Greenheck Fan Centrifugal Roof Downblast Exhaust Fans GB - Manual (Page 8)

8
Vari-Green ® Motor Option
Model G
Greenheck’s electronically commutated (EC)
Vari-Green (VG) motor combines motor
technology, controllability and energy-efficiency
into one single low maintenance unit and is the
industry’s first fully controllable motor. When combined
with Greenheck’s G fans, all the CFM and static
pressure ranges of a belt drive can be attained with the
benefits of a direct drive.
Benefits
Operates on AC power that’s converted to DC—
providing a more efficient motor operation as compared
to an AC operation.
• The motor can attain up to 85% efficiency and
reduce energy consumption.
• Watt savings of 30-70% depending on RPM.
Note: As motor speed is turned down, efficiency stays high
as compared to an AC motor that decreases dramatically.
• Operates cooler than a standard AC motor at lower
RPMs. A cooler motor has longer motor life and
reduces energy consumption.
• 80% usable RPM turndown versus 30%, see Motor
Turndown Comparison chart at right.
• G fans with Vari-Green motors can provide all the
CFM and static pressure ranges of a comparable
belt drive.
• Maintenance costs are reduced as there are
no belts or bearings to replace and no pulleys
to adjust.
• Direct drive fans are often preferred where
maintenance access is difficult.
• Provides a solution for demand controlled ventilation
applications.
Vari-Green Advantages
• Initial cost is similar to a belt drive
• Lower operating cost
• No maintenance, no belts, pulleys or bearings
• Easy RPM adjustment
8
600
500
400
300
200
100
0
0 350
50% 75% 100%
1750 FAN SPEED (RPM)
INPUT POWER (W
A
TTS)
Energy
Savings
G-123
with PSC
Not recommended
GB-123
Single Phase*
G-123 with
* GB is a belt driven fan
E E
S
S
The length of each curve indicates the practical turndown range.
Data is for 1/2 hp motors with load of 0.35 Bhp at full speed
Motor Turndown Comparison
Features
1. Dial on Motor Control - a potentiometer (dial on
motor control) is mounted on the motor for easy
speed adjustment for system balance. Simply turn
the dial. There are no belts and pulleys to adjust.
2. Control Wire Inputs - the motor accepts a
0-10V DC signal from Building Automated
Systems or other controls to adjust
motor speed.
1 2 1
®
Comparisons: Belt, Direct Drive with PSC
and Direct Drive with Vari-Green
Analysis is based on operating costs for a period of three years where
the fans operate continuously at 1725 rpm, 24/7, with an energy rate
of $0.10/kWh. Maintenance on the GB-121 is estimated at $65/yr.
Note: Example is based on a relative cost. Use and installation
variables may produce different results.
$ 2,000
1,750
1,500
1,250
1,000
750
500
250
$ 0
CUBE-
121
Three Year Cost Comparison
Initial Cost
Maintenance cost over three years
Operating cost over three years
CUE-
121-A5
CUE-
121-VG
Constant Volume Life Cycle Analysis
GB-
121 G-
123-A5
G-
123-VG
Motor Information
HP RPM Volts Phase FLA Enclosure
1/6 1725 115 Single 3.1 TENV
1/4 1725 115 Single 3.9 ODP
1/2 1725 115 Single 6.2 ODP
1/2 2500 115 Single 6.5 ODP
3/4 1725 115 Single 10.1 ODP
3/4 2200 115 Single 11.3 ODP
1 1725 115 Single 12.4 ODP
1 1725 115/208-230 Single 12.0/6.0 TEFC
2 1725 208-230 Single 12.0 TEFC