, the USES® system supplies
capacitive reactive current which reduces the harmful effects of harmonics. In a
properly sized system application, over thirty percent of the current on the circuit will be
free of harmonics, reducing the total harmonic current and total harmonic voltage on the
circuit. The reduction of harmonics results in added efficiency of motors and
transformers while minimizing the harmful effects of harmonic distortion.
USES® Spike & Surge Protection
The USES® system incorporates Metal Oxide Varistors (MOVs) and other electronics to
protect the electrical circuit against electrical spikes and surges, transients, ground
faults and lightning strikes. By shunting these disturbances from one phase to all three,
and then channeling them through the transformers and band-pass filters, these
disturbances are absorbed by the device and circuit protection is accomplished without
shunting power to neutral. Unlike TVSS systems which only suppress voltage surges
above a certain “clamping” voltage, the USES® system absorbs both voltage and
current spikes and surges, providing additional circuit protection.
Typical Sizing for the USES® Shunt Efficiency System
This system is sized to a specific circuit configuration to maximize its performance
relative to power factor correction, energy savings potential and/or circuit protection.
There are two configurations of the system for each voltage; a delta configuration and a
wye configuration. The wye configuration provides additional circuit protection of the
facility neutral conductor against transient voltage spikes and surges, ground faults and
lightning strikes. Typically, one wye configured unit is installed for each neutral
conductor.
Voltage
Model
# Units/Amps
KVAR Reduction
KW Demand Reduction
208 VAC
208 VAC
480 VAC
480 VAC
600 VAC
600 VAC
CMES-3Y-208
CMES-3D-208
CMES-3Y-480
CMES-3D-480
CMES-3Y-600
CMES-3D-600
1 per 100 amps
1 per 100 amps
1 per 85 amps
1 per 85 amps
1 per 100 amps
1 per 100 amps
5-6
10-12
10-12
21-23
21-23
42-44
0.37 - 0.75 kWh/hr/unit
0.75 - 1.5 kWh/hr/unit
0.75 - 1.5 kWh/hr/unit
1.5 - 3.0 kWh/hr/unit
1.5 - 3.0 kWh/hr/unit
3.0 - 4.5 kWh/hr/unit
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Performance Examples
The USES® system produces easily measured and verifiable results. Each unit is
connected through a 3-pole, 40-amp circuit breaker or equivalent fused disconnect,
allowing the unit to be switched on and off at intervals of 5, 10 or 15 minutes. The
following performance results were measured using an Amprobe DMII-Pro multi-meter
and data logger. This meter is NIST-certified and collects a reading every one-second.
Graph #1 – Wattage and Power Factor
W
Power Factor/kW Demand
0.98
110,000
0.97
105,000
100,000
5930 watt
instantaneous
reduction
95,000
0.96
0.95
0.94
0.93
0.92
90,000
0.91
85,000
0.9
80,000
1:00:00
Power Factor - 3Ø ([PF])
0.88
0.87
70,000
0.86
60,000
USES ON
PM
0.89
75,000
65,000
USES OFF
[PF]
115,000
0.85
0.84
0.83
Real Power - 3Ø (W)
Graph #1 shows the effects of two (2) USES® model CMES-3D-480 volt units at a
wastewater treatment plant in New Jersey. The blue line shows power factor which
improves from 85% to 99% when the USES® system is switched on. The green line
shows real power in watts and shows a 5930 watt (5.93 kW) instantaneous demand
reduction when the USES® system is switched on.
Graph #2 – Voltage, 3-Phase
V
468
Voltage, Three Phases
467
466
465
464
463
462
USES OFF
USES ON
12:30:00 PM
RMS Voltage - VA B (V)
RMS Voltage - VBC (V)
4
RMS Voltage - VCA (V)
Graph #2 shows the effects of two (2) USES® model CMES-3D-480 volt units at a
sludge processing facility in Bronx, NY. Significant voltage fluctuations are caused by
the facility’s Variable Frequency Drive (VFD) control system. When the USES® system
is switched on, there is an increase in voltage on each phase and a 12% reduction in
standard deviation between the three phases.
Graph #3 – Reactive and Apparent Power
Reactive & Apparent Power
USES OFF
USES ON
VAR
VA
400,000
650,000
350,000
600,000
300,000
550,000
250,000
500,000
200,000
450,000
150,000
100,000
9:00:00 AM
10:00:00 AM
11:00:00 AM
A pparent P ow er - 3Ø (V A )
12:00:00 PM
400,000
50,000
350,000
0
300,000
1:00:00 PM
Reactiv e P ow er - 3Ø (V A R)
Start: 8/23/2007 8:30:01 AM End: 8/23/2007 1:36:06 PM
Main Switch Gear
Graph #3 shows the effects of twelve (12) USES® model CMES-3D-480 volt units at a
wastewater treatment plant in Maine. The green line shows apparent power while the
red line shows reactive power. Reactive power is reduced by 247 KVAR while apparent
power is reduced by 87 KVA when the USES® system is switched on.
Graph #4 – Amperage, 3-Phase
USES OFF
USES ON
Amperage, 3-Phase
A
220
215
210
205
200
195
190
185
180
175
170
165
160
155
150
145
140
135
130
10:00:00 AM
10:10:00 AM
10:20:00 AM
RMS Current - IA (A )
10:30:00 AM
RMS Current - IB (A )
Start: 3/20/2008 9:55:02 A M End: 3/20/2008 10:59:39 A M
480 B Bus, West Wing, 032008
5
10:40:00 AM
RMS Current - IC (A )
10:50:00 AM
Graph #4 shows the effects of four USES® model CMES-3D-480 volt units at a hospital
in upstate NY. Amperage on each phase is reduced by about 55 amps when the USES
system is switched on.
Conclusion
The USES® Shunt Efficiency System presents a new, innovative way to correct several
different power quality problems in one package. The system has the potential to
reduce kilowatt demand beyond that which can be achieved through power factor
correction alone. This is accomplished by improving power factor while reducing
harmonics and increasing the efficiency of motors and transformers. The system also
acts to protect the facility from the damaging effects of spikes, surges, transients,
ground faults and lightning strikes.
For more information on the USES® Shunt Efficiency System, contact POM Energy
Concepts, Inc. at 866-350-4378. POM Energy Concepts offers a no-cost proposal,
baseline power quality check and performance testing, as well as a guaranteed return
on investment. The USES® system is UL listed and comes with a full 5-year warranty.
POM Energy Concepts is a sole-source distributor for the USES® system.
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