Carrier SUPRA 950Mt - Control Circuit Operation

3
-
5
6
2
-
-
6
1
1
X
X
-
-
2
0
(
0
3
/
0
4
)
e.
Unlock
the cont
rol pane
l
1.
2.
1.
Press the
CARRIER
logo
until th
e lig
ht is o
ff.
2.
The i
ndi
cato
r go
es o
ff.
REMARK
IT IS NOT NECESSARY FOR THE COMPARTMENT TO
BE RUNNING IN ORDER TO MODIFY OR SEE THE SET-
POINT VALUE AND THE TEMPERATURE OF THE COM-
PARTMENT.
THE UNIT CAN BE SHUT DOWN BOTH WITH THE CAB
COMMAND AND THE GENERAL SWITCH.
3.5
CON
TROL
CIR
CU
IT
OPE
RA
TION
3.
5.
1
In
tr
od
uc
ti
on
NOTE
T
o
ma
ke
it
ea
si
er
to
lo
ca
te
the
sc
he
ma
tic
co
mp
on
en
ts
referred to in the written text, the schematic in this
manual has map coordinates added to the margins.
These locations have also been added to the legend.
The
co
ntr
ol
le
r
bo
ard
s
sh
ow
n
on
the
el
ec
tri
ca
l
schematic that interface with unit components are the
an
al
og
in
ter
fac
e
or
pro
ce
sso
r
bo
ard
on
the
ri
gh
t
an
d
the
relay module on the left.
Connections to these boards are made through 3
mul
tip
le-p
in
plu
g
con
nec
tors HC,
HC2
,
&
MP
.
The
addres
s
system (example HCD2-MPW2) indicates a
wire between plug HC, pin D2 and microprocessor MP
& pin W2.
The processor board connections are mainly inputs
and outputs for control switches, temperature sensors,
safe
ty
,
and
aut
o
star
t
fun
ctio
ns
tha
t
con
trolthe
ope
rati
on
of
the
un
it.
The
pro
ce
ss
or
bo
ar
d
al
so
co
ntr
ol
s
the
operati
on of
the relay
board through plug connection
s.
Th
e
re
la
y
mo
du
le
,
wh
ic
h
co
nt
ai
n
s
pl
u
g-
in
interch
angea
ble
relays provides
the
microp
rocess
or
with a
mea
ns
for switch
ing the
uni
t
com
pon
ents to
achieve a desired operating mode.
3.
5.
2
T
em
per
at
ur
e
Co
ntr
ol
Log
ic
There are basically 3 modes of operation : Cool,
Hea
t
or
Defr
ost.
Con
trol
ler
wil
l
aut
oma
tica
lly
sel
ectsthe
ne
ce
ss
ary
mo
de
to
ma
in
tai
n
bo
x
tem
pe
ra
tur
e
at
setpoint.
There are two control ranges :
D
Froz
en
: set
poi
nt
< -12
_
C (54
_
F)
D
Perisha
ble
: se
tpoint
> -12
_
C (54
_
F)
In
the froze
n
ran
ge
the
re
ar
e
two
co
ntr
ol
lo
gi
c
de
pe
nd
in
g
if
he
at
is
al
lo
we
d
or
no
t
(re
fer
to
mi
cro
configuration section 4.19.2, CNF-4).
There are also two operating modes :
D
 Continuous
D
Start /
Stop
a.
Te
mpera
ture Contr
ol / Continuous Mode
Di
es
el
mo
de
:
si
nc
e
en
gi
ne
ha
s
two
op
era
tin
g
speeds, there are four possible states :
D
High speed
cool
D
Low speed
cool
D
Low speed
heat
D
High speed
heat
Standby mode : there are two possible states :
D
 Cool
D
 Heat
See Figure 3-2 and Figure 3-4.
b.
Te
mpera
ture control / Start Stop
Wh
en
sta
rt/
sto
p
mo
de
is
ac
tiv
ate
d
the
re
is
an
additional “off” state which correspond to unit shut off
when box temperature is closed to setpoint.
See Figure 3-1 and Figure 3-3.
c.
Operat
ion
Cool mode
: default mode for the micro.
Heat mode
: micro will energize MHR relay (which
controls the Main Heat Valve) via X1 output.
Depen
ding upon
which compartme
nt
requi
res
heat
the HGR 1, 2 or 3 (or any combination of the 3 relays)