Heart Interface HF12-1200 - Page 7

as much
power.-This
inductive
surgemust
be taken in to
account
when figuring
what
will
operate
on
the
Hearr.{ good
rule
of thumb
is
to figure
that your
HFl2-i260
wiil
operare
a
1/3 horsepowerinductive
motor.
Capacitor-start
motors
require
the minimum
surge
ro
ger
started
and are therefore
recommended
when possible.
THE LOAD DETBCTION
CIRCUIT:
Your
Heart
features
a
unique
load detection
circuit
that
allows it
to be left
on
and to
draw
very
little
power
if it
is not
actually
operating
any
loads.
This
circuit is automatic
and
virtually
instantaneous.
While in
idle
or no-load
the
unir
draws
about 65 milliamps
(.065
amp) from
the
battery bank
and
is putting
out
about
50 volts
RMS.
This
will typically
be measured
as 20-30
volts
on an
averaging
uott
merer.
The
load detection
circuit
is set
to
detect
a
7.5 wan
load.
If you
arrempt
to operare
an
appliance
which
draws
less
than
7.5 watts you
will
have
to run
an additional
load
simulta-
neously
to
insure
that the
Heart will
come
out of idle.
Oc-casionally
a small inductive
load
that
draws
around
?.5
watts
will f
ail
to
bring the
unit
out
of idle. An example
might
be an electric
shaver. If
this
happens you
musr
simplf
operate
a
resistive
load in conjunction
with
the
shaver.
A l5
watt tighi
Uutli will
be
enougli to force
the
unit
out of idle if
you
are running
a
very
small inductivE
load.
THE
PROTECTION
CIRCUITS:
The
Heart
has 4levels
of
protection
against
overloads
and
ground
faults,
and a
circuit
which
protects
against
excessively
high
or low
banery
voltage.
OVERLOAD
PROTECTION:
There
is
a very
fast
orrerload
protection
circuit
in
the
Heart
to
protect
against
short
circuits.
This is
activated
if
there
is
a short
circuit
in your
wiring
ot
if you
aitempt
ro
srart
a
large-induction
motor
in
excess
of
the
surge
rating
bf
the
Heait. The
overload protection
circuit
is indicated
by the
overload
LED
on
the front
of the
unit. This
LED
will
light
green
if
an
overload
condition
occurs.
The
overload
circuit
will
quickly
shut
down the
output
of
the
Heart
when
activated.
If
the
short
circuit
or inductive
overload is
removed
within
l0
seconds,
the
unit
will
automati-
cally reset
and
continue
normal
operation.
If
the
overload
condition pqrsiqtg
lor
more
than
10
seconds
the
unit will
completely
turn
itselfoff,
leaving
the greel
ovirload
LED_shining.
If
this situation
occurs
you
,nurt
discover
and
eliminate
the cause
of the
overload.
Once
the
overload
is
removed,
yL,
*uy
restart
the
Heart
by turning
the
power
switch
off,
pausing
a momenr,
and
ttren
swi"tctringlt
Uack
on.
CIRCUIT
BREAKER
PROTECTION:
..- T!"
10
ampcircuit
breaker
on the
front
of
the Heart
is
a relatively
slow
breaker
which
will
allow
the
unit to provide
ample
power
to
starr inductive
loads.
6