Carrier SUPRA 750Mt - Figure 2-8 Auto Start Sequence

2-25
on.
A
15
sec
ondnull
cyc
le
wil
l
ela
pse
befo
re
sub
seq
uen
t
start attempts. The run relay will remain energized until
the next starting sequence.
Befo
re
the
nex
t
start
ing sequen
ce,
the
oil pressur
e
al
ter
na
tor
au
xil
ia
ry
ou
tpu
t
is
che
ck
ed
to
in
su
re
tha
t
the
en-
gi
ne
is
no
t
run
ni
ng
.
For
the
se
con
d
an
d
thi
rd
sta
rt
att
em
pts
th
e
gl
ow
ti
me
is
in
cr
ea
se
d
by
5
se
co
nd
s
ov
er
th
e
gl
ow
ti
me
of the first attempt listed below. The control allows three
co
ns
ecu
tiv
e
sta
rt
att
em
pts
be
for
e
the
sta
rti
ng
is
lo
ck
ed
ou
t
and the start failure alarm is activated.
MAXIMUM
10 Seconds
Checked at
2 Seconds
VARIABLE
0 to
30 SECONDS
GLOW
CRANK
GLOW
FIRST
ATTEMPT “A”
SECOND
ATTEMPT
THIRD
ATTEMPT
15 Seconds
STOP
REPEA
T
“A”
+ 5 Seconds
GLOW
15 Seconds
STOP
REPEA
T
“A”
+ 5 Seconds
GLOW
Figure 2-8
Auto Sta
rt Seque
nce
e.
Va
riable G
low Time
The glow time for the first start attempt will vary in
duration based on engine coolant temperature and the
engine as follows :
Table 2-9 Engine Coolant Temperature Glow-
Time
T
e
m
p
e
r
a
t
u
r
e
T
V
D
I
Less than 0
_
C (32
_
F
)
1
5
5
5
1
_
C to 10
_
C (33
_
F to 50
_
F
)
1
0 4
0
1
1
_
C to 25
_
C (51
_
F to 77
_
F
)
5 2
5
Greather than 26
_
C (78
_
F
)
0
1
0
Th
e
se
co
nd
an
d
thi
rd
sta
rt
att
em
pts
ha
ve
a
gl
ow
tim
e
that is 5 seconds greater than the table amount. The
gl
ow
tim
e
ca
n
be
ma
nu
al
ly
ov
err
id
de
n
thr
ou
gh
the
fun
c-
tionparame
ters
.
If
the
coo
lan
t
temp
era
turesenso
r
is
de-
fective the con
trol
assume a tem
perature o
f less than
0
_
C (32
_
F) for the glow timing.
f.
Mini
mum
On
Tim
e
Un
it
mu
st
ru
n
for
themini
mu
m
run
-
-tim
e
be
for
e
it
ca
n
consid
er shutting off. This
time is
neces
sary to prevent
short cycling and ensure adequate air f
low through the
load to allow the micro to accuratel
y sense load
tempe-
rat
ur
e
an
d
bri
ng
the
ba
tte
ry
up
to
mi
ni
mu
m
vo
lta
ge
le
ve
l
Minimum on time value is selected via keypad.
g.
Minimum
Off-T
ime
Once the unit has cycled off, it will remain off for the
minimum off time. This prevents rapid cycling due to
changes in air temperature. Air temperature in the box
ca
n
ch
an
ge
rap
id
ly
bu
t it take
s
tim
e
for
the
pro
du
ct
tem
-
perature to change.
Minimum off time value is selected via keypad.
The minimum off-time is overridden if the tempera-
ture is more than
±
6
_
C (
±
1
1
_
F) from setpoint.
h.
Time st
art / T
emp star
t
Selection between time start or temp start is provi-
ded via the keypad
T
em
p
sta
rt
:
theunit
wi
ll
re
ma
in
of
f
un
til
bo
x
tem
pe
ra
-
ture deviates from
setpoi
nt
T
im
e
sta
rt
:
un
it
wi
ll
re
sta
rt
au
tom
ati
ca
ll
y
30
mi
n
aft
er
it has stopped regardless of the box temperature