Spec Sheet

Page 6
Hard Start kits vs. SureStart
Off-the-shelf products, such as a hard start kit, are
available for service technicians to install on an air
conditioner to solve the light fl icker problem. It is
relatively low cost and simple to install to attempt
to satisfy the homeowner complaints. As previously
mentioned, hard start kits are a simple device that is
used to provide a boost to the compressor to start it
faster. It does not reduce the in-rush current, therefore
does not eliminate problems created by high in-rush
current. A hard start also adds additional stress; hence
the name “hard start”. Compressors contain mechanical
moving parts and like most mechanical parts don’t
respond well to extra stress. When hard starts are used
the startup torque is increased which reduces life of
the compressor. In contrast, SureStart provides optimal
mechanical advantage keeping torque at a minimum;
therefore, improving long term reliability.
Other Compressor Starting Technologies
Conventional soft start philosophy adopts a simple
voltage reduction to contain this large starting current.
This begins by ramping up the input from say 30 % to
full voltage in a fi xed time interval. This, however badly
impacts the starting torque. So, under heavily loaded
conditions, the motor might stall. This implies poor
effi ciency during starting. In any case, this simplistic
solution will not reduce the staring current by more
than 30 to 40% and light fl icker is not reduced due to a
signifi cantly increased start time.
Before
Locked Rotor Amperage (LRA)
After
Using SureStart
M Pos: 150.0ms
CH1
Coupling
BW Limit
20MHz
Volts/Div
Probe
100X
Voltage
Invert
DC
On
Coarse
Off
M 50.0ms
CH4 50.0A
B
W
CH4 / 24.0A
<10Hz
Acq Complete
Ɣ
4
Tek
M Pos: 150.0ms
CH1
Coupling
BW Limit
20MHz
Volts/Div
Probe
100X
Voltage
Invert
DC
On
Coarse
Off
M 50.0ms
CH4 50.0A
B
W
CH4 / 24.0A
<10Hz
Acq Complete
Ɣ
4
Tek