bonitron M3645P, Reference Manual

Page: 52 / 56

M3645P
52
7.1.2.
C
ALCULATING
E
NERGY
S
AVINGS
The regen directs energy from the mechanical load to the power distribution
line, where the energy is available to other connected loads. These units
provide system energy savings over dynamic braking kits, because the net
energy required from the distribution system is reduced by the regenerated
energy. Additional savings also come from the lack of a need to provide air
conditioning with a dynamic braking kit and from reduced time spent stopping
loads.
To calculate the savings, the regeneration duty cycle, the length of operation,
the regen HP, and the cost of energy must be known. With these application
variables, the following calculation may be made to determine the cost
savings:
C
ALCULATE
S
AVINGS
P
ER
Y
EAR
Calculating total savings per year in dollars:
𝑆 =
𝐶𝑃(0.746
𝑘𝑊
𝐻𝑃
)𝐷𝐻𝑡
𝑜𝑛
𝑡
𝑐𝑦𝑐𝑙𝑒
Where
S is Savings per year.
C is the cost in dollars per kW.
P is the regenerated power.
D is the number of days the system is operated.
H is the number of hours per day the system is operated.
t
on
is the number of seconds per cycle T power is regenerated.
t
cycle
is the total time to complete a cycle.
S
AVINGS
E
XAMPLE
Assume the following values for this example:
C = $0.11 per kW
P = 20HP peak, 15HP average during deceleration
D = 365 days
H = 10 hours per day
t
on
= 5 seconds regen is on
t
cycle
= 15 seconds
Savings:
𝑆 =
($0.11/𝑘𝑊)(15𝐻𝑃)(0.746
𝑘𝑊
𝐻𝑃
)(365𝑑𝑎𝑦𝑠)(10ℎ𝑜𝑢𝑟𝑠)(5𝑠)
(15𝑠)
𝑆 = $1497.60